Combination of Freezing, Low Sodium Brine, and Cold Smoking on the Quality and Shelf-Life of Sea Bass (Dicentrarchus labrax L.) Fillets as a Strategy to Innovate the Market of Aquaculture Products

Emerging technologies in seafood processing: An overview of innovations reshaping the aquatic food industry

Seafood processing has traditionally been challenging due to the rapid spoilage rates and quality degradation of these products. With the rise of food science and technology, novel methods are being developed to overcome these challenges and improve seafood quality, shelf life, and safety. These methods range from high-pressure processing (HPP) to edible coatings, and their exploration and application in seafood processing are of great importance. This review synthesizes the recent advancements in various emerging technologies used in the seafood industry and critically evaluates their efficacy, challenges, and potential benefits. The technologies covered include HPP, ultrasound, pulsed electric field, plasma technologies, pulsed light, low-voltage electrostatic field, ozone, vacuum cooking, purified condensed smoke, microwave heating, and edible coating. Each technology offers unique advantages and presents specific challenges; however, their successful application largely depends on the nature of the seafood product and the desired result. HPP and microwave heating show exceptional promise in terms of quality retention and shelf-life extension. Edible coatings present a multifunctional approach, offering preservation and the potential enhancement of nutritional value. The strength, weakness, opportunity, and threat (SWOT) analysis indicates that, despite the potential of these technologies, cost-effectiveness, scalability, regulatory considerations, and consumer acceptance remain crucial issues. As the seafood industry stands on the cusp of a technological revolution, understanding these nuances becomes imperative for sustainable growth. Future research should focus on technological refinements, understanding consumer perspectives, and developing regulatory frameworks to facilitate the adoption of these technologies in the seafood industry.

Toward Sustainable and Healthy Fish Products-The Role of Feeding and Preservation Techniques

Fish is a fundamental component of the human diet, and in the near future the proportion of aquatic foods originating from aquaculture production is expected to increase to over 56%. The sustainable growth of the aquaculture sector involves the use of new sustainable raw materials as substitutes for traditional fishmeal and fish oil ingredients, but it is crucial that the substitution maintains the nutritional value of the fish meat. In addition, the preservation of the nutritional value should be a mandatory requirement of new technologies that extend the shelf life of fish. In this context, we evaluated the impact of a newly formulated feed and three preservation treatments (brine, pulsed electric field (PEF), and PEF plus brine) on the fatty acid composition and protein and lipid digestibility of sea bass fillets. In non-digested fillets, although slightly reduced by the newly formulated feed (standard = 2.49 ± 0.14; newly formulated = 2.03 ± 0.10) the n-3/n-6 PUFA ratio indicated good nutritional value. The preservation treatments did not modify the fatty acid content and profile of non-digested fillets. Conversely, protein and lipid digestibility were not affected by the different diets but were significantly reduced by brine, with or without PEF, while PEF alone had no effect. Overall, our results indicated that the newly formulated feed containing 50% less fishmeal is a good compromise between the sustainability and nutritional value of cultivated seabass, and PEF is a promising preservation technology deserving of further study.

Microbial and Physico-Chemical Characterization of Cold Smoked Sea Bass (Dicentrarchus labrax), a New Product of Fishery

The aim of this study was to investigate the microbial and physico-chemical characteristics of cold smoked sea bass (CSSB), a novel italian fish product. The microbiological analyses showed the presence of bacterial contamination from the raw material, the environment, and the production process. The microbial spoilage population was dominated by lactic acid bacteria (LAB) associated with Gram-negative fermenting bacteria, including Photobacterium phosphoreum and psychrotrophic Enterobacteriaceae. Brochotrix thermospacta and Aeromonas spp. were also present; in contrast, mould and yeast were not detected (<2 CFU/g). High levels (6-7 log CFU/g) of LAB and total bacteria count (TBC) were observed from day 45 of storage; however, their presence does not seem to have influenced the total volatile basic nitrogen (TVB-N), which always remained below 35 mg N/100 g. Consequently, the product is acceptable until day 60 of storage, considering that the malonaldehyde index (TBARS) was lower than 6.5 nmol/g. Pathogenic bacteria such as Salmonella spp. and Listeria monocytogenes were not detected. Currently, there is a growing demand for seafood due to its high quality and nutritional value. Cold smoked sea bass offers a source of macro- and micronutrients essential for the proper functioning of the human body. It is also rich in protein and omega-3 fatty acids. The WHO and FAO evaluated the benefits and risks and concluded that there is convincing evidence of health benefits from fish consumption, such as a reduction in the risk of heart failure and improved neurodevelopment in infants and young children when fish is consumed by the mother before and during pregnancy. The CSSB analysed in this study demonstrated to have health benefits due to long-chain omega-3 PUFAs and other nutrients, such as proteins, minerals, and vitamin D, which are sometimes difficult to obtain from other sources. The results show that CSSB has a high nutritional value and excellent microbial quality.

Contaminant-induced oxidative stress underlies biochemical, molecular and fatty acid profile changes, in gilthead seabream (Sparus aurata L.)

Chemical contaminants such as heavy metals, polybrominated diphenyl ethers (PBDEs) and drugs, are constantly found in the marine environment determining the interest of the scientific community for their side effects on animal welfare, food safety and security. Few studies have analyzed the effects of mix of contaminants in fish, in terms of molecular and nutritional composition response, beside it is indispensable to think more and more on effect of contaminants along the food web system. In this study, Sparus aurata specimens were exposed for 15 days, by diet, to a mixture of carbamazepine (Cbz), polybrominated diphenyl ether-47 (PBDE-47) and cadmium chloride (CdCl₂), at two doses (0.375 μg g-1 D1; 37.5 μg g-1 D2) (T15). After, fish were fed with a control diet, without contaminants mix, for other 15 days (T30). The study explored the effect on oxidative stress in the liver, analyzing specific molecular markers and effects on quality, by fatty acid profile and lipid peroxidation. Molecular markers involved in ROS scavenging, such as superoxide dismutase (sod), catalase (cat) and glutathione peroxidase (gpx) were evaluated by gene expression; as markers of quality and lipid peroxidation, the fatty acids (FAs) profile and the level of malondyaldeide (MDA) were assessed. Sod and cat genes underwent to up-regulation after 15 days of diet containing contaminants and showed down-regulation after the next 2 weeks of detoxification (T30). At T15, the FAs profile showed an increase of the saturated fatty acids (SFA), and a decrease of the polyunsatured fatty acids (PUFA). The MDA levels increased over time, indicating an ongoing radical damage. These results suggest that the effects of the contaminants can be perceived not only at molecular but also at nutritional level and that the molecular and biochemical markers adopted could be differently used to monitor the health of aquatic organisms in the marine environment.

The Development of Smoked Mackerel with Reduced Sodium Content

The World Health Organization recommends reducing salt (sodium chloride, NaCl) intake by 30% by 2025. Since smoked fish can deliver up to 4 g NaCl/100 g, the aim of this study was to develop safe, healthy and attractive smoked chub mackerel (Scomber japonicus) with a reduced NaCl content. Two brines (5% and 10%) were used with different ratios of NaCl and potassium chloride (KCl). In each brine, 0%, 25%, 50% and 75% of NaCl was replaced by KCl, resulting in 1.3, 1.1, 0.9 and 0.6 g NaCl (5% brine), and 2.6, 2.0, 1.2 and 0.8 g NaCl (10% brine) per 100 g, respectively. Similar yield, nutritional, safety, texture and colour properties were found in most formulations. The most desirable taste attributes (negligible bitterness and adequate saltiness) were obtained with a 5% brine prepared with 75% NaCl + 25% KCl. Such conditions seemed to allow for obtaining an attractive product for conscious consumers.

Effect of Cold Smoking and Natural Antioxidants on Quality Traits, Safety and Shelf Life of Farmed Meagre (Argyrosomus regius) Fillets, as a Strategy to Diversify Aquaculture Products

Aquaculture has been playing a leading role over the years to satisfy the global growing demand for seafood. Moreover, innovative techniques are necessary to increase the competitiveness, sustainability and profitability of the seafood production chain, exploiting new species from the aquaculture, such as meagre (Argyrosomus regius), to develop value-added products and diversify their production. In the present work, the effectiveness of cold smoking combined with antioxidants (SA) compared to cold smoking alone (S) on meagre fillets, the quality and shelf life were investigated. Sensory, biochemical, physical–chemical and microbiological analyses were performed on the smoked fillets during vacuum-packaged storage for 35 days at 4 ± 0.5 °C. The results showed positive effects of the SA treatment on the biochemical parameters of meagre fillets. The total volatile basic nitrogen (TVB-N) in smoked meagre fillets was significantly lower in the SA treatment at the end of storage compared to the S treatment. Moreover, SA had a positive effect on lipid peroxidation. Lower values of malondialdehyde (mg MDA/kg) were observed in the SA treatment during preservation compared to the S treatment. This work will contribute to the growth of the fish production chain, producing a value-added fish product by exploiting meagre, whose production has been increasing over decades.