College of Food science, Southwest University, Chongqing 400715, China; Research Center of Food Storage & Logistics, Southwest University, Chongqing 400715, China.
College of Food science, Southwest University, Chongqing 400715, China.
Int J Biol Macromol. 2022 Apr 1;203:184-194. doi: 10.1016/j.ijbiomac.2022.01.010. Epub 2022 Jan 8.
Biopolymers, e.g., polysaccharides and protein, have been employed as edible coatings for the preservation of fruits for many years and are the promising candidates for resolving the problems caused by the extensive using of synthesized polymers in recent years. Chitosan, a kind of polysaccharide with excellent antibacterial and coatings forming properties, has attracted a lot of research interests in being applied as an edible coating for the preservation of postharvest fruits. However, the applying of chitosan is restricted by its poor stability. In this study, we introduce the water-soluble dialdehyde cellulose (DAC) as the crosslinking agent for chitosan to enhance its stability. Fourier transform-infrared spectroscopy is applied to prove the happening of crosslinking and the detection of swelling ratio in water and mechanical properties of DAC-crosslinked chitosan (DAC/CS) confirms the enhanced stability. Furthermore, scanning electron microscope, thermogravimetric analysis, water contact angle, mechanical and gas barrier properties are performed to characterize DAC/CS films with different DAC contents. Finally, DAC/CS is employed as a coating agent to study the effect on the storage of mandarin fruit at room temperature. Chitosan, with enhanced stability by biopolymer, would be a promising candidate applied as a green edible coating in the preservation of fruits.
生物聚合物，如多糖和蛋白质，多年来一直被用作水果的可食用涂层，以解决近年来广泛使用合成聚合物所带来的问题。壳聚糖是一种具有优异抗菌和成膜性能的多糖，作为一种可食用的涂层，在保鲜水果方面引起了广泛的研究兴趣。然而，壳聚糖的应用受到其稳定性差的限制。在这项研究中，我们引入水溶性二醛纤维素（DAC）作为壳聚糖的交联剂，以提高其稳定性。傅里叶变换红外光谱用于证明交联的发生和在水中的溶胀比的检测，以及 DAC-交联壳聚糖（DAC/CS）的机械性能证实了其稳定性的提高。此外，通过扫描电子显微镜、热重分析、水接触角、机械和气体阻隔性能对不同 DAC 含量的 DAC/CS 薄膜进行了表征。最后，将 DAC/CS 用作涂层剂，研究其在室温下对蜜桔贮藏的影响。通过生物聚合物增强稳定性的壳聚糖，将成为一种有前途的候选材料，可作为绿色可食用涂层应用于水果的保鲜。
