양상치의 유통구조 개선 및 선도연장을 위해 생산지에서 직접 수확한 후 전처리하여 진공예냉시킨 다음 저온유통시험을 수행하였다. 양상치는 기존 상온 수송에 비하여 예냉처리후 냉장수송하였을 때 소비자에 도착시 관능적으로 신선도에 있어서 유의차를 인지할 수 있었으며, 각 방법에 의하여 수송해온 양상치를 $0{sim}15^{circ}C$에 저장하였을 때 저장 설정 온도에 도달하는데는 $10{sim}17$시간이 소요되었다. 양상치는 진공예냉장치에 의하여 27분만에 $1^{circ}C$까지 냉각이 가능하였으며, 예냉처리 및 냉장수송한 후 $0^{circ}C$에 저온저장하였을 때 감모율은 최고 5% 이하로 30일간 저장이 가능하였고, 아스코르브산은 86%, 클로로필은 52% 이상 유지되었다. 관능적 특성에 의하여 평가하였을 때 예냉 및 냉장수송을 한 양상치는 $15^{circ}C$에서는 5일, $0^{circ}C$에서는 40일 이상 저장이 가능하였으며 예냉처리하지 않고 상온수송을 하여 저장한 경우는 $15^{circ}C$에서 3일, $0^{circ}C$에서는 20일 정도 밖에 저장이 되지 않았다.
The improvement of distribution system and freshness prolongation of crisphead lettuce were carried out through vacuum cooling and distribution under the low temperature. Lettuce that vacuum-cooled and transported by cold storage car was shown better freshness than that distributed by conventional method when they arrived at cunsuming area. And it took $10{sim}17$ hours until their temperatures arrived at same temperatures when they were stored at $0{sim}15^{circ}C$ cold storage room. It was cooled to $1^{circ}C$ after 27 minutes with vacuum cooling apparatus. The weight loss of lettuce that vacuum cooled and transported by cold storage car was below 5% after 30 days cold storage. And ascorbic acid and chlorophyll retentions were 86% and 52%, respectively. The shelf-life of crisphead lettuce, distributed by vacuum cooling and cold storage car transportation, was 5 days at $15^{circ}C$ and over 40 days at $0^{circ}C$, respectively. However, when it was distributed by conventional method, it was only 3 days at $15^{circ}C$ and 20 days at $0^{circ}C$, respectively.
