玉米淀粉-大豆分离蛋白/卵白蛋白复合物体外消化率和理化特性的比较

Comparison of in Vitro Digestibility and Physicochemical Properties of Corn Starch-soy Protein Isolate/Ovalbumin Complexes

摘要:

为降低玉米淀粉（Corn Starch, CS）消化速率，增加抗性淀粉（Resistant Starch, RS）含量，该研究通过湿热处理（Heat Moisture Treatment, HMT）将玉米淀粉（CS）与大豆分离蛋白（Soy Protein Isolate, SPI）或卵白蛋白（Ovalbumin, OVA）制成淀粉- 蛋白质复合物，研究了蛋白质质量分数（5%、10%、15%和20%）对淀粉-蛋白质复合物的理化、流变和消化特性的影响。差示扫描量热法和动态黏弹性结果证明，蛋白质的加入限制了淀粉颗粒的溶胀。X-射线衍射数据显示添加SPI/OVA后玉米淀粉结晶度从28.75%分别下降到24.92%和25.29%。扫描电子显微镜表明，添加的蛋白质包裹着淀粉颗粒，作为物理屏障抑制淀粉的消化。体外消化结果表明，添加SPI和OVA使玉米淀粉快速消化淀粉（Rapidly Digestible Starch, RDS）含量分别降低了10.39%和14.9%。总之，添加这两种蛋白质都降低了玉米淀粉的消化率，且OVA对玉米淀粉消化速率的抑制作用大于SPI，该研究为开发含有淀粉- 蛋白质复合物的低血糖食品提供了可能性。

Abstract:

In order to reduce the digestion rate of corn starch (CS) and increase the content of resistant starch (RS), this study used heat moisture treatment (HMT) to prepare starch-protein complexes by combining CS with a soy protein isolate (SPI) or ovalbumin (OVA). The effects of the mass fractions of proteins (5%, 10%, 15%, and 20%) on the physicochemical, rheological, and digestive properties of the starch-protein complexes were studied. Differential scanning calorimetry and dynamic viscoelasticity revealed that the swelling of starch granules was limited by the addition of proteins. X-ray diffraction data showed that the crystallinity of corn starch decreased from 28.75% to 24.92% and 25.29% after the addition of SPI or OVA, respectively. Scanning electron microscopy showed that the added proteins wrapped around the starch granules and acted as a physical barrier inhibiting starch digestion. Moreover, in vitro digestion analysis showed that SPI and OVA additions lowered the rapidly digestible starch (RDS) content of corn starch by 10.39% and 14.9%, respectively. In conclusion, addition of both proteins decreases starch digestibility, and the OVA has a stronger inhibitory effect on the digestibility of starch than SPI. The findings of this study provide insights for developing low glycemic index foods containing starch-protein complexes.