Effects of Partial Homogenization of Milk on Yield and Quality of Cheddar Cheese

In the past decade, the cheese industry in the United States (US) has grown rapidly, with cheese sales increasing by 33% (36). The cheese industry, in 1983, utilized 29.2% of total US milkfat supply as compared to 20.3% utilization in 1973 (36). Compared to the total cheese production of 2,059,2Z8 kg (4,539,822 lb) in 1982, 2,185,611 kg (4,818,449 lb) of cheese were manufactured in 1983 in the .US (36). The increased production of cheese was made possible by modifications in the cheese making process and advent of modern equipment; and it was fostered by increased demand .and higher prices. One of the recent concepts in the cheese industry is use of preconcentrated milk for cheese making. Preconcentration of cheesemilk lessens the problems related to whey disposal. With reduced bulk and increased solids level in the raw material, increase in cheese production can be attained without increase in labor or equipment. Research also has indicated increased cheese yields can be obtained by preconcentrating cheesemilk (6). Since ultrafiltration is not legal for treating milk to be used in Cheddar cheese manufacture, vacuum concentration is employed. Vacuum concentration of milk involves considerable amount of agitation by pumping. This physical abuse of milk has a shattering effect on milk fat globules, which is similar in nature to homogenization, but not to as great an extent. Since the natural distribution of milk fat globules and milk proteins is modified by homogenization, it is presumed that this process modifies the properties of cheese curd. Even though some researchers (15,30,38) found increased cheese yields with homogenized milk, the reports (18,39) of its adverse effects on flavor and body of cheese cast doubt on the feasibility of homogenization of milk in Cheddar cheese making. As earlier research with homogenized milk was not totally applicable to cheese making with the modern equipment used in the dairy industry, it seemed practical to investigate the effects of homogenization of milk at various pressures on the properties of the resultant Cheddar cheese during making and curing