Studies on the Utilization of Korean Citrus Peel Waste -I. Drying of Citrus Peel by Hot Air-

한국산(韓國産) 감귤과피(柑橘果皮)의 효율적(效率的) 이용(利用)에 관(關)한 연구(硏究) -I. 감귤과피(柑橘果皮)의 열풍건조(熱風乾燥)에 관(關)하여-

  • Chang, Ho-Nam (Dept. of Applied Chemistry and Chemical Engineering, Korea Advanced Institute of Science) ;
  • Hur, Jong-Wha (Dept. of Food Engineering Jeju National University)
  • 장호남 (한국과학원 화학 및 화학공학과) ;
  • 허종화 (제주대학 식품공학과)
  • Published : 1977.12.28


Experiment were conducted to find out the effective drying method of citrus peel produced in Korea by varying the temperature of hot air, surface area of peels, peels from several citrus varieties and physicochemical treatment of the peel. 1. About $3{\sim}6\;days$ were required to reduce the moisture level of the peel from 70%(wet basis) to 20% at room temperature without forced convection. 2. Drying was speeded up until the temperature of hot air reached $60^{\circ}C$. Beyond that no significant increase in drying rate was observed. About 50 minutes were needed to reduce the moisture level (dry basis) to below 10% at $60^{\circ}C$ by forced convection 3. When the peel surface area was increased twice by cutting the peel into 256 fractions, the overall drying time (the time required to reduce the moisture level to 10%, dry basis) was shortened to 15 minutes from 50 mintes of the original peel. 4. No significant difference in drying rate was observed among the peels from several citrus varieties except Shaddock jabon and Citrus ponki tanaka, which dried more slowly than others. 5. Treatment of $Ca(OH)_2$ and the pressing of the peel before drying were effective in drying only when the initial moisture content was substantially higher.