不同预干燥方式对真空油炸香芋脆条品质及其微观结构的影响

Effects of different pre-drying methods on the quality and microstructure of vacuum fried taro crisp strips

探究真空微波(VMD)、热风(HAD)、热泵(HPD)、远红外辐射干燥(FIRD)4种不同预干燥方式对真空油炸香芋脆条品质的影响,同时对预干燥后香芋条的淀粉结构及真空油炸香芋脆条的微观结构进行分析。结果表明:经HAD预干燥处理的真空油炸香芋脆条的含油率最低,L^(*)值最高,硬度适中,酥脆适口。X衍射结果显示,HAD预干燥处理的香芋条的相对结晶度最高;差示扫描量热法结果显示,HAD、HPD、FIRD预干燥处理的香芋条的糊化程度低;傅里叶变换红外光谱结果显示,4种预干燥处理没有破坏香芋淀粉分子的化学键,也没有产生新的化学基团;扫描电子显微镜结果显示,HAD样品组织结构最紧密,蜂窝状结构最少。总体表明HAD预干燥处理的真空油炸香芋脆条的品质最佳。

The effects of four different drying methods,namely vacuum microwave drying(VMD),hot air drying(HAD),heat pump drying(HPD),and far infrared radiation drying(FIRD),on the quality of vacuum fried taro crisp strips were studied,and the starch structure of taro strips and the microstruc-ture of vacuum fried taro crisp strips were analyzed.The results showed that the vacuum fried taro strips treated with HAD pre-drying had the lowest oil content,the highest L^(*)value,moderate hardness,and crispy and palatable texture.The X-ray diffraction results showed that the relative crystallinity of taro strips treated with HAD pre-drying was the highest.The results of differential scanning calorimetry showed that the gelatinization degree of taro strips pre-drying with HAD,HPD,and FIRD was low.The Fourier transform infrared spectroscopy results showed that the four pre-drying treatments neither break the chemical bonds of taro starch molecules,nor produce new chemical groups.The scanningelectron mi-croscope results showed that the HAD sample had the most compact organizational structure and the least honeycomb like structure.Overall,the quality of vacuum fried taro strips treated with HAD pre drying was the best.