Processing Optimization of Low-temperature Vacuum Fried Persimmon Chips and Quality Analysis

In this study, effects of four single factors which including slice thickness, frying temperature, frying time and deoilling time on the quality of persimmon chips under low-temperature vacuum frying were analyzed. According to the Box-Behnken test principle, the processing technology of persimmon chips under low-temperature vacuum frying was further optimized by taking crispness and chromatic aberration ΔE of persimmon chips as response values. Meanwhile, the physicochemical composition, microbiological index and microstructure of the final product were further researched. The results showed that all of frying temperature, frying time, deoiling time and slice thickness affected the crispness and chromatic aberration of persimmon chips, the optimal technology of vacuum frying persimmon chips at low temperature was determined by response surface optimization experiment and then actual correction were as follows: Deoiling time of 5 min, frying time of 50 min, frying temperature of 80 ℃ and thickness 5.5 mm. Under these conditions, the crispness, ΔE, water content, oil content, titrable acid and V_C content of persimmon chips respective was 858.97 g, 17.28, 2.60%, 22.53%, 0.34 g/L and 31.20 mg/100 g. The persimmon chips were golden in color and complete in shape, and the inside of the chips presented a honeycomb-like porous and loose structure, the product had a crisp taste, and the microbial indicators met the health requirements. This research could provide technical support for the development of low-temperature vacuum frying persimmon chips.