姜黄素/茜素pH敏感蛋白纤维膜的制备及对金枪鱼鲜度的指示作用

Preparation of pH Sensitive Protein Fiber Membranes incorporated Curcumin/Alizarin and Its Indicative Effect on the Freshness of Tuna

采用静电纺丝技术制备载姜黄素(CUR)和茜素(ALI)及其混合色素的pH敏感玉米醇溶蛋白/明胶(ZG)纤维膜。分析各纤维膜的pH敏感度,通过扫描电镜(SEM)、红外光谱(FTIR)、X射线衍射(XRD)、差示扫描量热法(DSC)、水接触角(WCA)比较不同色素对ZG纤维膜形貌、结构、耐热及耐水性能的影响,并评价不同ZG纤维膜对4℃贮藏金枪鱼鱼片新鲜度的指示作用。结果表明,3种纤维膜在pH 6~12时,具有显著的颜色变化,CUR/ZG、ALI/ZG和CUR/ALI/ZG的纤维直径较ZG增大。FTIR和XRD结果表明,CUR和ALI通过分子间相互作用结合于ZG蛋白膜基质中。DSC结果表明,CUR/ZG和CUR/ALI/ZG较ZG膜的耐热性降低,而ALI/ZG较ZG膜耐热性提高。添加色素的ZG膜疏水性降低,然而,仍具有良好的耐水性。其中,CUR/ALI/ZG耐水性更强,在鱼类鲜度指示中更具应用前景。在金枪鱼鱼片贮藏的前5 d,3种纤维膜无明显的颜色变化,之后在第6天和第7天,3种纤维膜发生肉眼可见的颜色变化,指示鱼肉腐败。比色结果与金枪鱼贮藏期间菌落总数和TVB-N变化有良好的相关性。

In this paper, pH-sensitive zein/gelatin(ZG) fiber membranes incorporated with curcumin(CUR) and/or alizarin(ALI) were prepared by electrospinning. The pH sensitivity of each ZG fiber membrane was analyzed. The influences of different pigments on the morphology, structure, heat resistance and water resistance of ZG fiber membrane were compared by scanning electron microscopy(SEM), infrared spectroscopy(FTIR), X-ray diffraction(XRD), differential scanning calorimetry(DSC) and water contact angle(WCA). Furthermore, the freshness indicator effect of different ZG fiber membranes on tuna fillets stored at 4 ℃ was evaluated. The results showed that the three fiber membranes presented significant color change at pH 6-12, and the fiber diameters of CUR/ZG, ALI/ZG, and CUR/ALI/ZG were all larger than that of ZG. FTIR and XRD results showed that CUR and ALI were incorporated in the ZG protein membrane matrix through intermolecular interaction. DSC results showed that the heat resistance of CUR/ZG and CUR/ALI/ZG is lower than that of ZG, while the heat resistance of ALI/ZG is higher than that of ZG. ZG films with pigment possessed lower hydrophobicity, but still had good water resistance. Among them, CUR/ALI/ZG is more resistant to water and has a better application prospect in the indicator of fish freshness. During the first 5 days of storage, the three fiber membranes showed no obvious color changes, and then on the 6and 7days, the membranes showed visible color changes, indicating fish spoilage. The colorimetric results correlated well with the changes of total viable count and TVB-N during tuna storage.