Reducing the ripening time of Iranian brine cheese was the aim of this study. In this investigation, the lactic bacteria such as Streptococcus thermophilus and Lactobacillus bulgaricus were shocked by heat. The results showed that the optimal pH activity of L.bulgaricus slightly was lower than that of Str.therimophilus . The results obtained from total count tests during incubation approved that the permanent pH adjustment has a positive effect on the reducing of generation time, increasing of growth rate and effectiveness of culture. The results related to the best temperature time used as the conditions for heat shock for getting the least lactic acid production as well as best proteolysis activity were 6OC during 10 seconds. The proteolysis activity was evaluated by measuring the rate of non-protein nitrogen (NPN) on total nitrogen and our results displayed that a mixture of two percent of heat shocked microorganisms besides one percent of ordinary culture give the best performance. The results showed that the amount of NPN in curds in which the heat shocked culture had been used after twenty days preservation into 11 % brine was as high as the quantity of NPN after 60 days ripening at the same conditions in witness samples. A significant differences were not considered in the pH and total solids of two kinds of products (P>0.05), but organoleptic tests showed a superiority of the cheeses produced by using heat shocked lactic bacteria (P<0.01).
)