Gross Composition

The range of fat content in the milk of different animal species varies widely (Table 1.16). The milk of the cow, human, goat and camel have a low fat content. The milk of the buffalo and sheep have values that are a little higher, whereas the fat content of the milk of the rabbit and seal is much 

The fatty acids in milk fat are derived from two sources, de novo synthesis of fatty acids in the mammary gland and plasma lipids (see Pal-quist, Chapter 2). De novo synthesis generally involves short-chain and medium-chain fatty acids and some 16 0. The proportions of various fatty acids depend on the specific balance between enzymatic chain elongation and chain termination. The plasma lipids are derived from the diet and also from storage in the body tissues. For non-ruminants, the diet has a large influence on the fatty acid composition but for ruminants, biohydrogenation in the rumen results in much less impact of diet on the final fatty acids absorbed into the bloodstream. 

One distinct difference between the fatty acid composition of the various species is the proportion of short-chain fatty acids in the milk of 

(Creamer and MacGibbon, 1996) Sheep, (Glass et al., 1967) Goat, (Posati and Orr, 1976) Buffalo, (Glass et ah, 1967) Camel, (Gnan and Sheriha, 1981) Rabbit, (Glass et al., 1967) Antarctic fur seal, (Iverson 

Generally, the milk fat of non-ruminants has a higher level of polyunsaturated fatty acids than the milk fat of ruminants, due to the direct absorption of these fatty acids from the diet (Table 1.17). Marine mammals, such as the fur seal, have also high levels of long-chain polyunsaturated fatty acids, 20 5 and 22 6, due to the presence of these fatty acids in the diet (Iverson et al., 1997). 

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Bulk catalytic materials, in which the gross composition does not... 

Table 6. Estimates of Typical Gross Composition of Wines, wt %...

The composition of dairy substitutes is highly variable and generally represents the least-cost formulation consistent with consumer acceptance of the product. These imitations invariably have lower fat and protein levels than the dairy products that they are made to resemble. The gross compositions of filled milk, meUorine, synthetic milk, sour cream, coffee whiteners, whipped toppings, and cheese are Hsted in Table 10. A comparison of the composition of certain dairy products and their substitutes is presented in Table 11. 

Tissue component Gross composition Percentage of dry weight... 

Constituents Gross composition —> Sum formula —> Constitution —> Configuration Conformation — Quantitation Intramolecular Dimensions... 

One of the major problems lies in the extent of interference from other constituents of a sample. This can often be obviated by a prior separation using chromatography or solvent extraction (p. 55) or by the use of masking agents (p. 40), pH control or changes in oxidation state. Standards should always be matched to the gross composition of the sample as closely as possible, and calibration curves frequently checked. The precision of absorption measurements has already been discussed (p. 361). 

The isomerases (class 5) move groups within a molecule, without changing the gross composition of the substrate. 

Description of an object can be the determination of the gross composition for example, lots of a manufactured product, lots of raw material, single objects, the mean state... 

Table 3.9 Gross composition of the milk fat globule membrane...

In the two phase region, the oxygen pressure is constant or independent of the gross composition at constant temperature. 

Milk composition expressed in terms of the contents of water (or total solids = 100 - water), fat, protein, lactose, and ash is called gross composition. Protein is often calculated as crude protein by multiplying total N by 6.38, but sometimes it is corrected to true protein 6.38 (TN -NPN) in a few studies, casein and whey protein have been calculated separately. Lactose should be expressed on an anyhydrous basis, but as pointed out previously, this has not always been done. For bovine milk the sum of fat, true protein, anhydrous lactose, and ash would be expected to fall about 0.2-0.3 percentage units short of the total solids contents because of the materials (citrate, NPN, and mis-... 

The gross composition of bovine milk has been reviewed many times (Rook 1961 Laben 1963 Jenness 1974 Johnson 1975 Moore and Rook 1980). These reviews have delineated thoroughly the extent of the variation and factors affecting it. One of the reviews is presented in a previous edition of this volume (Johnson 1975). Consequently, the present discussion is somewhat abbreviated. 

Table 1.10. Gross Composition of Milks of Various Species. 

Inherited Variation. Genetically controlled variation in milk composition is evident from both interbreed and intrabreed studies. Some comparative studies of breed differences involve sampling from individual cows others use herd milk comparisons. Surveys with both kinds of sampling, summarized in Table 1.12, give a reasonably consistent picture of differences among breeds in the gross composition of milk. 

Table 1.12. Gross Composition of Milk of Various Breeds (g/100 g).

Armstrong, T. V. 1959. Variations in the gross composition of milk as related to the breed of the cow A review and critical evaluation of literature of the United States and Canada. J. Dairy Sci. 42, 1-19. 

Ultra-High-Temperature (UHT) Sterile Milk. Rapid increases in the production and sales of sterile, fluid milk in Europe and its entry into new markets around the world merit its consideration in this chapter. Although the gross composition of UHT sterile, aseptically packaged milk is essentially the same as that of its pasteurized counterpart, differences in its properties and minor constituents should be mentioned. 

Table 10.2. Gross Composition of Milk Lipid Globule Membranes. ...

Many milk constituents affect the manufacturing and various characteristics of cheese, but milk fat and casein are of primary importance since they constitute most of the solids in cheese (e.g., 91% of the solids in Cheddar cheese). These two constituents, plus water, influence the yield of cheese from milk and the gross composition of cheese (Van Slyke and Price 1952). Formulas used to predict the cheese yield from milk include the concentration factors of casein and fat in milk, a minor correction factor for other milk constituents, and the added salt and moisture content of cheese (Van Slyke and Price 1952 Lelievre et al. 1983 Banks et al. 1984). 

Pig submaxillary mucin (74) exists in two forms in individual glands one of these possesses A activity, and the other does not. Their gross compositions were identical. Five oligosaccharides were isolated, the largest having the structure... 

With a polyethylene backbone, this grafting technique will not yield pure poly (ethylene-g-vinyl chloride)—"pure graft copolymer —but a mixture of this compound with PVC homopolymer and unmodified polyethylene. We call this raw graft polymerization product "VC/PE graft copolymer. Sometimes, we add its gross composition between parentheses—for example, VC/PE (50-50) graft copolymer. The same statement applies to the other backbone polymers. 

Dependence of homogeneity range on gross composition of "Pmma and molecular weight... 

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