Effects of H_2O_2 Addition and Heat Treatments on Some Physical, Chemical and Microbiological Qualities of Milk

Authors: Nuray SAHAN, Atilla KONAR, Alfons KLEEBERGER

Abstract: Samples of (a) raw milk, (b) LTLT pasteurized milk, (c) 0.5% H 2O2-added milk at 30 ^0C for 8 hours, and (d) the same milk as in section "c" but heat-treated at 55^0C for 10 minutes, were analyzed for some physical, chemical, and microbiological qualities. Different treatments, of milk did not have a statistically significant effect (p>0.05) on pH, fat, lactose and protein values of milk samples. However, the treatments had significant effects on specific gravity, dry matter (at p>0.05 level)and solids not including fat contents (at p<0.01 level) of milk Titration acidity values of LTLT-pasteurized, H_2O_2-added and H_2O_2 plus heat-treated milks were similar to each other but they were lower than the acidity value of raw milk (p<0.01). Differences in lactic acid and total bacteria contents of all the milk samples were statistically significant at p<0.01 level, while teh differences in coliform bacteria figures proved to be significant (p>0.05). Amount of the rennin enzyme needed for cheesemaking increased with the H2O2-plus-heat treatment of milk and also by the addition of H2O2 alone (p<0.01).