Stability of Immunoglobulin G(IgG) by Heat Treatment

This study was carried out to obtain fundamental data when developing new colostrum component fortified milk products. Residual immunoglobulin G (IgG) activities of both IgG fortified milk products under different pasteurization conditions and colostrum fortified milk powder products under different dissolving temperatures were measured. In the study, residual IgG activities of raw milk and IgG (50 mg and 250 mg) fortified milk products were sharply reduced upon increasing the temperature of heat treatment. After the low temperature long time (LTLT) treatment residual IgG activities of raw milk, IgG 50 mg and 250 mg fortified milk products decreased to 79%, 30％ and 21.6%, as compared to those before heat treatment respectively. However, almost no residual IgG activities were detected when IgG fortified milk was heated at 95$^{\circ}C$ for 15 sec. There was no significant change in the residual IgG activities of IgG fortified milk powder products upon different dissolving temperatures (30$^{\circ}C$, 40$^{\circ}C$, 50$^{\circ}C$ and 60$^{\circ}C$).

면역단백질 G(IgG)의 열처리에 대한 안정성

초유성분을 이용한 유제품의 개발시 기초자료로 활용하기 위하여 IgG 강화우유의 살균온도에 따른 IgG 활성 잔존율과 초유관련 분말제품의 용해온도에 따른 IgG 활성 잔존율을 측정하였다. 그 결과, 원유, IgG 50 mg, 250 mg 강화한 우유는 살균처리 온도가 높을수록 활성 잔존율이 급격히 감소하였으며, LTLT 처리시 원유, 50 mg, 250 mg 강화우유의 활성 잔존율은 각각 79%, 30%, 21.6%였다. 그러나 9$0^{\circ}C$/15초 이상의 살균 처리시에는 IgG 활성이 거의 파괴되었다. 분말제품의 3$0^{\circ}C$, 4$0^{\circ}C$, 5$0^{\circ}C$, 6$0^{\circ}C$ 용해온도에 따른 IgG 활성 잔존율은 큰 차이를 나타내지 않았다.