龙眼间歇热泵干燥特性及干燥过程品质变化  

Study on Drying Characteristics and Quality Properties of Longan(Dimocarpus longan Lour.)during Intermittent Heat Pump Drying

作　　者：张晓敏 徐玉娟[1] 余元善[1] 李璐 邹波[1] 肖更生[1,3] 卜智斌 吴继军[1] 彭健[1] ZHANG Xiaomin;XU Yujuan;YU Yuanshan;LI Lu;ZOU Bo;XIAO Gengsheng;BU Zhibin;WU Jijun;PENG Jian(Sericultural&Agri-Food Research Institute,Guangdong Academy of Agricultural Sciences,Key Laboratory of Functional Foods,Ministry of Agriculture and Rural Affairs,Guangdong Key Laboratory of Agri-Food Processing,Guangzhou 510610,China;School of Public Health,Guangdong Pharmaceutical University,Guangzhou 510006,China;Zhongkai University of Agriculture and Engineering,Guangzhou 510225,China)

机构地区：[1]广东省农业科学院蚕业与农产品加工研究所,农业农村部功能食品重点实验室,广东省农产品加工重点实验室,广东广州510610 [2]广东药科大学公共卫生学院,广东广州510006 [3]仲恺农业工程学院,广东广州510225

出　　处：《食品工业科技》2024年第23期208-216,共9页Science and Technology of Food Industry

基　　金：“十四五”广东省农业科技创新十大主攻方向“揭榜挂帅”项目(2023SDZG04);广东省农业科学院学科团队建设项目(202109TD);科技创新战略专项资金(高水平农科院建设)项目(青年副研究员:R2022PY-QF004)。

摘　　要：为充分解析龙眼在实际干制生产过程中不同干燥阶段水分状态和品质变化,明确龙眼间歇干燥过程关键阶段,本文探讨了龙眼间歇热泵干燥和回软阶段水分分布状态及迁移规律、色泽、5-HMF、主要活性功能物质含量及抗氧化能力的变化规律。结果表明,龙眼水分在干燥阶段快速下降,在回软阶段缓慢下降,经干燥阶段2后龙眼果肉中自由水消失,转变成不易流动水;随着干燥的进行,果肉色泽、褐变度及5-HMF呈阶梯式上升,色泽在干燥阶段3变化最为显著,5-HMF含量在干燥阶段1显著增加到55.40μg/g DW;而总酚、总黄酮、总游离氨基酸则呈阶梯式下降,其在干燥阶段3后显著减少至鲜样的35.23%、41.05%和42.13%,且总游离氨基酸降解主要发生在干燥阶段1和3;抗氧化分析表明,龙眼干燥过程抗氧化能力的下降最主要发生在干燥阶段2,与总酚含量的变化一致。综合分析,龙眼间歇热泵干燥阶段1和干燥阶段3是影响龙眼干燥过程品质变化的关键阶段。In order to understand the change of water state and quality characteristics of longan during practical drying production and discover the pivotal drying stages,the dynamic changes of moisture content and state,color,5-HMF,main nutritional and functional qualities,and antioxidant capacity were monitored through whole intermittent heat pump drying and equilibrium stages.The results showed that the moisture content of longan decreased rapidly during drying stages,and decreased slowly during the equilibrium stages.After through drying stage 2,the free water of longan was removed and transferred coupled with the immobilized water increased.With the drying and equilibrium progress going,the color,browning degree and 5-HMF of longan increased in a step manner,color changes were most significantly occurred in drying stage 3,and the content of 5-HMF was dramatically increased to 55.40μg/g DW after drying stage 1.On the contrary,the total phenols,total flavonoids,total free amino acids were decreased in a step manner,and decreased to 35.23%,41.05%,and 42.13%after drying stage 3,respectively,when compared with fresh sample.Moreover,the degradation of total free amino acids was mainly decreased in drying stage 1 and 3.According to antioxidant analysis,the antioxidant capacity of longan was mainly decreased in drying stage 2,which was in conformity with the change of total phenols.Overall,drying stage 1 and 3 were the key stages during the intermittent heat pump drying process,which affected quality characteristics of longan mostly.

关 键 词：龙眼 间歇热泵干燥 水分状态 游离氨基酸 抗氧化性 

分 类 号：TS201.1[轻工技术与工程—食品科学]