干燥方式和贮藏对甘薯可溶性糖组分组成和变化的影响

目的 探究不同干燥方式和贮藏时期对甘薯可溶性糖分组成及其变化的影响。方法 以食用型甘薯烟薯25号和普薯32号为试验材料，按不同贮藏时期取样，分别进行冷冻干燥和热风干燥处理，采用超声振荡提取-离子色谱-脉冲积分安培法对样品中10种可溶性糖组分进行提取和同时测定。结果 冷冻干燥处理，烟薯25号和普薯32号甘薯中均检出大量的葡萄糖、果糖、蔗糖和少量麦芽糖、鼠李糖、阿拉伯糖、甘露糖、半乳糖，其可溶性糖组分总量分别为151.3 g/kg和112.9 g/kg；热风干燥处理，除以上糖组分外，还检出了棉子糖和水苏糖；两个品种甘薯可溶性糖组分总量分别为203.3 g/kg和151.8 g/kg；除蔗糖外，烟薯25号甘薯各糖组分含量及其总量均显著高于冷冻干燥处理。随贮藏时间延长，两个品种甘薯中可溶性糖组分总量均呈先增加后降低的趋势，其中，烟薯25号在贮藏45 d后达到最高，普薯32号则在贮藏15 d后达到最高；烟薯25号甘薯中葡萄糖、果糖、麦芽糖和可溶性糖组分总量在各贮藏期均显著高于普薯32号，而蔗糖则在整个贮藏期间均低于普薯32号。结论 贮藏过程可使甘薯中可溶性糖含量增加，贮藏15~45 d可溶性糖含量达到最高。冷冻干燥比热风干燥更好的保持了甘薯样品可溶性糖分组成的稳定性。

Effects of drying methods and storage on the composition and changes of soluble sugar components of Ipomoea batatas (L.) Lam.

Objective To investigate the effects of the composition and changes of soluble sugar of Ipomoea batatas (L.) Lam. under different drying methods and storage periods. Methods Taking the Yanshu No.25 and the Pushu No.32 edible Ipomoea batatas (L.) Lam. as experimental materials, samples were taken according to different storage periods and treated by freeze drying and hot air drying, 10 kinds of soluble sugar components were extracted by ultrasonic oscillation and detected through ion chromatography-pulse-integral amperometric detection. Results A large amount of glucose, fructose and sucrose and a small amount of maltose, rhamnose, arabinose, mannose, galactose were detected in Yanshu 25 and Pushu 32 under freeze drying treatment, the total soluble sugar components were 151.3 and 112.9 g/kg, respectively; in hot air drying treatment samples, raffinose and stachyose were also detected in addition to the above 8 soluble sugars, and the total soluble sugar components were 203.3 and 151.8 g/kg, respectively. Except sucrose, the content of every soluble sugar content and total soluble sugar components under hot air drying was significantly higher than those in freeze drying (P<0.05), with the extension of storage period, the content of total soluble sugar components increased first and then decreased. The total soluble sugar components of Yanshu No.25 reached the highest after 45 day storage, while that of Pushu No.32 reached the highest after 15 day storage, the glucose, fructose, maltose and total soluble sugar of Yanshu No.25 were significantly higher than that of Pushu No.32 (P<0.05), while the sucrose was lower than that of Pushu No.32 in the whole storage period. Conclusion The content of soluble sugar in Ipomoea batatas (L.) Lam. increases during storage, and reaches the highest after 15-45 days. Freeze drying is better than hot air drying to maintain the stability of soluble sugar composition of Ipomoea batatas (L.) Lam..