Bull Vet Inst Pulawy 55, 705-708, 2011

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DETERMINATION OF ALKALINE PHOSPHATASE ACTIVITY IN GOAT MILK AND CHEESE BY FLUORIMETRIC METHOD AS A VERIFICATION OF EFFICACY OF PASTEURISATION PROCESS

JOLANTA GRAŻYNA ROLA AND MACIEJ SOSNOWSKI

The aim of this study was the verification of completeness of pasteurisation by measuring the alkaline phosphatase activity in goat milk products. Enzyme activity was determined by the use of a fluorimetric method. In total, 75 samples of pasteurised milk, two samples of raw milk, and 17 samples of cheese were examined. Fifty-six percent of pasteurised milk samples had an alkaline phosphatase activity at a level below 50 mU·L ^-1 , 31% - from 50 to 100 mU·L ^-1 , and 13% above 100 mU·L ^-1 . Raw milk had an activity that equalled about 21,500 mU·L ^-1 . Alkaline phosphatase activity of 82% of the cheese samples was below 2 and 18% - above 2 mU·g ^-1 . The activity of alkaline phosphatase of all tested samples was below the tentative limits of 350 mU·L ^-1 for goat milk and 10 mU·g ^-1 for cheese, thus the limits had been supported.

Key words: goat milk, goat cheese, pasteurisation, alkaline phosphatase, fluorimetry.