【摘要】 【目的】研究不同干燥工艺对葡萄干颜色及次生代谢物质的影响,为传统干燥工艺的改进提供理论依据。【方法】运用晒干和晾干两种制干方式,测定含水量、色差值、水分活度、总酚含量、总黄酮,分析颜色、酚类、酮类及香气物质。【结果】晒干方式干燥速率显著晾干方式,晾干方式葡萄果实内水分活度变化晒干方式,有利于形成绿色葡萄干;晒干、晾干方式葡萄干中总黄酮、多酚类物质含量先下降后上升的趋势,晾干葡萄干总黄酮、多酚类物质高于晒干葡萄干。制干过程中香气种类含量均呈现先上升后下降的趋势。【结论】采用晾干方式制干,干燥速率、水分活度变化均低于晒干方式,能较好的保存葡萄果实内的香气成分、总黄酮和多酚物质。更多还原

【Abstract】 【Objective】 This project aims to study the effects of different drying methods on color and secondary metabolites of raisin in order to provide a theoretical basis for improving traditional technology of drying processes.【Method】With the white seedless grape as the research material, the samples were collected regularly during the drying process: air drying and sun drying to determine the moisture activity, the color, phenols, ketones and aroma substances for analyzing their differences and variation trends.【Result】The drying rate of sun drying was significantly higher than that of air drying. The change of moisture activity in grape fruit was lower than that in dry grape fruit. The water activity in the grape fruit by air drying was slower than that in the grape fruit by sun drying, which was conducive to the formation of green raisins. The contents of total flavonoids and polyphenols in dried raisins decreased first and then increased after sun drying and air drying. The total flavonoids and polyphenols in air dried raisins were higher than those in sun dried raisins. During the drying process, the types and contents of aromas showed a trend of increasing first and then decreasing. The kinds of free and bonded aroma in dried raisins were higher than those in drying treatments. 【Conclusion】The drying rate and the change of water activity in air dried grapes are lower than those in sun dried ones. The change of green color is the initial stage of drying, and the 4-6 d of drying is a key period for making differences. In addition, the aroma components, total flavonoids and polyphenols in the grape fruit can be well preserved.更多还原