Effect of hydrogen peroxide treatment on the quality of epsilon-poly-L-lysine products

• Published in: Biochemical engineering journal Vol. 171; p. 108017
• Main Authors: Chang, Sen-Lin, Li, Hang, Liu, Jia-Ning, Zhao, Ming-Xia, Tan, Ming-Hui, Xu, Peng-Wei, Wang, Xiao-dong, Wang, Li-Wei, Yuan, Xiao-Fan, Zhao, Qing-Sheng, Zhao, Bing
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2021
• Subjects: Antibacterial performance; Decoloration; Hydrogen peroxide treatment; ε-poly-l-lysine; Hydrogen peroxide treatment; ε-poly-l-lysine; Antibacterial performance; Decoloration
• ISSN: 1369-703X; 1873-295X
• DOI: 10.1016/j.bej.2021.108017

[Display omitted] •Hydrogen peroxide was used to decolorize ε-PL, thus improving products quality.•Optimum condition adopted in hydrogen peroxide processing was explored systematically.•Changes of ε-PL on molecular mass, composition, and structure caused by hydrogen peroxide treated was assessed.•The bioactivity including antioxidant activity, antibacterial performance, and cell cytotoxicity was determined. ε-poly-l-lysine (ε-PL) is a novel biopreservative with wide antibacterial spectrum, high safety, and stable property. However, the color of ε-PL generating from manufacturing process lowers its appearance and limits its application. This work aimed to decolorize ε-PL by hydrogen peroxide. Impacts of hydrogen peroxide concentration, pH, duration time and temperature were discussed. Physicochemical property and bioactivity of ε-PL were explored. Results indicated that 43.2 % color saturation and 94.54 % recovery rate were reached when the concentration of hydrogen peroxide, pH, duration time and temperature were 3.0 %, 7.0, 1.5 h and 70℃ respectively. Furthermore, the MIC (minimal inhibitory concentration) of the hydrogen peroxide treated ε-PL for Bacillus subtilis, Escherichia coli, and Staphylococcus aureus were 2 mg/mL, 0.1 mg/mL, and 0.1 mg/mL respectively, which was similar with untreated ε-PL. At last, cytotoxicity test indicated that no cytotoxicity could be observed at concentration lower than 2 mg/mL ε-PL. As a result, hydrogen peroxide treatment on ε-PL could significantly decolorize ε-PL without impairing the antibacterial performance and changing the cytotoxicity. Hydrogen peroxide treatment is a promising method to improve the appearance of products, to reduce the cost of decoloration, and to enlarge the application in food and cosmetics industry.