蝶豆花提取物-马铃薯氧化羟丙基淀粉/果胶指示标签的制备及应用

Preparation and application of potato oxidized hydroxypropyl starch/pectin-Clitoria ternatea extract indicator label

为实现冷鲜牛肉新鲜度的无损、实时及可视化监测,以马铃薯氧化羟丙基淀粉(potato oxidized hydroxypropyl starch,POHS)和果胶(pectin,P)作为成膜基材,添加蝶豆花提取物(Clitoria ternatea extract,CT)制备智能指示标签(P/POHS/CT),并将该标签应用于冷鲜牛肉的货架期检测。结果表明,CT添加量为1.0%(体积分数)的标签性能最佳,其拉伸强度为16.62 MPa,溶胀度为367.68%,显著高于其他组(P<0.05),含水率为10.42%,水蒸气渗透率为1.32×10^(-7)g/(m·s·Pa),显著低于其他组(P<0.05),扫描电镜结构紧密,红外光谱显示各组分间相容性较好。在贮藏过程中,随着贮藏时间延长,冷鲜牛肉的pH值、挥发性盐基氮含量、硫代巴比妥酸反应物值及菌落总数均显著升高(P<0.05),贮藏第4天时为次级新鲜度,第7天时腐败,智能指示标签的色泽对应的从紫色变为蓝色、绿色。结果表明,适量CT的添加可以改善智能标签的性能,且该标签对冷鲜牛肉新鲜度的变化响应能力强,具有作为预测冷鲜牛肉新鲜度变化的智能包装材料的潜质。

A smart indicator label(P/POHS/CT)was prepared by using pectin(P)and potato oxidized hydroxypropyl starch(POHS)as film-forming substrates and adding Clitoria ternatea extract(CT)to achieve nondestructive,real-time,and visual monitoring of chilled beef freshness and to predict the remaining shelf life.Results showed that the best mechanical and physical properties of the indi-cator label were achieved with 1.0%of CT addition(16.62 MPa of tensile strength and 367.68%of swelling degree),significantly high-er than the other groups(P<0.05).Meanwhile,P/POHS/CT-1.0%indicator label possessed 10.42%of moisture content and 1.32×10^(-7) g/(m·s·Pa)of water vapor permeability,significantly lower than the other groups(P<0.05).Besides,scanning electron micro-scope(SEM)images showed that P/POHS/CT-1.0%structure was tightly structured and attenuated total reflection-Fourier transform in-frared spectroscopy(ATR-FTIR)showed good compatibility between its components.In the storage experiments of chilled beef,the pH,total volatile base nitrogen(TVB-N)content,thiobarbituric acid reactive substances(TBARS)value,and total viable count(TVC)of beef was increased with the increasing storage time,and the color of the indicator label significantly changed.In detail,the freshness val-ues of the beef with labels exhibited different colors for fresh(purple,0-3 d),sub-fresh(blue,4-6 d),and spoiled(green,7 d),respectively.Results showed that the addition of an appropriate amount of CT can improve the performance of the indicator label,which is highly responsive to changes in the freshness of chilled beef,therefore has potential as a smart packaging material.