淀粉型甘薯品种直链淀粉含量、糊化特性和乙醇发酵特性的关系

Relationship among Amylose Content, Starch Pasting and Ethanol Fermenta-tion in Sweetpotato Varieties for Starch Use

以15个淀粉型甘薯品种为试验材料,测定其直链淀粉含量、糊化特性和乙醇发酵特性,并分析它们之间的差异和相互关系。结果表明,不同甘薯品种的干物率、淀粉含量和直链淀粉含量(AC)均存在较大差异,相关分析表明,AC与干物率、淀粉含量之间呈极显著正相关;不同品种甘薯的糊化特性之间存在一定差异,但RVA谱特征值之间关系密切;不同甘薯品种的乙醇发酵特性之间也存在较大差异,乙醇含量与发酵强度之间呈极显著正相关。进一步分析表明,AC与RVA各特征值之间相关性不显著,而干物率、淀粉含量与糊化温度(PT)均呈极显著正相关(相关系数分别为r=0.661,P<0.01;r=0.670,P<0.01);AC与乙醇含量、发酵强度之间有显著正相关关系(相关系数分别为r=0.653,P<0.01;r=0.698,P<0.01),但与发酵效率、发酵黏度的相关性不显著;发酵黏度与崩解值(BDV)呈显著负相关(r=–0.563,P<0.05),与消减值(SBV)显著正相关(r=0.639,P<0.05),而乙醇含量、发酵效率和发酵强度与淀粉RVA各特征值之间的相关性均不显著。聚类分析将15个品种分为3大类,第I类品种AC和BDV均较高,第II类品种的AC最高、BDV最低,而第III类品种AC最低、BDV最高。甘薯的AC和BDV可以作为评价甘薯乙醇发酵特性的指标,同时较高AC和BDV值应是燃料乙醇专用甘薯品种的选育方向。

Fifteen starch-based sweetpotato varieties were used to test amylose contents （AC）, starch pasting properties and ethanol fermentation characteristics, and analyze the difference and relationship among them. The results indicated that there were significant differences among dry matter content, starch content and AC of different sweetpotato varieties, and AC was significantly correlated to dry matter content and starch content. Differences presented among pasting properties in different varieties of sweetpotato, and the relationship among RVA eigenvalues was close. There were significant differences among ethanol fermentation characteristics of different sweetpotato varieties, and ethanol content was significantly correlated to fermen-tative strength. There were no significant correlation between AC and RVA eigenvalues, but pasting temperature （PT） was posi-tively correlated to dry matter content （r=0.661, P〈0.01） and starch content （r=0.670, P〈0.01）. AC was positively correlated to ethanol content （r=0.653, P〈0.01） and fermentative strength （r=0.698, P〈0.01）, but not significantly correlated to fermentation efficiency and fermented mash viscosity. Fermented mash viscosity was negatively correlated to breakdown value （BDV） （r= –0.563, P〈0.05） and positively correlated to setback value （SBV） （r=0.639, P〈0.05）, but ethanol content, fermentation efficiency and fermentative strength were not significantly correlated to RVA eigenvalues. The cluster analysis showed that 15 varieties were divided into three parts： the first part featured higher AC and BDV, the second part had the highest AC and the lowest BDV, and the third part had the lowest AC and the highest BDV. Consequently, AC and BDV could be used as the indexes to evaluate the ethanol fermentation characteristics of sweetpotato, and the sweetpotato with higher AC and BDV was the breeding targets for fuel ethanol.