Wood vinegar and chitosan compound preservative affects on fish balls stability

Abstract

The application of compound preservative of biological source of the two materials wood vinegar and chitosan increased the stability of food products. The application of chitosan in the food industry is limited by its insolubility. Like chitosan degradation products, the chitosan oligosaccharide (COS) in no high pH has high solubility. The aim of this study was to evaluate the combined effect of wood vinegar (WV) and COS on the quality of rainbow trout fish balls under vacuum storage. The fish balls with different amounts of WV and COS were vacuum packed. In the control group, no preservative was added and distilled water was used instead. The control group had higher aerobic plate count compared to treatment groups during 15 days storage (p < 0.05). All the treatment groups were kept at a lower level of total volatile basic nitrogen compared with the control group (p ≥ 0.05). The lightness of each treatment group was non-significantly lower than that of the control group, but the decreasing range was not obvious (p≥>0.05), and difficult to distinguish visually. The percentage of free water in all treatment groups (0–6 days) was significantly lower than that in the control group (p < 0.05). The pH value of the treatment group was lower than that of the control group (p < 0.05) from 9 to 15 days. The hardness, chewability and resilience of the treatment groups showed a downward trend with increasing storage time. The elasticity was unchanged. After 15 days storage, the gel strengths of all treatment groups were higher than that of the control group (p < 0.05).