Effect of edible coating and modified atmosphere packaging on the microbiological and physicochemical stability of retail maki sushi.

Abstract

The effect of pH, packaging atmosphere (100% air, 40%, or 70% CO2 balanced with N2 ), and an edible chitosan coating was tested on the retail maki Sushi's microbiological and physiochemical stability. In two experiments, maki sushi was studied using sushi rice with an initial pH of 4.2± 0.05 and 4.8± 0.05. In the first experiment (lower pH), no apparent effect of neither modified atmosphere packaging (MAP) nor coating on bacterial growth was observed. However, raising the pH showed an apparent effect of low-CO2 MAP and chitosan coating (p<0.05). Both MAP and coating partly affected the maki sushi cross-section's visual perception, but no significant adverse effects were observed. An important observation was the improved stability of the pink salmon color in chitosan-coated maki sushi stored in low-CO2 MAP compared to other groups. It is concluded that storage of Maki sushi at 4°C gives acceptable microbial stability and appropriate quality. However, an edible chitosan coating, especially in combination with low-CO2 MAP, increases the microbiological stability and preserves the colorimetric properties of maki sushi stored at 8°C. Notably, this combination could work as a safety measure against temperature abuse in the food cold chain. PRACTICAL APPLICATION: Using an edible coating with active packaging can improve retail maki sushi's temperature tolerance and preserve its colorimetric properties. It is a fast and cost-effective technology with a substantial industrial potential easy to implement.