Effects of refrigeration, freezing-thawing and pasteurization on IgG goat colostrum preservation

The aim of this paper was to evaluate the effects of refrigeration, several different methods of thawing, and pasteurization on the concentration of IgG in goat colostrum. Three different experiments were designed to analyse these effects. In the first of these, 50 samples of goat colostrum were stored in a cold-storage room at a temperature of 4degreesC for a 3-month period. No statistically significant effects were observed within this time, although there was a reduction in IgG concentrations (32.98 and 25.11 mg/ml IgG at day 0 and 91, respectively). In the second experiment, 20 samples of goat colostrum were frozen and subsequently thawed using four different methods: hot water (60 degreesC), refrigeration (4 degreesC, room temperature (27 degreesC) and microwave (55 degreesC). The process was carried out seven times for each of the four methods. The method of thawing did not affect the colostrum IgG concentration. However, the repetition of freezing and thawing tended to reduce IgG concentrations, albeit to no significant degree (15.50 and 10.73 mg/ml IgG at cycle 0 and 7, respectively). In the third experiment, 30 goat colostrum samples were used and a reduction of approximately 35% of IgG concentration after pasteurization was observed. Refrigeration, freezing and pasteurization are suitable methods for conserving goat colostrum. (C) 2002 Elsevier Science B.V. All rights reserved.