Studies on the proteolytic psychrotrophic bacteria in ice cream in sharkia governorate

One hundred random samples of ice cream (50 each of small and large scale producers) collected from different localities in Sharkia Govemorate,Egypt, were examined bacteriologically.Methylene blue reduction test results revealed that 20 out of 100examined samples (20%) were graded I, while 28 samples (28%), 32samples (32%) and 20 samples (20%) were graded II, III & IV respectively.The bacteriological examination of ice cream samples collected fromsmall scale and large-scale producers revealed that the psychrotrophicbacteria could be detected in (100%) and (54%) with a mean value 5.2xl06and 4.6xl 02/g respectively.The proteolytic psychrotrophic bacteria were present in (70%) and(16%) in ice cream samples collected from small scale and large scaleproducers, with a mean value of7.5x105 and 0.3xl02 /g respectively.Pseudomonas spp., Bacillus spp., Alcaligenes spp., Chromobacteriumspp., Micrococcus spp., Acientobacter spp. and Streptococcus spp. Couldbe isolated at varying percentages from the examined ice cream samples ofsmall and large scale producers. While, Staphylococcus spp.,Enterobacteriaceae and Flavobacterium spp. Could be isolated from theexamined ice cream samples collected from small scale producers only.