College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, PR China.
School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, USA.
Lett Appl Microbiol. 2020 May;70(5):380-387. doi: 10.1111/lam.13284. Epub 2020 Feb 28.
Chitosan with higher molecular weight exhibited higher antimicrobial efficacy against foodborne pathogens. However, the poor water solubility of higher or medium molecular weight chitosan limits its applications. To overcome the challenge, our research team searched for simple preparation procedure for fast-dissolving medium molecular weight chitosan in water. Throughout the process, we were able to obtain a higher concentration of medium molecular weight water-soluble (MMWWS) chitosan (400 kDa). The MMWWS chitosan showed physicochemical properties that are suitable for edible coating. Antibacterial activities of 400-kDa chitosan coating prepared in acetic acid (1% v/v) or aspartic acid (1% or 3% w/v) were examined. The surface of catfish cubes was inoculated with six foodborne pathogens and then coated with chitosan solutions. The survival of each pathogen was evaluated during shelf life storage. Compared with the control, 3% w/v chitosan coating in aspartic acid solution exhibited the most effective antibacterial activities among other coating treatments, completely inhibiting Vibrio parahaemolyticus on the surface of catfish. The study suggested that chitosan dissolved in aspartic acid has the potential for use as an alternative antimicrobial coating for catfish fillet.
分子量较高的壳聚糖对食源性病原体表现出更高的抗菌功效。然而，较高或中等分子量壳聚糖的水溶性差限制了其应用。为了克服这一挑战，我们的研究团队寻找了一种简单的制备方法，用于在水中快速制备中分子量水溶性壳聚糖。在整个过程中，我们能够获得更高浓度的中分子量水溶性壳聚糖（400 kDa）。这种 MMWWS 壳聚糖具有适合食用涂层的物理化学性质。我们检测了在醋酸（1% v/v）或天冬氨酸（1% 或 3% w/v）中制备的 400 kDa 壳聚糖涂层的抗菌活性。将六种食源性病原体接种到鲶鱼片表面，然后用壳聚糖溶液进行涂层。在货架期储存过程中，评估每种病原体的存活情况。与对照组相比，在天冬氨酸溶液中 3% w/v 的壳聚糖涂层在其他涂层处理中表现出最有效的抗菌活性，完全抑制了鲶鱼片表面的副溶血性弧菌。研究表明，溶解在天冬氨酸中的壳聚糖有可能替代鲶鱼片抗菌涂层。
