The Changes of Casein of Cheese Base Treated with Enzyme during Ripening

Enzyme의 처리에 의한 Cheese Base의 숙성중 Casein의 변화

This experiment was carried out to investigate the changes of casein of cheese base treated with substitute enzyme during ripening. The cheese base without enzyme treatment(control, D)and cheese base treated with only calf rennet(A), cheese base treated with mixed enzyme(calf rennet :porcine pepsin 1:1, B), cheese base treated with only porcine pepsin(C) were manufactured. The changes of casein were analyzed by means of HPLC and electrophoresis as experimental parameters during ripening. Gel filtration(HPLC) of casein by Superose 12 column in Cheddar cheese showed 5 fractions immediately after manufacturing and 8 fractions after six months ripening. Though D showed no difference in number of fraction(4 fraction) during 8 weeks ripening, A, B, C have represented the change of fraction number 4 to 5, 4 to 7, 4 to 8, respectively. As the mixing ratio of porcine pepsin increased, higher degradability of casein appeared. After 8 weeks ripening, electrophoresis of casein in cheese base showed three bands as an ${\alpha}$$_{s1}$casein from A and five bands from B, C. In case of D one major band and two minor bands were appeared as an ${\alpha}$$_{s1}$-casein. As the additional level of porcine pepsin increased the concentration of ${\beta}$-casein band decreased. however, that of ${\gamma}_1$ ${\gamma}_2$-casein band increased and para-${\kappa}$-casein band appeared from A, B, C, except D.

본 연구는 UF에 의한 cheese base제조과정 중 calf rennet 과 대용효소인 porcine pepsin을 각각 단독, 또는 1:1로 혼합첨가하여 cheese base를 제조한 후, HPLC와 전기영동을 이 용하여 casein의 변화를 관찰하기 위여 실시하였으며 얻어진 결과는 다음과 같다. HPLC를 이용, Superose 12 column에 의하여cheese casein을 gel filtration한 결과, Cheddar cheese는 제조직후 5개의 분획이었던 것이 6개월 숙성후 8개의 분획으로 분별되었으며, 효소처리하지 않은 대조구 cheese base는 8주 숙성중 4개의 분획으로 분별되어 분획수의 큰 변동은 없었고, calf rennet 단독처리구는 4개에서 5개로, 1:1혼합효소처리구(calf rennet : porcine pepsin)는 4개에서 7개로, porcine pepsin 단독처리구는 4개에서 8개로 각각 분별되어 porcine pepsin이 혼합됨에 따라 casein의 분해 정도가 높았다. 효소처리하여 8주간 숙성시킨 cheese base의 casein을 전기영동한 결과, ${\alpha}$$_{s1}$-casein의 경우, calf rennet 단독처리구는 3개의 band로 분리되었고, 1:1혼합효소처리구(calf rennet :porcine pepsin)와 Porcine pepsin 단독처리구는 5개의 band로 분리되었으며, 대조구는 1개의 major band와 2개의 minor band를 나타내었다. ${\beta}$-casein은 porcine pepsin의 첨가비율이 증가할수록 그 농도는 감소하였고, ${\gamma}_1$ ${\gamma}_2$-casein으로 추정되는 band는 상대적으로 증가함을 나타내었다. 또한 para-${\kappa}$-casein은 대조구를 제외하고 calf rennet, porcine pepsin단독처리구, 1:1혼합효소처리구에서 분리되었다.