IDENTIFICATION OF BACTERIA AND THEIR LOADS ISOLATED FROM DIFFERENT BRANDS OF BUTTER AND CHEESE

Abstract

The present study was conducted to identify the organisms in butter and cheese manufactured by different plants namely Milk vita and Quality sold in retail stores in Dinajpur town, Bangladesh. ‘the samples were analyzed to determine the hygienic status of butter and cheeses and also for the total viable count, presence of gram positive and gram negative pathogenic bacteria. Two butter and two cheese samples each of are popular varieties were collected from different retail stores of Dinajpur city. The bacteriological analyses were done at the Microbiology Laboratory of Hajee Mohammad Danesh Science and Technology University, Dinajpur. During July to December — 2013. 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 Milk vita butter 3.28 x 10°CFU/gm (log 5.5) was lower than local butter 5.45 x 10° CFU/gm (log 6.7) and average TVC for Quality cheese 4.5 x 10° CFU/gm(log 5.7) was lower than local cheese 5.14 x 10°CFU/gm (log 6.7). It was apparent from the present study that the bacterial load of butter and cheese samples of the different manufactures 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 bacterial contamination and proliferation of viable bacteria occurred in local butter and local cheese. The average E. coli counts obtained from the study was in Milk vita butter 8.26 x 10° (log 3.8), in local butter 6.25 x 10° (log 5.7), in Quality cheese 5.65 x 10° (log 4.7), in Local cheese5.5 x 10° (log 5.8). The presence of numbers of E. coli in local butter and cheese was little bit high indicate 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 in the samples of Milk vita butter 2.68 x 10° CFU/gm (log 3.4), Local butter 3.15x 10* CFU/gm (log 4.5), Quality cheese 4.46 x 10° CFU/gm (log 3.6) and Local cheese 1.19 x 10* CFU/gm (log 4.0) were respectively. The results demonstrated that Milk vita butter and Quality cheese are of superior quality product in respect of sanitary condition.