Abstract:

The interaction between food ingredients is one of the research focuses in food science. ε-Polylysine (ε-PL),
as a food additive, is a cationic polyelectrolyte with excellent antimicrobial properties, and it can interact with anionic
polymers such as sodium carboxymethylcellulose (CMC-Na) to affect its antimicrobial properties and the stability of related
food systems. In this study, the effects of degree of substitution (DS) and molecular weight of CMC-Na on the interaction
between ε-PL and CMC-Na as indicated by turbidity, Zeta potential and particle size were investigated. Results revealed that
the electrostatic interaction between ε-PL and CMC-Na mainly depended on the molar ratio of cationic amino groups in ε-PL
to carboxyl anion groups in CMC-Na. In addition, both DS and molecular weight of CMC-Na exerted a serious impact on
the interaction between ε-PL and CMC-Na and the effect of DS was more significant.

Key words: ε-polylysine, sodium carboxymethylcellulose, Zeta potential, degree of substitution