Shao Ping, Wu Weina, Chen Hangjun, Sun Peilong, Gao Haiyan
Department of Food Science and Technology, Zhejiang University of Technology, Zhejiang, Hangzhou 310014, PR China.
Institute of Food Science, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, PR China.
Food Res Int. 2020 Dec;138(Pt B):109795. doi: 10.1016/j.foodres.2020.109795. Epub 2020 Oct 15.
Bilayer edible films were fabricated with the stacking double layers, in which the outer and inner layer was consisted of hydrophobic ethyl cellulose and hydrophilic carboxymethyl chitosan hydrogel, respectively. Humidity regulating performance of the films varied with the change of substitution degree of carboxymethyl chitosan. The mechanical properties, water insolubility, water vapor permeability, water contact angle, moisture absorption/desorption characteristics and micro morphology of the film were characterized, which showed that the film can adjust the relative humidity and block the external moisture. The film prepared by carboxymethyl chitosan with the substitution degree of 120% was then selected for the packaging of fresh mushrooms (Agaricus bisporus). The browning of the mushrooms during storage was delayed, as well as the qualities were maintained well, Additionally, the activities and corresponding gene expression of PPO enzyme were inhibited, however for PAL enzyme, an increase was observed.
双层可食用薄膜是通过堆叠双层制成的，其中外层由疏水性乙基纤维素组成，内层由亲水性羧甲基壳聚糖水凝胶组成。薄膜的湿度调节性能随羧甲基壳聚糖取代度的变化而变化。对薄膜的机械性能、水不溶性、水蒸气透过率、水接触角、吸湿/解吸特性和微观形态进行了表征，结果表明该薄膜可以调节相对湿度并阻挡外部水分。然后选择取代度为120%的羧甲基壳聚糖制备的薄膜用于新鲜蘑菇（双孢蘑菇）的包装。储存期间蘑菇的褐变得到延迟，品质也得到很好的保持，此外，PPO酶的活性和相应基因表达受到抑制，然而对于PAL酶，观察到其活性增加。
