不同提取方法对甘薯淀粉性质的影响

Effects of extraction on properties of sweet potato starch

以甘薯为原料,采用重力沉降法、酸浆法、碱法和纤维素酶法提取淀粉,并对其性质进行研究,为甘薯淀粉的提取及应用提供依据。采用这4种方法提取淀粉的提取率分别为67.91%、68.76%、77.29%和53.20%;重力沉降法所得淀粉纯度为92%,小于其他3种方法提取的甘薯淀粉(均大于98%);酸、碱和纤维素酶均对淀粉颗粒均有一定的破坏作用。酸浆法提取的甘薯淀粉糊透明度较其他方法高,纤维素酶法提取的甘薯淀粉糊透明度、白度和碘蓝值较其他方法低,碱法得淀粉白度和碘蓝值略高于酸浆法和重力沉降法。纤维素酶法提取过程中直链淀粉减少,而不与碘结合的多糖增加。碱法提取的甘薯淀粉的峰值黏度最小,纤维素酶法提取的甘薯淀粉的糊化温度较其他方法略高,且最不易老化。

Sweet potato starches were isolated from sweet potato with gravitational sedimentation,acidic steeping liquor,alkaline and cellulase methods.Subsequently their properties were studied to provide the theoretical basis for the extraction and application of sweet potato starch.The extraction ratios of these four methods were 67.91%,68.76%,77.29% and 53.20% respectively.Compared to gravitational sedimentation（the purity was 92%）,which was lower than the other methods（all above 98%）.Acidic steeping liquor,alkali and cellulase had some damage effects on sweet potato starch particles.The starch with acidic steeping liquor isolation had higher transparency,and enzymatic digestibility than that with other methods.The starch with cellulase isolation had lower transparency,whiteness,iodine orchid value and enzymatic digestibility.The starch with alkaline isolation had slightly higher whiteness and iodine orchid value than acidic steeping liquor and gravitational sedimentation isolation.During cellulose extracting process,the content of amylose decreased and the content of polysaccharides increased which couldn＇t form complex with iodine.The peak paste of the starch isolated by alkali was the lowest.The pasting temperature of the starch isolated by cellulase was little lower than the other methods,and not easy to retrograde.