고전압 펄스 전기장 처리에 의한 우유 단백질과 물리화학적 특성의 변화

Abstract

Raw milk, skim milk, HTST-, LTLT-, and UHT-milk were treated with pulsed electric field (PEF) process and the changes in proteins and physicochemical properties of milk were examined. When protein profiles in samples were identified by SDS-PAGE, the denaturation of milk proteins by PEF treatment was not observed. When the denaturation temperature (Td) of milk proteins was analyzed with a differential scanning calorimetry (DSC), the Td of skim milk treated with PEF at 65oC increased from 87.66 to 97.18oC, which indicated that PEF treatment affected the denaturation of milk protein. The PEF treatment of raw milk and skim milk resulted in the decrease of alkaline phosphatase activity, whereas protease and lactoperoxidase activities were not affected. Raw milk treated with PEF at 65oC showed more browning reaction than non-treated raw milk. The pH and titratable acidity of milk were not affected by PEF treatment.