Economize and optimization of the drying process of irradiate pretreatment on kiwi slices by the response surface method in combination with the principal components analysis

Drying is one of the long-term food preservation methods that keeps the properties of the material. In this study, kiwifruit irradiated with different doses of 0, 2 and 4 kGy and were cuted offas slices  at 3, 5 and 7 mm and then dried using oven dryer at 55, 65 and 75 ˚C. During the experiment, the weight of kiwi slice and drying time were recorded and using the response surface method was carried out the effect of the main and the interaction effects of drying temperature, irradiation and sample thickness on drying time and fruit weight. The surface response method predicted the drying time and weight of kiwi fruit with accuracy of 99 and 96%, respectively.  Finally, the response surface method suggested the best and most optimal points as 298 min for drying time and the optimal 4.2 g fruit weight. The proposed optimum points were also obtained at dose of 4 kGy, a drying temperature of 55 ° C and a fruit thickness of 6 mm. Also, PCA samples from various kiwifruit were determined by the method of pattern recognition, based on different drying temperatures and sample thicknesses at 100% accuracy.