Cheese yield

The protein content of milk is primarily influenced by the breed of cow, the stage of lactation, type of diet being fed and the health status of the cow, and is important in processing because the protein (and specifically casein) content of milk determines its cheese yield. Milk provides a highly digestible source of protein for a large proportion of the world s population, either as raw milk or processed into dairy products. In addition to this basic nutrition, milk... 

Vitamin E supplementation has been shown to have positive effects on milk quality in a conventional commercial dairy herd. Milk obtained from cows that received supplemental vitamin E had lower somatic cell counts and plasmin concentrations than corresponding values in milk obtained from control cows. The reduction in plasmin as a result of vitamin E supplementation is very beneficial to the dairy industry because plasmin reduces the cheese-yielding capacity of milk, affects the coagulating properties of milk and its overall ability to withstand processing during cheesemaking (Politis et al., 2004). 

Barbano D M, Rasmussen R R and Lynch J M (1991), Influence of milk somatic cell count and milk age on cheese yield , Journal of Dairy Science, 74, 369-388. 

Politis I and Ng-Kwai-Hang K F (1988b), Association between somatic cell counts of milk and cheese yielding capacity , Journal of Dairy Science, 71, 1720-1727. 

Gel strength (curd tension). The gel network continues to develop for a considerable period after visible coagulation (Figure 10.8). The strength of the gel formed, which is very important from the viewpoints of syneresis (and hence moisture control) and cheese yield, is affected by several factors - the principal ones are summarized in Figure 10.9. 

Sellers, R. L. 1982. Effect of milk-clotting enzymes on cheese yield. 5thBienn. Cheese Ind. Conf., Utah State University, Logan. 

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). 

The changes in protein and salt equilibrium during storage at 4°C causes an increase in rennet clotting time, reduction of firmness of the rennet clot, and loss of cheese yield (Ali et al. 1980A). The extent of change is proportional to the degree of casein solubilization. 

Proteolysis of casein may be substantial under certain conditions, such as late lactation and mastitic infections. Under these conditions, the number of somatic cells increases. The most noticeable effect of high somatic cell counts is loss of cheese yield. Everson (1984) identified a loss of 0.045 kg of cheese per 45.36 kg of milk for every 106/ml increase of somatic cell count. Somatic cell counts above 4 x 106/ml were also correlated with enhanced lipolysis and with an increased... 

Z Puhan, E Jakob. 4.1 Genetic variants of milk proteins and cheese yield. In International Dairy Federation Special Issue 9402. Cheese Yield and Factors Affecting Its Control. Brussels International Dairy Federation, 1994, pp 111-122. 

Whey is a coproduct of cheese manufacturing. In 2000, California produced an estimated 1.5 billion lb of cheese, yielding 747,000 t of dried whey. It is costly to dispose whey in municipal water systems. Hence, an alternative use for whey would enhance the economics of cheese production. Currently, whey protein is used as a food additive, a protein supplement, and an animal feed. In addition, there are a few ethanol plants in California and the Midwest that use whey as a feedstock. The current California whey production would yield approx 4.7 million gal of ethanol. 

The enmeshed fat globules occupy the spaces between the protein strands and may be considered to impede physically the aggregation of the para-casein matrix, to a degree dependent on their volume fraction and size distribution. Consequently, a higher fat level leads to slower syneresis during manufacture (Dejmek and Walstra, 2004), and an increase in the level of MNFS in the cheese (Tunick et al., 1995 Poudaval and Mistry, 1999 Fenelon and Guinee, 1999) the increase in MNFS has a major impact on cheese yield and quality, as discussed in Sections 11.4, 11.6-11.9. 

Milk fat contributes directly and indirectly to cheese yield (Table 11.3). The direct contribution of fat to cheese yield is clearly reflected by prediction equations, which relate cheese yield to the concentrations, and recoveries, of milk fat and protein (Fox et al., 2000 Melilli et al., 2002). An example of such an equation is the modified van Slyke formula, (Fenelon and Guinee, 1999) ... 

Lemay, A., Paquin, P., Lacroix, C. 1994. Influence of milk microfluidization on Cheddar cheese composition, quality and yields. In Cheese yield and factors affecting its control. Proc. IDF Seminar, Cork, Ireland, 1993, pp. 288-292, International Dairy Federation, Brussels. 

Hicks, C.L., Purba, A., O Leary, J. 1990. Effect of cycle pumping milk on cheese yield. Cult. Dairy Prod. J. 25(1), 20-24. 

McCarney, T.A., Mullan, W.M.A., Rowe, M. T. 1994. The effect of carbonation of milk on the yield and quality of Cheddar cheese. In Cheese Yield and Factors Affecting its Control, Special Issue No. 9402, pp. 302-308, International Dairy Federation Brussels. 

Excessive proteolysis, however, leads to excessive loss of fat and cheese yield and adversely fects cheese flavour and texture. 

Jeng et al. (1997) characterized and partially purified bovine jS-casein (jS-CN) from the milk of transgenic mice. The approximate expression of the protein was 3.0 mg/ml of milk. The workers reported that phosphorylation of the bovine jS-CN in the milk of transgenic mice was the same as that of native bovine jS-CN. If the modification and/or enhancement in the jS-CN could be extrapolated into farm animals, there would be several other potential advantages to processing. The extra jS-CN would increase the cheese yield besides improving the curd strength. 

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