SOME PROPERTIES OF FREEZE-DRYING WHEY POWDERS
Whey is the main waste generated in the cheese making process and has high organic matter content and acidity. Beyaz, Kasar and Tulum are the most produced cheese types in Turkey. The whey of these cheeses are treated by freeze-drying to increase quality of whey and provide convenience in both shelf life and transportation. Whey of Beyaz, Kasar and Tulum cheeses were dried for 48 hours under the conditions of 5 mTorr pressure and (-80)ÂºC with freeze dryer in this study. Whey powders were packaged in vacuum with high density polyethylene packages and stored at room temperature then analyzed after 24 hours. According to the results, mean values of the pH, titratable acidity (l.a.%), total solid, fat, protein, ash are as follows.Â Whey powder obtained from Beyaz cheeses were 5.15 Â± 0.30, 1.56 % Â± 0.59, 91.70% Â± 3.91, 2.00% Â± 1.00, 9.30% Â± 0.49, 10.67% Â± 0.48. Whey powder obtained from Kasar cheeses were 6.14 Â± 0.21, 4.71% Â± 0.89, 92.95% Â± 1.49, 8.60% Â± 1.15, 13.28% Â± 2.41, 6.69% Â± 0.98. Whey powder obtained from Tulum cheeses were 4.88 Â± 0.64,Â 2.91% Â± 0.94, 93.08% Â± 0.59,Â 4.88% Â± 1.23, 14.33% Â± 1.17, 8.80% Â± 1.92. In the statistical analyzes, the difference in pH, titratable acidity, fat, protein and ash contents was found to be significant (p<0.05), while the differences in total solid values were not significant (p> 0.05).