Controlled fabrication, structure and property of lysozyme composite antibacterial film immobilized by calcium alginate-gelatin

Qingqing Zhang; Na Wu; Yao Yao; Shuping Chen; Lilan Xu; Yonggang Tu; Yan Zhao

doi:10.1016/j.foodchem.2025.145122

Controlled fabrication, structure and property of lysozyme composite antibacterial film immobilized by calcium alginate-gelatin

Food Chem. 2025 Jun 16:490:145122. doi: 10.1016/j.foodchem.2025.145122. Online ahead of print.

Authors

Qingqing Zhang¹, Na Wu², Yao Yao², Shuping Chen², Lilan Xu², Yonggang Tu³, Yan Zhao⁴

Affiliations

¹ Jiangxi Key Laboratory of Natural Products and Functional Food, Jiangxi Agricultural University, Nanchang 330045, China; Agricultural Products Processing and Quality Control Engineering Laboratory of Jiangxi, Jiangxi Agricultural University, Nanchang 330045, China; Nanchang Key Laboratory of Egg Safety Production and Processing Engineering, Jiangxi Agricultural University, Nanchang 330045, China; College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China.
² Jiangxi Key Laboratory of Natural Products and Functional Food, Jiangxi Agricultural University, Nanchang 330045, China; Agricultural Products Processing and Quality Control Engineering Laboratory of Jiangxi, Jiangxi Agricultural University, Nanchang 330045, China; Nanchang Key Laboratory of Egg Safety Production and Processing Engineering, Jiangxi Agricultural University, Nanchang 330045, China.
³ Jiangxi Key Laboratory of Natural Products and Functional Food, Jiangxi Agricultural University, Nanchang 330045, China; Agricultural Products Processing and Quality Control Engineering Laboratory of Jiangxi, Jiangxi Agricultural University, Nanchang 330045, China; Nanchang Key Laboratory of Egg Safety Production and Processing Engineering, Jiangxi Agricultural University, Nanchang 330045, China. Electronic address: tygzy1212@jxau.edu.cn.
⁴ Jiangxi Key Laboratory of Natural Products and Functional Food, Jiangxi Agricultural University, Nanchang 330045, China; Agricultural Products Processing and Quality Control Engineering Laboratory of Jiangxi, Jiangxi Agricultural University, Nanchang 330045, China; Nanchang Key Laboratory of Egg Safety Production and Processing Engineering, Jiangxi Agricultural University, Nanchang 330045, China. Electronic address: zhaoyan@jxau.edu.cn.

PMID: 40554277
DOI: 10.1016/j.foodchem.2025.145122

Abstract

Incorporating lysozyme as a preservative in food products faces challenges in the complex food environment, leading to reduced efficacy. Cross-linking sodium alginate with Ca²⁺ forms an intricate "egg box" network, ideal for carrying bioactive compounds. This study combined gelatin with calcium alginate to enhance the composite matrix's mechanical strength for lysozyme immobilization. The research assessed lysozyme immobilization efficiency, physicochemical properties, and antibacterial effectiveness of the calcium alginate-gelatin-lysozyme (Ca-ALG-Gel-LYS) composite film. Results showed unchanged lysozyme structure post-immobilization, with improved storage stability. The composite film exhibited compatibility without phase separation and had a water solubility of only 3.53 %. It also exhibited improved barrier properties and mechanical strength, with light transmittance nearly zero at 200-300 nm. Over an 8-h period, inactivation rates for S. aureus, L. monocytogenes, E. coli, and Salmonella were 3.42, 3.73, 2.66, and 2.90 log CFU/mL, respectively. Overall, immobilizing lysozyme in the cross-linked film enhanced its performance.

Keywords: Antibacterial film; Calcium alginate; Cross-linking; Gelatin; Immobilization; Lysozyme.