Drying and Shrinking Rate Equation of Root Vegetables

근채류의 수축 및 건조속도식

  • Cho, Duck-Jae (Department of Food and Nutrition, Kyung Nam Junior College) ;
  • Hur, Jong-Wha (Department of Food Science and Technology, Gyeong Sang National University) ;
  • Lee, Min-Kyu (Department of Chemical Engineering, Cheju National University)
  • 조덕제 (경남전문대학 식품영양과) ;
  • 허종화 (경상대학교 식품공학과) ;
  • 이민규 (제주대학교 화학공학과)
  • Published : 1989.04.01


The shrinking and overall drying rate equations which can accomodate experimental date and the rate of initial drying ratio were investigated. The results obtained from hot air drying experiments of radish and sweet potatoes were as follow. The drying rate constant and the order were affected by the thickness of sample and temperature. The empirical drying rate and shrinking equations at constant drying conditions (d=4mm, $Ta=50^{\circ}C$, RH=10%, U=0.8m/s) for radish and sweet potatoes were found to $dx/dt=0.112{\times}10^{-2}\;A(1-x)^{0.43}$, A=Ao(-0.480x+1) and rates of initial drying ratio were expressed of sample thickness, relative humidity and air velocity; for radish $dx/dt=0.0648(RH)^{-0.31}\;(d)^{-0.75}\;(U)^{0.39}$ and for sweet potatoes $dx/dt=0.0547(RH)^{-0.28}\;(d)^{-0.63}\;(U)^{0.37}$