Primary Processing and Storage Affect the Dominant Microbiota of Fresh and Chill-Stored Sea Bass Products

There is growing interest in Baltic herring (Clupea harengus membras) and other undervalued, small-sized fish species for human consumption. Gutting or filleting of small-sized fish is impractical; hence, the aim of this study was to explore the suitability of the whole (ungutted) herring for food use. The microbiological quality of commercially fished whole and gutted herring was analysed with culture-dependent methods combined with identification of bacterial isolates with MALDI-TOF Mass Spectrometry and culture-independent 16S rRNA gene amplicon sequencing. Whole and gutted herring had between 2.8 and 5.3 log10 CFU g−1 aerobic mesophilic and psychrotrophic bacteria and between 2.2 and 5.6 log10 CFU g−1 H₂S-producing bacteria. Enterobacteria counts remained low in all the analysed herring batches. The herring microbiota largely comprised the phyla Proteobacteria, Firmicutes, and Actinobacteria (71.7% to 95.0%). Shewanella, Pseudomonas, and Aeromonas were the most frequently isolated genera among the viable population; however, with the culture-independent approach, Shewanella followed by Psychrobacter were the most abundant genera. In some samples, a high relative abundance of the phylum Epsilonbacteraeota, represented by the genus Arcobacter, was detected. This study reports the bacterial diversity present in Baltic herring and shows that the microbiological quality was acceptable in all the analysed fish batches.

Section: Discussionsupporting

confidence: 92%

Characterization of Microbiological Quality of Whole and Gutted Baltic Herring

Huotari

Tsitko

Honkapää

et al. 2022

“…Shelf-life of fresh fish from the Mediterranean aquaculture, such as gilt-head seabream and European seabass, is usually ranged from 12 to 14 days for the whole fish in ice [ 13 , 14 ], and from 5 to 6 days for their fillets stored at 4 °C [ 8 , 17 ]. For meagre, shelf-life has been found to be 9 days for the whole and filleted fish in ice [ 6 , 35 ].…”

Section: Discussionmentioning

confidence: 99%

“…Under iced storage conditions, TVC was at higher population levels in fish of July than those of January for the same time points during storage, reaching spoilage population levels of 7–8 log cfu/g three days earlier in fish of July than those of January. In the case of fish fillets, filleting can increase significantly the population levels of bacteria and change the microbial composition compared to the whole fish [ 8 ]. This means that the most important factor that determines the shelf-life of meagre fillets (7 days for fish of both months) differs from the factors that mainly affect the shelf-life of the whole meagre.…”

Section: Discussionmentioning

confidence: 99%

“…Microorganisms in fish come from the environment wherein fish lives and from various sources of contamination in post-farm gate e.g., harvesting, handling, packaging, processing, and distribution [ 7 ]. Bacterial communities of fresh fish are much affected by post-harvest practices, such as handling, gutting, and filleting [ 8 ]. In storage, temperature and packaging conditions determine the predominant spoilage microbiota of fish.…”

Section: Introductionmentioning

confidence: 99%

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Spoilage Investigation of Chill Stored Meagre (Argyrosomus regius) Using Modern Microbiological and Analytical Techniques

Syropoulou

Parlapani

Anagnostopoulos

et al. 2021

Self Cite

Spoilage status of whole and filleted chill-stored meagre caught in January and July was evaluated using sensory, microbiological, 16S metabarcoding and Volatile Organic Compounds (VOCs) analysis. Based on the sensory analysis, shelf-life was 15 and 12 days for the whole fish taken in January and July, respectively, while 7 days for fish fillets of both months. For the whole fish, Total Viable Counts (TVC) at the beginning of storage was 2.90 and 4.73 log cfu/g for fish caught in January and July respectively, while it was found about 3 log cfu/g in fish fillets of both months. The 16S metabarcoding analysis showed different profiles between the two seasons throughout the storage. Pseudomonas (47%) and Psychrobacter (42.5%) dominated in whole meagre of January, while Pseudomonas (66.6%) and Shewanella (10.5%) dominated in fish of July, at the end of shelf-life. Regarding the fillets, Pseudomonas clearly dominated at the end of shelf-life for both months. The volatile profile of meagre was predominated by alcohols and carbonyl compounds. After univariate and multivariate testing, we observed one group of compounds (trimethylamine, 3-methylbutanoic acid, 3-methyl-1-butanol) positively correlating with time of storage and another group with a declining trend (such as heptanal and octanal). Furthermore, the volatile profile seemed to be affected by the fish culturing season. Our findings provide insights into the spoilage mechanism and give information that helps stakeholders to supply meagre products of a high-quality level in national and international commerce.

“…This might be because bacteria adapted to the fish skin environment, the major source of the development of microbial organisms during storage [ 35 ]. Other studies have suggested that processed fish products might be contaminated by microorganisms during fish processing and storage [ 61 ]. However, during storage, the total bacterial count rapidly increased in the FM group; moreover, the count was significantly higher after 18 days storage time when compared to the SSDM-CON and SSDM-SAL groups.…”

Section: Resultsmentioning

confidence: 99%

Assessment of the Effects of Salt and Salicornia herbacea L. on Physiochemical, Nutritional, and Quality Parameters for Extending the Shelf-Life of Semi-Dried Mullets (Chelon haematocheilus)

Chilakala

Kim

et al. 2022

Mullet, a coastal fish species, is commonly used as a salted dried fish in many countries, including Korea, Japan, and the southeastern United States. The purpose of this investigation was to develop high-quality products of salted semi-dried mullet (SSDM) using natural salt and Salicornia herbacea L. (SAL). The antioxidant activity of SAL was investigated by in vitro studies. The physicochemical and nutritional characteristics of fresh mullet (FM), salted control (SSDM-CON), and SAL-treated (SSDM-SAL) mullet groups were analyzed. The moisture, ash, and crude protein contents were significantly increased in the SSDM-SAL group, whereas the salinity was decreased when compared with the SSDM-CON group. Lipid oxidation occurred in the FM and SSDM groups, as indicated by the increase in peroxide (PV), acid (AV), and thiobarbituric acid reactive substance (TBARS) values during the storage period. The protein pattern on the sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed similarities between the groups, while the amino acid and fatty acid contents also varied in the FM and SSDM groups depending on their processing methods. Initially, the total bacterial count was significantly higher in the SSDM groups than in the FM group. However, the SSDM-SAL group had a markedly lower total bacteria count than the FM and SSDM-CON groups during 21 days of refrigerated storage. This result indicates that SAL treatment can improve mullet’s safety from microorganisms, includes beneficial biochemical parameters, and can extend their shelf-life through refrigerated storage.