ABSTRACT
Background: Milk is susceptible to contamination by many microorganisms including microbial pathogens responsible for causing diseases. Various processes including pasteurization, boiling or storage under refrigerated conditions are undertaken to minimize the microbial contamination of milk. Objective: This study was undertaken with an objective to evaluate the effect of household practices on the microbiological profile of milk. Materials and Methods: Milk samples of pasteurized, ultra heat treated (UHT) as well as unpasteurized milk (Vendor's milk) were collected. The effect of different storage practices and treatments on the microbiological profile (standard plate count (SPC), coliform, E. coli, Salmonella, Shigella, Staphylococcus aureus, yeast and moulds, anaerobic spore count, and Listeria monocytogenes) of milk was studied using National/ International Standard Test Methods. Results: Average SPC in vendor's milk was found very high as compared to pasteurized milk. Coliform, yeast and moulds, E. coli, and Staphylococcus aureus were detected in the samples of vendor's as well as pasteurized milk. Boiling the milk reduces SPC and kills the other microorganisms. Storage of boiled milk under room temperature or refrigerated condition resulted in a similar increase in SPC at the end of 24 h, but storage of un-boiled milk even under refrigerated conditions increased SPC manifold after 24 h. Conclusion: The pasteurization process and hygienic conditions at the milk processing units along with cold chain of milk from suppliers to end users needs improvement. Currently, even pasteurized milk does not match the microbiological standards. It is recommended that milk should be boiled before consumption and refrigerated for storage to improve its shelf life/keeping quality.
ABSTRACT
Background: It is a common practice to process milk before consumption. Processing generally involves boiling, addition of sugar and/or condiments, dilution with water, etc. The boiled milk is stored for subsequent use either at room temperature or under refrigerated conditions. Objective: The purpose of this study was to see the effect of household practices on the nutritional profile of milk. Materials and Methods: Different types of pasteurized milk samples: standardized, double toned, full cream, and unpasteurized milk were analyzed. The effect of household practices on the nutritional profile of all these milk samples was studied using National/International methods. Results: Boiling of milk increased the concentration of most of the components and minerals except for vitamins A, B 3 , B 5 , and B 12 where the decrease observed was 21%, 13%, 3%, and 21%, respectively. Addition of water decreased the concentration of minerals and vitamins. Addition of sugar increased the energy and condiments increased total solids, carbohydrate and minerals content but led to a decrease in the vitamin content. Storage of milk led to a decrease in total solids by 19% and vitamins A, B 3 , B 5 , and B 12 by 26%, 17-19%, 23%, and 18-26%, respectively. The pH was not influenced by any of the household practices. Conclusion: Every step during household practices in the handling of milk reduces its nutritional profile and significantly affects the quality. Vitamins play a very important role in health and loss during household processing becomes an interesting attribute that requires further research in detail.