Abstract
Various precooling treatments were applied to prolong the freshness of mibaek peaches that were harvested during the summer season. Peaches were cooled from $25.9^{\circ}C$ to $5^{\circ}C$ within 3 hours by a pressure cooler, and the cooling rate was accelerated by increasing the air velocity and static pressure. Respiration and ethylene production rates of mibaek peaches were about four times faster at $20^{\circ}C$ than at $7^{\circ}C$, while precooled peaches had better visual quality at $7^{\circ}C$ than at $20^{\circ}C$. Also, precooled peaches had higher soluble solid and ascorbic acid content than non-precooled peaches when stored at 7 and $20^{\circ}C$. However, weight loss was lower in precooled peaches than in non-precooled peaches during storage.
미백복숭아의 신선도를 연장시키기 위하여 수확후 예냉처리가 행해졌다. 복숭아에 대한 예냉 시험 결과 $25.9^{\circ}C$에서 $5^{\circ}C$까지 3시간 이내에 냉각이 가능하였으며 풍량과 정압을 증가시킬수록 냉각속도는 증가하였다. 복숭아의 호흡속도와 에틸렌발생속도는 $20^{\circ}C$의 경우 $7^{\circ}C$에서의 4배 빠르게 나타났다. 예냉처리한 복숭아는 $7^{\circ}C$와 $20^{\circ}C$에 저장한 경우 무예냉처리구에 비해 당도, 감모율, 비타민 C, 외관등에서 30% 이상 우수한 상품성을 유지하였다.