食用油脂与加热方式对小麦淀粉结构和体外消化性的影响

Effects of Edible Oil and Heating Methods on Structure and in Vitro Digestibility of Wheat Starch

研究了常用食用油脂和加热方式对小麦淀粉结构和体外消化性的影响.首先将黄油、棕榈油、大豆油等食用油与小麦淀粉按1∶5的比例(质量比)共混,然后对其分别进行恒定高温和持续升温两种热处理,制备淀粉-脂质复合物,并测定了复合物的脂质含量、颗粒形貌、结晶结构、热力学性质及体外消化性.结果表明:淀粉与脂质复合后,结合脂质含量显著增加,其结晶结构由A型转变为A+V型,其中棕榈油更易与小麦淀粉形成稳定的复合物;与恒定高温相比,持续升温热处理形成的复合物更稳定,且复合物的慢消化淀粉(SDS)及抗性淀粉(RS)含量均显著增加;恒定高温热处理后,小麦淀粉-大豆油复合物的SDS含量最高,为15.8%;持续升温热处理后,小麦淀粉-棕榈油复合物的SDS含量最高,达16.4%.

This paper deals with the effects of common edible oils and heating methods on structure and in vitro digestibility of wheat starch.First,butter,palm oil and soybean oil were blended with wheat starch at a mass ratio of 1∶5,and then were treated with constant high-temperature heating and consecutive heating-up to prepare starch-lipid complexes.Finally,the lipids content,particle morphology,crystalline structures,thermal properties and in vitro digestibility of the complexes were determined.The results show that(1) the complexed-lipids content of wheat starch increases significantly,and the crystalline structure of wheat starch changes from A type to A+V type after the complexation with lipids;(2) palm oil is easier to form stable complex with wheat starch than butter and soybean oil;(3) as compared with constant high-temperature heating,consecutive heating-up helps to form more stable complex with significantly increased slow digestible starch(SDS) and resistant starch(RS) contents;and(4) after constant high-temperature heating,the starch-soybean oil complex is of the highest SDS content(15.8%),while after consecutive heating-up,the starch-palm oil complex is of the highest SDS content(16.4%).