Skim milk powder

Standards and definitions for whole milk powder, partiy skimmed milk powder, and skimmed milk powder have been set by WHO. This standard apphes exclusively to dried milk products as defined, having a fat content of not mote than 40 mol %. 

Griepink B, Gonska H, Muntau H (1983) The Certification of the Contents (Mass Fractions) of Nitrogen, Phosphorus, Chloride, Sodium, Potassium, Magnesium and Calcium and of the Kjeldahl-Nitrogen Content of a Skim Milk Powder, BCR No. 63. Report EUR 9138 EN. Commission of the European Communities, Brussels. 

Animal muscle (pork), carrot powder, total diet, wheat flour Skim milk powder (elements), whole meal flour, bovine muscle, wholemeal flour, brown bread, cod liver oil (PCBs), rye flom, haricots verts (beans), pork muscle, mixed vegetables, carrot, bran breakfast cereal, unspiked milk powder (PCDDs, PCDFs), spiked milk powder (PCDDs, PCDFs), milk powder Rye flour, milk powder, whey powder Pork meat... 

Following research by Tossavainen et al. (1986), extrusion is often used to produce insoluble acid casein from skim milk powder and to convert acid casein into sodium caseinate. The procedure is faster than batch mixing (Akdogan, 1999). 

An immunoassay was developed to determine the penicillinase stable isoxazolyl penicillins cloxacillin and dicloxacillin in milk by Usleber et alJ The assay detected lOpgkg" of cloxacillin and 30pgkg of dicloxacillin with recoveries of 102% and 84%, respectively. The calibration curve was prepared by fortifying skimmed milk powder (lOOgL ) with standards. Fortified samples were prepared in pasteurized milk and analyzed directly after decreaming by centrifugation. This immunoassay was performed with minimal sample preparation, probably because the extensive water solubility of the penicillins prevents problems associated with more lipid-soluble analytes. 

Skim milk (35 g/L) and /1-lactoglobulin (5 g/L) solutions were prepared by dissolving skim milk powder and y6-lactoglobulin powder in distilled water and stirring at room temperature for 4 h. /1-Casein (5 g/L) had been hydrated in a phosphate buffer (100 mM, pH 8) and stirred at 4°C for one night [27]. Sodium azide (0.1%, wt/v) was added to prevent bacterial growth. 

Four reconstituted milks were prepared by blending hydrated skim milk powder (35g/L) with four different emulsions (35g/L) differing by composition of the fat-water interface. Whole reconstituted milks were coded MP (milk proteins), BCAS ( 6-casein), and BLG5 (j6-lactoglobulin 5 g/L). 

Skimming fresh whole milk allowed us to obtain milk fat globules with natural membranes that were blended at a concentration of 35 g/L with hydrated skim milk powder (35g/L). This reconstituted milk was coded CREAM. 

Originally, full cream milk solids were used but now where possible skim milk solids are substituted. A few products are still made from full cream milk solids but this is now rare. In some cases butter or butter oil is added to replace the fat that has been removed from the skim milk. In other cases the fat content of the milk is replaced with vegetable fat. It might appear curious that whole milk is effectively reconstituted from skim milk and butter but there are good reasons. Skim milk powder keeps better than full cream milk powder. Using skim milk and butter can under certain conditions be economically advantageous. 

Skimmed milk powder 30 Skimmed milk powder... 

While liquid milk is little used in biscuit manufacture for practical reasons to do with lack of stability, skimmed milk solids are used. The preferred ingredient is skimmed milk powder. This is normally dispersed in twice its own weight of water to ensure that it is evenly dispersed in the finished product. The reconstituted milk powder has the same keeping properties as liquid milk so it must be refrigerated. Merely dry blending the milk powder is likely to produce a finished product with small brown specks of caramelised milk powder in it. 

Vyas, H. K., and Tong, P. S. (2004). Impact of source and level of calcium fortification on the heat stability of reconstituted skim milk powder. /. Dairy Sci. 87,1177-1180. 

Detection of plant protein addition in skimmed milk powder Identification of plant protein... 

Figure 7.7 Serum volume fraction after 21 days storage in emulsions made with 0.14 wt% locust bean gum and skim milk powder (black columns) or sodium caseinate (white columns), and containing 400 ppm Ca2+, as a function of the added K-carrageenan concentration. Reproduced from Vega et al. (2005) with permission.

Figure 7.8 Con Focal microscopy images for some freshly prepared emulsions containing 0.14 wt% locust bean gum, made with either skim milk powder (a, b) or sodium caseinate (c, d), and with no added K-carrageenan (a, c) or 0.02 wt% K-carrageenan (b, d). As the protein phase was fluores-cently stained, it appears w hite. Scale bars correspond to 40 pm. Reproduced from Vega el al. (2005) with permission.

Dried milk and whey. Lactose is the major component of dried milk products whole-milk powder, skim-milk powder and whey powder contain c. 30, 50 and 70% lactose, respectively. Protein, fat and air are dispersed in a continuous phase of amorphous solid lactose. Consequently, the behaviour of lactose has a major impact on the properties of dried milk products. 

In general, dairy products are not major sources of B6 in the diet. Concentrations in cheeses and related products vary from about 0.04 (fromage frais, cream cheese) to 0.22 (Camembert) mg per 100 g (Appendix 6A). Whole-milk yogurt contains roughly 0.1 mg per lOOg and the concentration in skim-milk powder is c. 0.6 mg per 100 g. 

The specific heat of a substance is the amount of heat energy, in kJ, required to increase the temperature of 1 kg of the substance by 1 K. The specific heat of skim milk increases from 3.906 to 3.993 kJ kg-1 K-1 from 1 to 50°C. Values of 4.052 and 3.931 kJ kg-1 K-1 have been reported for skim and whole milks, respectively, at 80°C (Sherbon, 1988). The specific heat of milk is inversely related to its total solids content, although discontinuities have been observed around 70-80°C. Skim-milk powder usually has a specific heat in the range 1.172-1.340kJ kg-1 K-1 at 18-30°C. 

Microbiological tests have indicated that penicillin G is stable to heat. Pasteurization temperatures and times commonly applied to milk and milk products are inadequate for inactivation of tlie antibiotic if it is present (26-29). At 71 C, a total of 1705 min was required to inactivate completely penicillin G in milk, whereas at boiling temperatures or above, all data indicated that a portion of tire penicillin activity in milk survived boiling for 60 min or autoclaving at 15 psi steam pressure for 15-30 min (26, 29). Milk from treated cows retained some of its antimicrobial activity even after conversion to dried skim milk powder (30). 

V POUR % CUP SKIM MILK (OR MIXTURE OF 8 TEASPOONS SKIM MILK POWDER AND l/2 CUP WATER] INTO A CUSTARD CUP. HEAT GENTLY UNTIL IT FEELS JUST SLIGHTLY WARM WHEN YOU TEST IT WITH A FINGER. 

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. 

As mentioned previously, alcohol greatly reduces the solubility of lactose, but the glass or amorphous form dissolves in alcoholic solutions to form supersaturated solutions. This has been used to extract lactose from whey or skim milk powder with methanol or ethanol. A high-grade lactose subsequently crystallizes from the alcoholic solu-... 

Leviton, A. 1949. Methanol extraction of lactose and soluble proteins from skim-milk powder. Ind. Eng. Chem. 41, 1351-1357. 

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