干燥工艺对甘薯淀粉回生率影响

以甘薯淀粉为原材料,以甘薯淀粉回生率为指标,研究常温、太阳晒、真空减压、干燥箱和微波干燥等不同干燥工艺对甘薯回生抗性淀粉生成率影响。结果表明,各干燥最佳工艺参数为:常温下大气温度为16℃～19℃、大气湿度为68%～80%时,老化后甘薯淀粉5 d达至恒重,回生率由3.5%提高到4.5%,提高28.5%;阳光照射下,大气温度为23℃～36℃、大气湿度为42%～74%时,老化后甘薯淀粉5 d达至恒重,回生率由3.5%提高到4.7%,提高34.2%;真空干燥箱温度为120℃、真空度为0.08 MPa时,甘薯淀粉回生率最大,为14.62%,比空白提高3.1倍;干燥箱温度为90℃时,甘薯淀粉回生率最大,为12.24%,比空白提高2.5倍;微波温度为45℃时,甘薯淀粉回生率最大,为7.12%,比空白提高1倍;相比之下,真空干燥有利于甘薯淀粉回生。

The influence of drying process on retrograded rate of sweet potato starch

Taking the sweet potato as raw material and retrogradatoin rate of starch as the index,the effects of different drying processes such as room temperature,sun–shining,vacuum drying,drying oven and microwave drying etc on the formation of sweet potato retrograded resistant starch were studied.The results showed that the optimum conditions of different drying processes were:at room temperature drying,the samples reached constant weight after 5 d drying and the retrogradation rate of sweet potato increased from 3.5% to 4.5%,when the atmospheric temperature and humidity range were 16℃~19℃,68%~80% respectively,which was higher 28.5% than that of control group;for sun–shining drying,the rate increased from 3.5% to 4.7%,when the atmospheric temperature and humidity range were 23℃~36℃,42%~74% respectively,34.2% higher than that of control group;for vacuum drying,the maximum retrogradation rate reached 14.62% when temperature and vacuum degree were 120℃ and 0.08MPa respectively,3.1 times higher than that of control group;for drying oven,the maximum retrogradation rate was 12.24% when drying temperature was 90℃,2.5 times higher than that of control group;for microwave drying,the retrogradation rate reached 7.12% when temperature was 45℃,1 times higher than that of control group.Vacuum drying is conducive to the retrogradation of sweet potato starch.