miris ab | kungsgatan 11, 753 18 uppsala, sweden | tel: +46 18 146 907 | mid-ir and milk chemistry...

Miris AB | Kungsgatan 11, 753 18 Uppsala, Sweden | tel: +46 18 146 907 | www.miris.se

Mid-IR and Milk Mid-IR and Milk Chemistry Chemistry

Lina Jonsson MSc Animal Science

Production Manager Miris AB, Sweden


Content

• What is Mid-IR?-History about Mid-IR-The principle of Mid-IR-The advantage of Mid-IR

• How to make an accurate calibration and take a correct sample

• What is milk, what are we measuring? -Analytical methods for milk

• Human breast milk


Gamma- X-rays UV IR Micro- Radiorays waves 1 pm 1 nm 1 um 1 mm 1 m

NIR MIR

0.7 um 2.5 um 10 50 um

NITS NIRS

700 nm 1100 2500 nm

Liquid Transmission MIR

2.5 um 10 um Fat 3.5 5.7 Protein 6.5 Carbohydrate 9.5

VIS


• Liquid Transmission Spectroscopy

• J.D.S Goulden 1961

• IRMA

• Interference Filters

• FTIR

• Solid-State

History of Mid-IR



NIR MIR

0.7 um 2.5 um 10 50 um

NITS NIRS

700 nm 1100 2500 nm

Liquid Transmission MIR

2.5 um 10 um Fat 3.5 5.7 Protein 6.5 Carbohydrate 9.5

VIS



NIR MIR

0.7 um 2.5 um 10 50 um

NITS NIRS

700 nm 1100 2500 nm

VIS


Milk Spectra


Beräkningsenhet

Energy

Wavelength

Energy

Wavelength

Energy

Wavelength

IR source Cuvette Waveband

Selector

Detector CPU

Principles of Mid-IR


Milk Spectra


Milk Determination mid-IR

Milk Water


Spectra Milk


Milk vs Milkfat


Infrared Spectroscopy


Spectra of Milk and Skimmilk


Milk vs Milkprotein


Milk vs Lactose


The advantages of Mid-IR

• Quick analytical result• The milk can be used after the

composition is known• The composition of fat protein and

lactose in the same analyse• Identify dilution before the milk has

entered the manufacture


How to make an accurate calibration and take a correct sample

• A certified reference lab• High quality of the milk• Homogenous milk• Good sampling routines

imperative to obtain representative samples

• All result must be review critical, mistakes do happen


Sampling

Inhomogenity of milk demands special treatments of milk before sampling and/or analyse

-Creaming -Aggregation-Foaming

Protein Chain


Heating/Mixing

• Mixing more effective of warm samples (40-43 C)

• Fat aggregations are dissolved.

• Condensed water is mixed into the milk


Ultrasound Treatment

• Previously frozen milk ought to be treated ultrasound

• 1 second / ml• The efficiency of treatment is

increased by temp. 40°C is optimal for milk

• Protein aggregation are dissolved• Oil droplets are emulsified


Chemical/Physical factors that interferes with the “true” value of the milk

• Non Protein Nitrogen (NPN)

• Lactic acid

• Lipolysis

• Free fatty acids

• Creaming

• Oiling off


+

”Oiling off”

GOOD MILK

BAD MILK


Fat globule (schematic)

Lipophile part

Phospholipids + membrane

Hydrophile part


What is milk , what are we measuring?

What is milk according to definition???

Milk fatMilk proteinLactoseDry matter (Total solids)


Analytical Methods for Milk

Cow Milk– Different international standards

(ISO/IDF/AOAC) for measuring constituents in milk. Also valid for other species.

– (ISO 9622:1999; ISO 1211; ISO 8968-1 etc)

Human MilkNo international standards for human milk methods.


Analytical Methods

Fat

• Gerber, Babcock, Lindström• Röse-Gottlieb, Mojonnier• Turbimetric (Milko-Tester)• MIR (Mid Infrared Transmission)• NIR (Near Infrared Reflectance/Transmission)

• Ultrasonic high frequency


Analytical MethodsProtein

• Kjeldahl• MIR Mid Infrared Transmission• NIR Near Infrared Transmission/Reflectance• (Ultrasonic high frequency)


Analytical Methods

Lactose

• Luff-Schoorl• HPLC• Enzymatic• MIR Mid Infrared Transmission• (NIR)• (Ultrasonic)


Analytical Methods

• IDF recommended methods

• Röse-Gottlieb Milk fat• Kjeldahl Milk protein• Enzymatic Lactose• Drying oven 102°C Dry matter


Analytical Metods

Röse-Gottlieb %

• Neutral glycerider 98.7• FFA 0.1• Phospholipids 0.8• Sterols 0.3• Others (fat soluble vitamins.) 0.1


Analytical Methods

Kjeldahl Cow Human% % of milk % % of milk

Protein-N 95 3.04 75 0.9NPN-N 5 0.16 25 0.3Total-N 100 3.20 100 1.2

Urea-N, Creatine-N, Uric-N, Peptide-N,Ammonia-N


Analytical MethodsEnzymatic

• Water accounts about 5%• Lactose monohydrate 5.00 %-units• Lactose anhydrous 4.75 %-units


Analytical Methods

Drying oven

• All that evaporate is measured as water

• Volatile components (Lactic acid, fatty acids, CO2, NH3 )


Human breast milk

• Unsaturated fat• Day to day variation• Protein composition• Lactose


(% wt/wt)Fatty Acid Cow Human Rat4:0 4.06:0 2.68:0 1.4 1.110:0 3.1 1.3 7.012:0 3.3 3.1 7.514:0 10.6 5.1 8.215:0 0.9 0.416:0 27.7 20.2 22.616:1 0.9 5.7 1.917:0 0.5 0.318:0 8.2 5.9 6.518:1 15.4 36.4 26.718:2 2.4 13.0 16.3CLA 0.4718:3 0.8 1.4 0.8


Human breast milk Day to day variation

S. Polberger and B. Selander, 2007.


Protein

Casein Whey

α-casein κ-casein β-lactoglobul

in

α-lactalbumi

nβ-casein


Protein

Casein Whey

κ-casein Lactoferrin

α-lactalbum

inβ-casein


Analytical Methods

Oligosaccharides

Three to ten monosaccharides including glucose, galactose, fucose, sialic acid, N-acetylglucoseamine

Account for about 0.8-1.2 g/100 mlComplicated analytical methods, but mid-infrared methods seems to measure this carbohydrates due to hydroxyl (-OH) groups


Summary

• Milk is not a solution, it is a emulsion. The different components can aggregate or separate, which makes sampling difficult.

• The Mid-IR method only need one sample to give the complete major components of milk

• This reduce the source of error and makes the result more comparable

• A small amount of milk is needed, the result comes with in a minute

• No chemicals is needed• Approved by IDF


Questions?


Thanks for the attention!

miris ab | kungsgatan 11, 753 18 uppsala, sweden | tel: +46 18 146 907 | mid-ir and milk chemistry...

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