College of Food Science and Engineering, Shandong Agricultural University, Engineering and Technology Center for Grain Processing of Shandong Province, Tai'an, Shandong Province 271018, China.
Department of Food Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Carbohydr Polym. 2022 Feb 15;278:118990. doi: 10.1016/j.carbpol.2021.118990. Epub 2021 Dec 7.
Edible antimicrobial films made from starch/gelatin (S/G) incorporated with different ε-polylysine hydrochloride (ε-PL) contents were developed by low-temperature extrusion blowing process. ε-PL addition reduced the complex viscosity and storage modulus of blends, while promoted the formation of hydrogen bonding among film components. The control film had an A-type crystalline structure, while increasing the ε-PL content promoted its transformation to B-shaped structure. Without ε-PL and under the processing temperature used, the starch granules were not sufficiently gelatinized. However, ε-PL addition significantly enhanced the gelatinization degree. Increasing ε-PL content in S/G films increased film flexibility, water contact angle value, swelling degree, antimicrobial effect, and storage period of fresh bread, but decreased water vapor permeability and tensile strength. S/G film with 4 wt% ε-PL had the highest water contact angle (94°) and elongation at break (149%). This research demonstrates the plasticizing effects of ε-PL and potential of S/G films containing ε-PL for food preservation/packaging.
由淀粉/明胶（S/G）制成的可食用抗菌薄膜，通过低温挤出吹塑工艺掺入不同含量的ε-聚赖氨酸盐酸盐（ε-PL）。ε-PL 的添加降低了共混物的复合粘度和储能模量，同时促进了薄膜成分之间氢键的形成。对照薄膜具有 A 型晶体结构，而随着 ε-PL 含量的增加，其转化为 B 型结构。在没有 ε-PL 和所使用的加工温度下，淀粉颗粒没有充分糊化。然而，ε-PL 的添加显著提高了淀粉的糊化程度。在 S/G 薄膜中增加 ε-PL 的含量会增加薄膜的柔韧性、水接触角值、溶胀度、抗菌效果和新鲜面包的储存期，但会降低水蒸气透过率和拉伸强度。含有 4wt%ε-PL 的 S/G 薄膜具有最高的水接触角（94°）和断裂伸长率（149%）。这项研究证明了 ε-PL 的增塑作用以及含有 ε-PL 的 S/G 薄膜在食品保鲜/包装方面的潜力。
