food processing industeries

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FOOD PROCESSING INDUSTERIES

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Page 1: Food processing industeries

FOOD PROCESSING

INDUSTERIES

Page 2: Food processing industeries

WASEEM AKHTAR

NFC-IET-MULTAN

Page 3: Food processing industeries

INTORDUCTION

• Like a other industries food industries playing a big role in society

• The demand of pre processing and processing of food for the use food items in home has been increased day by day

• This demand for uniformity of quality food and high standards based at the remote areas

Page 4: Food processing industeries

• Food processing regardless of the type of food can be divided into three classes

1. Separation

2. Assembly

3. Preservation

These occur at food processing plant for sale point of view

Page 5: Food processing industeries

• Separation

Separation include rendering , skimming , boning, coring, defeathering , husking , peeling, shelling.

Assembly

Assembly include coating, enrobing, baking, homogenization , roasting,pelleting, stuffing

Preservation

To preserve the food stuff

Page 6: Food processing industeries

• Food is categorized as live tissue and non live tissue

• Live tissue food includes fresh fruits ,vegetable , meat , grains

• Non living tissue include beverages , milk ,cheese, butter etc.

• During the process control the taste ,color, nutritive value, cell structure as a fresh food

Page 7: Food processing industeries

• Qualities of food is achieved by use of enzyme ,food should not be in the approach of insects, bruising ,chemical degradation.

• The intensity of processing operation is limited by tissue itself in term of temperature range ,water activity, respiratory – gas composition ,mechanical stress, and concentration of chemicals . Certain fruits are stored at 0C .

Page 8: Food processing industeries

• Non living tissue food includes is determined for preservation food so that final quality food can be determined including vitamins , fats ,butter etc .these are free from the defects and good nutrition value.

Page 9: Food processing industeries

Toxicological implication of food deterioration and spoilage

• Primary Objective of food processing is ensure a safe food supply . Certain food harvested contain naturally occurring poisonous substances compound with pharmacological effects or compounds that can be interfere with utilization of neutrants present in food, when they are consumed togather .

• Harvested food maybe contaminated with spor,parsites ,full of pesticides and chemical that used for plant protection that is lathal food

Page 10: Food processing industeries

• Third source of health hazard during the supply toxic chemicals are used for preservation

Page 11: Food processing industeries

Food processing facilities

• Appropriate site selection for food processing plant

• Available of raw material

• Clean and fresh water supply

• Low cost waste disposal facilities

• Adequate and cheap source of energy supply

• Adequately supply of seasonal and non seasonal labor

Page 12: Food processing industeries

• Easy supply of rails ,trucks and transportation

• Maximum consumers facility

• Adequate storage areas

Page 13: Food processing industeries

Food processing

• Food processing operations can be grouped into three categories

• Preparation • Assembly • Preservation

Preparation process are used to convert raw plant or animal tissue into animal ingredients .this may include separation of inedible and hazardous components , extraction or concentration of nutrients , flavors , color and other useful components and removal of water .

Page 14: Food processing industeries

• Assembly process are used to combine and form ingredients into consumer products .

• Preservation process is used to prevent the spoilage of foods. Five sources of food spoilage must be addressed in order to deliver fresh , safe food and ingredients microbial contamination , including viruses ;enzyme activity from enzymes in the food itself and from external enzyme such as form microbial activity ; chemical deterioration such as oxidation and non enzymatic browning ; contamination from animals , insects and parasites ; and losses owing to mechanical damage such as bruising .

Page 15: Food processing industeries

• Preservation process can be used to extend the shelf life of fresh foods, such as produce or to manufacture products for long term storage where shelf lives are measured in years.

Plants and animals are the primary sources of food. The food processing industry devotes considerable research to the selection and improvement of plants and animals for raw materials . Genetic engineering , as well as conventional breeding methods , are being used to improve the yield , color , flavor , texture , nutrients contents , and resistance to diseases , insect loss , and climates stress .

Page 16: Food processing industeries

• However , products quality can vary oving to weather , soil , growing practices , harvest methods and post-harvest handling . Thus food processing unites operations must be design to aspect a raw material having a wide range of qualities in addition , provision often must be made for profit able use of byproducts and waste streams .

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REGULATIONS

• Food processing operations are regulated by government and international law

• Food safety include toxic regulations include standards for toxic and carcinogenic substances in foods

• Chemicals hazards include heavy metals, and herbicides and pesticides contents in food

• Physical hazardous materials suchasmetals,wood, pits ,glass , insect fragments

Page 18: Food processing industeries

• Food regulations are covered in federal code regulations

• Food processing operations can be optimisedaccording to principles and chemical processes

• Chemical processing include distillation, filtration ,crystallization ,size reduction material handelling should be follow the food laws

Page 19: Food processing industeries

• Food processing operation optimization, principles used for food chemical processes and thermo physical properties and structure of food is known

• For food processing optimization measurement include vitamins,physicalchanges such as viscosity ,level ascorbic acid ,thiamine can be used as indicator

Page 20: Food processing industeries

Theoretical basis

• Food preservation yielded the heating time and temperatures needed to produce foods by mathematical modeling is determined

• Mild heat tretment used in pasturization of milk

• Spore forming bacteria are most heat resitantorganism

Page 21: Food processing industeries

• Spore formation must be done at rate of population 10,000 spores at 121C for 16 minuts to complete inactivation

• Sporation process must be deactive for heat treated foods to avoid spoilage of food

• Deactivation of spore is done by heat treatment(100C for 10 mins) salts used pH and nitrates

Page 22: Food processing industeries

• Such substances must be known to stop the growth of spore of bacteria such as nisin C1433 H230N42O37S7 that stop the growth rate of bacteria in cheese food

• Water activity is linked with rates of chemical reactions and microbial and enzyme activity in food

• Water activity effect the humidity present around the food

• Standard moisture test is conducted to safe the food

Page 23: Food processing industeries

• At freezing point water content forms plastic material form bonds with protein that cause change the damage of food

• When water content is low food behave like a rubbery material .flow of water in tissue is decrease during the heating and at last react with tissue and proteins

• When food is freezed storage glassy crystalline structure of food is important

Page 24: Food processing industeries

Preservation of food

• Methods are adopted for food preservation so that to avoid food spoilage

1. Heat treatment: storage near or below freezing point of water

2 .Dehydration : control the water activity in food 3 Chemical preservation : chemical process such as washing

,peeling ,filtration, centrifuging ,grinding , ultra high hydrostatic pressure , and mechanical operations

4 packaging

Page 25: Food processing industeries

• For few days animals and vegetable products at room temperature is complex process

• During storage enzyme system is continouslyworking their effect of reaction affects the taste ,softness

• Fresh animals and vegetable products are affected by odor ,animals ,dust , insects and microbes

Page 26: Food processing industeries

Shortage -term -storage

• The composition of the gaseous atmosphere surrounding certain respiring fruits and vegetable can influence their rate of quality loss atmosphere of O2 1-2% ,CO2 and remainder ,nitrogen can prolong storage life of selected fruits such as apples in refrigerated storage for 9- 10 months possible

• For meat and poultry products gaseous mixture contain 50% oxygen , several %CO2 and remaining N2 can extended the useful shelf life (the life of using things) of these products from days to week . In this case oxygen show growth of anaerobic spoilage of bacteria under refirigeration

Page 27: Food processing industeries

• In packaging respiration system also provided to get fresh food

• Package materials can metabolized oxygen and release carbon di oxide to atmosphere

• In chemical storage ethylene is used for respiration

Page 28: Food processing industeries

Refrigeration

• For useful shelf life refrigeration is used to slow down the growth of microbes . The effectiveness of refrigeration can be improved by combing storage just above freezing with ionizing radiation or chemical preservation such as food acid , sodium benzoate and nisin

• To remove the microbes ultra high pressure 300 -400 Mpa .for liquid food filtration or centrifuge is done to remove microbes .

Page 29: Food processing industeries

• Vacuum packaging is effective in shelf life refrigeration for processed meat products . The use of combination of several preservation step to show the minimum spoilage the product

Page 30: Food processing industeries

Heat treatment

• Fish or sea food contain a lot of water and pathogenic virus

• For safe sea food proper heat treatment is necessary to kill the pathogenic micro organism

• Canned mushrooms are 90% toxin their toxicity is removed by on heating treatment their heating time is 19 mins for 121C

Page 31: Food processing industeries

preservative

• Bakery products loose their freshness within 24 hrs at room temperature, chemical changes occurred about water migration and starch crystallization this cause change the protienand starch structure of the product

• For this treatment molds of product should be proper stirrlized and during packing they remain in oxygen free atmosphere

Page 32: Food processing industeries

Long term storage

• In activation of microbes and enzymes in food and food ingredients is necessary to ensure a long shelf life .

• This can be achieved by using one or more preservation operations such as apply heating and using storage temperature below -18C, drying to water activity below 0.65 that is equilibrium relative humidity surrounding the product below 65% and adding chemical preservatives such as organic acid (acetic or lactic) or table salt . Heat is used to inactive the enzymes in food to freezing ,drying or chemical preservations is known as blanching

Page 33: Food processing industeries

• Food process firms producing heat preserved , frozen , dehydrated or chemically preserved food may classified by their finished product

• The ingredients used in product should be according to international standards regulation for the ready to eat meat or poultaty products

Page 34: Food processing industeries

Thermal preservation technology

• The heat preservation of food can be completed various combination of heating times and temperature depend upon numbers and type of heat spore present . Physically chracteritics of the food such as viscosity ,size of particals, size of packages and starting temperature influence the rate of heat penetration into slowest heating point in the package

Page 35: Food processing industeries

• The inactivation of heat resistant spore appears to follow first order kinetics . Thus if the rate of inactivation of spore population is known at different temperatures and rate of heating of slowest heating point in the package can be calculated for external heating condition with mathematical modeling and process operating condition such as steam pressure ,heat sterilized and product temperatures

Page 36: Food processing industeries

• Thermally processed food is preserved in sealed container depends upon slowest heating volume of container

• Heat resistant spores may present even after heat treatment

• Chemical changes in food flavors and vitamins are added in the food

Page 37: Food processing industeries

Equipment sterilization

• Equipment and processes for thermal preservation depend upon physical form of food and PH that lies below 4.5 for commercial sterilization at 100 C

• Acid food requires simple equipment for heat preservation at 100C and filled hot into suitable containers . These containers are sealed inverted to sterilized the closure () held at filling temperature for a short time to ensure

Page 38: Food processing industeries

• Low acid foods have PH grater than 4.5 requiring sterilization at temperature above 100C and thus treatment in pressure vessels

• Heat treatment temperature preservation temperature is above 100C can be carried out in batch or continous heat exchange equipment, it is a simple pressure vessel in which packaged food can be exposed to saturated steam , water, pressurized air , and spray water or mixture of air and steam

Page 39: Food processing industeries

• Microwave energy is utilized in plastic and glass industry while small containers are heated in pressure vessels by direct flame ,fluidized bed ,or electrical resistance heater

• Fluid or slurries foods can be heated in agitated vessel to increase the internal heat transfer increasing . Riged cans foods are heated in vacuum conditions with very little liquids to permot steam formation inside container cans

Page 40: Food processing industeries

Batch heat process

• Batch processes has main advantages of low capital investment

• These are designed according to size of food packaged and length of heat treatment . System is fully automatic process control

• Material handling are easily loaded and unloaded .

• Disadvantage of this process is slow cycle time because high energy and labor cost is needed for the process

Page 41: Food processing industeries

• Batch process is preferable for mixed food products in number of packages sizes with a limited number of cases for any product style con make

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Continuous heat process

• Continuous heat processing equipment can take the form of heat exchanger for pumped foods or material handling system that introduces indvidual packages into steam pressure chamber with mechanical valve system rotating pocket or hydrostatic legs of sufficient high pressure internal steam pressure of system . A hydrostatic cooker operating 121 C with gauge pressure 0.1 Mpa and 20m high hydrostatic inlet and outlet legs . This hight is needed a safety factor for water level in cooker

• In this system 1000 food container /min can be cooked

Page 43: Food processing industeries

• Food is continuously heat sterilized and cooled in heat exchangers must be handled under aseptic conditions and filled aseptically in presterilized packages .

• Microwave and induction heating allow particulate foods to be heated more rapidly and uniformly than conduction heating by conventional heat exchanger . All equipment used in food industry should be well sterilized

Page 44: Food processing industeries

• Food packaging is done at room temperature with help of car cans

• Aseptic filling in which metal cans are used for packaging the food that are sterilized by steam while paper, foil ,plastic laminates are sterilized by hydrogen peroxide

• Novel aseptic filling system designed for acid foods such as apple sauces and fruit juice uses as food grade organic and inorganic acid

Page 45: Food processing industeries

• For their filling they come in sterilized filling area so that microbes cannot enter in filling area where the food is filled in prestirilized packing in nitrogen and oxygen atmosphere they are sealed.

• Aseptic packing is used in milk and sauces packing

Page 46: Food processing industeries

FREEZING PRESERVATION

• The rate of loss of color, flavor, texture, and nutrients due to growth of microbes and activity of enzymes and other life form are all function of temperature

• Thus lower temperature storage prolong the useful life of food. Below 0C the free water starts to form ice crystals. Ice crystal formation is function of moisture content ,solute composition and storage temperature fluctuation .

Page 47: Food processing industeries

• Super cooling can occurs during the freezing process . Food having high concentrations of solutes can behave as glassy materials in which water may exist in non crystalline state at freezing temperature to show diffusion and high soluble solid content

• The condition needed for establishing and maintaining the glassy state in frozen food

Page 48: Food processing industeries

• Ice formation benefits are strengthen of food structure and removal of free moisture. Ice formation method is useful for plants cells,fruitsand vegetable product to preserve food . Ice crystal formation cease the microbial growth partial dehydration of water in tissue . Ice crystal disrupt cell structure and increase the concentration of electrolytes denaturation of protein occur. Quality of protein loss occur for better it is boiled in hot water and deep freezing is effective for protein storage

Page 49: Food processing industeries

• Food is cooled at -18C ensure that maximum ice crystal formation .the rapid cooling is cause of small ice crystal which minimize the disruption of protein cell

• Commercial frozen equipment can frozen at -18 to -24C shelf life for the product for these ate 1 year. Because at this temperature freezing reduces the enzyme activity

• Inactive temperature for these food are 100C • This phenomena is known as freeze drying.• Fishes can be stored by this method

Page 50: Food processing industeries

• For deep freezing technique high heat velocity air is necessary about 5m/s at temperature -40C . The air recycled through cooling coils and fans convey the air and returned.

• The cold has lowered partial vapour pressure than hot food so by evaporation many of water carried by air . Later on vapor of water condense in cooling coil and exit from air. In this way air performing good heat transfer media for food

Page 51: Food processing industeries

• For rapid cooling high velocity of air and lower temperatue are required . The main heat transfer media during freezing is conduction

• Some time liquid coolant is used as heat transfer media such as salt, alcohol, and esters that reduce pumping cost and help to permot high refrigeration , this method is for specific foods not for all such as turkey

• Frozen product are packed in polyethylene packing

Page 52: Food processing industeries

• Crygonic freezing method uses liquid nitrogen or dry ice snow . For rapid chilling some time refrigerants are sprayed over hot product that cause of rapid cooling . Meat ,poultry, sea food store like these methods.

Page 53: Food processing industeries

Dehydration process

• Dehydration of food one of the most oldest technique to save the food . Microbes are not grow below minimum water activity 0.65

• Water activity id defined as equilibrium relative humidity surrounding the food in sealed container at given temperature. Its means that no microbes grow if water activity in food is below 65% relative humidity at storage temperature in 0 -40C.

Page 54: Food processing industeries

• Each food or food ingredients show characteristic a equilibrium relative humidity at given moisture content and temperature moisture in food is considered 1 and reduces to 0.6 by means of drying . These product are are dried and soft .

• The remaining water acts as plasticizer and can be preserved in vacuum ,refrigeration .

• Baked products are prolongly saved by reducing water

Page 55: Food processing industeries

• Presence of sugar reduces the water activity can increase the microbial growth. Oil and seeds can prolong saved by reducing water activity up to 14%. Fresh food has water activity 97% which metabolic change during drying non enzymes , reduces ascorbic acid and amino acid reduces the sugar and maximum change occur during the drying

• Drying of fruits is carried out by passing the SO2 over fruits which change the enzyme activity of fruits and dried food are packed in oxgene or vacuum atmosphere

Page 56: Food processing industeries

• Continuous hot dry air are used for vegetable , fruits , meat and poultry products

• Hot air releases the moisture from the food

• During the drying wet bulb temperature , dry bulb temperature, relative humidity , air velocity and direction of air movement is controlled

• However drying has three zones and deep drying for food is avoided and controlled by wet and dry bulb temperature

Page 57: Food processing industeries

• Liquid and pastes are dried in spray , drum , or by freeze dryer.

• Rehydration is done for dried food .also quality of product also important in rehydration , food should be fresh , eating quality either hot or cold

• Freeze dried food such as sea food ,vegetable are useful for instant soup making and salad

• Rice carrot potato ,cereal product are dried by fluidized bed

Page 58: Food processing industeries

Chemical preservation

• Food additive or chemical addition is done for preservation by heat , refrigeration and drying methods

• The addition of food grade acid to low grade acid food shift the PH to below 4.5 allows heat preservation at temperature 100 C

• Antioxidants such as butylated hydroxyanisol can be added

• SO2 is used in wine and dry fruits and vegetable product to preserve color ,taste ,

Page 59: Food processing industeries

• Food can be preserved by fermentation by selecting suitable yeast that produces lactic acid by yeast .

• The production of ethanol ,lactic , and organic acid and antimicrobial agent in the food along with removal of fermentable sugar can yield a product of increased shelf life . Mild heating of foods acidified by fermentation and packaged to prevent further contamination for stable product

Page 60: Food processing industeries

• The fermentation is controlled by adding sodium chloride that increases the fermentation rate

• Lactic acid production is associated with dairy products and producing antibiotic medicine are called bacteriocins .

• Concentration of these antibiotics are increased by adding natural antibiotic in refrigerated food in extract form by fermentation process

• Natural antibiotics are penicillium roqueforti• Roquefort and blue cheese are made by

propioibacterbacterium which produces proponic acid and produces swiss type cheese

Page 61: Food processing industeries

Food packaging

• Food package include rigid glass or metal container

• Easily available moulds for paper and plastics

• Aluminum and pouched die

• Have potential to transport the food easily

• Avoid non standard materials .

• Proper marketing available for food packaging

Page 62: Food processing industeries

Foods( non conventional)

• Non conventional food differs from the usually materials of plant and animals origin that are used for human food or animals feed in that they can produced from chemicals such as carbohydrate , hydrocarbons or industerialorganic chemicals by process such microbiological , enzymatic or chemical synthysis or from natural products containing carbohydrate , proteins and fats and physical and chemical , enzyme modification

Page 63: Food processing industeries

Single cell protein

• Two broad classes of micro organism are interested for single cell protein production photosynthetic organisms including the algae and certain bacteria, and non photosynthetic organism actinomycetes ,yeast ,fungi,

Page 64: Food processing industeries

1. Photosynthetic organism

• Mass cultivation of algae in ponds under photosynthetic conditions using incident sunlight as a energy source and CO2 as carbon source . Artificial illumination system are also used for cultivation of algae

• These are used for food disposal plants and produced CO2 is used in carbonated bevrages

• The main parameter are temperature, PH, nitrogen , phosphorous inorganic source

Page 65: Food processing industeries

• Algae is good source of food for animal and human feed . It is good source of amino acid and protein source

• Dried alage are not acceptable by live stock .however dried algae is used in steam roasted barley

Page 66: Food processing industeries

2. Non photosynthetic organism

• Non photo-synthatic micro organisim for singular cell production of yeast ,molds , and higher fungai.

• Carbon and energy source that have been considered for growing these organism include carbohydrates to produce alcoholic and organic acid from sugar ,starch , cellose

Page 67: Food processing industeries

Plant and animals derived

• Leaf protein concentrates are prepared by crushing

Page 68: Food processing industeries

FOOD TOXICANTS

• Toxicants are substance that , upon ingestion , produce changes in homeostasis that are thrating to the normal function of organism.

• AflatoxinB1 cause of mycotoxin which is found in mouldy grain,nuts ,oilseeds ,raw egg

• Oxalic acid found rhubarb reduce the calcium in calcium of body

• Solanine found in potato, tomato and apple cause of glycoalkoaloid.

Page 69: Food processing industeries

Toxic proteins, peptides,amides and amino acids

• Nitrogenous compounds are present in every living cell and are most frequently implicated natural toxicants in foods.

• There mode of action is often obscure but they may be loosely grouped according to either gross manifestations or specific structural characteristics.

• Some vitamins distroying the enzyme of body and cause of carcinogens of protien

Page 70: Food processing industeries

Thiocyanates and related s-containing compounds

• Goitrogens are compounds that produce goiter by interfering with thyroxin synthesis in the thyroid gland .

• Food-borne goitrogens are often characterized by the presence sulphur and most are thiocyanates or closely related compounds.

Page 71: Food processing industeries

Oxalates ,phytates and other chelates

• Of nutrient chelates in human diet,oxalatesand phytates are the most common .

• Oxalic acid found in spanish, hubarb leaves, beet leves and mushrooms.

• Defficency of phosphrous is done in body by using of excessive use of pythic acid that is found in oaths. Most of essential ammines found in bannana, tomato,pineapple

Page 72: Food processing industeries

Vasoactive and psychoactive amines and alkaloids

• Most compounds producing hypertensive eposides are classifide as amines and found in greatest concentration in banana ,plantain tomato, avocado,pineapple broad beans , and various cheeses.

• Caffeine ,a xanthine derivative , is perhaps the best known of the natural stimulants and is found in cofee beans tea leave and cola nuts.

Page 73: Food processing industeries

Antinutrients

• Any substance that destroys , inactivates or in other ways renders unavalible an essential dietary constituent can be termed an antinutrient.

• Some anti vitmins are enzymes, thiaminase,niacin, biotin

Page 74: Food processing industeries

Vitamin toxicity

• Because fat soluble vitamins (e.g A and D) tend to accumulate in the body with a relatively inactive mechanism for excretion they cause greater toxicological difficulties then do water soluble vitamins.

• Water soluble vitamins , overdose of nicotine,and folic acid cause of adverse effect on health

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Essential minerals and heavy trace elements

• Toxic ingestion of essential minerals from naturally occurring foods is almost beyond comprehension .

Page 76: Food processing industeries

Cyanogenic glycosides

• Complex glycosides, which upon hydrolysis yield hydrocyanic acid are found commonly among plant materials.

• They are found in bitter almond pits stone fruits and lima beans .

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Nitrates , nitrites and nitrosamines

• The carcinogenicity of nitrosamines has created widespread concern over the safety of food products that are significant sources of nitrates and nitrites .

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Sodium chloride

• The fact that excessive intake of NACL contributes to increased fluid retention has led to the conclusion that they are may be relationship between NACL intake and hypertension.

Page 79: Food processing industeries

Mycotoxins

• The condition produce by the consumption of moulds foods containing toxic material is referred to as mycotoxicosis . Moulds and fungi fall into this category.

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Seafood toxins

• Several species of the moray eel have caused toxic reaction . The toxic principle appears to be proteinaceous , and is found predominantly in the blood but it may occur also in flesh as well.

Page 81: Food processing industeries

Food additives

• A food additives as a substance or mixture of substance other then a basic foodstuff that is present in food as a result of any aspect of production processing, storage and packaging.

• In most nations direct food additives legislation limite the use of a substance to maximum doses in specified foods and or subject to pre marketing approvals.

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Catagories

• Deponding on the nation food ingredients and additives are describe in following 52 food additives catagories.

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Milk and milks products

• Composition and properties

milk consist of 85 –89 wt % water and 11-15 wt% total solids.

• The non fat solids, fat solids and moisture relationship are well established and can be used as basis for detecting adulteration with water .

• Solid not fat found in milk 0.4% including proteins in milk but fats are 1%

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Nutritional contents

• Milk fat is a mixture of triglycerides and diglycerides.

• The triglycerides are short chains C24-C46 ,medium chain C34-C54,and long chain C40-C60.

• Milk fat contains more fatty acids than vegetable fats.

• Milk is an emulsion of fat in water (serum) stabilised by phospholipibs which are absorbed on the fat globules.

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Processing

• The processing operation for fluid milk or manufactured milk products includes centrifugal sediment removal and cream seperation , pasteurisation and sterilisationand homogenisation and packaging , handling and storing .

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1.Cooling

• After removal from a cow by a mechanical milking machines usually at 35c the milk should be cool as rapidly as possible to 4.4c or below to maintain quality .

• At this low temp this enzyme activity and growth of micro-organism are minimized .

• A meter may be in the line to measure the quantity of milk for each cow.

• On commercial scale milk from the cow is cooled and stored

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• Precaution is used during the milk cooling no air is mixed with milk.

• Milk flow through pipes are made of steel(s.s)

• Cleaning is most important factor during milk processing

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Centifugation

• Centifugal devices includes clarifiers for removal of sediment and extraneous particulates , and separators for removal of fats from milk.seperation of fats is done by centrifuge

• Bactofugation as a specialised process of clarification in which two high velocities centrifugal devises operate at 20000 rpm in series.

• The first device removes 90 % of bacteria .• Second removes 90% of the remaining bacteria

providing a 99% bacteria free product.

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Homogenisation

• Homogenisation is done by mechanical means to make a homogenised milk. Fats from milk is separated in cream form

• Milk that has been treated to insure the breakup of fat gloubes to such a extent that 48 hours at 7C is stored sothat no visible cream seperation occure in milk is called homodenised milk

Page 90: Food processing industeries

• Homogeniser or viscoliser are used for milk homogenisation. The milk is forced with high pressure throuh small opening by doing so globules are breaked by compressive and shearing force

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Pasteurisation

• It is the process of heating milk to kill yeasts,moulds and pathogenic bacteria and most other bacteria and to inactive certain emzimes without greatly altering the flavour .

• Pasteurisation may be carried out by batch or continuous flow process .

• In batch process milk is heated at 63C - 71C

• This is known as high temperature short time pasturization

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• For high temperature short time process 65 –74C for 15second

• In ultra high temperature milk is heated 87 -240 for 1-2 second for both batch and continous process

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Batch holding

• The milk is in the batch holding tanks is heated by a hot water spray on the tank liner a large diameter coil which circulates in the milk through which the hot water is pumped a flooded tank around which hot water or steam is circulated or by coils surrounding the liner through heating medium is pumped at high velocity .

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High temperature short time pasteurisers

• The principal continuous flow process is the high temperature short time method .

• The product is heated to at least 72 c and held at that temperature for not less than 15 sec .

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Cleaning systems

• Both manual and automatic method of cleaning food processing equipment are used .

• Even in a plant with advanced cleaning equipment some manual cleaning is involved .

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Cleaning in-place (CIP) systems

• CIP system evolved from recirculating of cleaning solutions in pipelines and equipment of a highly automatic system with valves controls and timers .

• In the early circulation system consider manual operation was required in assembly and disassembly of units.

• Homogeniser and heat exchanger were cleaned manually or by a system of circulating solution.

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Manufactured product

• Most of the milk production is used for manufactured products

• Evaporated and condensed milk and dry milk is produced from milk

1.EVAPORATED MILK2. CONDENSED MILK3. SWEETENED CONDENSED MILK4. CREAM5. CHEESE6.YOUGART

Page 98: Food processing industeries

EVAPORATED AND CONDENSEDMILK

• Evaporated and condensed milk are produced by removing moisture from milk under vacuum followed by packaging and sterilizing

In cans

The milk is condensed to half its volume in single effect or multiple effect evaporators

The products has a fats to solid not fat ratio is 1:2.3 and standardized before and after evaporation . It must have atleast 7.9% fats.and 25.9 of total milk solid

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SWEETENED CONDENSED MILK

• Sweetened milk is different from condensed milk and not strirrlized . Sugar is added as a preservative which replaces sterilization as a means of maintaining quality . The equipment is similar to that used for evaporated milk except that sugar is added in hot well before condensing the liquid . According to standards ,sweet condensed milk must contain 8.5% fats minerals and 28% total milk solid inclide fat to snf 1:2.3. the product contain 43-45%

Page 100: Food processing industeries

CREAM

• Cream is high fat product which is secured by gravity or mechanical separation through differential density of fats and serum . Fat content may range from 10-40% depend on use as per food laws.

• Whipping cream has fat content of 34-40% for coffee

• Light cream has fat content 20-25%. Half and half mixture of milk and cream contain10.5%milk fat, 10% eddible fats used as butter

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Cheese

• Chease production is based on coagulation of casien from milk .with a minor milk protien . The casien is precipitated of milk by acidification which can be accomplished by natural source of milk.

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Yougurt

• Yogurt is produced from fermented milk. Milk is fermented by lactobacillus bulgaricus and steptococus thermophilus organism producing lactic acid

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Poultry meat processing

• The poultry production is also increased due to intensive agriculture system and increase the grain production

• Poultry is the most efficient converter of grain and by products into meat with added of safe high productive

• Poultry is good source of protine and little fats and high yield of moisture

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Manufacturing process

• Poultry processing plant consist of two main processing zones . First processing zone consist of receiving , killing and defeathering units and second processing zone contain evisceration final processing and packing units. Separation of two zone is intended to facilitate sanitation by separating the inherently dirtier phases of processes from those involved in preparation of the final product.

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Poultry receiving Killing Scalding

Washing Singeing Defeathering

Pinning Eviscerating Washing

Packing Cutting Chilling

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RECEIVING

• Generally poultry meat processing plants are installed near poultry farms , poultry arrives at plant and convey to the shacking area . In shaking area poultry are shacked by their feet than it is transported to killing section.

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Killing

• It is usually done manually . Many plants employ electric stunning prior to killing . This reduce struggling and also relaxes the feather papillac , thereby facilitating feather removal.

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Bleeding

• After killing , blood comes approximately for 1.5 minutes . Incomplete bleeding cause discolouration of carcasses and consequent lowgrading .

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Scalding

• It is done at 123-128F for 1.5-2 minutes commonly, it is sufficient to allow feather removal, yet the outer layer of skin on the carcass remain intact. Over scalding may lead to irregular removal of outer skin , causing an unattractive splotchy appearance.

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Defeathering

• Defeathering of carcasses is completed in rotating drum. In the rotating drum carcasses are brought in contact with rubber finger, the feathers loosened by scalding are stripped away with little damage to skin.

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Singeing

• After defeathering process all poultry contain some hair like feather which is removed by passing the carcass quickly through a flame .

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Washing

• Spray washing is used to removed feather ,blood and other foreign materials from the outer skin of carcass.

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Pinning

• Some times carcass contain developing feather that have just pierced the skin are removed manually by grasping protuding pin feather between the thumb and the edge of knife and giving a strong tugging motion . The carcass is transported to eviscerating room .

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Eviscerating

• In the eviscerating process , first of all a vertical cut is made from the tip of the sternum to the vent , and with the vent still attached viscera and drawn out , but remain attached viscera is used for the postmortem inspection .

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Removal of varies parts

• After inspection the liver and gizzard are removed and remaining viscera discarded .then lungs and kidney removed mechanically or by use of a strong vacuum aspirator . Head of bird is removed by using v shape knife . The skin is slit along the dorsal surface of neck to the shoulder .then skin is cut on the dorsal side to the shoulder and neck is cut or broken off at the shoulders manually.

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Washing

• Carcasses are washed with cooled water to remove attached tissues , foreign materials, blood etc .

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Chilling

• Chilling of carcasses is done to remove body heat and to protect from microbial action . Normally chilling is done below 40 F for 30 minutes.

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Packing

• Sometime carcasses are cut into parts according to market demand , otherwise then are packed in frozen form .