Dried milk products composition

Milk or skim milk is standardized to meet milk fat and total milk solids compositional requirements in the final dry milk product e.g., NFDM must contain <1.5% milk fat DWM must contain >26% and < 40% milk fat, and both must contain <5% moisture on an MSNF basis (CFR, 1982). Dry milk products must also meet U.S. Department of Agriculture and American Dry Milk Institute standards for titratable acidity, scorched particle content, solubility, and bacteria content. Product users may also have specialized requirements for color, flavor, and dispersibility. 

Five dried milk products with various compositions, all provided by Nestle, Vers-chez-les-Blanc, Lausanne, Switzerland, and a-lactose were analyzed ... 

Raw milk is a unique agricultural commodity. It contains emulsified globular lipids and colloidally dispersed proteins that may be easily modified, concentrated, or separated in relatively pure form from lactose and various salts that are in true solution. With these physical-chemical properties, an array of milk products and dairy-derived functional food ingredients has been developed and manufactured. Some, like cheese, butter, and certain fermented dairy foods, were developed in antiquity. Other dairy foods, like nonfat dry milk, ice cream, casein, and whey derivatives, are relatively recent products of science and technology. This chapter describes and explains the composition of traditional milk products, as well as that of some of the more recently developed or modified milk products designed to be competitive in the modern food industry. 

Cultured buttermilk is manufactured by fermenting whole milk, reconstituted nonfat dry milk, partly skimmed milk, or skim milk with lactic acid bacteria. Most commercial cultured buttermilk is made from skim milk. Mixed strains of lactic streptococci are used to produce lactic acid and leuconostocs for development of the characteristic diacetyl flavor and aroma. Buttermilk is similar to skim milk in composition, except that it contains about 0.9% total acid expressed as lactic acid. The percentage of lactose normally found in skim milk is reduced in proportion to the percentage of lactic acid in the buttermilk. According to White (1978), the fat content of buttermilk usually varies from 1 to 1.8%, sometimes in the form of small flakes or granules to simulate churned buttermilk, the by-product of butter churning. Usually 0.1% salt is added. 

Milk and milk products are important components of the diet in many countries. Milk is one of the few foods produced over large areas and collected on a daily basis. Its composition is almost identical all over the world, and it is easy to collect a representative sample that can be analysed in liquid or dried form. 

Specialty dried egg products include a scrambled-egg mix that has good storage capability and low-cholesterol egg products. Most low-cholesterol egg products contain egg white, with nonfat milk, vegetable oil, and pigments substituting for yolk. The final composition is similar to that of a whole egg. 

In a meantime, primiparous cows were fed the same basal diet than in the experiment described previously and supplemented daily with folic acid and rumen-protected methionine. The effects of weekly intramuscular injections of saline (0.95 NaCl) or 10 mg of vitamin Bj2 on milk production were monitored from 4 to 18 weeks of lactation. Supplementary vitamin Bj2 tended to increase milk yield from 28.5 to 31.1 kg/d and increased energy-corrected milk as well as milk yields of solids, fat and lactose but had no effect on dry matter intake or milk composition. Furthermore, packed cell volume and blood haemoglobin increased and serum methylmalonic acid decreased in cows that received vitamin Bj2 injections. The first observation suggests that low vitamin B 2 supply interfered with folate metabolism because folic acid deficiency, through its role in DNA synthesis, affects hematopoiesis (Bills et al., 1992). The second one indicates that low vitamin Bj2 supply interfered with the other vitamin B j 2-dependent enzyme, methylmalonyl-CoA mutase. These findings supported the hypothesis that vitamin Bj2 supply is suboptimal in early lactation (Girard and Matte, 2005) and may have limited the potential role of folic acid in these first studies. 

Whey is the fluid obtained by separatiag the coagulum from cream and/or skim milk, and is a by-product of either caseia or cheese manufacture. The composition of whey is determined by the method of curd formation, curd handling practices, and methods of handling whey as it is separated from the curd. Dried acid whey contains ca 12.5 wt % proteia (total nitrogea x6.38), 11.0 wt % ash, and 59 wt % lactose, whereas sweet whey contains 13.5 wt % proteia, 1.2 wt % fat, 8.4 wt % ash and 74 wt % lactose. The composition varies with the type of acid used (7). 

A process for making a soy milk having a minimum beany flavor is presented in Figure 5. The recommended compositions for a fluid and for a dry product are given in Table 16. 

Fermented milks are cultured dairy products manufactured from whole, partly skimmed, skim, or slightly concentrated milk. Specific lactic acid bacteria or food-grade acids are required to develop the characteristic flavor and texture of these beverages. Fermented milks are either fluid or semifluid in consistency, with various proportions of lactic acid. Fermented products are regulated by federal standards in the United States, as stated in Table 2.2. Other fermented milks without established federal standards are regulated by state standards. Compositional standards for fermented milks have been proposed by the International Dairy Federation (Hargrove and Alford 1974). Typical analyses of various fermented milks, as well as of their condensed and dried counterparts, are given in Table 2.4. 

Table 2.4. Percent Composition of Concentrated Milk and Dried Products. 

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