MILK GEL STRUCTURE. X. TEXTURE AND MICROSTRUCTURE IN CHEDDAR CHEESE MADE FROM WHOLE MILK AND FROM HOMOGENIZED LOW‐FAT MILK1

ABSTRACT Reduced‐fat cheese (17% fat, 44% moisture) was considerably firmer and more elastic than full‐fat cheese (35% fat, 35% moisture), even though the moisture levels in the nonfat matter (MNFM) of the cheese were the same, at 54%. Electron microscopy and compositional analysis revealed about 30% more protein matrix in the reduced‐fat cheese. Apparently more of this matrix must be cut or deformed in sensorial and texture assessments. A practical implication is that MNFM should be slightly higher in the reduced‐fat cheese than in full‐fat cheese to achieve more similar texture. Homogenization of milk tended to increase the moisture content and decrease firmness and elasticity, but not markedly. The smaller fat globules, per se, did not apparently affect texture as measured in these experiments. Curd granule junctions were prominent in nonhomogenized‐milk cheese, because large fat globules were lost at the granule surfaces leaving protein‐dense junctions; those in homogenized‐milk cheese were less apparent because the protein‐dense areas, which resulted from the loss of small fat globules, were narrower. Sensory and textural parameters for firmness and elasticity were inter‐correlated. The Bite Test was more useful than Instron measurements of deformation (20%), apparently because the latter was markedly affected by a slight openness in the cheese.