IDENTIFICATION OF BACTERIA AND THEIR LOADS ISOLATED FROM DIFFERENT BRANDS OF ICE CREAM

Abstract

A study was conducted to identify the organisms in ice cream manufactured by three different plants namely Igloo, Polar and Kwality sold in retail stores in Dinajpur town, Bangladesh. The samples were analyzed to determine the hygienic status of the ice creams and also for the total viable count, presence of Gram positive and Gram negative pathogenic bacteria.Three cups ice cream samples each of three popular varieties including Igloo, Polar and Kwality were collected from different retail stores in Dinajpur city. The bacteriological analyses were done at the Microbiology Laboratory of Hajee Mohammad Danesh Science and Technology University, Dinajpur. During July to December -2012. Total viable count (TVC) was performed according to the American Public Health Association, using plate count agar medium for TVC and Eosine methylene blue (EMB) agar media for total E. coli count and Staphylococcus agar no. 110 for total staphylococcus count. The average TVC for Kwality ice cream was lower (8.53 x 103 CFU/ml) in comparison to Polar ice cream (1.39 x 104 CFU/ml). It was apparent from the present study that the bacterial load of the ice cream samples of the three manufacturers were within the acceptable limit of public health safety, since the count was well below the acceptable limit. It was found that the highest extent of microbial contamination and proliferation of viable bacteria occurred in Polar ice cream. The average E. coli counts obtained from the study was in Igloo 9.26 x 103 CFU/ml (log 4.0), in Polar 1.14 x 10° CFU/ml (log 3.0) and in Kwality 7.95 x 102 CFU/ml (log 2.9) . The presence of numbers of E. coli in Igloo ice cream was little bit high indicated the poor hygienic practices during manufacture, post process contamination and unsatisfactory transportation. Statistically the E. coli were more closely related to total viable counts than the staphylococcal counts. The average staphylococcal counts in the samples of Igloo, Polar and Kwality were 2.60 x 10°CFU/ml (log 3.4), 0.0 CFU/ml (log 0.0), and 0.0 CFU/ml (log 0.0), respectively. The results demonstrated that kwality ice creams are of the superior quality product in respect of sanitary condition.