Microstructure and thermal and functional properties of biodegradable films produced using zein

Abstract Research is being conducted in an attempt to produce biodegradable packaging to replace plastic products, thereby reducing solid waste disposal. In this work, zein films were produced from vegetable oils (macadamia, olive and buriti) and from pure oleic acid. The surface of zein-based films made using oleic acid has a good lipid distribution. The high content of oleic acid produced a film with the greatest elongation at break (8.08 ± 2.71%) due to the greater homogeneity of the protein matrix. The different oils did not affect the glass transition temperature (Tg). Tg curves of films with fatty acids showed a reduction in mass at between 50 and 120 °C due to water evaporation. At 120 °C the weight loss was 3-5% and above this temperature further weight loss was observed with the highest loss being seen in the film made using pure oleic acid. In conclusion, although biodegradable films were produced using the four different oils, the film made from pure oleic acid has the best characteristics.

摘要 本研究旨在开发可生物降解包装材料以替代塑料制品，进而降低固体废弃物处置负担。本工作以植物油（澳洲坚果油、橄榄油及布里蒂油）与纯油酸为原料制备玉米醇溶蛋白（zein）薄膜。采用纯油酸制备的玉米醇溶蛋白基薄膜，其表面具有良好的脂质分布。由于蛋白基质均一性更高，高含量油酸所制得的薄膜断裂伸长率最优，可达(8.08 ± 2.71)%。不同植物油对薄膜的玻璃化转变温度（glass transition temperature, Tg）无显著影响。含脂肪酸的薄膜的Tg曲线显示，在50~120 ℃区间内因水分蒸发出现质量损失；120 ℃时质量损失率为3%~5%，高于该温度后则出现进一步质量损失，其中纯油酸制备的薄膜质量损失最为显著。综上，尽管本研究利用四种不同原料制备了可生物降解薄膜，但纯油酸制备的薄膜综合性能最优。