COMPOSITION AND MICROSTRUCTURE OF COMMERCIAL FULL-FAT AND LOW-FAT CHEESES

The objective of this study was to analyze the composition of commerci al full-fat and low-fat cheeses and to evaluate their microstructure. Commercial cheeses evaluated included full-fat and low-fat Cheddar, Mo zzarella, processed, and Swiss cheeses. Cheddar cheeses ranged from 8. 2% fat and 51.1% moisture in the 75% low-fat product to 33.2% fat and 35.9% moisture in the full-fat cheese. Mozzarella cheeses ranged in fa t from a low of 2.1% to a high of 24% with corresponding moisture cont ent of 56.6 to 45.5% respectively. Fat-free processed cheese had 0.9% fat and 58.7% moisture, while the full-fat cheese had 32.3% fat and 37 .4% moisture. Full-fat Swiss cheese had fat and moisture content of 34 .8 and 36.7%, respectively. The corresponding values for the low-fat c heese were 27.6 and 40.1%. Total protein content of all cheeses increa sed with decreasing fat, but the percent increase in protein was less than the percent reduction in fat. The ash content of Cheddar and Swis s also increased with a decrease in fat content. The fat content of ch eeses affected the microstructure. Full-fat cheeses for all varieties were characterized by a protein matrix interspersed with fat globules of varying shape and size. Low-fat cheeses had fewer fat globules with in the protein matrix, and the globules were usually smaller than in t he full-fat cheese. The protein matrix dominated the structure of low- fat cheeses which would explain the firm, rubbery body and texture cha racteristics.