RHEOLOGY AND TEXTURE OF COMMERCIAL QUESO FRESCO CHEESES MADE FROM RAW AND PASTEURIZED MILK

Queso Frescos made in Mexico from raw milk (RM) were compared with cheeses made in Mexico and the U.S.A. from pasteurized milk (PM) to determine textural and rheological differences. RM cheese, considered the ideal Queso Fresco, contained more moisture than PM cheeses, displayed higher cohesiveness and shear strain and exhibited lower hardness and shear stress. The U.S.-made cheeses were harder and more brittle and crumbly than the Mexican cheeses. The shear stress decreased as fat content increased in all samples, and the shear strain decreased as the pH increased in the Mexican cheeses. An understanding of the differences between the RM and PM versions should allow cheese makers to adjust manufacturing procedures so that PM Queso Fresco cheeses will meet consumer expectations. PRACTICAL APPLICATIONS Hispanic cheeses such as Queso Fresco are gaining in popularity in the U.S.A. The milk for making Queso Fresco in the U.S.A. must be pasteurized, and the resulting cheese is perceived by some consumers to be inferior in flavor and texture to the traditional variety made from raw milk. Queso Fresco samples made in Mexico from both kinds of milk and made in the U.S.A. from pasteurized milk were analyzed to see if there were differences in texture, structure, and the ability to twist and break pieces of the cheese. The cheeses made in the U.S.A. contained less moisture and were too hard, crumbly, and brittle when compared to the raw milk cheeses. The differences observed should enable U.S. companies to make Queso Fresco with properties close to those of the raw milk variety.