Sannabhadti, S. S.Patel, Dilip Ambalal2018-05-182018-05-181992http://krishikosh.egranth.ac.in/handle/1/5810046524The study was planned and conducted to study the effect of handling, thermization and activation of lactoperoxidase system on microbiological quality and shelflife of raw buffalo milk. the study on cow raw milk was taken for comparison. To study the effect of milk handling on its bacteriological quality, samples were collected from randomly selected individual milk producers at the point of milk collection, at RMRD of a dairy plant and from chilling centre of the dairy. To study the influence of LP treatment and thermization treatment, pooled raw milk samples were collected from Students Training Dairy. To study the sources of contamination, foremilk, middlemilk and dung samples wepe collected from buffalo herd of Reproductive Biology Research Unit. Can rinses samples were collected from randomly selected milk collection centres of a commercial dairy plant. Activation of LP system at the levels of 15:10 ppms (B)and 45:30 ppms (C) of SCN : H2O2, respectively, gave significant extension in shelflife of buffalo milk stored at 37°C. The former treatment gave extension in shelflife of 3 hours (total 8 hours) and latter gave 6 hours (total 11 hours) as compared to untreated raw milk which had the shelflife of 5 hours as judged by CoB test. LPS at three times higher level i.e. 45:30 ppms of SCN H2O2; failed to give proportional advantage as compared to 15:10 ppm level of SCN:H2O2, suggested by IDF. Thus, higher level of addition may not be necessary if the application of LPS is thought for procurement of unoooled raw milk. Treatment B and C showed predominantly bacteriostatic influence on raw milk flora upto 3 hours of activation of LPS. Acid producing bacteria, proteolytic bacteria, coliform bacteria and thermoduric bacteria exhibited varying response to LPS. B and C showed reduction in Log APC of about 3.72 and 3.63 cfu per ml respectively, in comparison to untreated buffalo raw milk which had 4.13 Log cfu per ml. However, proliferation of acid producing bacteria remained unchecked soon after 3 hours of incubation. Coliforitis were most sensitive among all groups of micro-organisms enumerated. At 0 hour, Log CC for B and C was 3.38 and 2.99 cfu per ml respectively as against 4.07 Log cfu per ml of untreated raw milk. Conforms also tended to multiply profusely from third hour of incubation. Proteolytic bacteria and thermoduric bacteria were found to be quite resistant to LPS. They tended to multiply significantly through the storage period. Thermization at higher temperature i.e. 65°C/20s as well as lower temperature of heating i.e. 60 C/20s did not give significant enhancement in shelflife in comparison to untreated milk.However, there was marked arrest of acidity in treated milks upto 3 to 4 hours as compared to untreated raw milk. Successive thermization followed by LP (ExC) with sensitisation at 37 C for two hours, showed significant arrest of acidity in cow milk as compared to C alone however, in case of buffalo milk, ExC and C were comparable. It was observed that milkers hands, teat surfaces and / or interior of the udder could be some of the important initial sources of contamination because milk samples collected using sterilized containers also showed SPC of more than 10 cfu per ml and CC more than 3 10 to the power 3 cfu per ml. Rinsing of milk cans with potable water prior to addition of milk may be useful because this step followed in the study reduced the bacterial load by about ten times. Similar care about the coat and hind quarters of the animal is very important because falling of even 1 gm dung may contribute as high as 10 bacteria. If care can be exercised to preclude above dominant sources of contamination, shelflife of LP activated milk can be further improved. From the results of this study , it can be indicated that thermisation alone or in combination with LP treatment has no real practical advantage over LP treatment alone under the conditions existing in our country. So LP treatment alone, at the level suggested by IDF or at three times higher concentration suggested by Thakar and Dave (1986) can be recommended under our conditions of raw milk procurement for both cow and buffalo milk to extend its shelflife.enDAIRY MICROBIOLOGYA STUDYThesis