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In this paper, the effects of three postharvest treatments (aerobic,vacuum,vacuum+1-MCP) on browning, active oxygen metabolism and saccharides during storage of deastringent persimmon were researched. Meanwhile, the correlations between browning and other indexes were analyzed. BI of vacuum and vacuum+1-MCP was lower than that in aerobic group, and the browning degree in vacuum+1-MCP group was the lowest. The SOD and APX activities of the three kinds of persimmon treated after harvest decreased and increased respectively, and the SOD activities of the vacuum group were the lowest，the APX activities under vacuum and vacuum+1-MCP conditions were higher than that in aerobic group. At vacuum and vacuum+1-MCP conditions，the increase of CAT activity of persimmon was inhibited, and the accumulation of H2O2 was reduced, with lower ability to inhibit hydroxyl radical and ascorbic acid content. The reducing sugar content of persimmon in vacuum and vacuum+1-MCP groups was lower than that in aerobic group, and the increase in vacuum+1-MCP group was the slowest, from 14.10% at the beginning of storage to 14.87% on 12 d. The pectin content of persimmon in vacuum+1-MCP group decreased slowly. Correlation analysis showed that the correlations between browning and various indexes under different postharharvest treatments were different. The persimmon BI was always negatively correlated with pectin, meanwhile positively correlated with reducing sugar. It can be concluded that vacuum and vacuum+1-MCP conditions are more conducive to inhibiting the browning of persimmon after deastringent.

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 VC 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.

In this paper, the effects of three kinds of microwave (MVD, 1.5, 2.0, 2.5 min) and hot air (HAD) drying at 60 ℃ on the drying characteristics and quality of jasmine were compared and analyzed. The results showed that in microwave drying stage, the water content of jasmine decreased rapidly, which accelerated the moisture decline in jasmine in hot air drying stage. The water-soluble extract, hydroxyl radical inhibitory ability, total amino acid and essential amino acid content of jasmine flower dried by combined microwave and hot air drying were higher than those of HAD group. The color and peak area of total volatile components, benzyl alcohol and α-fendene and of jasmine flowers in MVD2.0+HAD and MVD2.5+HAD groups were higher than those in HAD, which indicated that the typical fragrance of jasmine dried by MVD1.5+HAD and MVD2.0+HAD could be better retained. The difference of volatile components of jasmine dried by combined microwave and hot air drying could be distinguished by LDA analysis in electronic nose. In conclusion, jasmine dried by MVD2.0+HAD had the best quality.

The effects of heat pump drying, microwave drying and vacuum freeze drying on the color, powder properties, amino acid components and volatile components in mulberry leaf powder were compared and analyzed. The results showed that L* and b*were the highest, while a* was the lowest of mulberry leaf powder dried by vacuum freeze drying. Wettability, water holding capacity and oil holding capacity of mulberry leaf powder dried by microwave drying were the worst, while solubility and bulk density were the strongest. Meanwhile wettability, hygroscopicity, water holding capacity and oil holding capacity of mulberry leaf powder dried by vacuum freeze drying were the highest , and the lowest bulk density. The content of total amino acids, essential amino acids and proportions of essential amino acids in microwave dried mulberry leaf powder were 11.68 mg/g, 3.40 mg/g and 29.11%. The contents and relative contents of sweet amino acids, aromatic amino acids and bitter amino acids in microwave drying were higher than others. Microwave drying and vacuum freeze drying were similar in the volatile components of mulberry leaf powder, with high content of alcohols and aldehydes. In conclusion, vacuum freeze dried mulberry leaf powder had better physical characteristics and volatile aroma components, while microwave drying was more suitable for industrial processing of mulberry leaf powder.