糯麦淀粉-脂质复合物的结构及体外消化特性

Structure and in Vitro Digestion Properties of Waxy Wheat Starch-Lipid Complexes

探究饱和脂肪酸的碳链长度对糯麦A、B淀粉-脂质复合物结构及体外消化特性的影响。以糯麦A、B淀粉为主要原料,将其经过复合酶改性后,分别与月桂酸、肉豆蔻酸、棕榈酸和硬脂酸进行复合,并对复合物的复合指数(CI值)、溶解度和膨胀力、碘吸收特性、晶体结构、红外光谱和预测血糖指数(pGI值)等指标进行了考察。结果表明,随着碳链的延长(12~18),糯麦A、B淀粉-脂质复合物的CI值分别从53.66%降到了38.15%,60.35%降低为41.04%;糯麦A、B淀粉-脂质复合物的溶解度和膨胀力随着温度的升高和碳原子数的增加逐渐增大,其中糯麦A淀粉-月桂酸在90℃下的溶解度和膨胀力分别为1.99%和3.34 g/g,糯麦B淀粉-月桂酸在90℃下的溶解度和膨胀力分别为1.74%和3.18 g/g;在四种脂质复合物中,糯麦A、B淀粉与月桂酸形成的复合物的相对结晶度较高,分别为25.37%和23.50%,其在1047/1022 cm^(-1)处的比值也较高,分别为0.993和0.989,pGI值与未复合脂质改性的糯麦淀粉相比有了较大幅度的降低,分别为从47.63降低为36.61,从48.30降低为35.49。本研究能够为淀粉-脂质复合物的结构及体外消化特性研究提供参考依据。

To explore the effect of saturated fatty acid carbon chain length on the structure and in vitro digestive properties of waxy wheat A and B starch-lipid complexes.Using waxy wheat A and B starch as the main raw materials,after being modified by compound enzymes,they were compounded with lauric acid,myristic acid,palmitic acid and stearic acid respectively,and the compound index(CI value),the solubility and swelling power,iodine absorption characteristics,crystal structure,fourier transform infrared spectroscopy and predicted glycemic index(pGI value)were investigated.The results showed that with the increasing of carbon chain(12~18),the CI values of starch-lipid complexes of waxy wheat A and B decreased from 53.66%to 38.15%,and from 60.35% to 41.04%.The solubility and swelling power of starch-lipid complexes of waxy wheat A and B increased gradually with the increasing of temperature and the number of carbon atoms.The solubility and swelling power of waxy wheat A starch-lauric acid at 90℃ were 1.99% and 3.34 g/g,the solubility and swelling power of waxy wheat B starch-lauric acid at 90℃ were 1.74% and 3.18 g/g respectively.Among the four lipid complexes,the complexes formed by waxy wheat starch A,B and lauric acid had relatively high crystallinity,reaching 25.37% and 23.50%,and their ratios at 1047/1022 cm^(-1) were also high,which were 0.993 and 0.989.Compared with the uncomplexed lipid-modified waxy wheat starch,the pGI values decreased significantly,from 47.63 to 36.61,and from 48.30 to 35.49 respectively.This study can provide a reference for the structure and in vitro digestion characteristics of starch-lipid complexes.