紫甘蓝花青素/大豆分离蛋白复合膜的制备与性能研究

Preparation and Characterization of Purple Cabbage Anthocyanins/Soy Protein Isolate Composite Film

为研究不同紫甘蓝花青素添加量〔0%、5%、10%、15%、20%,(w/w)〕对大豆分离蛋白复合膜性能的影响,以大豆分离蛋白(SPI)、紫甘蓝花青素(PCA)为原料制备复合膜并对其形貌、结构、热性能和pH色敏性进行表征分析。结果显示:15%PCA添加量的复合膜拉伸强度为2.14 MPa、断裂伸长率为129.37%。随着PCA添加量的增加,PCA/SPI复合膜不透明度呈上升趋势;扫描电镜、傅里叶红外光谱、X-射线衍射和差示量热扫描仪分析表明,花青素与大豆分离蛋白之间形成较为致密的结构,分子间作用力加强,当PCA添加量为15%时,复合膜中的PCA与SPI相容性最好,此时复合膜熔融温度为138.47℃;花青素和复合膜pH响应性分析表明,PCA和复合膜对不同酸碱度下颜色变化趋势一致,复合膜中PCA含量15%对酸碱变化最敏锐。

In order to study the effect of different addition amounts(0%,5%,10%,15%,20%,w/w)of purple cabbage anthocyanins(PCA)on the properties soy protein isolate(SPI)composite film,the composite film were prepared by SPI and PCA,and their morphology,structure,thermal properties and pH color sensitivity were characterized and analyzed.The results showed that the tensile strength of the composite film with the addition of 15% PCA was 2.14 MPa,and the elongation at break was 129.37%.With the increase of PCA content,the opacity of PCA/SPI composite film increased.Scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction and differential scanning calorimetry analysis showed that a relatively dense structure was formed between anthocyanin and soy protein isolate,which enhanced the intermolecular force.When the addition amount was 15%,the compatibility between PCA and SPI was the best,and the melting temperature of the composite film was 138.47℃.The pH response analysis of PCA and composite film showed that their color change trends were consistent.Meanwhile,the composite film with the addition of 15%PCA was the most sensitive to the acid-base change.