Optimization for the Process of Osmotic Dehydration for the Manufacturing of Dried Kiwifruit

건조키위 제조를 위한 삼투건조공정의 최적화

  • Hong, Joo-Hun (Department of Food Science and Technology, Kyungpook National University) ;
  • Youn, Kwang-Seob (Department of Food Science and Technology, Catholic University of Taegu-Hyosung) ;
  • Choi, Yong-Hee (Department of Food Science and Technology, Kyungpook National University)
  • 홍주헌 (경북대학교 식품공학과) ;
  • 윤광섭 (대구효성가톨릭대학교 식품공학과) ;
  • 최용희 (경북대학교 식품공학과)
  • Published : 1998.04.01

Abstract

The developments of various processed foods and the high quality dried fruits, in particular, are urgently needed for the enhancement of fruit consumption and their competitive values. Therefore, in this study, three variables by three level factorial design and response surface methodology were used to determine optimum conditions for osmotic dehydration of kiwifruit. The relationships of moisture losses, solid gains, weight reductions, sugar contents, titratable acidities and vitamin C contents depending on changes with temperature, sugar concentration and immersion time were investigated. The moisture loss, solid gain, weight reduction and reduction of moisture content after osmotic dehydration were increased as temperature, sugar concentration and immersion time increased. The effect of concentration was more significant than those of temperature and time on mass transfer. Sugar content was increased by increasing sugar concentration, temperature, immersion time during osmotic dehydration. Titratable acidity and vitamin C content were increased by decreasing temperature, immersion time and increasing concentration during osmotic dehydration. The regression models showed a significant lack of fit (P>0.05) and were highly significant with satisfying values of $R^2$. At the given conditions such as $66{\sim}69%$ moisture content, above $24^{\circ}Brix$ sugar content and more than 23 mg% vitamin C, the optimum condition for osmotic dehydration was $37^{\circ}C,\;55^{\circ}Brix$ and 1.5 hour.

Keywords

kiwifruit;osmotic dehydration;RSM