甘薯甜度与薯块蒸煮前后糖分的相关性研究

Study on the Correlation Between Sweetness and Sugar of Sweet Potato Before and After Steaming

测定了357个干率范围在17.26%～42.42%的甘薯育种选种圃群体蒸煮前后的还原糖、可溶性糖及其甜度。研究表明:甜度与熟薯的可溶性糖、还原糖、生薯可溶性糖呈极显著相关,相关系数分别为0.360**、0.277**0、.274**,与生薯还原糖没有明显相关性,其相关系数仅为0.039。对熟薯的可溶性糖进行分解研究表明,蒸煮过程中产生的还原糖和可溶性多糖对甜度的贡献率分别为47.66%、32.07%。按甜度分级的群体平均数分析,甜度同样与熟薯的可溶性糖、还原糖、生薯可溶性糖呈显著相关性,相关系数分别为0.977**、0.974**0、.962**,与生薯还原糖没有明显相关性,其相关系数仅为0.225。对上述糖分指标的群体分布研究表明,生薯还原糖、生薯可溶性糖、熟薯还原糖呈较窄的正态分布,而熟薯可溶性糖呈较宽的正态分布。综合分析得出,熟薯可溶性糖与甜度具有较高的相关性和品种间的差异,更适合作为甘薯甜度评价的指标和食用品种品质育种指标,甘薯的甜度主要来源于蒸煮过程中产生的糖分而非鲜薯糖分。

357 sweet potato breeding selective nursery colony with dry matter content 17.26%~42.42% before and after steaming were used to detect reducing sugar, soluble sugar and sweetness. Study shows high significant corre- lation between sweetness and reducing sugar, soluble sugar of cooked potato and soluble sugar of crude potato, with correlation coefficient 0.360 ＊ ＊ ,0. 277 ＊ ＊ ,0.274＂ ＊ , and it has no obvious correlation between sweetness and reducing sugar with correlation coefficient only 0.059. Decomposition studies of soluble sugar of cooked potato have shown that reducing sugar and soluble sugar produced during steaming provided with the sweetness of the contribution rate re- spectively 47.66% ,32.07%. According to the colony average analysis of sweetness grade, it also shown very signifi- cant correlationbetween sweetness and soluble sugar of cooked potato, and soluble sugar of crude potato with correla- tion coefficient 0. 977 ＊ ＊ ,0.974 ＊ ＊ ,0. 962 ＊ ＊ , and it has no obvious correlation between sweetness and reducing sugar with correlation coefficient only 0. 225. Colony distribution studies of the above sweetness index shown that reducing sugar, soluble sugar of crude potato and reducing sugar of cooked potato appeared a narrow normal distribution, and sol- uble sugar of cooked potato appeared a wide normal distribution. Drawing a comprehensive analysis, there is more signif- icant correlation between soluble sugar of cooked potato and sweetness, more differences among varieties. So, the soluble sugar of cooked potato is more suitable for the index of sweetness evaluating of sweet potato and edible food quality breeding The sweetness of sweet potato is mainly from the sugar produced during steaming instead of fresh potato.