Lactose preparation from milk

Josephson (1943) reported that butterfat prepared from butter heated to 149°, 177°, and 204.5°C was extremely stable to oxidation, while that heated to 121 °C oxidized readily when stored at 60°C. When butter oil itself was heated from 121 to 204.5 °C, it also oxidized rapidly. However, the addition of 1% skim milk powder to butter oil prior to heating at 204.5°C for 10 min also resulted in a significant antioxidative effect, which Josephson concluded was the result of a protein-lactose reaction (carmelization). Wyatt and Day (1965) reported that the addition of 0.5% nonfat milk solids to butter oil followed by heating at 200 °C and 15 mm Hg for 15 min caused the formation of antioxidants which protected the butter oil against oxidative deterioration for 1 year, surpassing the effectiveness of many synthetic antioxidants tested. 

Permits commercialization of concentrated fresh milk, manufacture of milk for those with lactose intolerance, and conversion of a lactose fraction from whey to prepare a syrup. 

A) Preparation of Casein from Milk. To 40 ml of milk in a 250 ml beaker, add 40 ml of water and five drops of 6iV acetic acid. The coagulated protein to which the fat adheres settles out. Filter the precipitate and wash it with water twice, so that it collects at the lower point of the folded filter paper. When most of the water has drained, remove the filtrates if it is desired to isolate the lactose. Wash twice with a 5 ml portion of alcohol and then twice with a 5 ml portion of ether. Collect the alcohol and ether washings separately and place them in a bottle provided for this... 

Lactose.— Lactose, lactobiose, or milk sugar, is present in the milk of mammals to the extent of 3 to 6 per cent., and may be prepared from whey by boiling to coagulate albuminoids and concentrating the filtrate, using animal charcoal for decolorizing the syrup. 

Since lactose intolerance is most often associated with those segments of the world s population which need the nutrients provided by milk, considerable interest has been manifested in the possible development of techniques which would permit the selective removal of lactose from milk. One such approach is to subject milk to a prehydrolysis treatment whereby lactose could be converted into absorbable monosaccharides prior to general distribution. This has been accomplished by treating fresh raw whole milk with an immobilized form of lactase derived from Saccharomyces lactis (65). A preparation of this enzyme from Saccharomyces fragilis has also been used for this purpose without immobilization (66). As much as 90% of the lactose of milk can be hydrolyzed in this fashion. 

Dairy products, such as mUk powder, should be prepared exclusively from milk and should not contain solids from whey. The absence of rennet whey solids from mUk powder is required according to legislation. Considering the lower price of rennet whey, it can be an attractive adulterant of milk powder. Thus, the presence of CMP can be a good marker to evaluate milk powder authenticity. Whey powders contain about 12% protein and 75% lactose. Caseinomacropeptide can account for more than 16% of the protein content. RP-HPLC can be used to detect rennet whey in mUk powder by CMP measurement. For this purpose, powdered milks were reconstituted with deionized water. Skim milks were prepared by separating the fat from the whole milk by centrifugation at 700 X g (at 4°C) for 10 min. Caseinomacropeptide and... 

One-lower and one-higher concentrations of lactose containing cow milk (milk from the certified laboratories with known lactose) are chosen as quality control samples. Cow milk samples are diluted to 150,000-fold to meet optimal concentrations that UPLC-MS/MS can detect with high sensitivity and specificity. Cow milk is first diluted to 200,000-fold and is used as the baseline to conserve the matrix effect for the development of calibration curves. Five different lactose concentrations are produced by adding different lactose concentrations in cow milk. The aqueous lactose solution is prepared by adding 1.1 mg lactose monohydrate (MW 360.32 g/mol) in 100 mL of water, and 2,5,10,15, and 20 (iL of the aqueous lactose solution is added to 198, 195, 190, 185, and 180 pL of diluted cow milk, respectively. As the internal standard, a 100 pL labeled lactose (26.86 pmol/L) is subsequently added, resulting in a total dilution of milk 300,000-fold. One milk sample is prepared without adding any external lactose so that the lactose concentration itself within the cow milk can be determined. 

Kefir is also prepared from commercial starters using bovine milk and it has been reported that the lactose concentration effectively decreased from 4.92%(w/v) to 4.02%(w/v) and the L(+)- lactic acid concentration increased to 0.76%(w/v) from 0.01%(w/v) after 24 hours of incubation. The acetic acid content increased from 2.10 to 2.73 mg/ml while the pH value was reported to be low as 4.24 in the first 24 hours after which it decreased gradually. The concentration of L(+)- lactic acid subsequently decreased while that of D(-)- lactic acid subsequently increased. These fermentation values depend on the type of starter culture used, the storage period and the medium used to grow the kefir (for example the mammalian species from which the milk is derived, the coconut water, etc.), (Garcia Fontan, Martinez, Franco, Carballo, 2006 Magalhaes, Pereira, et al., 2011 Oner, Karahan, 0akmak9i, 2010). 

Enzyme preparations from fungi (Aspergillus niger) or from yeast are used in the dairy industry to hydrolyze lactose. Immobilized enzymes are applied to produce milk suitable for people suffering from lactose malabsorption. Milk treated in this way can also be used to make products like skim milk concentrate or ice cream, thus avoiding interference by lactose due to its low solubility. 

D (+) Galactose is a constituent of numerous polysaccharides It is best obtained by acid hydrolysis of lactose (milk sugar) a disaccharide of d glucose and d galactose L (—) Galactose also occurs naturally and can be prepared by hydrolysis of flaxseed gum and agar The principal source of d (+) mannose is hydrolysis of the polysaccharide of the ivory nut a large nut like seed obtained from a South American palm... 

The most common naturally occurring disaccharides are sucrose (table sugar) and lactose (milk sugar). While sucrose is derived from plants and is prepared commercially from sugar cane and sugar beet, lactose is found in the milk of animals. Other common disaccharides that are produced by breaking down polysaccharides include maltose (obtained from starch) and cellobiose (obtained from cellulose). 

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