超声辅助去糖处理对热风干燥及压差闪蒸干燥红枣脆片品质的影响

Effects of ultrasound-assisted desugaring on quality of red jujube crisps dried with hot air drying and instant controlled pressure drop

为探究不同去糖预处理方法对热风干燥及压差闪蒸干燥红枣脆片品质的影响,利用超声(US)、超声辅助酶法(US+EM)、超声辅助碱法(US+AM)、超声辅助热水法(US+WM)4种不同预处理方法处理红枣脆片,分析干燥后红枣脆片的色泽、质构、滋味和主要营养成分含量。结果显示,不同超声辅助去糖预处理方法对热风干燥及压差闪蒸干燥红枣脆片品质均有较大的影响,对比不同去糖预处理组,超声(US)和超声辅助酶法(US+EM)处理下红枣鲜样固形物减少率分别为2.53%和3.36%,显著低于超声辅助碱法(US+AM)和超声辅助热水法(US+WM)处理;超声辅助热水法(US+WM)处理下热风干燥及压差闪蒸干燥红枣脆片多糖含量最低,去除多糖效果最佳,其次是超声辅助酶法(US+EM)处理;超声辅助酶法(US+EM)去糖处理下压差闪蒸干燥红枣脆片黄酮保留量最高,VC损失量最小。电子舌结果显示超声辅助酶法处理下压差闪蒸干燥红枣脆片口感最佳。结果表明,超声辅助酶法处理在减少糖分的同时最大程度地保留了红枣脆片的风味和营养成分。

Four different pre-treatment methods including ultrasound(US),ultrasound assisted enzy⁃matic method(US+EM),ultrasound assisted alkaline method(US+AM),and ultrasound assisted hotwater method(US+WM)were used to study the effects of different desugaring pretreatment on the quali⁃ty of red jujube crisps dried with hot air drying and instant controlled pressure drop.The color,texture,taste,and the content of main nutrients in the dried red jujube crisps were analyzed.The results showed that different ultrasound assisted desugaring pretreatment had a significant impact on the quality of red jujube crisps dried with hot air drying and instant controlled pressure drop.Compared with different desugaring pre⁃treatment,the solid reduction rate of fresh jujube samples treated with US and US+EM was 2.53%and 3.36%,significantly lower than that with US+AM and US+WM.The content of polysaccharide in US+WM was the lowest with the best effect of desugaring,followed by US+EM treatment with hot air drying and instant controlled pressure drop of red jujube crisps.The US+EM with instant controlled pressure drop of red jujube crisps resulted in a high retention rate of flavonoid and the smallest loss of VC content.The re⁃sults of electronic tongue showed that the taste of red jujube crisps pretreated with US+EM and dried with instant controlled pressure drop was best.It is indicated that ultrasound assisted enzymatic(US+EM)treat⁃ment reduces the content of sugar while retain the flavor and nutrients of red jujube crisps to the greatest ex⁃tent.