韧化处理对甘薯淀粉糊化特性的影响

Effects of Annealing on the Gelatinization Properties of Sweet Potato Starch

本文采用差示扫描量热分析、快速粘度分析等现代仪器分析方法研究了不同韧化时间、韧化温度和含水量等韧化处理方法对甘薯淀粉糊化特性的影响。结果表明,不同韧化温度处理后,甘薯淀粉的起始糊化温度、峰值糊化温度和终止糊化温度均呈升高趋势,其中起始糊化温度升高趋势明显,由甘薯淀粉的62.47℃升高到70.37℃,糊化温度范围变窄,糊化热焓值增加;其峰值黏度呈下降趋势,55℃时为1342 cp比甘薯淀粉下降了321 cp,破损值降低、回生值升高。不同韧化时间处理后,甘薯淀粉To升高,糊化温度范围变窄,由甘薯淀粉的21.35℃减少到60 h的15.09℃,回生值上升了29.89%。不同水分含量韧化处理后,85%时糊化热焓值提高了36.20%,峰值黏度比甘薯淀粉下降了378 cp。甘薯淀粉经韧化处理后糊化温度、热焓值升高,黏度下降,回生值增加。

Effects of different annealing times,annealing temperatures,moisture content,and other annealing methods on the gelatinization properties of sweet potato starch were investigated using modern analytical instruments,including a differential scanning calorimeter（DSC） and a rapid viscosity analyzer（RAV）.The results showed that the onset temperature,peak temperature,and conclusion temperature of the sweet potato starch increased after annealing treatment at different temperatures.Among them,the onset temperature（To） exhibited an apparent upward trend and increased from 62.47 ℃ to 70.37 ℃,the gelatinization temperature range was narrowed,and the gelatinization enthalpy increased.The peak viscosity showed a downward trend and decreased by 321 cp to 1342 cp at 55 ℃,the breakdown value was decreased,and the setback value was increased.After treatment for different annealing times,the To of sweet potato starch increased,the gelatinization temperature range was narrowed from 21.35 ℃（native sweet potato starch） to 15.09 ℃（sample after 60 h treatment）,and the setback value was increased by 29.89%.The annealing treatments were performed at different moisture content;when the moisture content was 85%,the gelatinization enthalpy increased by 36.20% and the peak viscosity decreased by 378 cp,compared with the native sweet potato starch.Annealing treatment increased the gelatinization temperatures and enthalpy of sweet potato starch,decreased the viscosity,and increased the setback value.