Drying 2004 – Proceedings of the 14th International Drying Symposium (IDS 2004) São Paulo, Brazil, 22-25 August 2004, vol. C, pp. 2127-2132 2127 FORMULATION AND QUALITY IMPROVEMENT OF DRIED KIWIFRUIT SLICES USING AN OSMOTIC PRE-TREATMENT Behzad Allaeddini and Zahra Emam-Djomeh Transfer Properties Lab (TPL), Department of food science and engineering, Agricultural engineering faculty, University of Tehran, Iran emamj@ut.ac.ir Keywords: osmotic dehydration, quality improvement, kiwifruit, taste, texture ABSTRACT Osmotic dehydration can be used a single process or in combination with other processes such as different methods of drying, freezing, frying and so on. In this study osmo-dehydration is used as a pretreatment for producing dehydrated kiwifruit (cultivar: Hayward or Abbot) slices. Therefore, the effects of operational variables: solution concentration (30%, 40% and 50%), bufferic agent and temperature (20, 40 and 60ºC) on dehydration efficiency were studied. Both osmosed and control samples were dried by hot air drying. Then, dried products were analyzed in order to measure their textural and organoleptic properties. Our results show that using osmotic solution can improve both textural and organoleptic properties of dried product. And the best product was obtained in following operational condition: C sucrose = 40%, C buffer = 6%, T= 40ºC and t= 120 minutes. Also we can observe that there is a significant difference between two cultivars. INTRODUCTION Osmotic dehydration is considered as a preservation method that makes the obtaining of high quality product possible by means of water removal without phase change. This process consists of immersing foodstuff such as a piece of fruit or vegetable in a hypertonic solution (saccharides, sodium chloride, sorbitol, glycerol and etc.) (Lenart, 1996). During osmotic pre-concentration, two major concurrent flows take place simultaneously under the water and solute activity gradients across the semi-permeable