In the present investigation the diversity of the Staphylococcus species in different street vend food samples was studied. A total of 35 staphylococcal food isolates comprising of various species from 14 different st...In the present investigation the diversity of the Staphylococcus species in different street vend food samples was studied. A total of 35 staphylococcal food isolates comprising of various species from 14 different street vend food samples were identified and characterized phenotypically. Staphylococcus aureus was found to be the most prevalent species in these foods. A PCR-RFLP analysis based on 16S rRNA gene was used for identification of Staphylococcus species. Isolates showing distinct RFLP pattern for AluI restriction digestion were selected for nucleotide sequence analysis. Phylogenetic tree constructed using the multiple alignments of 16S rRNA gene sequences of isolates showed a hotspot region of 169 bp and the relationship among species was evaluated by bootstrap values generated in phylogenetic analysis. 16S rRNA gene sequences allowed bacterial identification that was reproducible and more accurate than that obtained by phenotypic testing. 16S rRNA gene sequence analysis would be helpful in timely and correct identification of pathogens.展开更多
Milk chocolates were prepared by replacing skim milk powder in the formulation with yoghurt powder at 50% and 100% levels. The effect of incorporating yoghurt powder on quality of chocolates was studied. No significan...Milk chocolates were prepared by replacing skim milk powder in the formulation with yoghurt powder at 50% and 100% levels. The effect of incorporating yoghurt powder on quality of chocolates was studied. No significant changes were observed in fatty acid profile and hardness of the chocolates. Sour taste of chocolate with yoghurt powder due to its acidity was neutralized by adding calculated amount of sodium bicarbonate. Sensory analysis showed that probiotic chocolates were highly acceptable and similar to control chocolate. Microbiological studies of chocolates showed the presence of Lactobacillus species to the extent of 3.37 log·cfu/g, which were not present in the control sample prepared only with skim milk powder. Rheological studies showed that milk chocolate prepared using yoghurt powder at 50% showed no significant changes in yield value compared to that of control, but at 100% addition a considerable decrease in yield value was observed. Microstructural properties of chocolate with 50% addition of yoghurt powder showed smaller particles adhering to the cocoa and sugar crystals but at 100% addition of yoghurt powder, the cocoa particles were completely covered by smaller yoghurt powder matrix.展开更多
文摘In the present investigation the diversity of the Staphylococcus species in different street vend food samples was studied. A total of 35 staphylococcal food isolates comprising of various species from 14 different street vend food samples were identified and characterized phenotypically. Staphylococcus aureus was found to be the most prevalent species in these foods. A PCR-RFLP analysis based on 16S rRNA gene was used for identification of Staphylococcus species. Isolates showing distinct RFLP pattern for AluI restriction digestion were selected for nucleotide sequence analysis. Phylogenetic tree constructed using the multiple alignments of 16S rRNA gene sequences of isolates showed a hotspot region of 169 bp and the relationship among species was evaluated by bootstrap values generated in phylogenetic analysis. 16S rRNA gene sequences allowed bacterial identification that was reproducible and more accurate than that obtained by phenotypic testing. 16S rRNA gene sequence analysis would be helpful in timely and correct identification of pathogens.
文摘Milk chocolates were prepared by replacing skim milk powder in the formulation with yoghurt powder at 50% and 100% levels. The effect of incorporating yoghurt powder on quality of chocolates was studied. No significant changes were observed in fatty acid profile and hardness of the chocolates. Sour taste of chocolate with yoghurt powder due to its acidity was neutralized by adding calculated amount of sodium bicarbonate. Sensory analysis showed that probiotic chocolates were highly acceptable and similar to control chocolate. Microbiological studies of chocolates showed the presence of Lactobacillus species to the extent of 3.37 log·cfu/g, which were not present in the control sample prepared only with skim milk powder. Rheological studies showed that milk chocolate prepared using yoghurt powder at 50% showed no significant changes in yield value compared to that of control, but at 100% addition a considerable decrease in yield value was observed. Microstructural properties of chocolate with 50% addition of yoghurt powder showed smaller particles adhering to the cocoa and sugar crystals but at 100% addition of yoghurt powder, the cocoa particles were completely covered by smaller yoghurt powder matrix.
