Optimization of Vacuum Frying Parameters in Combination with Osmotic Dehydration of Kiwi Slices to Produce Healthy Product

Abstract

Osmotic dehydration under discontinuous reduced pressure is one of the newmethods of preparation fruits and vegetable processing with in view of good health. Processing offoods at high temperatures used to cook them can cause the formation of carcinogenic substanceslike acrylamide, and this risk remains even if the trans-fat is removed. The low temperaturesemployed in this method resulted in the products with the desired texture, nutritional, and colour.The purpose of this research was evaluation of the variable effects of osmotic dehydration process(ambient pressure, contact time of product and solution, concentration and temperature of osmoticsolution) on the quality factors of product (colour changes, texture, moisture, oil uptake, and waterloss to solid gain ratio) and achieving the optimum process conditions. Studying the qualityparameters of the product, the temperature range of osmotic solution, pressure, concentration of theosmotic solution and contact time of product and solution were assumed as to C, tombar, to and to min, respectively. The test plans involving tests were obtained byusing response surface statistical models and central composite design. They were fried at thecondition of ºC, min and mbar by using statistical correlations, ºC for the osmoticsolution temperature, mbar for the pressure, min for the time and for theosmotic solution. Concentrations were obtained as optimum conditions of osmotic dehydration ofkiwi slices under reduced pressure. In summary combination of osmotic dehydration and vacuumfrying improved the quality of the final fried kiwi, so this method is recommended for production ofhealthy products.