复配乳化剂HLB值对壳聚糖精油复合膜物理和结构性能的影响

通过复配吐温和司盘获得不同亲水亲油平衡(hydrophile lipophilic balance,HLB)值的复配乳化剂,探究乳化剂HLB值对壳聚糖精油复合膜的物理和结构性能的影响。结果表明,HLB值在9~15之间,单独乳化剂与精油体积比1∶5和1∶10均可获得较小的精油粒径。乳化剂加入壳聚糖精油复合膜中,随着乳化剂HLB值的升高,膜乳液的粒度逐渐减小。与加入精油的对照膜相比,乳化剂的添加可以提高膜的L*值,降低膜的厚度、膨胀度和水溶性,但乳化剂HLB值对膜的抗拉强度和断裂伸长率影响较小。在乳化剂HLB值11~15之间时,可获得较高的DPPH自由基清除率。从扫描电镜结果来看,乳化剂能显著降低复合膜中精油的粒径。综合来看,HLB值为13时,能获得性能较好的复合膜。

Effect of Compound Emulsifier HLB Value on Physical and Structural Properties of Chitosan-Essential Oil Composite Films

The complex emulsifiers with different HLB values were obtained by compounding Tween and Span.The effects of emulsifier HLB on the physical and structural properties of chitosan oil composite film were investigated.The results showed that a smaller particle size was obtained by the proportion of 1∶5 and 1∶10 between the single emulsifier and essential oil when HLB value was from 9 to 15.When the emulsifier was added into the chitosan essential oil composite film solution,the particle size of the film solution gradually decreased with the increase of the HLB value.Moreover,compared with the control film,the L*value of the film increased with the addition of emulsifier,the thickness,swelling and water solubility of film were reduced.But the effect of the emulsifier HLB value on the tensile strength and elongation at break of the film was little.Higher DPPH free radical scavenging rates were obtained with the HLB values from 11 to 15.From the results of scanning electron microscope,the particle size of the essential oil was significantly reduced with the added emulsifier in the composite film.In general,an optimized composite film could be obtained with the HLB value of 13.