挤压膨化对山药全粉理化性质、加工特性和淀粉体外消化性的影响

Effects of Extrusion on the Physicochemical Properties, Processing Properties and Starch Digestibility in Vitro of Chinese Yam Powder

以山药全粉为原料,分析比较了其挤压膨化前后理化性质、加工特性和淀粉体外消化特性的变化。结果表明,山药全粉经挤压膨化后,总淀粉、总脂肪含量分别从(67.80±0.01)%、(14.5±0.06)%下降到(65.47±0.01)%和(8.23±0.02)%,多酚和多糖含量分别增加了4.20%和38.38%,而可溶性蛋白、还原糖和皂苷含量显著下降;吸水性和溶胀性分别增加了10.44%和51.13%,溶解度提高了4倍,吸油性和析水性分别下降了28.05%和66.28%;挤压膨化后山药全粉亮度降低,颜色发黄;挤压膨化还使得山药全粉中RDS含量显著增加,更易消化。山药挤压粉部分营养成分存在一定程度损失,但仍处于较高水平,多糖、多酚等活性成分含量增加,冻融稳定性、溶解度和淀粉消化性明显提高,食用口感佳,具有较好的应用价值。

Effects of extrusion on the physicochemical properties,processing properties and starch digestibility in vitro of whole yam powder were analyzed in this study.The results showed that after whole yam powder was extruded,the contents of total starch and total fat decreased from (67.80±0.01)% and (14.5±0.06)% to (65.47±0.01)% and (8.23±0.02)% respectively.The contents of polyphenols and polysaccharides increased by 4.20% and 38.38% respectively,while the contents of soluble protein,reducing sugar and saponin decreased significantly.The water absorption and swelling properties were increased by 10.44% and 51.13% respectively,the solubility was increased by 4 times,and the oil absorption and syneresis were decreased by 28.05% and 66.28% respectively.The extrusion reduced the brightness of the whole yam powder and made its color yellow.The extrusion also significantly increased the RDS content in the whole yam powder and made it easier to digest.After extrusion,whole yam powder exhibited different degrees of loss in some nutritional components.However,the content of active components such as polysaccharides and polyphenols in extruded yam powder was increased,the freeze-thaw stability,solubility and in vitro digestibility of the starch were significantly improved,the edible taste was good,and it had good application value.