木质素纳米颗粒/茶多酚/海藻酸钠复合膜性能及其在辣椒保鲜中的应用

Lignin Nanoparticle/Tea Polyphenol/Sodium Alginate Composite Membrane Properties and Applications in Pepper Preservation

摘要:

采用共混法将自组装制备而成的木质素纳米颗粒（Lignin Nanoparticles, LNPs）以及茶多酚（Tea Polyphenol, TP）掺入海藻酸钠（Sodium Alginate, SA）多糖膜液，采用流延法制备SA/TP/LNPs复合膜。研究了LNPs添加量对SA/TP/LNPs复合膜性能影响及复合膜在辣椒保鲜中的应用。实验显示制备的LNPs粒径最小约为98.33 nm。SA薄膜可作为LNPs和TP的优良载体。随着LNPs添加量的提高，复合膜颜色逐渐加深，透光率逐渐降低。与SA薄膜相比，SA/TP/LNPs-5复合薄膜（LNPs质量分数为5%）整体性能较好，其拉伸强度提高了114.67%，断裂伸长率降低了47.81%，水蒸气透过率降低了72.04%。SA/TP/LNPs-5复合薄膜对大肠杆菌和金黄色葡萄球菌的抑菌率分别为91.28%、89.20%、DPPH自由基清除率为88.75%，ABTS自由基清除率为87.21%。保鲜实验显示，与CK组和PE薄膜组相比，SA/TP/LNPs-5复合膜能有效降低辣椒的失重率，延缓辣椒Vc含量的消耗，贮藏第10天时，其失重率分别降低了49.93%、39.12%，（P<0.05），贮藏10 d后，SA/TP/LNPs-5复合膜组辣椒Vc（维生素C）含量最高为54.17 mg/100 g。综上，该实验制备出一种具有抗菌和抗氧化的环境友好型复合膜，为木质素的应用提供了新思路，同时该复合膜在食品保鲜领域具有良好的应用前景。

Abstract:

Lignin nanoparticles (LNPs) and tea polyphenol (TP) were prepared through self-assembly and infused with a sodium alginate (SA) polysaccharide membrane solution using a blending technique. SA/TP/LNPs composite films were prepared using a casting method. The effects of the LNPs content on the properties of the SA/TP/LNPs composite film and its application in pepper preservation were studied. The prepared LNPs were approximately 98.33 nm thick. The SA film is an excellent carrier for LNPs and TP. With increasing levels of the LNPs, the color of the film gradually deepened, and the light transmittance gradually decreased. The overall performance of the SA/TP/LNPS-5 composite film (LNP mass fraction of 5%) was improved compared with that of the SA film, as the tensile strength increased by 114.67% and the elongation at break and water vapor transmission rate were reduced by 47.81% and 72.04%, respectively. The composite film exhibited inhibition rates of 91.28% against Escherichia coli and 89.20% Staphylococcus aureus. The free radical scavenging rates of DPPH and ABTS were 88.75% and 87.21%, respectively. A preservation experiment demonstrated that the SA/TP/LNPs-5 composite film effectively reduced the weight loss rate of pepper and delayed the consumption of Vc content in pepper compared to the CK and PE film groups. On the 10th day of storage, the weight loss rates were reduced by 49.93% and 39.12%, respectively (P<0.05). The highest Vc content in the SA/TP/LNPs-5 composite membrane group was 54.17 mg/100 g. In summary, this study introduced an environmentally friendly composite film with antibacterial and antioxidant properties, providing novel insights for the application of lignin. The composite film has promising application prospects in food preservation.