Changes in Temperature during Storage of Lunch-Box and Effects of the Heat Insulator Use on the Lunch-Box Freshness

도시락 보관중 온도변화와 신선도 유지를 위한 단열재 사용효과

  • Kim, Joong-Man (Dept. of Agri. Chemistry, College of Agriculture, Wonkwang University) ;
  • Chun, Chong-Nam (Dept. of Agri. Chemistry, College of Agriculture, Wonkwang University)
  • 김중만 (원광대학교 농과대학 농화학과) ;
  • 전종남 (원광대학교 농과대학 농화학과)
  • Published : 1987.11.30

Abstract

This study was executed to investigate proper storage conditions for freshness of lunch-box and prevention of lunch-box borne illness. When boiled rice was put into the empty lunch-box without cooling, temperature of the lunch-box was $70^{\circ}C$ to be able to destroy vegetative cell of microoganism in the lunch-box. Temperature of the side-dish canister that is placed on the hot lunch-box was increased from $15^{\circ}C$ to $53^{\circ}C$. The use of the insulator(one to two layer) between the lunch-box and side-dish canister was effective in insulation of the heat that is conducted from the hot lunch-box to the side-dish canister. The insulation layer(asbestos) was also effective to inhibit the decrease of pH value and growth of microoganisms in the toiled rice and side-dish during storage of the lunch-box. The number of microoganisms in the lunch-box covered without cooling was less than in the case of lunch-box covered after cooling; however, the amount of generation in condensed water that is responsible for swelling of boiled rice in the lunch-box occurred much more in the one than in the other, and was a little generated in the case of high temperature storage, insulator use, and when covering the lunch-box after cooling, and pre-evaporation by stirring boiled rice in the cooking pot before filling it. In addition, inserting the heat insulators on and bottom of the lunch-box the boiled rice can be eaten without coldness in winter season.

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