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Subject: Veterinary Public Health × Author: Kakati, Smita × End date: 2016 × Start date: 2015 × Type: Thesis ×
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    ThesisItemOpen Access
    QUALITY EVALUATION AND DETECTION OF ADULTERANTS IN RAW AND PASTEURIZED MILK MARKETED IN AND AROUND GUWAHATI CITY
    (College of Veterinary Science, Assam Agricultural University Khanapara, Guwahati-781022, 2016-07) Kakati, Smita; TALUKDAR, ARCHANA
    Milk in its natural form is a unique food for the nourishment of human being since time immemorial as it provides immunogenic protection and supplies nutrients in an easily digestible form than any other single food. With growing consumer concern for their daily consumables, there is increased awareness regarding safety and quality issues of milk and dairy products. The presence of adulterants, preservatives and pathogens of zoonotic importance is of primary concern in the effort of achieving a safe milk supply to the consumers. The present investigation was undertaken to study the quality, to determine the presence of different adulterants and preservatives as well as to assess the microbial load of raw and pasteurized milk marketed in and around Guwahati city. A total of 200 pooled milk samples were collected comprising of 8 samples each from 25 different locations in and around Guwahati city. Five different pasteurized packaged milk samples were collected from different dairies viz. Purabi Dairy, Amul Taaza, Central Dairy, Mother Dairy and Nandini. Physical evaluation of raw milk samples revealed mean titratable acidity of 0.14 - 0.20% lactic acid, pH of 5.60 - 6.91, specific gravity of 1.024 - 1.030, fat content of 1.57 - 3.55% and solids-not-fat (SNF) content of 6.634 - 8.350%; the respective values of which in packaged milk samples were 0.14 - 0.19% lactic acid, 6.10 - 6.70, 1.024 - 1.029, 3.00 - 3.05% and 8.515 - 8.580. Both raw and packaged milk samples showed negative result on clot-on-boiling test. Presence of added water, neutralizers, ammonia and salt were recorded in raw milk while the packaged milk samples were found to be properly pasteurized and free from any type of adulterant and preservative. Methylene blue reduction test of raw milk indicated more than 50% of the samples to be of poor and very poor quality in contrast to good quality in all the packaged milk from dairies. The viable bacterial count and coliform count of raw milk were 10.59 - 14.62 and 6.34 - 7.50 log cfu/ml, respectively, while no coliform could be isolated from the packaged milk. Based on physical evaluation, chemical analysis and microbial assessment, the raw milk marketed in and around Guwahati city was found to be of poor quality whereas all the packaged milk samples were found to be properly pasteurized and free from any coliform organism and harmful adulterants and preservatives.