Antibacterial activities and preservative effect of chitosan oligosaccharide Maillard reaction products on Penaeus vannamei

The purpose of this study was to understand the influence of Maillard reaction (MR) on bioactivity of chitosan oligosaccharide (COS). The antibacterial activity against Pseudomonas aeruginosa and Vibrio parahaemolyticus wand preservative effect of two kinds of COS MR products (MRPs) on Penaeus vannamei were evaluated. The structures of CG (MRPs of COS and glucose) and CM (MRPs of COS and maltose) were characterized by FT-IR and their molecular weights were measured by gel permeation chromatography (GPC). The results showed that CG has enhanced antibacterial activity and preservative effect compared to COS by evaluating total volatile base-nitrogen (TVB-N), trimethylamine (TMA), pH, total bacterial count (TBC) and sensory evaluation. Meanwhile, CM showed decreased antibacterial activity and preservative effect compared to COS by evaluating TMA, pH and TBC. The results indicated that antibacterial activity and preservative effect of COS increased or decreased after MR. In other words, the type of reducing sugar involved in MR had a great impact on the functional properties of COS-saccharide MRPs and their application to be used as a food preservative. (C) 2017 Elsevier B.V. All rights reserved.