机构地区: 华南理工大学轻工与食品学院
出 处: 《华南理工大学学报(自然科学版)》 2011年第9期7-11,共5页
摘 要: 对4种不同直链/支链淀粉含量的玉米淀粉(蜡质玉米淀粉、普通玉米淀粉、Hy-lon V和Hylon VII)的热力学性质及体外消化性进行测定,进一步分析了淀粉热力学性质与消化性的关系.结果表明:高支(蜡质和普通)玉米淀粉与高链玉米淀粉(Hylon V和Hylon VII)的热力学性质存在显著差异;高支玉米淀粉的起糊温度在70℃左右,而高链玉米淀粉(Hylon VII)在煮沸的情况下也难以糊化;4种淀粉的峰值黏度随直链含量升高显著下降;具有适当直链含量的普通玉米淀粉具有较高的膨胀度,普通玉米淀粉、Hylon V和Hylon VII在90℃的膨胀度分别为13.07、5.63和4.54 g/g.差示扫描量热(DSC)分析结果表明:蜡质玉米淀粉只有单一的吸热峰,而普通玉米淀粉和高链玉米淀粉还有直链淀粉与脂质复合物吸热峰,但吸热焓值较蜡质玉米淀粉低;淀粉经蒸煮处理后,糊化温度较低且具有较高膨胀度的普通玉米淀粉的慢消化淀粉含量较高;而糊化温度较高、膨胀度较低的高链玉米淀粉中的抗性淀粉含量较高. Four kinds of corn starches with different amylose/amylopectin contents, namely, waxy corn starch, norreal corn starch, Hylon Ⅴand Hylon Ⅶ, were investigated in the aspects of thermodynamic property and in vitro digestibility, and the relationship between the two properties was further analyzed. It is found that the thermodynamic property difference between the native high-amylopectin (waxy and normal) corn starches and the high-amylose (Hylon Ⅴand Hylon Ⅶ) ones is great, that the pasting temperatures of the high-amylopectin corn starches are about 70℃ while the high-amylose corn starch ( Hylon Ⅶ) is resistant to gelatinization even in the boiling water, that the peak viscosities of four kinds of corn starches varieties significantly decrease with the increase of amylose content, that the normal corn starch with proper amylose content is of high swelling power, and that the swelling powers of normal corn starch, Hylon Ⅴ and Hylon Ⅶ at 90℃are respectively 13.07, 5.63 and 4.54g/g. DSC analysis reveals that the waxy corn starch is of one single endothermic peak, while both the normal corn starch and the high amylose starch are not only of an additional endothermic peak of amylose-lipid complex but also of a lower total enthalpy change, and that, after the treatment with the boiling water, the normal corn starch with lower pasting temperature and higher swelling power is of higher slowly-digestible starch content, while the high-amylose corn starches with higher pasting temperature and lower swelling power are of higher resistant starch content.