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Mid-IR and Milk 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
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Mid-IR and Milk 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
VIS NIRMIR 0.7 um 2.5 um 10 50 um Liquid Transmission MIR 2.5 um 10 um Fat 3.5 5.7 Protein 6.5 Carbohydrate 9.5 NITS NIRS 700 nm 1100 2500 nm Gamma- X-rays UV IR Micro- Radio rays waves 1 pm 1 nm 1 um 1 mm 1 m
History of Mid-IR • Liquid Transmission Spectroscopy • J.D.S Goulden 1961 • IRMA • Interference Filters • FTIR • Solid-State
VIS NIRMIR 0.7 um 2.5 um 10 50 um Liquid Transmission MIR 2.5 um 10 um Fat 3.5 5.7 Protein 6.5 Carbohydrate 9.5 NITS NIRS 700 nm 1100 2500 nm Gamma- X-rays UV IR Micro- Radio rays waves 1 pm 1 nm 1 um 1 mm 1 m
VIS Gamma- X-rays UV IR Micro- Radio rays waves 1 pm 1 nm 1 um 1 mm 1 m NIRMIR 0.7 um 2.5 um 10 50 um NITS NIRS 700 nm 1100 2500 nm
IR source Cuvette Waveband Selector Detector CPU Beräknings enhet Principles of Mid-IR
Milk Determination mid-IR Milk Water
Milk Determination mid-IR Water Milk
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
”Oilingoff” + BAD MILK GOOD MILK
Fat globule (schematic) Lipophile part Phospholipids + membrane Hydrophile part
What is milk , what are we measuring? What is milk according to definition??? Milk fat Milk protein Lactose Dry matter (Total solids)
Analytical Methods for Milk Cow Milk • Different international standards (ISO/IDF/AOAC) for measuring constituents in milk. Alsovalid for other species. • (ISO 9622:1999; ISO 1211; ISO 8968-1 etc) Human Milk No 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 Methods Protein • 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 0.9 NPN-N 5 0.16 25 0.3 Total-N 100 3.20 100 1.2 Urea-N, Creatine-N, Uric-N, Peptide-N, Ammonia-N
Analytical Methods Enzymatic • 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
Human breast milk Day to day variation S. Polberger and B. Selander, 2007.
Analytical Methods Oligosaccharides Three to ten monosaccharides including glucose, galactose, fucose, sialic acid, N-acetylglucoseamine Account for about 0.8-1.2 g/100 ml Complicated 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