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% CO 2 balanced with N 2 ), 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-CO 2 MAP and chitosan coating (p < 0.05). Both MAP and coating partly affected the maki sushi crosssection'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-CO 2 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-CO 2 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. K E Y W O R D Sactive packaging, edible coating, functional properties, ready-to-eat (RTE), retail maki sushi 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.

Design and Development of an Edible Coating for a Ready-to-Eat Fish Product

“…These findings align with other studies on chitosan coatings, which reported an antimicrobial effect of chitosan [8,10,11,13]. The impact of chitosan on microbial stability in RTE maki sushi during storage under abused conditions has been previously reported [9], emphasising an enhanced safety profile for RTE products not only during an optimal refrigerated chain but also when exposed to adverse conditions. Therefore, it is recommended to conduct further investigations to assess the efficacy of a chitosan coating under simulated real shelf-life conditions.…”

“…Martínez et al [10] studied the effect of a chitosan coating in combination with a vacuum package as a conservative method for smoked sea bass fillets and found that the coating inhibited microbiological growth. Sørbø und Lerfall [9] reported increased microbial stability and improve colour stability in RTE maki sushi when coated with chitosan and packed under low-CO 2 MAP conditions.…”

“…Chitosan is a suitable material for edible coatings as it is nontoxic, biodegradable, biocompatible, and generally recognised as safe by the US Food and Drug Administration [7]. Chitosan coatings have shown excellent coating behaviour by forming a transparent, invisible, and adhesive layer around food products, and they have been shown to control microbial growth [8,9] and reduce fat oxidation [10]. Variations in chitosan coatings' composition and processing factors have been reported, e.g., chitosan with different degrees of acetylation from 70 to 95%, chitosan concentrations from 0.5 to 3%, different solvents with concentrations from 1…”

“…Polymers 2024, 16, 346 2 of 16 to 2%, stirring temperatures from 23 to 40 • C, or the addition of glycerol from 0.5 to 75% of w/w chitosan [8,9,[11][12][13][14][15][16]. The potential of chitosan coatings is well studied for different fresh fish products [8,11,14,17], but limited studies for ready-to-eat (RTE) food products, particularly RTE seafood products [9,10,12], could be found.…”