Korean Journal of Food Science and Technology (한국식품과학회지)

Korean Society of Food Science and Technology (한국식품과학회)
권호 표지

The Drying Characteristics of Apples at Various Drying Conditions

사과의 건조조건(乾燥條件)에 따른 건조특성(乾燥特性)

  • Jung, Shin-Kyo (Department of Food Science and Technology, Kyungpook National University) ;
  • Choi, Yong-Hee (Department of Food Science and Technology, Kyungpook National University) ;
  • Shon, Tae-Hwa (Department of Food Science and Technology, Kyungpook National University) ;
  • Choi, Jong-Uck (Department of Food Science and Technology, Kyungpook National University)
  • 정신교 (경북대학교 식품가공학과) ;
  • 최용희 (경북대학교 식품가공학과) ;
  • 손태화 (경북대학교 식품가공학과) ;
  • 최종욱 (경북대학교 식품가공학과)
  • Published : 1986.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

This study was performed to examine the drying characteristics of apples at various drying conditions. Air velocity has no effect on the drying rate except the constant rate period. In this experiment the diffusion coefficients of moisture in the apple tissue were in the range of $1.1470-2.2148{\times}10cm^2/sec$. As a result of balance of heat and mass transfer during the falling rate period. an empirical equation based on Fick's law was obtained as follows; $log{\Delta}t\;=\;log\;t_o\;-\;D{\frac{{\pi}^2{\theta}}{4d.}}$ This equation can be used to calculate the temperature of apples during the falling rate period, provided the diffusion coefficients of apple are known. The experimental values of the internal moisture distribution during apple dehydration were nearly in accord with the theoretical values.

홍옥(紅玉)을 시료(試料)로 하여 건조조건(乾燥條件)을 다르게하여 건조특성(乾燥特性), 수분이동현상(水分移動現像), 건조중(乾燥中) 시료온도(試料溫度) 및 내부수분(內部水分)의 분포(分布)를 조사하였다. 사과의 수분확산계수(水分擴散係數)는 $1.1470{\sim}2.2148{\times}10^{-5}cm^2/sec$, 확산활성화(擴散活性化)에너지는 6.6 kcal/g mole 이었으며 Fick's law에서 아래의 식을 유도할 수 있었다. $${\In}\;{\Delta}t=In\;{\Delta}to-{\frac{D{\pi}^2{\theta}}{4d^2}}$$ 건조중(乾燥中) 내부수분분포(內部水分分布)의 이론치(理論値)와 실측치(實測値)는 거의 일치하였다.

Keywords