Ag/TiO_(2)/Ag_(3)PO_(4)-LNCF/淀粉复合膜的制备与保鲜性能研究

Preparation and preservation performance of Ag/TiO_(2)/Ag_(3)PO_(4)-LNCF/starch composite film

为改善果蔬保鲜中的微生物侵染和乙烯催熟问题,采用原位沉淀和辐照法合成Ag/TiO_(2)/Ag_(3)PO_(4)(ATAP)三元异质结光催化剂,利用流延法制备ATAP-木质纳米纤维素(LCNF)/淀粉复合膜。探究ATAP负载条件、光催化剂类型对乙烯的吸附、分解性能,以及抑菌效果的影响。利用SEM观察复合薄膜的微观形貌,评估不同光催化薄膜对南瓜的保鲜效果。结果表明,适宜的ATAP掺杂量能使光催化剂均匀分散在淀粉膜基质中,从而提升其光催化性能;当ATAP外掺杂量为3%、内掺杂量为2%时,复合膜具有最佳的乙烯分解性能和抑菌效果,其分解率为7.73%,抑菌圈直径为11.46 mm。复合膜具有较好的南瓜保鲜作用,保鲜7 d后的南瓜表面与内部的霉菌覆盖面积显著降低,失重率减小至28.27%;复合膜对金黄色葡萄球菌和霉菌均具有显著的抑制效果,其菌落总数、金黄色葡萄球菌数和霉菌数分别为5.55×10~4,4.95×10~4,3.00×10~4 CFU/g,均优于其他材料及对照组。研究为果蔬保鲜新材料的开发提供理论参考。

In order to improve the microbial infestation and ethylene catalysis in the preservation of fruits and vegetables,Ag/TiO_(2)/Ag_(3)PO_(4)(ATAP)ternary heterojunction photocatalysts were synthesized by in-situ precipitation and irradiation,and ATAP-lignin nanofibrillar cellulose(LCNF)/starch composite films were prepared by using casting method in this study.The effects of different ATAP loading conditions and different types of photocatalysts on ethylene adsorption,ethylene degradation,and bacterial inhibition were investigated.The microscopic morphology of the composite films was observed by SEM,and preservation effect of different photocatalysis film was evaluated.The results show that the appropriate amount of ATAP internal and external doping can make the photocatalyst uniformly dispersed on the surface of the starch film and thus enhances its photocatalytic performance.The ATAP-LCNF/starch composite film possesses the optimal ethylene degradation and bacterial inhibition when the ATAP external doping amount is 3%and the internal doping amount is 2%with the degradation rate of 7.73%,and the diameter of the inhibition circle of 11.46 mm.ATAP-LNCF/starch composite film has better freshness preservation for pumpkin.The mould coverage area on the surface of and inside pumpkin after 7 d of freshness preservation is significantly reduced,and the weight loss rate is reduced to 28.27%.Meanwhile,the composite films show significant inhibitory effects on S.aureus and moulds with colony counts.The total number of colonies,the number of Staphylococcus aureus colonies and the number of mould colonies are 5.55×104,4.95×104 and 3.00×104 CFU/g,respectively,better than those of other materials and the control group.The study provides theoretical reference for the development of new materials for fruits and vegetables preservation.