Long Life Dairy, Food and Beverage Products
White Paper
22000-06-01-2013-G B2
Long Life Dairy, Food and Beverage Products
TABLE OF CONTENTS
Executive Summary 3
Introduction to SPX Flow Technology 3Vision and commitment 3Customer focus 3
Introduction to long life dairy, food and beverage products 4
Microbiology 5Bacteria 5Spores 6Enzymes 6Moulds 7Yeast 7Bacteriophages 7Toxicity 7
Process classification 7Pasteurisation 7Extended shelf life 8UHT treatment 8Sterilisation 9EU classification 9
Process evaluation 9The logarithmic reduction of spores and sterilising efficiency 9Terms and expressions to characterise heat treatment processes 10Residence time 12Commercial sterility 12Chemical and bacteriological changes at high temperatures 12Raw material quality 12Shelf life 13
Choosing the right process 13The heat treatment processes 14Plate heat exchangers 14Tubular heat exchangers 15Corrugated tubular heat exchangers 15Steam injection nozzles 16Steam infusion 16Scraped surface heat exchangers 17
Various aseptic UHT systems 17Indirect Plate Steriliser 17Indirect Tubular Steriliser 19Spiratherm® 20Steam Infusion Steriliser 21High Heat Infusion Steriliser 22Instant Infusion Pasteuriser 23Steam Injection Steriliser 24Scraped Surface Heat Exchanger Steriliser 25Pilot UHT Plant 25Sterile Tank 26Deaerator 27
Extended shelf life/ESL 27The Pure-LacTM process 27
Comparison between different systems 28
Process controls 28
Filling and packaging 30
Product development 30
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Long Life Dairy, Food and Beverage Products
VI S ION AN D COM M ITM E NT
SPX's Flow Technology segment designs, manufactures
and markets process engineering and automation
solutions to the dairy, food, beverage, marine,
pharmaceutical and personal care industries through its
global operations.
We are committed to helping our customers all over the
world to improve the performance and profitability of
their manufacturing plant and processes. We achieve this
by offering a wide range of products and solutions from
engineered components to design of complete process
plants supported by world-leading applications and
development expertise.
We continue to help our customers optimise the
performance and profitability of their plant throughout its
service life with support services tailored to their individual
needs through a coordinated customer service and spare
parts network.
CUSTOM E R FOCUS
Founded in 1910, APV, an SPX Brand, has pioneered
groundbreaking technologies over more than a century,
setting the standards of the modern processing industry.
Continuous research and development based on
customer needs and an ability to visualise future process
requirements drives continued mutual growth.
Executive Summary Introduction to SPX Flow Technology
There are a number of important microbiological factors
that need to be addressed in the production of long
life dairy, food and beverage products. The presence of
microorganisms in the milk must be reduced to a safe
number in order to ensure sufficient shelf life under
appropriate storage conditions.
This can be achieved by a variety of thermal processes.
The efficiency of these processes is a factor of
temperature and holding time and can, if not properly
controlled, lead to adverse effects on flavour and
appearance.
A number of systems of relevance to the dairy, food and
beverage industries are discussed and advice is offered
on how to achieve the best quality product at a reasonable
cost, taking into account safe and trouble-free operation.
Efficient aseptic processing is an important factor in
development of new products. The SPX Innovation Centre
in Denmark offers Pilot Plant Testing and application
solution guidance services to help customers maximise
the performance of their plant. Pilot Testing can also be
conducted on customers’ own premises based on rental
equipment and, if required, with support from SPX experts.
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Long Life Dairy, Food and Beverage Products
Introduction to long life dairy, food and beverage productsAs one of the most complete food products of all, dairy products
are very important in human nutrition. However, dairy products are
also highly perishable and would easily lose their nutritional value,
flavour and appearance if protective measures were not taken.
Consequently, the dairy industry is one of the most advanced
industries in the food processing area, taking care of the
milk from when it leaves the udder of the cow - through
transportation to the dairy, processing, packaging, and
distribution - until it reaches the consumer.
The technology of producing long-life products is today applied
throughout the food and beverage industries and in many cases
the processing plants are designed for multipurpose operation.
When aseptic technology was introduced more than 50 years
ago, it revolutionised the food industry by making it possible to
distribute high quality food products over long distances in a
cost-effective way.
The heart of aseptic technology for production of long-life
dairy products is aseptic processing, and since its introduction
this concept has been developed and refined to a point where
any need in respect of capacity, product viscosity, particulate
content, acidity or sensitivity to heat treatment can be met while
securing high quality, long-life products.
SPX Flow Technology was one of the pioneers in aseptic
processing and over the years we have developed a wide range
of processing concepts to satisfy all the needs of the industry.
In this publication, we will first discuss some of the micro-
biological factors, which must be considered in all aseptic
processing, together with the heating processes most
commonly used for reducing micro-organisms in dairy products:
pasteurisation, sterilisation and ultra high temperature (UHT)
treatment.
So-called commercial sterility is the aim of all UHT processes,
and the extent to which this is achieved in a particular process
can be measured, notably by reference to the bacteriological
effect (B*) and the chemical effect (C*) of such processes.
These factors are explained in the section “Process Evaluation”.
The main part of the publication is devoted to an analysis of
the processing systems of most interest to the dairy, food and
beverage industry: Indirect Plate Steriliser, Indirect Tubular
Steriliser, Steam Infusion Steriliser, High Heat Infusion Steriliser,
Instant Infusion Pasteuriser, Steam Injection Steriliser and
Indirect Scraped Surface Heat Exchanger (SSHE) Steriliser.
In each case we describe the system, discuss its advantages
and limitations, and list a number of products for which the
system in question is particularly suitable (See Tables 1 and 4).
The Pilot UHT Plant is able to combine most of the aseptic
processes in one unit, which provides an efficient tool for pilot
trials and product development.
In aseptic processing, special consideration must be given to
some of the auxiliary equipment required. Aseptic tanks are not
a necessary requirement but often serve as a useful buffer for
sterilised products.
The area of extended shelf life products is becoming
increasingly important, and the development of the Pure-
LacTM concept is offering the industry and the consumers new
solutions and exciting opportunities.
With the large number of options available it becomes important
to be able to choose the solution, which provides the best
quality product at a reasonable cost, giving safe and trouble-
free operation. A separate section has been made to cover this
subject.
The process control system is not only necessary, it must
incorporate up-to-date technology - not least on the software side.
Special attention must be given to the subsequent filling and
packaging of aseptically processed products.
Finally, we address the area of product development. SPX
Flow Technology’s world wide capabilities in respect of product
testing makes it possible to work closely with customers in their
efforts to upgrade production and launch new products.
This publication is purely dealing with the indirect and direct
heat transfer processes.
SPX Flow Technology is also manufacturing various types of
electrical - or “electroheat” thermal processing equipment. This
is dealt with in a separate publication.
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Long Life Dairy, Food and Beverage Products
TAB LE 1: A VAR I ETY O F DAI RY, FO O D AN D B EVE RAG E P R O D U CTS
AN D TH E I R S U ITAB I L ITY FO R TR EATM E NT I N TH E R MAL H EAT
P R O C E S S I N G SYSTE M S.
MicrobiologyThe key to production of long-life products with aseptic technology
is a detailed understanding of the microbiology of food. Using
the example of the dairy industry, the milk in the udder of a
healthy cow is free from bacteria, but as soon as the milk comes
into contact with the air it becomes contaminated with micro-
organisms.
If the temperature is favourable, the micro-organisms multiply
and very soon the milk will turn sour (or putrefy), developing an
unpleasant flavour. To prevent this from happening, the raw milk
is sub jected to heat treatment.
The term aseptic is usually defined as “free from or keeping
away” disease producing or putrefying microorganisms. In the
food industry the terms aseptic, sterile and commercially sterile
are often used interchangeably. This is not strictly correct.
Sterilisation means 100% destruction of all living organisms,
including their spores, and this is very difficult to achieve.
Commercial sterility means that the product is free from
microorganisms, which grow and consequently contribute to the
deterioration of the product. Microorganisms are extremely small
and can only be seen under a microscope. However, hundreds or
thousands of individual cells or groups of cells can form colonies,
which are visible to the naked eye, and some colonies have
colours, shapes, textures or odours, which make the organism
identifiable.
BAC TE RIA
The term bacteria strictly means rod-shaped microorganisms
only, but is also used in a loose sense to include all micro-
organisms except yeast and moulds. The individual bacterium
varies in size from 0.5 to 3 micron.
The groups of bacteria, which are most important in the
dairy industry are the lactic acid, coliform, butyric acid, and
putrefaction bacteria. The bacterial count in milk coming from
the farm varies from a few thousands bacteria/ml for high
quality milk to several millions if the standard of cleaning,
disinfection and chilling is poor.
For milk to be classified as top quality, the CFU (Colony Forming
Units) should be less than 100,000/ml.
Bacteria are single-celled organisms, which normally multiply by
binary fission, i.e. splitting in two. The simplest and most common
way to classify bacteria is according to their appearance and
shape. However, in order to be able to see bacteria, they must
first be stained and then studied under a microscope at a
magnification of approximately 1,000 X.
DAI RY, FOOD & B EVE RAG E PROD UCTS
PL
AT
E S
TE
RIL
ISE
R
TU
BU
LA
R S
TE
RIL
ISE
R
ST
EA
M I
NF
US
ION
S
TE
RIL
ISE
R
HIG
H H
EA
T I
NF
US
ION
S
TE
RIL
ISE
R
INS
TAN
T I
NF
US
ION
P
AS
TE
UR
ISE
R
ST
EA
M I
NJE
CT
ION
S
TE
RIL
ISE
R
SC
RA
PE
D S
UR
FA
CE
HE
AT
EX
CH
AN
GE
R S
YS
TE
MS
M I LK X X X X X
M I LK (F LAVO U R E D) X X X X X
M I LK (EVAP O RATE D) X X X X
M I LK (C O N C E NTRATE D) X X X X X
M I LK (S HAK E M I X) X X X X X
C R EAM X X X X X
C R EAM (WH I P P I N G) X X X X
C R EAM (SYNTH ETI C) X X X X X
YO G H U RT X X X X
YO G H U RT (D R I N K I N G) X X
YO G H U RT (F R U IT) X X
Q UAR K P R O D U CTS X
S OYA M I LK X X X X X
BABY FO O D X X X X
I C E C R EAM M I X X X X X X
C H E E S E D I P S X X X X
P R O C E S S E D C H E E S E X X X
D E S E RTS / P U D D I N G S X X X X
WH EY P R OTE I N C O N C. X X
C O F F E E WH ITE N E R X X X X X X X
E G G-BAS E D P R O D U CTS X
SAU C E X X X
S O U P S X X
C O F F E E / I C E TEA X X
F R U IT J U I C E X X
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Based on a method of staining, developed by the Danish
bacteriologist Gram, bacteria are divided into Gram negative
(red) and Gram positive (blue). The three characteristic shapes
of bacteria are spherical, rod-shaped and spiral. Diplococci
arrange themselves in pairs, staphylococci form clusters, while
streptococci form chains.
Another way of classification is according to temperature
preference:
• Psychrotrophic bacteria (cold-tolerant) reproduce at temperatures of 7°C or below.
• Psychrophilic bacteria (cold-loving) have an optimum growth temperature below 20°C.
• Mesophilic bacteria ( loving the middle range) have optimum growth temperatures between 20°C and 44°C.
• Thermophilic bacteria (heat-loving) have their optimum growth temperatures between 45°C and 60°C.
• Thermoduric bacteria (heat-enduring) can tolerate high temperatures - above 70°C. They do not grow and reproduce at high temperatures, but can resist them without being killed.
Bacteria can only develop within certain temperature limits,
which vary from one species to another. Temperatures below
the minimum cause growth to stop, but do not kill the bacteria.
They are, however, damaged by repeated freezing and thawing.
If the temperature is raised above the maximum, the bacteria
are soon killed by heat. Most cells die within a few seconds of
being exposed to 70°C, but some bacteria can survive heating
to 85°C for 15 minutes, even though they do not form spores.
A third way of classifying micro-organisms is by their oxygen
requirement. The availability of oxygen is vital to the metabolism
of all organisms. Some bacteria consume oxygen from the
atmosphere; they are called aerobic bacteria. However, to some
bacteria free oxygen is a poison; they are called anaerobic
bacteria and obtain the oxygen they need from chemical
compounds in their food supply. Some bacteria consume free
oxygen if it is present, but they can also grow in the absence of
oxygen; they are called facultatively anaerobic.
The acidity of the nutrient substrate for bacteria is also
important. Sensitivity to pH changes varies from one species to
another, but most bacteria prefer a growth environment with a
pH around 7. Furthermore the salt and/or sugar concentration
of a substrate has an important influence on the growth of
bacteria. The higher the concentration, the more growth is
inhibited. This is caused by the high osmotic pressure, which
will draw water out from the cell, thereby dehydrating it.
Osmotic pressure is used as a means of food preservation in
sweetened condensed milk, salted fish and fruit preserves like
jam and marmalade.
S POR E S
The spore is a form of protection against adverse conditions,
e.g. heat and cold, lack of moisture, lack of nutrients, or
presence of disinfectants. Only a few bacteria are spore
forming e.g. Bacillus and Clostridium. The spores germinate
back into a vegetative cell and start reproduction when
conditions become favourable again. The spores have no
metabolism and can survive for years in dry air and are much
more resistant to adverse conditions than bacteria. This
includes heat treatment and it takes typically 20 minutes at
120°C to kill them with 100 percent certainty. The UHT time/
temperature combination reduces the number of bacteria
spores by a minimum of log 9, leaving very few bacteria spores
in UHT treated products.
E N ZYM E S
When the milk leaves the udder it contains enzymes, the
so-called original enzymes. Enzymes are also produced by
the bacteria in the milk, the so-called bacterial enzymes.
Enzymes are not micro-organisms but are formed as a result
of the metabolism of micro-organisms. The ability of enzymes
to trigger chemical reactions can be important when UHT
products are produced.
Temperature
Time
135ºCPure-Lac TM
85ºCHigh pasteurisation
72ºCLow pasteurisation
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Some of the bacterial enzymes are able to cause sweet
coagulation of milk products, which destroys the product. The
majority of these enzymes are produced by Gram negative
Pseudomonas bacteria developing mainly in cold raw milk
stored for excessive time in milk cooling tanks, road tankers
or milk silos. This problem will be aggravated if the milk has
been contaminated because of unhygienic conditions or lack
of cleaning-in-place (CIP). The vast majority of enzymes will be
destroyed by UHT treatment, but a few may still be active in the
final product.
MOU LD S
Moulds belong to the fungi group of micro-organisms, which
are very widely distributed in nature among plants, animals and
human beings. Moulds normally grow anaerobically, and their
optimum growth temperature is between 20 and 30°C. Moulds
can grow in substrates with pH 2 to 8.5, but many species prefer
an acid environment. The most common species in milk do not
survive pasteurisation conditions, and the presence of mould
in pasteurised products is therefore a sign of reinfection. The
penicillium family is one of the most common types of moulds.
Their powerful protein splitting properties make them the chief
agent in ripening of, for instance, Blue Cheese.
YEAST
Yeast also belong to the fungi group of micro-organisms. They
vary greatly in size. Saccharomyces cerevisiae, used for brewing
of beer, has a diameter of 2 to 8 micron, but other species may
be as large as 100 micron.
Yeast has the ability to grow both in the presence and absence
of oxygen. The optimum temperature is between 20 and
30°C. Optimum pH values are 4.5 to 5.0, but yeast will grow in
the pH range of 3 to 7.5.
From a dairy point of view, yeast are generally undesirable
organisms. They ferment milk and cream and cause defects
in cheese and butter. In the brewing, baking and distillation
industries, on the other hand, they are very valuable
organisms.
BACTE R IOPHAG E S
Bacteriophages belong to the group of micro-organisms
called viruses. Viruses have no metabolism of their own and
therefore cannot grow on a nutrient substrate. Viruses infect
living cells in plants and animals. Bacteriophages (also known
as phages) infect bacteria and are consequently a problem in all
dairy processes where bacteria cultures are used. They are very
small in size - in the order of 0.02 to 0.06 micron and can only
be seen in an electron microscope.
Bacteriophages grow at temperatures between 10 and 45°C.
They are killed by exposure to 63 to 88°C for 30 minutes and
tolerate pH values in the range of 3 to 11.
TOXICITY
Micro-organisms, which are harmful to man or animals are called
pathogens. They can cause death or severe illness by the secretion
of toxins either directly into contaminated foodstuffs, which are
subsequently eaten, or by transfer to an animal host offering ideal
conditions for reproduction and further generation of toxins. Some
toxins are inactivated by heat treatment at 60°C for one hour.
Process classificationA number of different expressions are commonly used in the
food industry in relation to food preservation. This section will
briefly describe the most common terms used.
PASTE U R I SATION
Most commercial liquid food products undergo some form of
heat treatment, and pasteurisation is the most common. As
it is usually bacterial growth that causes food to deteriorate,
pasteurisation preserves the freshness of the food product.
There are basically two ranges of pasteurisation:
• Low-temperature pasteurisation. For milk, this is based on heating the product to 72 to 76°C and holding at that
F I G. 1: LOW-TE M P E RATU R E PASTE U R I SATI O N
ºC150
100
50
010 20 30 40 50 60
Minutes
0
50
100
150
Time
ºC
Direct Infusion
High Heat Infusion
Indirect UHT
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Long Life Dairy, Food and Beverage Products
temperature for at least 15 to 20 seconds (or equivalent) (Fig. 1). The pasteurisation may vary from country to country according to national legislation. A common requirement in all countries, however, is that the heat treatment must guarantee the destruction of unwanted micro-organisms and all pathogenic bacteria. The shelf life of pasteurised milk is limited (typically 5 to 7 days) and primarily depends on raw milk quality and storage temperature. During the low-temperature pasteurisation the phosphatase enzyme is destroyed, while the peroxidase enzyme is preserved. This serves as a measure to control the process and distinguish it from high-temperature pasteurisation.
• High-temperature pasteurisation. This is based on heating the product to 85°C or higher for a few seconds (or equivalent) (Fig. 1). The aim is to kill the entire population of bacteria, which are pathogenic for both man and animals and almost all other bacteria as well. By careful monitoring of the process parameters a product with excellent quality can be obtained with minimum heat damage. The shelf life can be extended to several weeks in the cooling chain. The so-called Pure-LacTM process is based on high-temperature pasteurisation. During the high-temperature pasteurisation both the phosphatase and the peroxidase enzymes are destroyed, and this serves as a measure to control that the process has actually taken place as specified.
EXTE N D E D S H E LF LI FE
The term extended shelf life or ESL is being applied more and
more frequently.
There is no single general definition of ESL. Basically what
it means is the capability to extend the shelf life of a product
beyond its traditional well-known and generally accepted shelf
life without causing any significant degradation in product quality.
A typical temperature/time combination for high-temperature
pasteurisation of ESL milk is 125 to 130°C for 2 to 4 seconds.
This is also known in the USA as ultra-pasteurisation.
SPX Flow Technology has in recent years developed a patented
process where the temperature may be raised to as high as
135°C but only for fractions of a second. This is the basis for the
Pure-LacTM process described in a separate chapter, see table of
contents.
U HT TR EATM E NT
UHT - or Ultra High Temperature - treatment is based on the
fact that higher temperatures permit a much shorter processing
time. By proper time and temperature combination it is possible
to achieve commercial sterility with only limited undesirable
chemical changes in the product. In terms of nutritive value,
flavour and appearance, the quality of the product is more
vulnerable to the duration of the treatment than to the
temperature applied.
In the UHT process, the milk is typically heated to 137 to 150°C
and held at that temperature for just a few seconds before it
is cooled rapidly down to room temperature (Fig. 2). After the
product has been cooled it is led to an aseptic filling machine in
a closed piping system - either directly or by way of an aseptic
storage tank. The product obtained in this way has a shelf life at
room temperature of several months.
The quality of the final product depends on the raw material
quality but also to a large extent on the type of heat treatment
system applied. This is the case for UHT milk and for a wide
range of long life food products like sauces, salad dressings,
mayonnaise and soups, as well as for juices and soft drinks.
F I G. 3: TE M P E RATU R E P R O F I LE S FO R C O NVE NTI O NAL I N-C O NTAI N E R
STE R I L I SAT I O N
F I G. 2: TE M P E RATU R E P R O F I LE S FO R D I R E CT I N F U S I O N, H I G H H EAT
I N F U S I O N AN D I N D I R E CT U HT P R O C E S S E S.
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Long Life Dairy, Food and Beverage Products
TAB LE 2: P R E S E NT LE G I S LAT I O N AC C O R D I N G TO E U D I R E CTIVE 92/46 * * I D F & E U S U G G E STI O N S FO R D UAL C H E M I CAL C R ITE R IA
In order to combat the Heat Resistant Spores (HRS) SPX Flow
Technology has developed the patented so-called High Heat Infusion
system enabling heat treatment temperatures as high as 150ºC
without adversely affecting the product quality and still maintaining
acceptable running times in the order of 24 hours between cleaning.
Products with very high viscosity are more difficult to handle in a UHT
system, and SPX Flow Technology has developed a special patented
version of the infusion system to handle high viscosity products.
This so-called Instant Infusion system is based on very short but
controllable and well defined retention time in the infusion chamber.
STE R I LI SATION
Sterilisation is another type of heating process used for products to
increase keeping quality without refrigeration. The heat treatment
takes place after the product is packed. The package with its
content is heated to approx. 120°C and held at that temperature
for 10 to 20 minutes after which it is cooled to room temperature
(Fig 3). Because of the lengthy heat treatment at a relatively
high temperature this process reduces the nutritive value of
the product, and it is also liable to change its colour and flavour
considerably.
E U CLASS I FICATION
In the EU Milk Hygiene Directive (92/46) it is suggested that “limits
and methods to enable a distinction to be made between different
types of heat treated milk” may be established (Article 20).
The proposed parameters, limits and methods may be
summarised as shown in Table 2.
By this method the hygienic requirements concerning food safety
can be satisfied taking into consideration the keeping qualities
over varying length of time. This method also makes it possible to
establish a new definition of different types of fluid milk products
in a way that is independent of the technology of the heat
treatment and the filling such as for instance, Pure-LacTM.
It should be noted that the chemical criteria in Table 2 are the
recommendation given by IDF and EU to the legislators, but the
general perception is that this proposal will be followed.
Process evaluationAll UHT processes are designed to achieve commercial sterility.
This calls for application of heat to the product and a chemical
sterilant or other treatment that render the equipment, final
packaging containers and product free of viable micro-organisms
able to reproduce in food under normal conditions of storage
and distribution. In addition it is necessary to inactivate toxins
and enzymes present and to limit chemical and physical changes
in the product. In very general terms it is useful to have in mind
that an increase in temperature of 10°C increases the sterilising
effect 10-fold whereas the chemical effect only increases
approximately 3-fold. In this section we will define some of
the more commonly used terms and how they can be used for
process evaluation.
THE LOGARITHMIC REDUCTION OF S POR E S
AN D STE R I LI S I NG E FFICI E NCY
When micro-organisms and/or spores are exposed to heat
treatment not all of them are killed at once.
However, in a given period of time a certain number is killed
while the remainder survives. If the surviving micro-organisms
are once more exposed to the temperature treatment for the
same period of time an equal proportion of them will be killed.
On this basis the lethal effect of sterilisation can be expressed
mathematically as a logarithmic function:
M I LK HYG I E N E D I R ECTIVE 92/46/ E U
TH E R M I S E D PASTE U R I S E D H IG H TE M PE RATU R EPASTE U R I S E D HTP U HT STE R I LI S E D
63 - 65ºC/15 S E C. 71.7ºC/15 S E C.O R E Q U IVALE NT >135ºC AN D >1 S E C. >135ºC AN D > 1 S E C.
P H O S P HATAS E+ P H O S P HATAS E-P E R OX I DAS E+
P H O S P HATAS E-P E R OX I DAS E-
15 DAYS AT 30ºC O R7 DAYS AT 55ºC 0 ⇒
<10 C F U /0.1 M L
15 DAYS AT 30ºC O R7 DAYS AT 55ºC 0 ⇒
<10 C F U /0.1 M L
** * * * * * *
B ETA-LACTO G LO B U LI N> 2600 M G / L
&
B ETA-LACTO G LO B U LI N> 2000 M G / L
&
> 50 M G / L&
B ETA-LACTO G LO B U LI N< 50 M G / L
O R
LACTU LO S EN OT D ETE CTAB LE
LACTU LO S E< 40 M G / KG
LACTU LO S E< 600 M G / KG
LACTU LO S E> 600 M G / KG
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A logarithmic function can never reach zero, which means that
sterility defined as the absence of living bacterial spores in an
unlimited volume of product is impossible to achieve. Therefore
the more workable concept of “sterilising effect” or “sterilising
efficiency” is commonly used.
The sterilising effect is expressed as the number of decimal
reductions achieved in a process. A sterilising effect of 9
indicates that out of 109 bacterial spores fed into the process
only 1 (100) will survive.
Spores of Bacillus subtilis or Bacillus stearothermophilus are
normally used as test organisms to determine the efficiency of
UHT systems because they form fairly heat resistant spores.
TERMS AND EXPRESSIONS TO CHARACTERISE
HEAT TREATMENT PROCESSES
Q10 value. The sterilising effect of heat sterilisation increases
rapidly with the increase in temperature as described above.
This also applies to chemical reactions, which take place as a
consequence of an increase in temperature. The Q10 value has
been introduced as an expression of this increase in speed of
reactions and specifies how many times the speed of a reaction
increases when the temperature is raised by 10°C. Q10 for
flavour changes is in the order of 2 to 3, which means that a
temperature increase of 10°C doubles or triples the speed of
the chemical reactions.
A Q10 value calculated for killing bacterial spores would range
from 8 to 30 depending on the sensitivity of a particular strain to
the heat treatment.
D-Value. This is also called the decimal reduction time and is
defined as the time required to reduce the number of micro-
organisms to one-tenth of the original value corresponding to a
reduction of 90%.
Z-Value. This is defined as the temperature change which gives
a 10-fold change in the D-value.
F0 value. This is defined as the total integrated lethal effect
and is expressed in terms of minutes at a selected reference
temperature of 121.1°C. F0 can be calculated as follows:
F0 = 10(T - 121.1) /z · t / 60 , where
T = processing temperature (°C)
z = Z-value (°C)
t = processing time (seconds)
F0 = 1 after the product has been heated to 121.1°C for one
minute. To obtain commercially sterile milk from good quality raw
milk, for example, an F0 value of minimum 5 to 6 is required.
B* and C* Values. In the case of milk treatment some
countries are using the following terms:
• Bacteriological effect: B* (known as B star)
• Chemical effect C* (known as C star)
B* is based on the assumption that commercial sterility is
achieved at 135°C for 10.1 seconds with a corresponding
Z-value of 10.5°C; this reference process is giving a B* value of
1.0, representing a reduction of thermophilic spore count of 109
per unit (log 9 reduction).
The B* value for a process is calculated similarly to the F0 value:
B* = 10 ( T - 135 ) / 10.5 · t / 10.1, where
T = processing temperature (°C)
t = processing time (seconds)
The C* value is based on the conditions for a 3 percent
destruction of thiamine (vitamin B1); this is equivalent to 135°C
for 30.5 seconds with a Z-value of 31.4°C. Consequently the C*
value can be calculated as follows:
C* = 10 ( T - 135 ) /31.4 · t / 30.5
Fig. 4 shows that a UHT process is deemed to be satisfactory
with regard to keeping quality and organoleptic quality of the
product when B* is > 1 and C* is < 1.
K · t = log N/Nt , where
N = number of micro-organisms/spores originally present
Nt = number of micro-organisms/spores present after a
given time of treatment (t)
K = constant
t = time of treatment
2.7 2.6 2.5 2.4 2.3
1T
4000
2000
3000
1000
800900
600700
400
500
200
300
100
80
60
70
90
40
50
20
30
10
8
6
4
5
7
9
2
3
1110100 120 130 140 150 160ºC
loss of thiamine = 80%
threshold range of discolouration
loss of thiamine = 3% / C*=1
HMF 1 µm
ol/l
HMF 100 µmol/l
HMF 10 µmol/l
60%
40%
10%
loss of lysine = 1%
lactulose 600 mg/l
lactulose 400 mg/l
20%
region ofsterilisation
thermal death value = 9
thermophilic spor es / B*=1
UHT-region
Hea
ting
time
or e
quiv
alen
t hea
ting
time
in s
econ
ds
·10 in K3 -1
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Long Life Dairy, Food and Beverage Products
F I G. 4: BACTE R I O LO G I CAL AN D C H E M I CAL C HAN G E S O F H EATE D M I LK (H.G. K E S S LE R)
The B* and C* calculations may be used for designing UHT
plants for milk and other heat sensitive products. The B* and C*
values also include the bacteriological and chemical effects of the
heating up and cooling down times and are therefore important in
designing a plant with minimum chemical change and maximum
sterilising effect.
FromAPV InfusionChamber
ToVacuumChamber
TURBULENT FLOW OF IS WELL DEFINEDLIQUID
V
ToVacuumChamber
SIGHT GLASS
SIGHT GLASS
V1V2
3V
HOLDING TIME NOT DEFINED
V > V > V3 2 1
Holding Tube without Centrifugal Pump
Holding T ube with Centrifugal Pump
From otherDirect UHT Systems
Multi-phase system:
Single-phase system:
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Long Life Dairy, Food and Beverage Products
The more severe the heat treatment is, the higher the C* value
will be. For different UHT plants the C* value corresponding to a
sterilising effect of B* = 1 will vary greatly. A C* value of below 1
is generally accepted for an average design UHT plant. Improved
designs will have C* values significantly lower than 1.
The APV Steam Infusion Steriliser has a C* value of 0.15.
R E S I D E NCE TI M E
Particular attention must be paid to the residence time in a
holding cell or tube and the actual dimensioning will depend on
several factors such as turbulent versus laminar flow, foaming, air
content and steam bubbles. Since there is a tendency to operate
at reduced residence time in order to minimise the chemical
degradation (C* value < 1) it becomes increasingly important to
know the exact residence time.
In SPX Flow Technology the infusion system has been designed
with a special pump mounted directly below the infusion chamber,
which ensures a sufficient over-pressure in the holding tube
in order to have a single phase flow free from air and steam
bubbles.
This principle enables SPX Flow Technology to define and
monitor the holding time and temperature precisely and makes it
the only direct steam heating system, which allows true validation
of flow and temperature at the point of heat transfer.
The concept is illustrated in Fig. 5.
COM M E RCIAL STE R I LITY
The expression of commercial sterility has been mentioned
previously and it has been pointed out that complete sterility in
its strictest sense is not possible. In working with UHT products
commercial sterility is used as a more practical term, and a
commercially sterile product is defined as one which is free from
micro-organisms which grow under the prevailing conditions.
CH E M ICAL AN D BACTE R IOLOG ICAL
CHANG E S AT H IG H TE M PE RATU R E S
Heating milk and other food products to high temperatures
results in a range of complex chemical reactions causing changes
in colour (browning), development of off-flavours and formation
of sediments. These unwanted reactions are largely avoided
through heat treatment at a higher temperature for a very short
time, and it is important to seek the optimum time/temperature
combination, which provides sufficient kill effect on spores but,
at the same time, limits the heat damage, in order to comply with
market requirements for the final product.
Even though the time/temperature combination is decisive for
the final quality of the product attention also has to be paid to
the actual heating profile since various reactions take place at
different temperatures. This is illustrated in Fig. 6 in which type
A deposit is a voluminous protein-rich deposit, whereas type
B deposit is a mineral rich deposit developing primarily at high
temperatures. In particular type A deposit, which originates from
protein denaturation, must be minimised since it is harmful to the
product quality.
RAW MATE R IAL QUALITY
It is important that all raw materials are of very high quality as the
quality of the final product will be directly affected. Raw materials
must be free from dirt and have a very low bacteria spore count,
and any powders must be easy to dissolve.
All powder products must be dissolved prior to UHT treatment
because bacteria spores can survive in dry powder particles even
at UHT temperatures. Undissolved powder particles will also
damage homogenising valves causing sterility problems.
Heat stability. The question of heat stability is an important
parameter in UHT processing.
Different products have different heat stabilities and although the
UHT plant will be chosen on this basis it is desirable to be able to
measure the heat stability of the products to be UHT treated.
For most products this is possible by applying the alcohol test. When
samples of milk are mixed with equal volumes of an ethyl alcohol
solution the proteins become unstable and the milk flocculates.F I G. 5: H O LD I N G TU B E
80 90 100 110 120 130 140
Type A deposit
Deposit build-up
Type B deposit
Temperature, ºC
Inlet to Heater Milk Flow Outlet to Holding Tube
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Long Life Dairy, Food and Beverage Products
The higher the concentration of ethyl alcohol is without
flocculation the better the heat stability of the milk. Production
and shelf life problems are usually avoided provided the milk
remains stable at an alcohol concentration of 75%.
High heat stability is important because of the need to produce
stable homogeneous products, but also to prevent operational
problems like fouling in the UHT plant. This will decrease
running hours between CIP cleanings and thereby increase
product waste, water, chemical and energy consumption.
Generally it will also disrupt smooth operation and increase the
risk of insterility.
S H E LF LI FE
The shelf life of a product is generally defined as the time for
which the product can be stored without the quality falling below
a certain minimum acceptable level. This is not a very sharp and
exact definition and it depends to a large extent on the perception
of “minimum acceptable quality”. Having defined this it will be
raw material quality, processing and packaging conditions and
conditions during distribution and storage, which will determine
the shelf life of the product.
Milk is a good example of how wide a span the concept of shelf
life covers:
The usual organoleptic factors limiting shelf life are deteriorated
taste, smell and colour, while the physical and chemical limiting
factors are incipient gelling, increase in viscosity, sedimentation
and cream lining.
Choosing the right processIn order to be able to produce a product with specific product
qualities in the most cost-effective way it is essential to make the
correct choice with respect to processing system and technology.
In many cases the choice is straightforward, but in other cases
there may be more options to choose between. Some of the
more important questions to ask when choosing a system are:
• What is the specification of the product to be processed?
• Which are the quality requirements to the final product?
• Viscosity specifications of products and raw materials?
• Specification of particulate and fibre content/size and shape and variation in content?
• Acidity of product/high or low acid?
• Sensitivity to high temperatures/heat stability?
• Requirement for flexibility/multi-purpose systems?
• Requirement for variable capacity?
• Requirement for direct or indirect systems?
• Skills of technical personnel/operators?
Fig. 7 illustrates three of the selection criteria - viscosity,
capacity and content of particulates - for the most common
processing systems.
The systems are often flexibly designed to allow for processing
a range of products in the same plant.
It is quite common to process both low-acid (pH>4.5) and high-
acid (pH<4.5) products in the same UHT plant.
However, only low-acid products require UHT treatment to make
them commercially sterile.
Spores cannot develop in high-acid products such as juice, and the
heat treatment is therefore only intended to kill yeast and moulds.
Consequently high temperature pasteurisation at 90 - 95°C for
15 to 30 seconds is sufficient to make most high-acid products
commercially sterile.
F I G. 6: D E P O S ITS I N U HT P LANTS.
Product Shelf life Storage
Pasteurised milk 5 to 10 days refrigerated
ESL/Pure-LacTM 20 to 45 days refrigerated
UHT milk 3 to 6 months ambient temp.
Capacity l/h35.000 l/h
50 cP
200 cP100 cP
50,000 cP
500 cP
Plate Steriliser
Steam Injectio
n Steriliser
Steam Infusio
n Steriliser
Tubular Sterili
ser
SSHE Steriliser
Increasingparticle size
Viscosity cP
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In some cases where new products have to be processed it may
be necessary to carry out trials in small scale to observe the
performance of specific products in different types of systems.
SPX Flow Technology has designed a pilot unit for this purpose.
The trend for processors to focus increasingly on flexibility to
process a range of products and the importance of being able to
produce high quality products has driven the choice of systems
towards indirect tubular systems and direct steam infusion
systems.
The following sections will deal with the various heating
principles and UHT systems followed by a more detailed
comparison of the individual systems.
TH E H EAT TR EATM E NT PROCE SS E S
SPX Flow Technology invented the plate heat exchanger
in 1923 and has ever since pioneered new heat treatment
principles. Scraped surface heat exchangers were developed in
the USA while the direct steam infusion system was developed
in Denmark. The tubular systems were developed partly in
Denmark and partly in Germany and later supplemented by the
corrugated tubular heat exchangers in Spain. In addition SPX
Flow Technology is known for electroheat thermal processing
equipment, which is dealt with in a separate publication.
PLATE H EAT EXCHANG E R S
The plate heat exchanger is the most cost-effective and versatile
method for indirect heating or cooling of liquid food pro -
ducts. Today SPX Flow Technology’s comprehensive Paraflow
range of plates is the basis for a wide range of plate heat
exchanger applications in many industries, and in the food
and dairy industry the plate heat exchanger is one of the most
indispensable pieces of equipment.
As illustrated in Fig. 8.1 the plate heat exchanger incorporates a
number of parallel, closely spaced stainless steel, gasketed and
corrugated plates, which are compressed and locked together
in a rugged frame. As product is pumped through the plate heat
exchanger, the flow is distributed through narrow, corrugated
flow passages, which produce a high level of turbulence
F I G. 7: AS E PTI C P R O C E S S I N G SYSTE M S
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Long Life Dairy, Food and Beverage Products
resulting in high rates of heating or cooling with low hold-up
volume. Product contact time is thereby reduced to a matter of
seconds minimising thermal damage.
A very important advantage of the plate heat exchanger is
its extremely high regenerative capability, reducing energy
requirements for heating or cooling by more than 90%. Plate
heat exchangers provide a maximum amount of heat exchange
surface in a minimum amount of floor space.
TU B U LAR H EAT EXCHANG E R S
SPX Flow Technology has developed a range of sanitary tubular
heat exchangers for the food industry, and an increasing number
of customers choose this system. Various tubular systems are
available, but the most commonly used system is the multi-
tube-in-tube (MTNT) system as illustrated in Fig. 8.2. The heat
transfer modules are multiple small diameter sanitary tubes
aligned within a large diameter shell.
The diameter of the inner tubes may vary, but is usually in the
range of 10 to 12 mm for low viscous products like milk and
juice.
The SPX Flow Technology tubular system is designed with a
“loose” jacket around the tube bundles giving a floating head
design.
This allows thermal expansion without any risk of tube cracking,
prevents stress corrosion and allows easy inspection of all heat
exchange surfaces.
In some countries, e.g. Germany, the tubular system has become
very popular because of its rugged construction and easy
operation and maintenance.
COR R UGATE D TU B U LAR H EAT EXCHANG E R S
SPX Flow Technology has extended its range of heat
exchangers with corrugated tubular heat exchangers. By
corrugating the tube wall it is possible to improve the heat
transfer coefficient and consequently reduce the requirement
for heating surface area. The corrugation causes increased
turbulence and breaks the laminar flow in high viscosity
products.
Double-tube, triple-tube, quadruple-tube and multi-tube are the
basis for the range as illustrated in Fig. 8.3.1, 8.3.2, 8.3.3 and
8.3.4. The design of the double-, triple- and quadruple-tube
makes it possible to arrange direct regeneration because both
sides of the tube wall are a sanitary design.
Through a variety in corrugation depth, pitch and angle it is
possible to optimise heat transfer and pressure drop depending
on shear characteristics of the product. Furthermore, the
possibility of adjusting the annular space adds one further
parameter for optimising the design.
F I G. 8 .3 .1: AP V D O U B LE TU B E
F I G. 8 .3 .2: AP V TR I P LE TU B E
F I G. 8 .3 .4: AP V M U LT I-TU B E- I N-TU B E
F I G. 8 .3 .3: AP V Q UAD R U P LE TU B E
Product in Product out
Media inMedia out
F I G. 8 .1: AP V P LATE H EAT E XC HAN G E R
Media out
Media in
Productout
Productin
F I G. 8 .2: AP V TU B U LAR H EAT E XC HAN G E R
Air out
CIP in
Holding tube
Steam in Product in
Cooling waterin/out
Steam
Product
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STEAM I NJ ECTION NOZ Z LE S
SPX Flow Technology was one of the pioneers in applying steam
in direct contact with a product to heat it to aseptic temperatures.
The first generation systems were based on the steam injection
principle and were launched under the Uperiser brand name.
The system operates by direct injection of steam through a
specially designed nozzle as illustrated in Fig. 8.4. The injection
of steam raises the product temperature instantly. In order to
prevent the product from boiling it is necessary to pressurise the
product during the steam injection to a pressure of 3 to 4 bar
depending on the sterilisation temperature.
Flash cooling takes place in a vacuum expansion vessel where
the vacuum is maintained by means of a vacuum pump. The
vacuum is controlled in order to ensure that the same amount
of water is flashed off as was injected into the product as steam
thereby preventing dilution/concentration of the product.
STEAM I N FUS ION
In the 1960s APV, An SPX Brand, launched the first steam
infusion system under the Palarisator brand name. Since then
significant developments and progress have taken place, which
have led to one of the most sophisticated systems in the world.
After pre-heating the product is pumped into the infuser, which
is a pressure vessel fitted with cones at both top and bottom as
illustrated in Fig 8.5.
At the top cone the product is distributed through a number
of nozzles (patented) and passes down through a steam
atmosphere in a number of jets without hitting the walls of the
vessel until it reaches the bottom cone.
This is equipped with a cooling jacket keeping the temperature
of the inner cone wall below the product temperature inside the
vessel. This creates a condensate film on the inner cone wall,
which effectively prevents any burn-on of product. During the
heating air, unwanted gases and odours are stripped off through
the CIP inlet at the top of the cone.
The product leaves the infusion chamber through the bottom
of the cone through a pump and an expansion valve before
it passes through the holding tube into the expansion vessel
where the product is cooled down in a similar way as described
for the injection heating system.
As previously mentioned (Fig. 5) this system ensures a single
phase flow and a very accurate flow profile.
The pump and the valve in the holding tube also serve as level
control, which means that there is no product level prior to the
pump and consequently no influence on the holding time due to
varying liquid level at the bottom of the cone, since it will always
be empty.
The heating in the infuser is extremely rapid, and the final
sterilisation temperature is reached in less than 0.2 seconds,
which corresponds to a heating rate of 500 to 600ºC/second.
The system is very flexible and can be used for a wide range
of products covering a broad viscosity range. It provides an
excellent product quality due to the gentle and rapid heating and
subsequent cooling.
F I G. 8 .4: AP V STEAM I NJ E CTI O N N O Z Z LE
F I G. 8 .5: AP V STEAM I N F U S I O N C HAM B E R
Product out Product in
Media in Media out
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SCRAPED SURFACE HEAT EXCHANGERS
SPX Flow Technology’s product range includes a number
of scraped surface heat exchangers specially designed to
heat or cool viscous or sticky products or products containing
particulates.
The scraped surface heat exchanger consists of a smooth
cylinder through which the product is pumped, counter current to
the service medium in the surrounding jacket.
Rotating scraper blades keep the heating surface free from
deposits. The scraper blades are fixed to a rotating shaft called a
dasher (Fig. 8.6).
Selection of different blades and dasher types depends on the
product being processed. The cylinders are usually characterised
by their diameter and SPX Flow Technology supplies units of 4,
6 and 8 inches.
Furthermore, both vertical (Fig. 9) and horizontal models (Fig.
10) are available.
The most recent addition to the range is a VT+660 model with 0,65
m2 surface area, which is 41 percent higher than for the 4” range.
The maximum operating pressure for the VT range is 6 bar while
the HD range is able to operate at 12 bar maximum pressure.
In terms of viscosity the VT model is able to process
products with viscosity up to 100,000 cP.
The HD range is a Heavy Duty model able to handle viscosity as
high as 500,000 cP.
Various aseptic UHT systemsThe best way to characterise UHT systems is to rank them
according to the primary type of heating principle used for
bringing the product into the aseptic area.
The type of system preferred has developed differently in
different countries at different times. In the following section
we will give a brief description of each type of system available
on the market today. For each system the advantages and
limitations will be emphasised and finally the products most
commonly processed in the system will be listed.
All SPX Flow Technology UHT systems are pre-assembled and
tested in the factory with steam. This minimises installation and start-
up costs and ensures a safe and trouble-free plant commissioning.
I N D I R ECT PLATE STE R I LI S E R
UHT systems based on plate heat exchangers are used where
the manufacturer’s primary requirement is a dependable system
for heating liquid products at minimum operating costs.
In Fig. 11.1 a flow diagram illustrates the principle design
including some of the processing parameters.
Careful design of the heating and regenerative systems
optimises the performance of the SPX Flow Technology system
and minimises product damage. Fig. 11.2 compares some key
data for plate and tubular systems.
PRODUCT FILLING
STEAM
1. Product to productregenerative
2. Homogeniser
3. Indirect heating4. Holding tubes5. Indirect cooling
6. Sterile tank7. Cip unit8. Sterilising loop
COOLINGWATER
31
2
6
7
8
5ºC 75ºC
3 5
CHILLEDWATER
4 490ºC 138ºC
5
<25ºC25ºC
F I G. 11.1: F LOWD IAG RAM FO R P LATE STE R I L I S E R
F I G. 9: AP V VT+660 S C RAP E D
S U R FAC E H EAT E XC HAN G E R
F I G.10: AP V H D S C RAP E D
S U R FAC E H EAT E XC HAN G E R
F I G. 8 .6: AP V S C RAP E D S U R FAC E H EAT E XC HAN G E R
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The SPX Flow Technology system has a high degree of flexibility
and can be supplied with variable capacity and with two-speed
or variable speed homogenisers.
The system can be built up to a maximum capacity of 25 to
30,000 l/h.
Fig. 11.3 shows a typical design for an APV Plate Steriliser.
Advantages
• Excellent for low viscosity products
• High regenerative effect and low energy consumption
• High heat transfer area in minimal space
• Easy inspection
• Low hold-up volume
• High degree of flexibility
• Variable capacity Large capacity plants
• Relatively low investment
• Low CIP costs
Limitations
• Limited capability for particulates or fibres
• Exchange of gaskets required periodically
• Unsuitable for high pressure drops
• Some product degradation may occur
Products
• Milk, flavoured milk
• Fermented milk products, drinking yogurt
• Cream, coffee whiteners
• Soy milk
• Baby food
• Juice
• Coffee, tea
• Combination plants for milk, juice, coffee, tea, etc.
LOW MEDIUM HIGH
Energy recovery
PLATE
TUBULAR
LOW MEDIUM HIGH
Heat transfer at equivalent surface
PLATE
TUBULAR
LOW MEDIUM HIGH
Product shear at equivalent heat transfer
PLATE
TUBULAR
LOW MEDIUM HIGH
Plant volume at 90% regenerative
PLATE
TUBULAR
F I G. 11.2: C O M PAR I S O N O F DATA FO R P LATE AN D TU B U LAR STE R I L I S E R
F I G. 11.3: AP V P LATE STE R I L I S E R
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Long Life Dairy, Food and Beverage Products
I NDIRECT TUBULAR STERILISER
UHT systems based on tubular heat exchangers have become
popular in many countries and are typically chosen where large
volumes of commodity products has to be processed at the
lowest possible costs.
In Fig. 12.1 a flow diagram illustrates the principle design
including some of the processing parameters.
In Fig. 12.2 it is shown how the pressure drop affects the
maximum running hours. In a plate based steriliser the increase in
pressure drop is limited to 30 to 40 percent.
This is not a limiting factor in tubular systems and 16 to 20 hours
operating time between CIP is possible. It is also possible to
operate with an intermediate cleaning each 20 hours and reduce
the full CIP cycles to once a week, which may increase the
capacity with as much as 7 to 9 percent.
Exact times will depend on particular products and
microbiological considerations.
Advantages
• Less vulnerable to fouling giving long production runs
• High operating pressures are acceptable
• Processes products with fibres and particulates
• Processes high viscosity products
• Low shear characteristics for cream
• Low requirement for gasket material and easy gasket exchange
• Very robust design
• Low maintenance costs
• Can be designed as a multi-purpose plant
• Easy to operate
Limitations
• Lower regenerative effect than for plate sterilisers
• Slightly higher investment costs compared with plate sterilisers
• Higher degree of product degradation
Products
• Milk, flavoured milk
• Fermented milk products, drinking yogurt
• Cream, coffee whiteners
• Whipping cream, ice cream mix
• Evaporated milk, desserts, puddings
• Soy milk
• Coffee, tea
• Juices, juices with pulp
• Salad dressings
• Gravy, sauces, soups
• Combination plants for milk, juice, coffee, tea, etc.
Tolerated pressure drop (bar)0 50 80 90706010 20 30 40 100
Tubular UHTPlate UHT
10 305 252015
Particle sizes/Fibre lengths (mm)
Tubular UHTPlate UHT
Running time (hours)0 84 12 16 20 24
Tubular UHTPlate UHT
240
220
200
180
160
140
120
100
80
Operating Time of Plant [hour]5 10 15 20 25
Tubular UHT
Common practice tube
Common practiceplate
Plate UHT max. limit
Pre
ssur
e in
crea
sere
lativ
to c
lean
pla
nt (%
)
Plant Feed Pressure -Milk Fouling in Tubular UHT Plant
FIG. 12.2: COMPARISON OF DATA FOR TUBULAR AND PLATE STER ILISER
PRODUCT FILLING
4
8
5
10
6
79
5ºC
75ºC
21 1
95ºC 140ºC
25ºC
STEAM
COOLINGWATER
1. Tubular regenerativepreheaters
2. Homogeniser3. Holding tubes
4. Tubular final heater5. Tubular regenerative
cooler6. Final cooler
7. Sterile tank8. CIP unit9. Sterilising loop10. Water Heater
3 3
F I G. 12.1: F LOW D IAG RAM FO R TU B U LAR STE R I L I S E R
F I G. 12.3: AP V TU B U LAR STE R I L I S E R
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S PI RATH E R M®
APV Spiratherm UHT system is a unique type of process system.
Development of the Spiratherm concept was initiated in the
beginning of the 1960’s based on feed back from the market
place.
Many UHT systems suffer from one or more of the following:
high maintenance costs, contamination risk, limitation in running
time or long CIP periods.
The Spiratherm provides an optimal solution to mitigate all of the
above worries.
Longer operation period
The heart of the Spiratherm system is the unique design of the
tubular heat exchanger.
The natural scrubbing action of the high velocity product through
the Spiratherm heaters cuts down on the product build up found
in conventional heat exchangers.
Spiratherm makes a perfect selection for UHT production of a
wide range of products, including high fouling products.
Reduced CIP time
The tubes are cleaned more easily and less frequently thanks
to CIP capabilities which ensure a minimum of downtime and
greater productivity.
Reduced maintenance cost
The Spiratherm tubes operate more efficiently than coil, plate,
multitube or double-tube methods, allowing faster, more even
heat exchange without hot spots.
Maintenance cost reduction results from the long tube life and
the fact that there is never a need to replace gaskets.
Reduced contamination risk
After sterilisation under high pressure within the sealed Steritherm,
the product travels to a homogenising valve. The valve can be
sterilised and easily cleaned and will maintain sterility. An exclusive
valve stem feature and gauge position assure that no air pockets,
cracks, or crevices can contaminate the product zone. And this
valve, remotely mounted from the pump, eliminates the need for
aseptic homogeniser, reducing lifetime maintenance costs.
No steam / product mixing
The unique heating performance achievable with the Spiratherm
Heat Exchangers assures a rapid heating and cooling time, reducing
any chemical induced impact on the product. In fact, the heating and
cooling profiles are quite similar to those of a direct UHT system.
The Spiratherm differs from direct UHT systems by omitting
direct mixture of product and steam and subsequently the need
to remove the added steam downstream under vacuum.
All Spiratherm models are designed with variable-range
operating capacities for direct connections with fillers operating
at various speeds.
F I G. 12.4: AP V S P I RATH E R M TU B U LAR
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STEAM I N FUS ION STE R I LI S E R
UHT systems based on the infusion heating are used where the
manufacturer wants to produce a high quality product with as
little heat degradation as possible. Also flexibility in throughput
and variety in product range speak for an infusion based system.
In Fig. 13.1 a flow diagram illustrates the principle design
including some of the processing parameters.
The system can basically be supplied from 150 l/h (pilot plant) to
44,000 l/hour with a temperature profile as shown in Fig. 13.2.
The plate heat exchangers for pre-heating and cooling can be
replaced with tubular heat exchangers as an option.
The SPX Flow Technology infusion UHT concept can also be
supplied as an add-on solution to all common UHT plants from
other manufacturers.
Fig. 13.2 shows a comparison of various temperature profiles for
infusion based processes, which are all characterised by a very
rapid and controlled heating and cooling profile and a short and
carefully monitored holding time.
Fig 13.3 shows an APV Steam Infusion Steriliser.
Advantages• Gentle and accurate heating in the infusion chamber
• Accurate holding time
• Superior product quality
• Closed loop during pre-sterilising
• High product flexibility
• Low fouling rate
• Long operating time
• Operator friendly
Limitations• Relatively higher capital costs compared to indirect systems
• Relatively higher operating costs due to lower heat regeneration
• Requirement for culinary steam
Products• Milk, flavoured milk, creams
• Soy milk products
• Vla, custard, pudding
• Soft ice mix, ice cream mix
• Baby food, condensed milk
• Processed cheese
• Sauces
6 6
143ºC 75ºC 25ºC <25ºC
FILLING
5
7
VACUUM
STEAM
1. Plate preheaters2. Steam infusion chamber3. Holding tube
4. Flash vessel5. Aseptic homogeniser6. Plate coolers
7. Aseptic tank8. Non aseptic cooler9. Condenser
COOLINGWATER
2
STEAM
75ºC
COOLING
COOLING
WATER
WATER
4
9
3
1
PRODUCT
5ºC
8 COOLINGWATER
Various Temperature Profiles for Direct Infusion
5
25
50
75
100
125
ºC150
Time
Hot FillIing /Spray Drying
Filling
Cold Filling
Instan
t ESL UHT
F I G. 13.3: AP V STEAM I N F U S I O N STE R I L I S E R
F I G. 13.2: T I M E /TE M P E RATU R E P R O F I LE S FO R VAR I O U S I N F U S I O N
BAS E D P R O C E S S E S
F I G. 13.1: F LOW D IAG RAM FO R STEAM I N F U S I O N STE R I L I S E R
22 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
H IG H H EAT I N FUS ION STE R I LI S E R
The growing incidents of heat resistant spores (HRS) are
challenging traditional UHT technologies and setting new targets.
The HRS are extremely heat resistant and require a minimum of
145 to150°C for 3 to 10 seconds to achieve commercial sterility.
If the temperature is increased to this level in a traditional indirect
UHT plant it would have an adverse effect on the product quality
and the overall running time of the plant. Furthermore it would
result in higher product losses during start and stop and more
frequent CIP cycles would have to be applied. Using the traditional
direct steam infusion system would result in higher energy
consumption and increased capital cost. On this basis SPX Flow
Technology developed the new High Heat Infusion system.
In Fig. 14.1 a flow diagram illustrates the principle design
including the most important processing parameters while
Fig. 14.2 shows the temperature/time profile in comparison to
conventional infusion and indirect systems.
Note that the vacuum chamber has been installed prior to the
infusion chamber. This design facilitates improvement in energy
recovery and it is possible to achieve 75% regeneration compared
to 40% with conventional infusion systems and 80 to 85% with
indirect tubular systems.
Fig. 14.3 shows a design of a High Heat Infusion system delivered
as a combi-plant consisting of an APV Tubular Steriliser with the
infuser module added on.
Advantages
• Micro-biological product safety by elimination of HRS spores
• Very long operating time between CIP
• Reduced contamination risk having vacuum chamber on non-aseptic side
• No flavour losses
• Add-on solutions and combi-systems
Limitations
• Capital investment costs
• Requirement for culinary steam
Products
• Milk and milk products
• Desserts
• Other products with conventional infusion systems
UHT of products with HRS (comparative temperature profiles with Fo= 40)
0
50
100
150
Time
ºC
Direct UHT 150ºCHigh Heat Infusion 150ºCIndirect UHT 147ºCReference Indirect UHT 140ºC
PRODUCT
FILLING
64
9
VACUUM
COOLINGWATER
5
STEAM
711 7
5ºC 60ºC
2
90ºC 125ºC
2
810 8
150ºC 75ºC 25ºC
STEAMSTEAM
1. Tubular preheaters2. Holding tube3. Flash vessel (non aseptic)
4.5. Steam infusion chamber6.
Non aseptic flavour dosing (option)
Homogeniser (aseptic)
7.8.9.10.
Tubular coolersTubular HeatersAseptic tankNon aseptic cooler
COOLINGWATER
3
F I G.14.3: AP V H I G H H EAT I N F U S I O N STE R I L I S E R
F I G. 14.1: F LOW D IAG RAM FO R H I G H H EAT I N F U S I O N STE R I L I S E R
F I G. 14.2: T I M E /TE M P E RATU R E P R O F I LE S I LLU STRATI N G H I G H H EAT
I N F U S I O N P R O C E S S I N G PARAM ETE R S
23 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
I N STANT I N FUS ION PASTE U R I S E R
The infusion heating principle has increasingly been used for
high viscous and sticky products. However, some products have
been found to be very difficult or nearly impossible to handle
unless very short run-times were accepted.
This challenge led SPX Flow Technology to develop the
patented Instant Infusion system. The objective was to
design a system where a high kill rate can be achieved using
high pasteurisation temperatures and very low holding time
(<0.5 second) for products like egg white and whey protein
concentrate.
The patented design principle for the Instant Infusion Pasteuriser
is based on the conventional infusion system.
In order to have an efficient removal of the viscous and sticky
product from the infusion chamber, a positive displacement pump
has been placed in the outlet tube from the bottom cone very
close to the actual cone.
This effectively prevents any type of build-up of product at the
bottom of the infusion chamber and it has been possible to
increase the number of operating hours between CIP cleanings
from a few to more than 20 hours for some products.
In Fig 15.1 is shown the design of the infusion chamber with the
pump arrangement.
Fig. 15.2 shows an industrial installation of an Instant Infusion
plant.
Advantages
• Can handle high fouling products with long running time (>20 hours)
• High degree of flexibility
• Reduced chemical changes in comparison to conventional infusion
• Very high product quality
Products
• Whey protein concentrate
• Egg-based products
• Baby food
• Processed cheese
F I G. 15.2: AP V I N STANT I N F U S I O N PASTE U R I S E R
F I G. 15.1: I N STANT I N F U S I O N C HAM B E R
24 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
STEAM I NJ ECTION STE R I LI S E R
This system operates by direct injection of steam into the product
through a specially designed nozzle as previously described (Fig.
8.4).
The heating is followed by flash cooling and final cooling, which
take place in either plate heat exchangers or tubular heat
exchangers.
The system is in its basic design quite similar to an infusion
system where the infuser has been replaced with an injection
nozzle. (Fig. 16.1)
Long operating times are possible because only a very small area
in the nozzle is subject to fouling.
The operating economy has been optimised through optimisation
of plant design, processing parameters and careful process
control.
The injection system handles low to medium viscosity products, in
the capacity range from 2,000 to 25,000 l/hour.
Fig. 16.2 shows an APV Steam Injection Steriliser.
Advantages
• Good product quality
• Long production runs
• Handles heat-sensitive products
Limitations
• Higher capital costs than for indirect systems
• Higher operating costs due to lower heat regeneration
• Mostly used for low viscosity products
• Requirement for culinary steam
Products
• Milk, flavoured milk, cream
• Soy milk
• Ice cream mix
PRODUCT
6 6
143ºC 75ºC 25ºC <25ºC
FILLING
5
7
VACUUM5ºC
STEAM
1. Plate preheaters2. Steam injection nozzle3. Holding tube
4. Flash vessel5. Aseptic homogeniser6. Plate coolers
7. Aseptic tank8. Non aseptic cooler9. Condenser
2
STEAM
75ºC
COOLING
COOLING
WATER
WATER
4
9
3
1
8 COOLINGWATER
Steam
Product
F I G. 16.1: F LOW D IAG RAM FO R STEAM I NJ E CTI O N STE R I L I S E R
F I G. 16.2: AP V STEAM I NJ E CTI O N STE R I L I S E R
25 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
SCRAPE D SU R FACE H EAT EXCHANG E R
STE R I LI S E R
Scraped surface heat exchangers (SSHE) are the most suitable
equipment for treatment of high viscosity food products and
food products containing larger particles.
In a typical aseptic plant the product is pumped by a rotary
lobe pump or similar to feed one or more heating cylinders
followed by a holding tube and one or more cooling cylinders.
Capacities up to approximately 10,000 l/hour are available but
this depends to a large extent on the physical characteristics of
individual products.
Since the nature of the products can vary considerably in terms
of viscosity, stickiness or size and fragility of the particles, each
system is individually engineered to suit a particular product.
Even though systems based on SSHE are relatively expensive,
both in terms of investment and energy consumption, they are
still very competitive compared with batch sterilising systems.
Fig. 17 shows an SSHE based steriliser equipped with VT 4“
cylinders.
Advantages
• Handles high-viscosity products
• Handles sticky products
• Handles particulates up to approximately 13 mm
• Handles heavy-fouling products
Limitations
• Relatively high capital cost
• Relatively high energy requirements
• Higher maintenance costs owing to scraper blades, bearings and seals
• High spare parts requirement
• Limitation in respect of size of particulates
Products
• Milk concentrate
• Yogurt
• Processed cheese
• Whey protein concentrate
• Quark products
• Baby food
• Compotes
• Puddings, dips
• Sauces, soups
PI LOT U HT PLANT
The constant pressure on manufacturers to produce quality
products at the lowest possible cost creates a need for
evaluating the most suitable process system and optimising
processing parameters. Using production plants for tests on new
products and processes is both uneconomical and difficult.
Therefore SPX Flow Technology has developed a new
generation of pilot plants, which gives manufacturers the
possibility of performing tests on a small scale with easy
operation, flexibility and scaling up accuracy.
The continuous UHT pilot plant Fig. 18 has a capacity of 60 to
200 l/h and is designed for indirect tubular and direct steam
infusion heating.
F I G. 17: AP V S S H E STE R I L I S E R
F I G. 18: AP V U HT P I LOT P LANT.
26 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
However, the following options can be included in the standard
system:
• High Heat Infusion
• ndirect Plate
• Direct Steam Injection
• Pasteurisation
• Deaeration/Deodorisation
• Scraped Surface Heat Exchanger
• and/or any combinations.
It is also possible to provide variable temperature and holding
time profiles. This makes the pilot plant extremely versatile. The
plant can be supplied with a 500 litre sterile tank, which will form
a link between the pilot plant and a filling machine.
Many manufacturers choose to invest in their own pilot plant
for in-house testing and product evaluation, but in other cases
they may choose to use one of SPX Flow Technology’s test and
development centres.
STE R I LE TAN K
It is not always practically possible to feed a sterile product
directly from the processing plant to the filling machine.
This is where the aseptic tank comes in as a buffer between
processing and filling units.
Besides serving as a buffer and storage tank for the sterilised
product the aseptic tank also adds an important degree of
flexibility to the production process as it provides for:
• Continuation of production regardless of interruption in filling rate. Usually one UHT line is connected to several filling machines with variable capacity. If the filling rate is not at a maximum, the UHT plants need to have a variable capacity or the product must be recirculated if allowed by local regulations.
• Continuation of filling during intermediate CIP or interruption in UHT operations. Many UHT plants need intermediate CIP after 8 to12 hours of operation, depending on the UHT system, product quality and type of product to be processed. The aseptic tank ensures that this process can be performed without interrupting the operation of the filling lines.
• Reduced investment. As the filling machines are the most expensive part of an aseptic processing line, it is important that they are utilised to their full capacity. To this end the aseptic tank is installed. By increasing the operating time of the fillers, a small increase in the capacity of the UHT plant creates the possibility of lengthening the production run significantly.
The aseptic tank is equipped with steam-shielded aseptic valve
clusters and supplied with sterile air at constant pressure. This
provides for a perfect balance between supply and demand from
the aseptic tank.
The aseptic tank is also fully automated, using programmable
logic controllers (PLC), and the control system can be
connected either to the UHT control system or to one of the
filling machines.
Fig. 19 shows the APV Sterile Tank.
F I G. 19: AP V STE R I LE TAN K
27 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
D EAE RATOR
Deaeration is essential for production of high quality products.
While the products in the infusion systems are deaerated in
the infusion chamber this is not the case when indirect heating
systems are used.
In these cases the dearation can be solved through the
installation of the APV Parasol Deaerator, designed to remove
dissolved or entrained air under vacuum. The product is sprayed
into a vessel as a thin film in a parasol form, maximising product
surface area and deaeration efficiency.
The APV WI+ centrifugal pump is used to ensure pumping of
high viscous products under vacuum. The APV WI+ pump is
equipped with an APV - Universal inducer acting as a helical
screw pump mounted to the pump shaft in front of the impeller,
which reduces the risk of cavitation especially when pumping
high viscous products. The air content can be reduced to as low
as 0.5 ppm oxygen.
The APV Parasol Deaerator is shown in Fig. 20
Extended shelf life/ESLIn many parts of the world the production of fresh milk presents
a problem in regard to keeping quality. This is due to inadequate
cold chains, poor raw material and/or insufficient process and
filling technology. Until recently, the only solution has been to
produce UHT milk with a shelf life of 3 to 6 months at ambient
temperature. In order to try to improve the shelf life of ordinary
pasteurised milk, various attempts have been made to increase
pasteurisation temperature and this led to the extended shelf
life concept as referred to earlier in this publication.
SPX Flow Technology has in cooperation with Elopak developed
the Pure-LacTM concept, which in a systematic way attacks the
challenge of improving milk quality for the consumer.
THE PURE-LACTM PROCE SS
Based on investigations of consumer requirements and the present market conditions in a large number of countries the objective of Pure-LacTM was defined as follows:
• A sensory quality equal to or better than pasteurised products
• A “real life” distribution temperature of neither 5°C, nor 7°C but 10°C
• A prolonged shelf life corresponding to 14 to 45 days at 10°C depending on filling methods and raw milk quality
• A method to accommodate changes in purchasing patterns of the consumer
• An improved method for distribution of niche products
• To cover the complete milk product range, i.e. milk, creams, desserts, ice cream mix, etc.
• To provide tailored packaging concepts designed to give maximum protection using minimum but adequate packaging solutions
Having reviewed the range of “cold technologies” available it
became obvious that most of them were only suited for white
milk. Furthermore the actual microbiological reduction rate for
some of the processes were inadequate to provide sufficient
safety for shelf life of more than 14 days at 10°C.
Table 3 is a comparison between various processes and their
ability to reduce bacteria and various types of spores. Using the
data in Table 3 on a milk containing 10 to 100 spores/ml in the
raw milk out of which 10 percent are psychrotrophic spores, the
following result is achieved:
F I G. 20: AP V PARAS O L D EAE RATO R
D ECI MAL R E D UCTION OF VAR IOUS BACTE R IA AN D S POR E S
TYPE CE NTR I-FUGATION
M ICRO- FI LTRATION PU R E-LACTM
TOTAL BACTE R IA 1 2.5 10
AE R O B I C S P O R E S 1.3 2.4 6
AE R O B I C P SYC H R O-TR O P H I C S P O R E S
<1 2.4 8
AE R O B I C S P O R E S 1.7 4
TAB LE 3: C O M PAR I S O N O F VAR I O U S M ETH O D S FO R R E D U C I N G TH E
N U M B E R O F BACTE R IA AN D S P O R E S I N L I Q U I D M I LK
28 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
• Microfiltration, log 3 reduction
1 to 10 psychrotrophic spores per litre in the final product
Every carton is a potential risk
• Pure-LacTM, log 8 reduction
< 1 psychrotrophic spore per 10.000 litre in the final product
Large safety margin and excellent quality buffer
Bacteria-removing centrifuges are also used to improve the
quality of drinking milk. As shown in Table 3 the decimal
reduction of bacteria and spores is less efficient than for
microfiltration. By reducing the throughput to half of the nominal
capacity or by double centrifugation the reduction is improved
by at least one decimal, which brings it closer to microfiltration.
However, double centrifugation increases the investment and
operating costs considerably, and this combined with the loss of
milk in the bacterial concentrate in the order of 1 to 6% reduces
the attractiveness of using bacteria removing centrifuges to
extend the shelf life of milk.
The basis for the process is the infusion technology as
described. Several years of research and development have
resulted in a technology, which provides an extremely gentle
heating to a temperature of 130 to145°C in less than 1 second.
The rate of heating is very fast in the order of 500 to 600°C/s
providing all the benefits previously described.
With a combination of this process technology, the appropriate
filling technology and a suitable carton it is possible to produce
and guarantee products with as good a taste and flavour as
pasteurised milk, having a shelf life up to 45 days at a storage
temperature of 10°C. For comparison the same milk pasteurised
at 72°C would have a shelf life of 1 to 2 days under the same
storage conditions, while it would keep fresh for 10 days at a
storage temperature of 4°C.
Comparison between different systemsAs illustrated in the presentation of the various technologies
there is a wide choice and there are several considerations to be
made before the final decision is taken. SPX Flow Technology’s
team of experts is available to advise on selecting the most
appropriate technology for each specific requirement.
Table 4 provides a rough guideline of the advantages and
disadvantages of different technologies in relation to a variety of
products. This is meant as a guideline to make the right choice,
which in many cases may be obvious while in other cases
more difficult. As mentioned in the section on the APV Pilot
Plant this provides a tool for testing different products using
different heating technologies, and this may sometimes become
necessary to ensure the correct choice.
Process controlsOne of the most important aspects of an aseptic plant is the
process control system. It must continuously monitor all process
parameters and take reliable corrective action in case of a failure.
Today all of SPX Flow Technology’s UHT systems operate under
a PLC (Programmable Logic Controller) or a DCS (Distributed
Control System) based on the world leading brands, providing
the best possible repeatability and reliability in the operation.
This means consistent product quality, package after package,
day after day. Human error is minimised and greater production
efficiency is achieved.
There are many systems, which are capable of successfully
operating an aseptic plant. However, when it comes to choosing
the right concept for the process control system there are
additional factors to take into consideration. Such factors include
hardware durability and availability, service from the supplier
and communication ability with surrounding control systems in
the plant. The operating personnel’s familiarity with a particular
control system is also important, and there may be special
regulatory codes, which require adaptation of control systems.
The world leading process technology - a result of many years’
development and experience - is built into our software packages.
The control system has already been tested in many similar
applications and they are always pretested prior to delivery.
Fig. 21 shows an SPX Flow Technology production management
system: The APV Factorty Expert Concept.
29 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
LOR E M I PSOM PLATE STE R I LI S E R
TU B U LAR STE R I LI S E R
STEAM I N FUS ION
STE R I LI S E R
STEAM I NJ ECTION
STE R I LI S E R
H IG H H EAT I N FUS ION
STE R I LI S E R
I N STANT I N FUS ION PASTE U R-
I S E R
SS H E STE R I LI S E R
M I LK
LOW C O ST 1 2 5 4 3 5 5
H I G H Q UALITY 3 3 1 2 2 1 5
P O O R Q UALITY 4 2 1 2 2 1 5
H EAT R E S I STANT S P O R E S 3 3 2 2 1 5 5
F LAVO U R E D M I LK
FO U LI N G P R O D U CT (C H O C O LATE) 3 2 1 2 2 1 5
VO LATI LE AR O MA 1 1 3 3 2 3 5
D I F F I C U LT TO STE R I L I S E (C O C OA) 3 2 1 1 1 3 5
S E N S IT IVE C O LO U R 3 3 1 2 2 1 5
C R EAM
WH I P P I N G C R EAM 3 3 1 2 2 1 5
STAB I L I S E D D E S S E RTS 4 3 1 2 2 1 5
C O O K E D C R EAM 2 2 1 2 2 4 5
C O F F E E WH ITE N E R S
M I LK-BAS E D 1 1 2 3 1 3 5
VEGETABLE OIL-BASED (EMULSIFIED) 1 1 2 3 1 3 5
FO U LI N G / H I G H P R OTE I N C O NTE NT AN D STAB I L I S E R 4 4 2 3 4 1 5
J U I C E
W ITH P U LP, F I B R E S >1 M M 5 1 5 5 5 5 5
W ITH P U LP, F I B R E S <1 M M 3 1 5 5 5 5 5
W ITH O UT P U LP AN D F I B R E S 1 1 5 5 5 5 5
YO G H U RT 1 1 4 4 4 4 4
Q UAR K 5 5 4 4 5 3 1
BABY FO O D 3 3 1 2 3 1 1
M I LK C O N C E NTRATE 4 4 2 3 4 1 2
P U D D I N G S
STAB I L I S E D, H I G H S O LI D S, STAR C H 5 4 2 4 4 1 3
STAB I L I S E D W ITH CAR RAG E E NAN 3 3 2 3 3 2 3
S OY M I LK
LOW C O ST 1 2 5 4 5 5 5
H I G H Q UALITY 3 3 1 2 1 1 5
P O O R Q UALITY RAW MATE R IAL 4 3 1 2 2 1 5
C O F F E E AN D TEA 1 1 4 4 4 4 5
S O U P S AN D SAU C E S 5 2 4 4 5 5 1
OTH E R C O N S I D E RATI O N S
H EAT STAB I L ITY 3 3 1 2 3 1 3
AS E PTI C P R O D U CT 1 1 1 1 1 4 1
F LE X I B I L ITY 3 3 1 2 1 1 1
MAI NTE NAN C E 2 1 2 2 2 2 3
1 = E XC E LLE NT 2 = G O O D 3 = AC C E PTAB LE 4 = P O S S I B LE 5 = N OT R E C O M M E N D E D
TAB LE 4: C O M PAR I S O N B ETW E E N TH E M O ST C O M M O N LY U S E D P R O C E S S I N G SYSTE M S RATE D O N A S CALE F R O M 1 TO 5:
30 22000-06-01-2013-G B
Long Life Dairy, Food and Beverage Products
Filling and packagingIn order to preserve their high micro-biological quality, aseptically
processed products must be packed aseptically. Even at room
temperature, the packaged product then has a shelf life of
several months.
In aseptic filling and packaging, the aseptically processed
product is filled under aseptic conditions into commercially sterile
containers, which are either preformed or formed in conjunction
with the filling operation. After the filling has been completed,
the containers are hermetically sealed. The resultant packages
are liquid-proof and exclude air, light and bacteria. This method
of processing and packaging allows for the use of paperboard,
plastic containers or pouches as packaging materials, and
eliminates the need for cans and energy inefficient retort heating
systems.
The choice of packaging concept depends on product type, unit
cost and customer preference. Environmental concerns, volume
of waste and the possibility of recycling of packaging material
become increasingly important depending however, on the stage
of development of the community.
SPX Flow Technology is not a manufacturer of packaging
systems but co-operates with all companies in the packaging
sector and is able to supply the appropriate solution for
complete and turnkey systems.
With an SPX Flow Technology system, customers are assured of a
complete aseptic processing line producing high quality products
packed for the specific market in the most cost-effective way.
Product developmentNew products are developed more rapidly than ever before in
order to satisfy demands in the consumer market. Simultaneously
the life-cycle of the individual products tends to shorten. These
conditions force the producers to intensify and accelerate
product development. Capabilities in aseptic processing and
related disciplines enable SPX Flow Technology to support
customers to develop new value added products at the highest
possible speed.
This can be achieved through product testing in the SPX Flow
Technology test and development centres around the world or by
means of an APV Pilot Plant installed at the customers site.
SPX Flow Technology is keen to work in partnership with
customers in order to accelerate the product development
process.
It is the objective of SPX Flow Technology to deliver innovation,
quality and reliability to the dairy, food and beverage industry and
in this way contribute to safe and high quality products for the
consumer.
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Long Life Dairy, Food and Beverage Products
F I G. 21: AP V FACTO RY E X P E RT
S PX FLOW TECH NOLOGY
Pasteursvej
DK-8600 Silkeborg, Denmark
Phone: +45 70 278 278
Fax: +45 70 278 330
SPX reserves the right to incorporate our latest design and material changes without notice or obligation.
Design features, materials of construction and dimensional data, as described in this bulletin, are provided for your information only and should not be relied upon unless
confirmed in writing. Please contact your local sales representative for product availability in your region. For more information visit www.spx.com.
The green “>” is a trademark of SPX Corporation, Inc..
ISSUED 01/2013 22000-06-01-2013-GB
COPYRIGHT © 2010 SPX Corporation
ABOUT S PX
Based in Charlotte, North Carolina, SPX Corporation (NYSE: SPW) is a global Fortune 500 multi-industry manufacturing leader.
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