桑葚花青素共混羧甲基纤维素膜的性能研究及应用

Research into the Properties and Applications of Mulberry Anthocyanins Blended with Carboxymethyl Cellulose Film

以羧甲基纤维素为成膜基材,桑葚花青素为指示剂制备包装指示膜,研究不同质量分数的桑葚花青素对膜性能的影响。结果表明,添加桑葚花青素后,膜的拉伸强度、阻湿性、阻光性均有所提高,但断裂伸长率略有下降。桑葚花青素降低了膜的水蒸气透过率,质量分数为0.3%时膜的水蒸气透过系数达到最低值[1.39×10^(-10)g(/cm·s·Pa)];另一方面花青素可增强膜对光的阻隔作用,0.4%的花青素含量可完全阻挡紫外光。扫描电镜结果表明桑葚花青素与羧甲基纤维素有着良好的相容性,截面光滑平整。傅里叶红外光谱显示二者之间形成了较强的分子间作用力。此外,桑葚花青素增强了膜的抗氧化性,当桑葚花青素含量为0.5%时,DPPH自由基清除率达到最大值(96.75±0.35)%,较羧甲基纤维素膜(14.96±0.08)%明显增加。将指示膜应用于鱼肉新鲜度的检测,随着储藏时间的延长,鱼肉变质,pH值以及硫代巴比妥酸反应物(thiobarbituric acid reactive substance,TBARS)值逐渐上升,此时指示膜颜色随之改变。

Carboxymethyl cellulose was used as a substrate,and mulberry anthocyanin was used as an indicator to prepare indicator packaging film.The effects of different concentrations of mulberry anthocyanins on film properties were explored.Blended films exhibited increased tensile strength,moisture resistance,and light transmittance,but displayed a slight decrease in elongation to breaking point.Blended films displayed lower wa-ter vapor permeability.Films with a mulberry anthocyanin concentration of 0.3%had the lowest water vapor per-meability[1.39×10^(-10)g(/cm·s·Pa)].Incorporation of mulberry anthocyanins significantly improved the films'impermeability to ultraviolet light,completely blocking transmission with an anthocyanin concentration of 0.4%.Scanning electron microscopy indicated that mulberry anthocyanins displayed good compatibility with car-boxymethyl cellulose,yielding smooth,flat cross sections.Fourier transform infrared spectroscopy revealed a strong intermolecular force between them.In addition,mulberry anthocyanins enhanced the films'antioxidant properties.At 0.5%anthocyanin,the DPPH free radical scavenging rate reached its maximum value(96.75±0.35)%,significantly increased relative to pure carboxymethyl cellulose films(14.96±0.08)%.This indicator film was applied to monitor fish freshness during extended storage time.As the fish began to deteriorate,pH and TBARS values gradually increased,and the color of the indicator film changed accordingly.