Impact of Red Wine Vinegar-Based Solution on Bacterial Communities of Squid and Shrimp Skewers: A Classic and Genomic Approach

Abstract Seafood is an essential component of a balanced and healthy diet, which increases its demand. However, its biological composition and high moisture content make these products extremely perishable. To prevent spoilage, and the consequent food waste and financial expenses throughout the seafood supply chain, new technologies have been successfully developed to inhibit bacterial growth, the main cause of seafood spoilage. This work aimed to test a shelf life extension technique for seafood skewers whilst maintaining an all-natural label using a financially feasible red wine vinegar treatment applied by immersion or pulverisation. Bacterial growth was monitored by classical methods and by 16S rRNA gene amplicon sequencing during the 5 days of storage. Immersion of samples in a vinegar-based solution effectively reduced Pseudomonas and Enterobacterales counts (by 2 log cfu/g), immediately after application and throughout storage. The overall structure and diversity of the bacterial community were analysed, and a strong reduction in bacterial diversity and impact on bacterial composition was observed immediately after immersion in the red wine vinegar solution. In untreated samples, Pseudomonadota (especially the Gammaproteobacteria class) was the principal phylum, whereas the microbiota of the treated samples was dominated by Bacillota (mainly the Bacilli class). Sensory analysis revealed a mild vinegar or vinaigrette flavour in treated samples; however, these characteristics were not unpleasant. Although applying a vinegar-based solution by immersion promoted a significant reduction in the growth of spoilage bacteria during the first days of storage, further tests are required to confirm the shelf life extension.