Fresh Fish Degradation and Advances in Preservation Using Physical Emerging Technologies

Enhanced water and oxygen barrier properties of deacetylated konjac glucomannan/high acyl gellan gum water gradient film for improved frozen fish fillet preservation

The use of konjac glucomannan (KGM)/high acyl gellan gum (HAGG) edible film with single-sided unsaturated water swelling, designated as a water gradient film (WGF), has been shown to effectively enhance the preservation quality of frozen fish fillets. This study investigates the potential of using partially deacetylated konjac glucomannan (DKGM)/HAGG WGFs to enhance the preservation of frozen fish fillets. The partial deacetylation of KGM improved the water vapour and oxygen barrier properties of the frozen KGM/HAGG WGF, which exhibited a combination of film and ice structural characteristics. This improvement is attributed to strengthened interactions between DKGM and HAGG, resulting in a more structured film matrix that exhibited reduced permeability to both water vapour and oxygen. Furthermore, the improved interactions between DKGM and HAGG led to the formation of smaller polysaccharide ice crystals, which in turn increased the oxygen diffusion path along the intercrystalline boundaries, further decreasing oxygen permeability. Over a 90-day freezing period, the DKGM/HAGG WGF significantly outperformed traditional KGM/HAGG WGF, ice glazing, and polyethylene film packaging in preserving the quality of frozen fish fillets. This study provides a promising strategy for the design and development of DKGM-based WGFs for frozen fish fillet preservation applications.

Gelatin-chitosan interactions in edible films and coatings doped with plant extracts for biopreservation of fresh tuna fish products: A review

The preservation of tuna fish products, which are extremely perishable seafood items, is a substantial challenge due to their instantaneous spoilage caused by microbial development and oxidative degradation. The current review explores the potential of employing chitosan-gelatin-based edible films and coatings, which are enriched with plant extracts, as a sustainable method to prolong the shelf life of tuna fish products. The article provides a comprehensive overview of the physicochemical properties of chitosan and gelatin, emphasizing the molecular interactions that underpin the formation and functionality of these biopolymer-based films and coatings. The synergistic effects of combining chitosan and gelatin are explored, particularly in terms of improving the mechanical strength, barrier properties, and bioactivity of the films. Furthermore, the application of botanical extracts, which include high levels of antioxidants and antibacterial compounds, is being investigated in terms of their capacity to augment the protective characteristics of the films. The study also emphasizes current advancements in utilizing these composite films and coatings for tuna fish products, with a specific focus on their effectiveness in preventing microbiological spoilage, decreasing lipid oxidation, and maintaining sensory qualities throughout storage. Moreover, the current investigation explores the molecular interactions associated with chitosan-gelatin packaging systems enriched with plant extracts, offering valuable insights for improving the design of edible films and coatings and suggesting future research directions to enhance their effectiveness in seafood preservation. Ultimately, the review underscores the potential of chitosan-gelatin-based films and coatings as a promising, eco-friendly alternative to conventional packaging methods, contributing to the sustainability of the seafood industry.

Post-harvest bacterial contamination of fish, their assessment and control strategies

Healthy fish populations lead to healthy aquatic ecosystems and it is our responsibility to be a part of the solution. Fish is one of the most favored foods and is suitable for people of all ages. Fish is an essential source of protein, vitamins, and minerals and a source of income for millions of people. Human population growth and climate change are putting a strain on our food system, demanding the development of sustainable services to enhance global food production and its security. Food safety is an intricate problem in both developed and developing countries. Fresh fish is a highly perishable food with a limited life span; as a result, it must be delivered and kept carefully to minimize deterioration and assure safety. Fish spoilage is linked to biochemical changes that occur post-harvest, such as storage and transportation. These modifications can account for fish spoilage by altering the taste, texture, and appearance. Fish harvesting, distribution, and post-harvest handling are all unhygienic, resulting in poor and unpredictable fish quality in the market. Many innovative and effective control measurements of various bacteria in fish have been proposed and evaluated. This review is a systematic approach to investigating post-harvest fish spoilage, its assessment, and control strategies.

Acetic and citric acids effect the type II secretion system and decrease the metabolic activities of salmon spoilage-related Rahnella aquatilis KM05

Rahnella aquatilis causes seafoods to spoil by metabolizing sulfur-containing amino acids and/or proteins, producing H2S in products. The type II secretion system (T2SS) regulates the transport of proteases from the cytoplasm to the surrounding environment and promotes bacterial growth at low temperatures. To prevent premature fish spoilage, new solutions for inhibiting the T2SS of bacteria should be researched. In this study, global transcriptome sequencing was used to analyze the spoilage properties of R. aquatilis KM05. Two of the mapped genes/coding sequences (CDSs) were matched to the T2SS, namely, qspF and gspE, and four of the genes/CDSs, namely, ftsH, rseP, ptrA and pepN, were matched to metalloproteases or peptidases in R. aquatilis KM05. Subinhibitory concentrations of citric (18 µM) and acetic (41 µM) acids caused downregulation of T2SS-related genes (range from - 1.0 to -4.5) and genes involved in the proteolytic activities of bacteria (range from - 0.5 to -4.0). The proteolytic activities of R. aquatilis KM05 in vitro were reduced by an average of 40%. The in situ experiments showed the antimicrobial properties of citric and acetic acids against R. aquatilis KM05; the addition of an acidulant to salmon fillets limited microbial growth. Citric and acetic acids extend the shelf life of fish-based products and prevent food waste.

Inter-facility characterization of bacteria in seafood processing plants: Exploring potential reservoirs of spoilage organisms and the resistome

A study was conducted in fish processing facilities to investigate the microbial composition, microbial metabolic potential, and distribution of antibiotic resistance genes. Whole metagenomic sequencing was used to analyze microbial communities from different processing rooms, operators and fish products. Taxonomic analyses identified the genera Pseudomonas and Psychrobacter as the most prevalent bacteria. A Principal Component Analysis revealed a distinct separation between fish product and environmental samples, as well as differences between fish product samples from companies processing either Gadidae or Salmonidae fish. Some particular bacterial genera and species were associated with specific processing rooms and operators. Metabolic analysis of metagenome assembled genomes demonstrated variations in microbiota metabolic profiles of microbiota across rooms and fish products. The study also examined the presence of antibiotic-resistance genes in fish processing environments, contributing to the understanding of microbial dynamics, metabolic potential, and implications for fish spoilage.

Evaluating the inhibition effect of a novel bio-packaging on histamine content in mackerel (Scomber scombrus): a new strategy with environment respect

This is the first study in which the impact of a new bio-packaging on histamine formation in mackerel was investigated. To monitor the preservation of fresh fish samples a treatment with innovative polymeric film and a soaking procedure in liquid new biomaterial was adopted. Ultra HPLC diode array detection (UHPLC-DAD) analyses for histamine monitoring were performed on fresh, packaged, and soaked mackerel samples at different time. The histamine content threshold value was up to 7 days, and after this period the results showed that histamine levels were affected by application of biomaterial. Significant increase was detected in sample that was not treated with biofilm. The new biofilm extended the shelf-life and reveals a promising packaging system to prevent histamine biosynthesis.

Evaluation of Antimicrobial and Preservative Effects of Cinnamaldehyde and Clove Oil in Catfish (Ictalurus punctatus) Fillets Stored at 4 °C

This study aimed to evaluate cinnamaldehyde (CN) and clove oil (CO) effectiveness in inhibiting growth and killing spoilage and total aerobic bacteria when overlaid with catfish fillet stored at 4 °C. A 1.00 mL concentration of CO inhibited growth by 2.90, 1.96, and 1.96 cm, respectively, for S. baltica, A. hydrophilia, and total bacteria. Similarly, treatment with 1.00 mL of CN resulted in ZIB of 2.17, 2.10, and 1.10 cm, respectively, for S. baltica, A. hydrophilia, and total bacteria from catfish exudates. Total bacteria from catfish exudates treated with 0.50 mL CN for 40 min, resulted in a 6.84 log decrease, and treatment with 1.00 mL resulted in a 5.66 log decrease at 40 min. Total bacteria exudates treated with 0.50 mL CO resulted in a 9.69 log reduction at 40 min. Total bacteria treated with 1.00 mL CO resulted in a 7.69 log decrease at 7 days, while untreated pads overlaid with catfish resulted in ≥9.00 CFU/mL. However, treated absorbent pads with catfish at 7 days, using 0.50 mL and 1.00 mL CN, had a bacterial recovery of 5.53 and 1.88 log CFU/mL, respectively. Furthermore, CO at 0.50 mL and 1.00 mL reduced the bacteria count to 5.21 and 1.53 log CFU/mL, respectively, at day 7.

Applying innovative technological interventions in the preservation and packaging of fresh seafood products to minimize spoilage - A systematic review and meta-analysis

Seafood, being highly perishable, faces rapid deterioration in freshness, posing spoilage risks and potential health concerns without proper preservation. To combat this, various innovative preservation and packaging technologies have emerged. This review delves into these cutting-edge interventions designed to minimize spoilage and effectively prolong the shelf life of fresh seafood products. Techniques like High-Pressure Processing (HPP), Modified Atmosphere Packaging (MAP), bio-preservation, and active and vacuum packaging have demonstrated the capability to extend the shelf life of seafood products by up to 50%. However, the efficacy of these technologies relies on factors such as the specific type of seafood product and the storage temperature. Hence, careful consideration of these factors is essential in choosing an appropriate preservation and packaging technology.

Changes in volatile compounds and lipid oxidation in various tissues of Nile tilapia (Oreochromis niloticus) during ice storage

Changes in the lipid oxidation and volatile compounds of a variety of tilapia tissues (Oreochromis niloticus) including the muscle, gills, and skin during ice storage were investigated by evaluating peroxide values (PVs), lipoxygenase (LOX) activity, fatty acid (FA) composition, and volatile substances. LOX activity and PV were determined in the gills, skin, and muscles throughout 9 days of storage in ascending order to the extended storage time. The highest level of LOX activity was found in the gills, whereas the highest PV was determined in the skin. FA content of all tissues decreased during the storage period. Oleic acid was the predominant monounsaturated fatty acid, whereas linoleic acid and docosahexaenoic acid were the main polyunsaturated fatty acids and omega-3 in all tissues. The fish gills were shown to have the highest level of volatile compounds followed by the skin and muscle, based on headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry. Principal component analysis indicated gradual changes in the volatile compound composition with increasing storage time. 2-Butanone and nonanal in the muscle, 6-methyl-2-heptanone and 2-nonenal in the gills, and 1-heptanol, and 1-nonanol in the skin were found to be the potential freshness indicators. In addition, hexanal could be a general potential marker for measuring the degree of lipid oxidation in all tissues. PRACTICAL APPLICATION: Understanding the volatile compound formation related to lipid oxidation within storage time at various tissues of tilapia could be critical to the side-stream processing to yield the desired quality.

Bio-nanocomposite active packaging films based on carboxymethyl cellulose, myrrh gum, TiO2 nanoparticles and dill essential oil for preserving fresh-fish (Cyprinus carpio) meat quality

This study developed a composite film for packaging refrigerated common carp fillets using carboxymethyl cellulose (CMC) (1.5 % w/v)/Myrrh gum (MG) (0.25 % w/v) base with the addition of titanium dioxide nanoparticles (TiO2 NPs) (0.25 %, 0.5 %, and 1 %) and Dill essential oil (DEO) (1.5 %, 2.25 %, and 3 %). The film was produced using a casting method and optimized for mechanical and barrier properties. The incorporation of DEO and TiO2 NPs into CMC/MG composite films significantly reduced moisture content (MC) and water vapor permeability (WVP), improved their tensile strength (TS), and increased their antimicrobial and antioxidant properties. Moreover, MG can improve the physicomechanical properties of the CMC/MG composite films. The film components had good compatibility without significant aggregation or cracks. In conclusion, the optimized CMC/MG (1.5 %/0.25 %) film containing TiO2 NPs (0.5 %), and DEO (2.25 %) has the best overall performance and can be a good source for making edible film. Functionally, this bioactive nanocomposite film significantly increased the shelf life of refrigerated fish fillet samples for 12 days by inhibiting microbial growth and reducing the oxidation rate compared to the control sample. The knowledge obtained from this study can guide the development of bio-nanocomposite and biodegradable food packaging films based on CMC/MG to increase the shelf life of food products and environmental protection.

Red Yeast Rice and Optimal Fermentation Periods Improve the Quality of Esan Fermented Fish Sausage

Esan fermented fish sausage (EFFS) has an unappealing off-white color. The incorporation of an appropriate amount of red yeast rice (RYR) and the selection of an optimal fermentation period may yield visually appealing, high-quality sausages. This study is aimed at investigating the effects of different RYR levels (0, 0.35, and 0.7%) and fermentation periods (0, 2, 4, and 6 days) on the quality parameters of EFFS. The following parameters were examined for raw EFFS: CIE color values (L∗, a∗, and b∗), microbial analyses (total viable count, lactic acid bacteria, and yeast and mold counts), titratable acidity (TA), pH, weight loss, cooking loss, texture profile analysis (TPA), and sensory evaluation (color, odor, hand-feel texture, overall acceptability, and overall preference ranking). The quality parameters of the cooked EFFS were CIE color values and sensory evaluation (color, odor, mouthfeel, texture, flavor, overall acceptability, and overall preference ranking). The results showed that 0.35 and 0.7% RYR increased the a∗ (red/green) values of raw and cooked EFFS but decreased the L∗ (lightness) and b∗ (yellow/blue) values. These RYR levels significantly improved the sensory color, overall acceptability, and overall preference ranking of the raw and cooked EFFSs. However, no statistical differences were observed between the effects of 0.35 and 0.7% RYR. RYR levels did not affect the microbial analyses, TA, pH, weight loss, cooking loss, or TPA. Moreover, they had no effect on the odor and hand-feel texture of raw EFFS, or the odor, mouthfeel texture, or flavor of cooked EFFS. Therefore, RYR supplementation improved the color quality of the EFFSs without altering the other quality parameters, with 0.35% RYR deemed optimal. Moreover, the fermentation period significantly influenced most quality parameters, except CIE color values and sensory color perception of raw and cooked EFFSs. Most sensory parameters improved by day 2, remained unchanged until day 4, and then deteriorated on day 6.

Studying the impact of phycoerythrin on antioxidant and antimicrobial activity of the fresh rainbow trout fillets

Marine cyanobacteria present a significant potential source of new bioactive compounds with vast structural diversity and relevant antimicrobial and antioxidant activities. Phycobiliproteins (PBPs) like phycocyanin (PC), phycoerythrin (PE), and water-soluble cyanobacterial photosynthetic pigments, have exhibited strong pharmacological activities and been used as natural food additives. In this study, phycoerythrin (PE) isolated from a marine strain of cyanobacterium Nostoc sp. Ft salt, was applied for the first time as a natural antimicrobial as well as an antioxidant to increase the shelf life of fresh rainbow trout i.e., (Oncorhynchus mykiss) fillets. Fresh trout fillets were marinated in analytical grade PE (3.9 μg/mL) prepared in citric acid (4 mg/mL), and stored at 4 °C and 8 °C for 21 days. Microbiological analysis, antioxidant activity and organoleptic evaluation of both control and treated fish fillets were then statistically compared. The results demonstrated noticeable (P < 0.05) differences in the microbial counts, antioxidant activity, and organoleptic characteristic values between PE-treated and non-treated groups. In addition, we observed that treating fresh fish fillets with a PE solution leads to a significant increase in shelf life by at least 14 days. Consequently, PE could be an alternative to synthetic chemical additives since it does not contain the potentially dangerous residues of the synthetic chemical additives and is thus healthier to the consumers.

New strategies for sterilization and preservation of fresh fish skin grafts

The introduction of fish skin as a biological dressing for treating burns and wounds holds great promise, offering an alternative to existing management strategies. However, the risk of disease transmission is a significant concern. Therefore, this study aimed to examine how established sterilization and preservation procedures affected fish skin grafts' microbiological and histological properties for long-term usage. Lyophilization of the fish skin graft followed by rehydration in normal saline for 15 min did not change the collagen content. Furthermore, gamma irradiation of the lyophilized fish skin graft at different lengths 5, 10, and 25 KGy showed a significant reduction in microbial growth (aerobic bacteria, aerobic yeasts, and fungi) at 15- and 30 days after the irradiation. However, exposure to 10 KGy was found to be the most effective intensity among the different gamma irradiation lengths since it preserved the collagen fiber content and intensity in the lyophilized fish skin grafts at 15- and 30 days after the irradiation. These findings provide efficient preservation and sterilization methods for long-term usage of the fresh Tilapia skin grafts used for biological dressings.

Current applications and future trends of artificial senses in fish freshness determination: A review

Fish is a highly demanding food product and the determination of fish freshness is crucial as it is a fundamental factor in fish quality. Therefore, the fishery industry has been working on developing rapid fish freshness determination methods to monitor freshness levels. Artificial senses that mimic human senses are developed as convenient emerging technologies for fish freshness determination. Computer vision, electronic nose (e-nose), and electronic tongue (e-tongue) are the emerging artificial senses for fish freshness determination. This review article is uniquely worked upon to investigate the current applications of the artificial senses in fish freshness determination while describing the steps, and fundamental principles behind each artificial sense, comparing them with their advantages and limitations, and future trends related to fish freshness determination. Among the artificial senses, computer vision determines the freshness of fish in a completely nondestructive way while the e-tongue determines the freshness of fish in a completely destructive way. There are developed e-noses for fish freshness determination in both destructive and nondestructive ways. By analyzing visual cues such as color, computer vision systems can assess fish quality without the need for physical contact and it makes computer vision suitable for large-scale industrial fish quality assessing applications. Overall, this review study reveals artificial senses as a proven replacement for traditional sensory panels in determining fish freshness precisely and conveniently. As future trends, there is a demand for developing applications for consumers to determine fish freshness based on artificial senses.

Advancements in nonthermal physical field technologies for prefabricated aquatic food: A comprehensive review

Aquatic foods are nutritious, enjoyable, and highly favored by consumers. In recent years, young consumers have shown a preference for prefabricated food due to its convenience, nutritional value, safety, and increasing market share. However, aquatic foods are prone to microbial spoilage due to their high moisture content, protein content, and unsaturated fatty acids. Furthermore, traditional processing methods of aquatic foods can lead to issues such as protein denaturation, lipid peroxidation, and other food safety and nutritional health problems. Therefore, there is a growing interest in exploring new technologies that can achieve a balance between antimicrobial efficiency and food quality. This review examines the mechanisms of cold plasma, high-pressure processing, photodynamic inactivation, pulsed electric field treatment, and ultraviolet irradiation. It also summarizes the research progress in nonthermal physical field technologies and their application combined with other technologies in prefabricated aquatic food. Additionally, the review discusses the current trends and developments in the field of prefabricated aquatic foods. The aim of this paper is to provide a theoretical basis for the development of new technologies and their implementation in the industrial production of prefabricated aquatic food.

One Health Perspectives on Food Safety in Minimally Processed Vegetables and Fruits: From Farm to Fork

While food markets and food production chains are experiencing exponential growth, global attention to food safety is steadily increasing. This is particularly crucial for ready-to-eat products such as fresh-cut salads and fruits, as these items are consumed raw without prior heat treatment, making the presence of pathogenic microorganisms quite frequent. Moreover, many studies on foodborne illnesses associated with these foods often overlook the transmission links from the initial contamination source. The prevention and control of the dissemination of foodborne pathogens should be approached holistically, involving agricultural production, processing, transport, food production, and extending to final consumption, all while adopting a One Health perspective. In this context, our objective is to compile available information on the challenges related to microbiological contamination in minimally handled fruits and vegetables. This includes major reported outbreaks, specific bacterial strains, and associated statistics throughout the production chain. We address the sources of contamination at each stage, along with issues related to food manipulation and disinfection. Additionally, we provide potential solutions to promote a healthier approach to fresh-cut fruits and vegetables. This information will be valuable for both researchers and food producers, particularly those focused on ensuring food safety and quality.

Extension of shelf life of Nile tilapia (Oreochromis niloticus) fillets using seaweed extracts during refrigerated storage

The effects of seaweed (Padina tetrastromatica, Sargassum natans, and Sargassum fluitans) ethanolic extracts on the quality and shelf life extension of Nile tilapia (Oreochromis niloticus) fillets were investigated during refrigerated storage for 20 days. Each of the seaweed ethanolic extracts solution (2%, w/v) was used for dipping the fish fillets for 10 min at 4°C. The control and seaweed extract-treated fillets were stored at 4 ± 1°C in air-tight polyethylene bags, and chemical, bacteriological, and sensory evaluation were performed at every 4 days' intervals. During the storage period, P. tetrastromatica extract significantly (p < .05) reduced the increment of pH, peroxide value, thiobarbituric acid reactive substances, and total volatile basic nitrogen values in Nile tilapia fillets compared to other seaweed extracts-treated and untreated fillets. The maximal total viable count of control, P. tetrastromatica, S. natans, and S. fluitans extracts-treated fillets was 6.53, 7.11, 6.75, and 7.10 log CFU/g at the 8th, 20th, 12th, and 16th days of storage, respectively. The total psychrotrophic count of control and seaweed extracts-treated fillets was also significantly increased (p < .05) throughout the storage period. The P. tetrastromatica extracts-treated fillets showed better sensory characteristics than other seaweed extracts-treated and control fillets. Results of this study suggest that ethanolic extracts (2%, w/v) of P. tetrastromatica extend the shelf life for 12 days longer than the control fillets in refrigerated conditions.

Gallic and ferulic acids suppress proteolytic activities and volatile trimethylamine production in the food-borne spoiler Rahnella aquatilis KM05

BACKGROUND

Rahnella aquatilis is a recognised microbial threat that alters the sensory properties of seafood. The high frequency with which R. aquatilis is isolated from fish has prompted a search for alternative preservatives. In the present study, in vitro and fish-based ecosystem (raw salmon-based medium) approaches were used to validate the antimicrobial effects of gallic (GA) and ferulic (FA) acids against R. aquatilis KM05. The results were compared with data describing the response of KM05 to sodium benzoate. Bioinformatics data of the whole genome were used to analyse the potential for fish spoilage by KM05 in detail, and the results revealed the main physiological characteristics that underlie reduced seafood quality.

RESULTS

In the KM05 genome, the most abundantly enriched Gene Ontology terms were 'metabolic process', 'organic substance metabolic process' and 'cellular process'. Through an evaluation of the Pfam annotations, 15 annotations were found to be directly involved in the proteolytic activity of KM05. Peptidase_M20 was the most abundantly represented (abundance value of 14060). Proteins representing the CutC family (abundance value of 427) indicated the potential for KM05 degradation of trimethyl-amine-N-oxide. Subinhibitory concentrations of GA and FA suppressed the proteolytic activities of KM05 both in vitro and in RS medium by an average of 33-45%. These results were confirmed by quantitative real-time PCR experiments, which also showed that the expression levels of genes involved in proteolytic activities and volatile trimethylamine production were also decreased.

CONCLUSION

Phenolic compounds can be used as potential food additives for preventing quality deterioration of fish products. © 2023 Society of Chemical 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.

Rapid Assessment of Fish Freshness for Multiple Supply-Chain Nodes Using Multi-Mode Spectroscopy and Fusion-Based Artificial Intelligence

This study is directed towards developing a fast, non-destructive, and easy-to-use handheld multimode spectroscopic system for fish quality assessment. We apply data fusion of visible near infra-red (VIS-NIR) and short wave infra-red (SWIR) reflectance and fluorescence (FL) spectroscopy data features to classify fish from fresh to spoiled condition. Farmed Atlantic and wild coho and chinook salmon and sablefish fillets were measured. Three hundred measurement points on each of four fillets were taken every two days over 14 days for a total of 8400 measurements for each spectral mode. Multiple machine learning techniques including principal component analysis, self-organized maps, linear and quadratic discriminant analyses, k-nearest neighbors, random forest, support vector machine, and linear regression, as well as ensemble and majority voting methods, were used to explore spectroscopy data measured on fillets and to train classification models to predict freshness. Our results show that multi-mode spectroscopy achieves 95% accuracy, improving the accuracies of the FL, VIS-NIR and SWIR single-mode spectroscopies by 26, 10 and 9%, respectively. We conclude that multi-mode spectroscopy and data fusion analysis has the potential to accurately assess freshness and predict shelf life for fish fillets and recommend this study be expanded to a larger number of species in the future.

Irradiation as a Promising Technology to Improve Bacteriological and Physicochemical Quality of Fish

Fish is an excellent source of protein and other essential minerals and vitamins; nevertheless, several food-borne disease outbreaks have been linked to the consumption of different types of fish. Therefore, we aimed to overcome these health threats by evaluating gamma radiation as a good fish preservation method. The aerobic plate count (APC), identification of most common pathogenic bacteria, organoleptic properties, proximate composition, and other chemical evaluations were detected in both untreated and gamma-treated fish. The overall grades of organoleptic evaluations ranged from good to very good. Fortunately, the overall chemical analysis of all examined fish samples was accepted. For the untreated fish samples, the APC was within and above the permissible limit (5 × 10⁷ CFU/g). Pathogenic bacteria were detected with a high prevalence rate, especially S. aureus, which was found in high percentages among examined untreated fish samples. Regarding the treated fish samples, APC and pathogenic bacterial counts were reduced in a dose-dependent manner, and the irradiation at dose 5 KGy resulted in complete eradication of the aerobic plate count (not detectable) with a mean reduction percentage equal to 100%. However, gamma irradiation has no significant effect on proximate composition; particularly, carbohydrates, proteins, and lipids were not significantly affected by low and medium doses of radiation. Therefore, gamma irradiation is a highly effective fish preservation method without any effect on fish quality. Additionally, gamma irradiation as a cold process is an attractive technology for solving the problem arising from fish-borne pathogens, and it has been purposed in this study as a cheap and safe method for reducing microbial contamination of fish.

Effect of sage seed gum film incorporating Zataria multiflora Boiss essential oil on the storage quality and biogenic amine content of refrigerated Otolithes ruber fillets

The effect of an edible film based on sage seed gum (SSG) incorporating 3 % Zataria multiflora Boiss essential oil (ZEO) was investigated on the storage quality and shelf life of tiger-tooth croaker (Otolithes ruber) fillets during storage at 4 ± 1 °C compared to the control film (SSG film without ZEO) and the Cellophane. The SSG-ZEO film significantly decelerated microbial growth (evaluated by total viable count, total psychrotrophic count, pH, TVBN) and lipid oxidation (evaluated by TBARS) compared to the others (P ˂ 0.05). The antimicrobial activity of ZEO was the highest and the lowest on E. aerogenes (MIC: 0.196 μL/mL) and P. mirabilis (MIC: 0.977 μL/mL), respectively. E. aerogenes was identified as an indicator biogenic amine-producer in O. ruber fish at refrigerated temperature. The active film significantly lowered biogenic amine accumulation in the samples inoculated with E. aerogenes. A clear relationship was observed between the release of ZEO's phenolic compounds from the active film to the headspace and the reduction of microbial growth, lipid oxidation, and biogenic amine production in the samples. Consequently, SSG film containing 3 % ZEO is proposed as a biodegradable antimicrobial-antioxidant packaging to extend the shelf life and decrease the biogenic amine production in refrigerated seafood.

Microbial Spectrum and Antibiotic Sensitivity Pattern of Bacteria Isolated from the Spiny Lobster, Panulirus regius (De Brito Capello, 1864)

Microbial spectrum and antibiogram of bacteria isolated from Panulirus regius of the coast of Lagos were analysed using standard techniques. The lobster head had higher total bacteria and total coliform counts with respective significant (P < 0.05) values of 4.17 x 106 ± 1.46 CFU g−1 and 3.06 x 103 ± 1.56 CFU g−1. A higher total fungi count (2.99 x 102 ± 1.63) was recorded in the lobster tail. In the bacterial group, Bacilus megaterium had the highest frequency of occurrence (22.6%) while in the fungal group, Aspergillus niger had the highest frequency of occurrence (20.0%). All isolates were sensitive to ciprofloxacin and showed resistance to rocephin and zinnacef except Micrococcus sp. and Salmonella sp. The presence of antibiotic-resistant bacteria from the lobsters is a serious concern.

Active Packaging Material Based on Immobilized Diatomaceous Earth/Zinc Oxide/High-Density Polyethylene Composite for Sea Food and Products

One of the key factors of supporting the rapidly expanding seafood product industry in terms of quality control is the utilization of active packaging materials. Microorganisms are primarily responsible for the perishability and rapid disintegration of seafood. The incorporation of an inorganic compound, such as silica-based diatomaceous earth (DE), and a metal oxide, such as zinc oxide (ZnO), is proposed to develop active packaging materials with excellent antibacterial activity, minimized fishy odor, and brittleness at subzero temperatures. The mechanical, morphological, and physicochemical properties of these materials were investigated. The results show that the addition of DE/ZnO improved the antibacterial activity of high-density polyethylene (HDPE) samples by up to approximately 95% against both gram-positive and -negative bacteria. Additionally, it enhanced the Izod strength and stability at subzero temperatures of the samples. The odor evaporation test revealed that trimethylamine can be minimized in proportion to increasing DE/ZnO composite concentration. As a result, the development of active packaging materials from DE/ZnO composites is an emerging polymeric packaging technology for seafood products, wherein packaging and seafood quality are linked.

Research Progress on Nutritional Value, Preservation and Processing of Fish-A Review

The global population has rapidly expanded in the last few decades and is continuing to increase at a rapid pace. To meet this growing food demand fish is considered a balanced food source due to their high nutritious value and low cost. Fish are rich in well-balanced nutrients, a good source of polyunsaturated fatty acids and impose various health benefits. Furthermore, the most commonly used preservation technologies including cooling, freezing, super-chilling and chemical preservatives are discussed, which could prolong the shelf life. Non-thermal technologies such as pulsed electric field (PEF), fluorescence spectroscopy, hyperspectral imaging technique (HSI) and high-pressure processing (HPP) are used over thermal techniques in marine food industries for processing of most economical fish products in such a way as to meet consumer demands with minimal quality damage. Many by-products are produced as a result of processing techniques, which have caused serious environmental pollution. Therefore, highly advanced technologies to utilize these by-products for high-value-added product preparation for various applications are required. This review provides updated information on the nutritional value of fish, focusing on their preservation technologies to inhibit spoilage, improve shelf life, retard microbial and oxidative degradation while extending the new applications of non-thermal technologies, as well as reconsidering the values of by-products to obtain bioactive compounds that can be used as functional ingredients in pharmaceutical, cosmetics and food processing industries.

Biopreservation of Refrigerated Mackerel (Auxis thazard) Slices by Rice Starch-Based Coating Containing Polyphenol Extract from Glochidion wallichianum Leaf

Both microbial decomposition and oxidative deterioration contribute to the qualitative degradation of fresh or minimally preserved fish, which negatively impacts the shelf-life of fish, especially those with dark flesh like mackerel. It is becoming more typical to use edible coatings to preserve the freshness of fish products. Herein, the effects of a rice starch (RS) based coating incorporated with dried crude, aqueous Mon-pu (Glochidion wallichianum) leaf extract (MPE) at varying concentrations (0, 0.02, 0.1, 0.5, and 1.0% w/w) on the quality characteristics of mackerel (Auxis thazard) slices during storage at 4 °C were investigated. Uncoated slices had a shelf-life of 6 days, whereas samples coated with RS and 0.5% MPE extended the shelf-life to 9 days by keeping the overall microbiological quality below the permitted level of 6 log CFU/g. The changes in thiobarbituric acid reactive substances (TBARS; <2 mg malondialdehyde equivalent/kg), propanal content, heme iron degradation, myoglobin redox instability, and surface discoloration (a* value and total color difference; ΔE) can all be delayed by this coating condition. Additionally, the RS-MPE coating can maintain the sensory quality of refrigerated mackerel slices and preserve the textural property (water holding capacity and hardness), as well as postpone the development of an off-odor as indicated by lowered contents of total volatile base-nitrogen (TVB-N; not exceeding the acceptable limit of 25 mg/100 g) and trimethylamine (TMA; not exceeding the acceptable limit of 10 mg/100 g). Therefore, a biopreservative coating made of RS and MPE, especially at 0.5%, can be employed to extend the shelf-life of refrigerated mackerel slices up to 9 days.

A Comprehensive Review on the Processing of Dried Fish and the Associated Chemical and Nutritional Changes

Fish is a good source of nutrients, although it is easily spoiled. As such, drying is a common method of preserving fish to compensate for its perishability. Dried fish exists in different cultures with varying types of fish used and drying methods. These delicacies are not only consumed for their convenience and for their health benefits, as discussed in this review. Most commonly, salt and spices are added to dried fish to enhance the flavours and to decrease the water activity (aw) of the fish, which further aids the drying process. For fish to be dried effectively, the temperature, drying environment, and time need to be considered along with the butchering method used on the raw fish prior to drying. Considering the various contributing factors, several physicochemical and biochemical changes will certainly occur in the fish. In this review, the pH, water activity (aw), lipid oxidation, and colour changes in fish drying are discussed as well as the proximate composition of dried fish. With these characteristic changes in dried fish, the sensory, microbial and safety aspects of dried fish are also affected, revolving around the preferences of consumers and their health concerns, especially based on how drying is efficient in eliminating/reducing harmful microbes from the fish. Interestingly, several studies have focused on upscaling the efficiency of dried fish production to generate a safer line of dried fish products with less effort and time. An exploratory approach of the published literature was conducted to achieve the purpose of this review. This evaluation gathers important information from all available library databases from 1990 to 2022. In general, this review will benefit the fishery and food industry by enabling them to enhance the efficiency and safety of fish drying, hence minimising food waste without compromising the quality and nutritional values of dried fish.

Halochromic Inks Applied on Cardboard for Food Spoilage Monitorization

Control of food spoilage is a critical concern in the current world scenario, not only to ensure the quality and safety of food but also to avoid the generation of food waste. This paper evaluates a dual-sensor strategy using six different pH indicators stamped on cardboard for the detection of spoilage in three different foods: beef, salmon, and strawberries. After function validation and formulation optimizations in the laboratory, the halochromic sensors methyl orange and bromocresol purple 2% (w/v) were stamped on cardboard and, in contact with the previously mentioned foods, were able to produce an easily perceptible signal for spoilage by changing color. Additionally, when it comes to mechanical characterization the inks showed high abrasion (>100 cycles) and adhesion resistance (>91%).

Edible Xanthan/Propolis Coating and Its Effect on Physicochemical, Microbial, and Sensory Quality Indices in Mackerel Tuna (Euthynnus affinis) Fillets during Chilled Storage

Worldwide aquaculture production is increasing, but with this increase comes quality and safety related problems. Hence, there is an urgent need to develop potent technologies to extend the shelf life of fish. Xanthan gum is commonly used in the food industry because of its high-water solubility, stability of its aqueous solutions in a wide pH range, and high viscosity. One of its modern food applications is its use as a gelling agent in edible coatings building. Therefore, in this study, the effect of xanthan coating containing various concentrations (0, 1, 2%; w/v) of ethanolic extract of propolis (EEP) on physicochemical, microbial, and sensory quality indices in mackerel fillets stored at 2 °C for 20 days was evaluated. The pH, peroxide value, K-value, TVB-N, TBARS, microbiological and sensory characteristics were determined every 5 days over the storage period (20 days). Samples treated with xanthan (XAN) coatings containing 1 and 2% of EEP were shown to have the highest level of physicochemical protection and maximum level of microbial inhibition (p < 0.05) compared to uncoated samples (control) over the storage period. Furthermore, the addition of EEP to XAN was more effective in notably preserving (p < 0.05) the taste and odor of coated samples compared to control.

Introduction to the Special Issue: Advanced Strategies to Preserve Quality and Extend Shelf Life of Foods

We are pleased to present this Special Issue, which includes 13 papers that highlight the most important research activities in the field of food quality assurance and shelf-life extension [...]

Large volume headspace GC/MS analysis for the identification of volatile compounds relating to seafood decomposition

Decomposition in seafood products in the United States is monitored by the Food and Drug Administration (FDA) laboratories using sensory testing, which requires highly trained analysts. A large‐volume headspace (LVHS) gas chromatography/mass spectrometry (GC/MS) method was developed to generate analytical results that can be directly compared to sensory evaluation. Headspace vapor was withdrawn from a 1‐L vial containing 50 g seafood sample using a large volume headspace autosampler. Various volatile compounds were collected simultaneously. Analytes were preconcentrated by a capillary column trapping system and then sent through a cryo‐focuser mounted onto the GC injector. A selected ion monitoring (SIM) MS acquisition method was used to selectively monitor 38 compounds of interest. Samples of red snapper, croaker, weakfish, mahi‐mahi, black tiger shrimp, yellowfin tuna, and sockeye salmon that have been assessed and scored by an FDA National Seafood Sensory Expert (NSSE) were used for method performance evaluation. Characteristic compounds potentially associated with seafood quality deterioration for each seafood species were identified by quantitative analysis using pooled matrix‐matched calibrations and two‐sample t‐test statistical analysis. Classification of fresh and decomposed samples was visualized on the analysis of variance (ANOVA)–principal component analysis (PCA) score plots. The results determined that the LVHS‐GC/MS technique appeared promising as a screening tool to identify compounds representative of sensory analysis.

Seasonal Pattern of the Effect of Slurry Ice during Catching and Transportation on Quality and Shelf Life of Gilthead Sea Bream

The objective of the present study was the evaluation of the effect of slurry ice, as an alternative cooling medium during harvesting and transportation, on the quality parameters (e.g., microbiological stability, sensory attributes, physicochemical changes) and shelf life of fish. The effect of seasonal variability of seawater temperature on fish preservation using the tested cooling media was also investigated. Gilthead sea bream (Sparus aurata) was slaughtered and transported in different mixtures of conventional flake ice and slurry ice for 24 h. Three mixtures of ice were tested as T: slaughtered in flake ice and transported in flake ice (control), TC: slaughtered in slurry ice and transported in flake ice, T50: slaughtered and transported in slurry ice 50%–flake ice 50%. Samples were subsequently stored isothermally at 0 °C for shelf-life evaluation. Three independent experiments were performed at three different periods, i.e., January, April, and September, referring to a sea water temperature range of 13.3–26.8 °C. Higher sea water temperatures at catching led to lower microbial growth rates and proteolytic enzyme activities and longer shelf life of refrigerated whole fish. The partial replacement of conventional flake ice with slurry ice improved the quality and extended the shelf life of fish at 0 °C by 2–7 days. The results of the study support that the use of slurry ice may enable better quality maintenance and significant shelf-life extension of whole gilthead sea bream.

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)

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.

Seafood Processing, Preservation, and Analytical Techniques in the Age of Industry 4.0

Fish and other seafood products are essential dietary components that are highly appreciated and consumed worldwide. However, the high perishability of these products has driven the development of a wide range of processing, preservation, and analytical techniques. This development has been accelerated in recent years with the advent of the fourth industrial revolution (Industry 4.0) technologies, digitally transforming almost every industry, including the food and seafood industry. The purpose of this review paper is to provide an updated overview of recent thermal and nonthermal processing and preservation technologies, as well as advanced analytical techniques used in the seafood industry. A special focus will be given to the role of different Industry 4.0 technologies to achieve smart seafood manufacturing, with high automation and digitalization. The literature discussed in this work showed that emerging technologies (e.g., ohmic heating, pulsed electric field, high pressure processing, nanotechnology, advanced mass spectrometry and spectroscopic techniques, and hyperspectral imaging sensors) are key elements in industrial revolutions not only in the seafood industry but also in all food industry sectors. More research is still needed to explore how to harness the Industry 4.0 innovations in order to achieve a green transition toward more profitable and sustainable food production systems.

Freeze-Chilling of Whitefish: Effects of Capture, On-Board Processing, Freezing, Frozen Storage, Thawing, and Subsequent Chilled Storage-A Review

The current review investigates how whitefish quality is affected by capture at sea, on board handling, freezing, double freezing, frozen storage, thawing, and chilled storage. Packaging of fillets in MAP and vacuum are also covered. The main goal was to evaluate the freeze-chilling concept as a possible method for the fishing industry for all-year-round marketing of fish captured during the relatively short fishing period. The review covers both the effect of each processing step in the supply chain as well as the combined effect of all steps in the chain from sea to consumer, including post-thawing chilled storage, defined as the freeze-chilling method.