酚酸接枝壳聚糖对壳聚糖膜性能的影响及其保鲜应用

Effects of phenolic acid-grafted-chitosan on the properties and preservation of chitosan film

以制得的3种接枝率相近的酚酸壳聚糖为原料制备复合膜,考察酚酸的结构对壳聚糖膜性能的影响,并研究了膜的物理性质、生物活性及其在保鲜方面的应用。结果表明,与酚酸接枝降低了壳聚糖膜的水分含量和水蒸气渗透性,同时提高了膜的不透明度、水溶性、拉伸强度、断裂伸长率、杨氏模量、抗氧化和抗菌活性。其中,咖啡酸接枝壳聚糖(caffeic acid-grafted-chitosan,CA-g-CS)膜比对香豆酸/阿魏酸接枝壳聚糖膜表现出更好的上述性能,这可能是由于咖啡酸中存在2个酚羟基造成的。同时,CA-g-CS膜能更有效地延缓南美白对虾贮藏过程中的失重率和pH值的升高,抑制挥发性盐基氮积累和微生物生长。研究表明,酚酸接枝壳聚糖膜对南美白对虾的保鲜作用及其性能受酚酸中羟基位置和数量的影响。

The mechanical and biological properties of chitosan films need to improve.This paper aims to prepare three kinds of phenolic acid-grafted-chitosan with similar grafting rates,and then prepare composite films.The physical properties,bioactivities,and preservation application of the films were evaluated.Results showed that the grafting of phenolic acids with chitosan decreased the moisture content and water vapor permeability and increased the opacity,water-solubility,tensile strength,elongation at break,Young’s modulus,antioxidant,and antimicrobial activities of chitosan film.Caffeic acid-grafted-chitosan(CA-g-CS)film exhibited better above-mentioned properties than p-coumaric acid/ferulic acid-grafted-chitosan films,which may be caused by the phenomenon that there were two phenolic hydroxyl groups in caffeic acid.Meanwhile,CA-g-CS film could more effectively retard weight loss,pH increase,volatile base nitrogen accumulation,and microbial growth of Penaeus vannamei during storage.Our work revealed that the preservative of phenolic acid-grafted-chitosan films’effect on P.vannamei and its properties were significantly influenced by the position and number of hydroxyl groups in phenolic acids.