Dried milk products cream

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. 

Most dry buttermilk is prepared from sweet cream buttermilk, and is produced in a manner similar to that of nonfat dry milk. Dry buttermilk has a higher phospholipid content than other dry milk products and therefore is a natural emulsifier for use in the dairy and baking industries and for dry mixes and other foods. A dry, high-acid buttermilk can be produced from milk fermented by L. bulgaricus. It is difficult to dry, however, and has found only limited use in the baking industry. There are no United States and FAO standards for this product, although typically the moisture content is less than 5%. 

Procedures based on rotation have been used for quantitative measurement of the amounts of a- and /3-lactose in fluid and dry milk products and in ice cream (Roetman (1981). 

In the United States, 62% of fluid milk production is used for manufactured products, mainly cheese, evaporated and sweetened condensed milk, nonfat dry milk, and ice cream. Evaporated and condensed milk and dry milk are made from milk only other ingredients are added to make ice cream and sweetened condensed milk. 

Yogurt. Yogurt is a fermented milk product that is rapidly increasing in consumption in the United States. Milk is fermented with Uactobacillus bulgaricus and Streptococcus thermophilous organisms that produce lactic acid. Usually some cream or nonfat dried milk is added to the milk in order to obtain a heavy-bodied product. 

Ice Crea.m, Ice cream is a frozen food dessert prepared from a mixture of dairy iugredients (16—35%), sweeteners (13—20%), stabilizers, emulsifiers, flavoriug, and fmits and nuts (qv). Ice cream has 10—20% milk fat and 8—15% nonfat solids with 38.3% (36—43%) total soHds. These iugredients can be varied, but the dairy ingredient soHds must total 20%. The dairy iugredients are milk or cream, and milk fat suppHed by milk, cream butter, or butter oil, as well as SNF suppHed by condensed whole or nonfat milk or dry milk. The quantities of these products are specified by standards. The milk fat provides the characteristic texture and body iu ice cream. Sweeteners are a blend of cane or beet sugar and com symp soHds. The quantity of these vary depending on the sweetness desired and the cost. 

Dairy work Applications include vessels for milk storage and sterilisation, cooling units, cream separators and cheese and butter-making equipment, as well as general dairy fittings, bottle-washing machinery and tankers for bulk milk transport. Extensive use is made of these steels in equipment used in production of ice cream and dried milk. 

The consumption of dairy products plays a significant role in providing high-quality protein, vitamins, minerals, and other bioactive compounds to the American diet. Dairy products are consumed fresh in the United States in the form of fluid milk, cheese, yogurt, butter, and ice cream. Dried and condensed products such as nonfat dried milk, whey, whey protein concentrates, and isolates are also produced which are used as ingredients to boost the nutritional and functional properties of a host of other food... 

Table 2.1 lists the approximate percentages of the total milk supply used for various products in the United States and in nine major milk-producing countries. In such countries as New Zealand and Ireland, where per capita production of milk is high, most milk is used in storable manufactured products like butter, cheese, and nonfat dry milk. Where per capita production is low, as in the United States and the United Kingdom, greater amounts are used as fluid milk and creams. 

Time-temperature relationships have been established by various workers as being optimum for preventing or retarding the development of oxidized flavors in dairy products cream, 88 °C for 5 min condensed milk, 76.5°C for 8 min dry whole milk, preheated at 76.5°C for 20 min and frozen whole milk, 76.5°C for 1 min (Parks 1974). Few, if any, instances of a tallowy flavor have been reported in evaporated... 

Prolonged storage of ice cream and exposure to severe temperature fluctuation commonly causes shrinkage, which is a defect due to partial thawing and loss of moisture and air. An additional defect common to ice cream after prolonged storage is oxidized flavor, which is caused by autoxidation of milk fat. This defect is especially important in ice cream products that contain frozen or dried milk ingredients. 

Despite the above difficulties, several specific chemicals have been associated with specific off-flavors in dairy products. Forss et al. (1955a,b) reported that -hexanal, 2-octenal, 2-nonenal, 2,4-heptadienal and 2,4-nonadienal are the principal carbonyls contributing to the copper-induced cardboard off-flavor in milk. Hall and Lingnert (1986) associated this flavor defect with n-hexanal in spray-dried whole milk. l-Octen-3-one has been associated with a metallic off-flavor in dairy products (Stark and Forss, 1962), the metallic off-flavor being reproduced by addition of l-octen-3-one to milk or cream (Bassette et al., 1986). l-Octen-3-one has a threshold concentration of 1 pg/kg in butterfat (Shipe et al., 1978). 

The effect of storage temperature on the oxidative stability of milk and milk products is unclear. Storage, in air, at 2°C inhibited the development of oxidized flavor in dry whole milk when compared with control samples held at 38°C (Pyenson and Tracy, 1946). Oxidative deterioration of UHT cream occurred two to three times more rapidly at 18°C than at 10°C, while little or no oxidation occurred at 4°C (Downey, 1969). The oxidation-reduction potential of butter and the rate of flavor deterioration have been reported to increase as the storage temperature increased (Weihrauch, 1988). 

Processed milk products, which Include condensed, evaporated, malted and dry milks, cheese, whey, and ice cream and other frozen desserts, account for a large part of the overall Increase in zinc from the dairy products group. Cheese with its markedly increased use is chiefly responsible. Since 1909-13, the amount of zinc provided by cheese Increased more than fourfold and beginning in 1978, it has exceeded the amount contributed by fluid whole milk. In 1981, cheese provided 0.9 mg of zinc per capita per day or 7 percent of all the zinc in the food supply. Use of ice cream and other frozen desserts is now more than 10 times higher than in 1909-13. Half of this Increase occurred before the late 1930 s, and, since 1957-59, the small contribution of zinc from ice cream and other frozen desserts has been relatively stable. Other processed milk products have accounted for more zinc in recent years than at the beginning of the century. The amount, however, is somewhat less than the 0.6 mg per capita per day provided in 1946 when consumption of these products was highest. 

Milk Products. Cardboardy or metallic or tallowy flavors resulting from oxidative changes in the cream fraction of cows milk are distasteful in fluid milk and dairy products. These flavors develop more intensely in certain lots of fluid milk when the cows are fed dry rations. 

The main branches into which the industry is commonly divided are covered by textbooks. The fluid milk division has Market Milk and Related Products (28) by Sommer, Market Milk (19) by Kelly and Clement, and The Market Milk Industry (26) by Roadhouse and Henderson. The ice cream division can refer to The Theory and Practice of Ice Cream Making (29) by Sommer or The Ice Cream Industry (34) by Turnbow, Tracy, and Raffetto. Wilster s Practical Butter Manufacture (38) is an up-to-date practical manual, including recent developments in continuous butter making. Hunziker s The Butter Industry (15) has long been a standard work, as has his Condensed Milk and Milk Powder (14), which deals with sweetened condensed milk, evaporated milk, dried milk, and malted milk. Whittier and Webb, in Byproducts from Milk (37), cover a whole galaxy of products derived from skim milk, whey, and buttermilk. 

Riickold et al., 2000). This leads to greater or smaller discrepancies between the "official" results for moisture and the water content, depending essentially on the lactose content of the product. For the typical spray-dried milk such as full cream or skimmed milk powder these discrepancies are normally small as the lactose is in most cases amorphous. 

Whole milk, partially skimmed milk, skim milk, or cream may be used as a base component for yogurt. In addition to the milk base, other ingredients may be used which include other dairy products (concentrated skim milk, nonfat dry milk, whey. 

Coffee whiteners are products that are available in liquid, but more often in dried instant form. They are used like coffee cream or condensed milk. A formulation typical of these products is shown in Table 10.28. In contrast to milk products, plant fats are used in the production of coffee whiteners. Caseinates are usually the protein conpo-nent. The most important process steps in the production are preemulsification of the constituents at temperatures of up to 90 °C, high-pressure homogenization (cf. 10.1.3.4), spray drying, and in-stantization (cf. 10.2.5). 

A fat test is needed in order to establish the market value of milk and cream. Also, a fat test is important for numerous other purposes. For example, in Cheddar cheese 50% of the dry matter must be fat hence, a fat test provides a means of standardizing milk for the production of such cheese. Similarly, fat content must be known for the production of nonfat dry milk from skim milk, butter from cream, ice cream from numerous possible sources of fat, and evaporated milk from milk. 

Fluid milk processors are located in and near population centers, where most fluid milk is consumed. The Great Lakes and Midwest regions of the United States are the primary centers for manufacturing grade milk. Thus, with the exception of ice cream production, the processing of manufacture dairy products—butter, nonfat dry milk, cheese, evaporated and condensed milk, and other products of minor importance—is concentrated near these aretis of production. Other major production areas California, New York, and Pennsylvania— produce substantial quantities of manufactured dairy products from excess Grade A milk. 

Cultured buttermilk Bulgarian buttermilk—The fluid remaining after churning cream to make butter is called buttermilk. Today, this product is used primarily by the baking industry and most buttermilk for beverage purposes is a cultured product. Most of the cultured buttermilk marketed in the United States is made from fresh pasteurized skim or low-fat milk with added nonfat dry milk solids, cultured with Streptococcus lactls. However, cultured buttermilk can also be made from fluid whole milk, concentrated fluid forms, or reconstituted nonfat dry milk. 

Filled milk—These are milk products (milk, lowfat milk, half-and-half or cream, whether or not condensed, evaporated, concentrated, powdered, dried, or desiccated) from which all or part of the milkfat has been removed and to which any fat or oil other than milkfat has been added. The American Academy of Pediatrics does not recommend the use of filled milks for feeding infants and small children. 

CREAM, Cream is the liquid milk product, high in fat, separated from milk, which may have been adjusted by the addition of milk, concentrated milk, dry whole milk, skim milk, concentrated skim milk, or nonfat dry milk. Federal standards of identity require that cream contain not less than 18% milkfat. The several cream products on the market are ... 

Ytar Milk Cream Milk Product Butterfat Butter Cheese Cheese Cream NBIk Dry Hift Yogurt aicnt... 

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). 

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