Milk composition that can be affected by cooling or freezing is crucial for the performance of chesese making, and it is an important parameter in economic terms. The objective of this study was to evaluate, during 7 days, the effect of milk cooling and freezing on the yield of the curd produced with the sheep milk and on the physical characteristics of the obtained whey. Between January and December 2011 samples of the sheep milk were collected every month, directly from the bulk tanks. A part of it was subject to analysis in the same day, and the rest was stored for up to 7 days. One of the samples was kept under refrigeration (5°C - cooled milk) and another was kept in a domestic freezer (-4°C - frozen milk). The yield and density of the curd, pH and titratable acidity of the obtained whey was determined. The treatment applied showed a significant difference (P<0.05) in the yield of the curd, whereas the yield obtained with the cooled milk (3.64±0.34L kg-1) and the frozen milk (3.18±0.23L kg-1) showed no differences with the fresh milk (3.38±0.22 L kg-1), but these treatments were not the same. The average density of the obtained whey (1.025g mL-1) did not present differences between the applied treatments. The whey pH and titratable acidity were similar in both fresh and frozen milk treatments, but there was a difference (P<0.05) with the cooled milk, which had a higher acidity. Even though the whey of the curb obtained from the cooled milk is more acid, the cooling and freezing of the sheep milk, for a period of 7 days, do not affect the yield in cheese making, and the obtained whey does not present density differences between the applied treatments.
cheese yield; sheep milk whey; freeze
