摘要：The contamination of raw milk with psychrotrophic micro-organisms has become a concern because they are able to multiply at refrigeration temperatures and produce heat resistant enzymes that affect the quality of milk and dairy products. The objective of this study was to evaluate the effect of acidification with CO 2 and HCl on mesophilic and psychrotrophic bacteria present in raw milk during cold storage. Raw milk samples were acidified with CO 2 and HCl 1N until pH 6,0 and stored at 5 °C for 10 days. The results showed an average reduction of 1 logarithmic cycle in the growth of psychrotrophic and mesophilic microorganisms in samples treated with CO 2 . Acidification with HCl showed no effect, indicating that inhibitory action was due to CO 2 not by pH reduction. DOI: http://dx.doi.org/10.14685/rebrapa.v2i2.68
