Μελέτη της επίδρασης της συσκευασίας σε τροποποιημένες ατμόσφαιρες στην μικροβιολογική αλλοίωση με την μέθοδο NGS και στην ποιότητα των νωπών ιχθύων

Abstract

Whole gilthead seabream was packed (a) aerobically in polystyrene boxes with an adequate quantity of flake ice, based on the conventional practices (AIR) and (b) under modified atmospheres (MAP: 60% CO2, 30% N2, 10% O2). Next- Generation Sequencing (NGS) analysis of fish microbiome on skin, gills, and intestines was performed at the initial (packaging, 1 day after harvesting) and final (end of shelf life) points. End of shelf life was assessed by a sensory evaluation carried out by a panel of experts. NGS results indicated statistically significant differences in families’ richness and diversity among the two types of packaging (i.e. AIR and MAP) as well as among the packaging types and the initial seabream’s microbiome. The NGS analyses of the microbiota, at the Phylum level, showed that the most persistent bacteria, both at the initial microbiome and at the end of shelf life, was Proteobacteria, either in AIR or MAP samples. As regards gilthead seabream skin microbiota, the initially prevailing Families were Comamonadaceae, Enterobacteriaceae, and Moraxellaceae while on the intestines prevailed Comamonadaceae, Anaplasmataceae, Bacillaceae, and Enterobacteriaceae. Statistical analyses indicated positive correlations between the skin and intestinal microbiota. By the end of fish shelf life, the composition of the initial microbiome was modified in both types of packaging (AIR, MAP). In general, several of the initially predominant families have been partially or completely replaced by psychotropic and psychrophilic families like Pseudoalte- romonadaceae, Psychromonadaceae, and Shewanellaceae. However, there were families, such as Comamonadaceae, persistent under MAP conditions. By the 8th day of isothermal storage at 0°C fish under MAP exhibited higher sensory scorings than the respective AIR samples, indicating better retention of quality attributes of fish under MAP.