Gelling properties of silver carp surimi incorporated with konjac glucomannan: Effects of deacetylation degree.

Effects of konjac glucomannan (KGM) with different deacetylation degrees on silver carp surimi gel properties were studied. As deacetylation degree increased, viscosity, solubility, and water absorption capability of KGM decreased gradually while particle size increased. The gel strength of surimi gel increased with the KGM deacetylation degree up to 50.72% and then significantly decreased. The maximum gel strength was 3.26 times higher than that of surimi gel with native KGM. The relaxation time of immobilized water decreased from 108.22 to 104.70 ms and then increased up to 110.92 ms with the deacetylation degree, while the proportion of the immobilized water increased from 92.74 to 98.59% and then decreased to 97.46%. Water distribution became less uniform as the deacetylation degree exceeded 50.72%. Surimi gel with KGM of a higher deacetylation degree formed a denser microstructure along with a higher dimensional fraction value. However, the microstructure was disrupted and the dimensional fraction value decreased as the deacetylation degree exceeded 50.72%. Chemical interactions including hydrogen bonds, hydrophobic interactions, and cross-linking extent increased with the KGM deacetylation degree up to 50.72% and then gradually decreased. The results suggest that KGM with a deacetylation degree of 50.72% is the most suitable for surimi products.

A starch-based pH-sensing and ammonia detector film containing betacyanin of paperflower for application in intelligent packaging of fish.

An easy-to-use food packaging label with pH and ammonia sensitivity was developed by adding betacyanin (5, 10 and 15 mg per g of starch) from flowers of paperflower (Bougainvillea glabra) to potato starch film made using the solvent casting method. The betacyanin was well dispersed into the starch matrix and formed new interactions with it as revealed by FTIR. The film containing 15 mg/g of betacyanin showed a color change from light pink to yellow as a response to pH adjustment of between 2 to 13. It was also able to detect the presence of ammonia in a range of 0.1 and 0.01 mg of ammonia per ml of water. Surface hydrophobicity and water vapor barrier capacity of the starch film increased by addition of the betacyanin, yet their mechanical strength decreased in the presence of the betacyanin. The ability of the film in the real-time indication of fish quality as a label was also evaluated during the storage of Caspian sprat at 4 °C. A visual change in the color of the packaging label from pink to yellow in parallel with the increase in the total volatile basic nitrogen (TVB-N), microbial count of the fish samples was detected. The starch/betacyanin film could be a novel intelligent label for application in food packaging.

Synergistic anti-oxidative and antimicrobial effects of oat phenolic compounds and ascorbate palmitoyl on fish balls during cold storage.

This study investigated the effect of antioxidants on lipid stability of mackerel (Scomber japonicus) fish balls. Oat phenolic acid compounds (OPC) and ascorbate palmitoyl (AP) were used to prolong the shelf life of steamed mackerel fish balls. Fish balls were stored at 4°C for 21 days, and the total bacterial count, hardness, whiteness, water holding capacity (WHC), pH, total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) value were monitored regularly. The results indicated that OPC+AP composite as a biological preservative could significantly inhibit the increase of the total bacterial count. Meanwhile, OPC and AP could maintain better hardness, whiteness, and WHC of fish balls during refrigerated storage. Furthermore, OPC and AP slowed down the increase of TVB-N and TBARS values. The results showed that OPC+AP had a synergistic effect on the storage time and could prolong the shelf life within the storage time. Adding OPC and AP was a promising strategy to improve the quality and shelf life of fish balls. PRACTICAL APPLICATION: The research provided a new application of OPC and AP for improving fish balls quality and shelf life during cold storage (4°C). OPC is a natural plant secondary metabolite from oat which exhibits excellent anti-oxidation. The research showed that OPC and AP combined with synergistic effect as biological preservatives can effectively inhibit the total bacterial count and reduce TBARS and TVB-N value of fish balls during the shelf life and maintain the hardness, which improved the quality and shelf life of fish balls.

Illegal, Unreported, and Unregulated Fisheries Threatening Shark Conservation in African Waters Revealed from High Levels of Shark Mislabelling in Ghana.

Mislabelling of fish and fish products has attracted much attention over the last decades, following public awareness of the practice of substituting high-value with low-value fish in markets, restaurants, and processed seafood. In some cases, mislabelling includes illegal, unreported, and unregulated (IUU) fishing, contributing to overexploit substitute species that are undetectable when sold under wrong names. This is the first study of DNA barcoding to assess the level of mislabelling in fish marketed in Ghana, focusing on endangered shark species. Genetic identification was obtained from 650 base pair sequences within the cytochrome c oxidase I (COI) gene. All except one of 17 shark fillets analysed were wrongly labelled as compared with none of 28 samples of small commercial pelagic fish and 14 commercial shark samples purchased in Europe. Several substitute shark species in Ghana are endangered (Carcharhinussignatus and Isurusoxyrinchus) and critically endangered (Squatina aculeata). Shark products commercialized in Europe (n = 14) did not reveal mislabelling, thus specific shark mislabelling cannot be generalized. Although based on a limited number of samples and fish markets, the results that reveal trade of endangered sharks in Ghana markets encourage Ghanaian authorities to improve controls to enforce conservation measures.

Starch-fatty acid complexes improve the gel properties and enhance the fatty acid content of Nemipterus virgatus surimi under high-temperature treatment.

The effect of high amylose corn starch (HAS)-fatty acid complexes on the gel properties, protein secondary structure, microstructure, fatty acid content, and sensory properties of surimi under high-temperature treatment were investigated. The formation of HAS-fatty acid complexes increased melting temperature and decreased average particle size of HAS. The addition of HAS-fatty acid complexes significantly improved the breaking force, deformation and whiteness of surimi gels. The water in surimi gels containing HAS or HAS-fatty acid complexes became increasingly immobilized. HAS or HAS-fatty acid complexes promoted protein conformational transition from α-helix structure to other three secondary structure. Surimi gels added with HAS-fatty acid complexes had more compact network structure and higher fatty acid content. Moreover, the better sensory properties were obtained in surimi gels containing HAS-fatty acid complexes. Therefore, starch-fatty acid complexes not only could improve the gel properties of surimi, but also enhance its fatty acid content.

The heritable landscape of near-infrared and Raman spectroscopic measurements to improve lipid content in Atlantic salmon fillets.

BACKGROUND: Product quality and production efficiency of Atlantic salmon are, to a large extent, influenced by the deposition and depletion of lipid reserves. Fillet lipid content is a heritable trait and is unfavourably correlated with growth, thus genetic management of fillet lipid content is needed for sustained genetic progress in these two traits. The laboratory-based reference method for recording fillet lipid content is highly accurate and precise but, at the same time, expensive, time-consuming, and destructive. Here, we test the use of rapid and cheaper vibrational spectroscopy methods, namely near-infrared (NIR) and Raman spectroscopy both as individual phenotypes and phenotypic predictors of lipid content in Atlantic salmon. RESULTS: Remarkably, 827 of the 1500 individual Raman variables (i.e. Raman shifts) of the Raman spectrum were significantly heritable (heritability (h2) ranging from 0.15 to 0.65). Similarly, 407 of the 2696 NIR spectral landscape variables (i.e. wavelengths) were significantly heritable (h2 = 0.27-0.40). Both Raman and NIR spectral landscapes had significantly heritable regions, which are also informative in spectroscopic predictions of lipid content. Partial least square predicted lipid content using Raman and NIR spectra were highly concordant and highly genetically correlated with the lipid content values ([Formula: see text] = 0.91-0.98) obtained with the reference method using Lin's concordance correlation coefficient (CCC = 0.63-0.90), and were significantly heritable ([Formula: see text] = 0.52-0.67). CONCLUSIONS: Both NIR and Raman spectral landscapes show substantial additive genetic variation and are highly genetically correlated with the reference method. These findings lay down the foundation for rapid spectroscopic measurement of lipid content in salmonid breeding programmes.

Fish Consumption and Cardiovascular Health: A Systematic Review.

Studies evaluating fish consumption and cardiovascular disease events have shown inconsistent results. We performed a systematic review of peer-reviewed publications from an extensive query of Ovid MEDLINE, Ovid Embase, Ovid Cochrane Database of Systematic Reviews, Scopus, and Web of Science from database inception to September 2020 for observational studies that reported the association between fish consumption and cardiovascular disease events. We identified and reviewed 24 studies related to fish consumption and the effect on cardiovascular outcomes. The study population included a total of 714,526 individuals and multiple cohorts from several countries. We found that nonfried fish consumption is probably associated with a reduced risk of overall cardiovascular disease events and myocardial infarction risk. In contrast, fried fish consumption is probably associated with an increased risk of overall cardiovascular disease events and myocardial infarction risk. No studies to date have shown any significant association between fish consumption and stroke. Our analysis suggests that fish consumption may reduce cardiovascular disease events, but fried fish consumption was associated with an increased risk of cardiovascular events.

Microalgae-blend tilapia feed eliminates fishmeal and fish oil, improves growth, and is cost viable.

Aquafeed manufacturers have reduced, but not fully eliminated, fishmeal and fish oil and are seeking cost competitive replacements. We combined two commercially available microalgae, to produce a high-performing fish-free feed for Nile tilapia (Oreochromis niloticus)-the world's second largest group of farmed fish. We substituted protein-rich defatted biomass of Nannochloropsis oculata (leftover after oil extraction for nutraceuticals) for fishmeal and whole cells of docosahexaenoic acid (DHA)-rich Schizochytrium sp. as substitute for fish oil. We found significantly better (p < 0.05) growth, weight gain, specific growth rate, and best (but not significantly different) feed conversion ratio using the fish-free feed compared with the reference diet. Fish-free feed also yielded higher (p < 0.05) fillet lipid, DHA, and protein content (but not significantly different). Furthermore, fish-free feed had the highest degree of in-vitro protein hydrolysis and protein digestibility. The median economic conversion ratio of the fish-free feed ($0.95/kg tilapia) was less than the reference diet ($1.03/kg tilapia), though the median feed cost ($0.68/kg feed) was slightly greater than that of the reference feed ($0.64/kg feed) (p < 0.05). Our work is a step toward eliminating reliance on fishmeal and fish oil with evidence of a cost-competitive microalgae-based tilapia feed that improves growth metrics and the nutritional quality of farmed fish.

Effect of the sodium reduction and smoking system on quality and safety of smoked salmon (Salmo salar).

Excessive sodium (Na) intake has been associated with high blood pressure and cardiovascular diseases. Therefore, sodium reduction is a public health challenge worldwide. The aim of this study was to develop smoked salmon with a reduced Na content. Sodium chloride (NaCl) was replaced by potassium chloride (KCl) at 25% and 50% (molar replacement) and studied in combination with two smoking procedures (natural wood and liquid smoke) as well as two smoking temperatures (18-19 °C or 56 °C). Smoked salmon samples were characterized by physicochemical, sensory and microbiological analyses. No major differences were observed regarding physicochemical properties in the studied treatments. Smoked samples with 50% of NaCl replaced by KCl were slightly more bitter than those with 25% whereas samples with 25% of replacement did not show differences to those with non-reduced Na content (5 g of added NaCl per 100 g of salmon). Molar Na:K ratio decreased from 4,3 in controls to 1,4 and 0,6 in samples with a NaCl reduction level of 25% and 50% respectively. Microbiological assessment indicates that 2-week shelf-life would be appropriate and safe in terms of accomplishment of the EU regulation, taking into account foreseeable storage temperatures (up to 8 °C). Thus, it is possible to achieve a reduction of 25-50% of NaCl in smoked salmon by replacing NaCl by KCl and considerer this product as a "source" of K.

Characterization of surface Aspergillus community involved in traditional fermentation and ripening of katsuobushi.

A soup stock made from katsuobushi is an important element of, and the basic seasoning responsible for the taste of, traditional Japanese cuisine. Fermented and ripened katsuobushi, called karebushi, is manufactured via a repeated molding process on the katsuobushi surface. Our aim was to characterize the surface Aspergillus community and their enzymes involved in the fermentation and ripening. Five dominant Aspergillus species isolated from the karebushi surface were identified-A. amstelodami, A. chevalieri, A. pseudoglaucus, A. ruber, and A. sydowii. Analyses were performed on final molding stage-samples from different manufacturers, and 1st to 4th molding stage-samples from the same manufacturer. The composition ratios of the five Aspergillus spp. varied according to the manufacturer of the karebushi. A. amstelodami and A. chevalieri tended to be detected as dominant species when the water content of the karebushi fillet was >15% and the fat content was >3.5%, respectively. In samples from a given manufacturer, the dominant species in the final molding stage tended to be A. chevalieri and A. pseudoglaucus. Mixed molds were cultured by solid-state fermentation using katsuobushi powder medium at two different water activity (aw) levels. Crude extracts from each culture showed lipase, aminopeptidase, carboxypeptidase, and protease activities. Notably, the crude extracts cultivated at 0.85 aw showed higher protease activity toward hemoglobin and lipase activity toward p-nitrophenyl palmitate than those at 0.95 aw. These hydrolytic enzymes are probably involved in decolorization of katsuobushi and lipid degradation during the long fermentative and ripening period. In addition, mixed cultures could transform 2,6-dimethoxyphenol into 1,2,3-trimethoxybenzene, previously reported as an attractive and mild flavor component. Our results may help promote the use of desirable Aspergillus spp. as starter cultures for manufacturers to stabilize and improve the quality of fermented and ripened karebushi.

Quality, functionality, and microbiology of fermented fish: a review.

Fermentation is a traditional food preservation method and is widely used for improving food safety, shelf life, and organoleptic and nutritional attributes. Fermented fish are produced and consumed in different parts of the world and are an integral part of many food cultures. Furthermore, fermented fish are a source of interesting microbes and are an important industry in many countries. This review tries to update the types and manufacturing processes for fermented fish around the world. The emphasis is on this work related to fermented fish and their health benefits, as well as the contribution of microorganisms to their fermentation. A variety of different approaches have been used to determine and understand microbial composition and functionality. Moreover, some challenges and future research directions regarding fermented fish are also discussed in this review. Further research into fermented fish products is of crucial importance not only for the food industry but also for human health. However, extensive in vivo and toxicological studies are essential before the application of bioactive-rich fermented fish products for human health benefits.

Study on assessment of proximate composition and meat quality of fresh and stored Clarias gariepinus and Cyprinus carpio / Estudo da avaliação da composição centesimal e da qualidade da carne de Clarias gariepinus e Cyprinus carpio

Abstract The organoleptic evaluation and proximate analysis of Clarias gariepinus and Cyprinus carpio were determined in fresh fish and when refrigerated at two different temperatures (-21 °C and 4 °C) for a period of six weeks. A panel of twelve trained judges evaluated the color (live), texture, softness and flavor of fish meat after two minutes' steam cooking. Average score revealed a general decline in organoleptic properties such as color, texture, freshness, and taste of C. gariepinus and C. carpio stored at two temperatures compared to the fresh fish. Proximate analysis revealed a more decrease in crude protein and lipid contents and increase in ash content in C. gariepinus and C. carpio at the two storage temperatures compared to the fresh fish muscle. Moisture content decreased in the fish muscle samples of both the fish species stored at -21 °C but increased in the 4 °C stored samples. pH of fish was found to increase in the two stored temperatures. There were significant differences (P<0.05) in the organoleptic and proximate composition of the ice stored and fresh C. gariepinus and C. carpio, the same temperature and between the two different temperatures. The quality of fish muscle stored at 4 °C deteriorated faster than that of the -21 °C. Thus, storage temperature and duration have adverse effects on the nutritional quality of fish meat.

Resumo A avaliação organoléptica e a análise aproximada de Clarias gariepinus e Cyprinus carpio foram determinadas em peixe fresco e refrigerado a duas temperaturas diferentes (-21 °C e 4 °C) por um período de seis semanas. Um painel de doze juízes treinados avaliou a cor (ao vivo), textura, maciez e sabor da carne de peixe após dois minutos de cozimento a vapor. O escore médio revelou um declínio geral nas propriedades organolépticas, como cor, textura, frescor e sabor de C. gariepinus e C. carpio armazenados a duas temperaturas em comparação com o peixe fresco. A análise imediata revelou uma maior diminuição nos teores de proteína bruta e lipídios e aumento no teor de cinzas em C. gariepinus e C. carpio nas duas temperaturas de armazenamento em comparação com o músculo do peixe fresco. O teor de umidade diminuiu nas amostras de músculo de peixe de ambas as espécies de peixes armazenadas a -21 °C, mas aumentou nas amostras armazenadas a 4 °C. O pH dos peixes aumentou nas duas temperaturas armazenadas. Houve diferenças significativas (P <0,05) na composição organoléptica e próxima do gelo armazenado e fresco C. gariepinus e C. carpio, a mesma temperatura e entre as duas temperaturas diferentes. A qualidade do músculo do peixe armazenado a 4 °C deteriorou-se mais rapidamente do que a temperatura de -21 °C. Assim, a temperatura e duração do armazenamento têm efeitos adversos na qualidade nutricional da carne de peixe.

Effect of Tartary Buckwheat Peptides on Shelf Life of Tilapia (Oreochromis niloticus) Fillets.

Tartary buckwheat peptides (TBPs), produced from tartary buckwheat through solid-state fermentation, were used as a dip treatment solution to preserve tilapia fillets. Fillets were dip treated with different concentrations of TBPs (0.5, 1, and 2% [v/v]) and stored at 4°C for 12 days. The effect of TBPs on thiobarbituric acid, total volatile base nitrogen, surface color, texture profile analysis, total viable counts, and changes in sensory properties of tilapia fillets during storage was investigated. Compared with the control group, the groups treated with TBPs displayed reduced rates of quality deterioration in physicochemical, bacteriological, and sensory characteristics. Based on total volatile base nitrogen content, total viable counts, and sensory scores, the shelf life of control tilapia fillets was 4 days and that for TBP-treated fillets was 8 days, twice as long as that of the control group. Thus, TBPs can be used as preservatives to maintain the quality and extend the shelf life of tilapia fillets stored at 4°C.

DNA Barcoding Revealed Mislabeling and Potential Health Concerns with Roasted Fish Products Sold across China.

HIGHLIGHTS: 75.5% of products were identified as species outside the expected family. Six products were identified as containing multiple species from distinct families. Species from distinct families were verified in products of same brand for six groups. Identification of potentially toxic pufferfish species highlighted health concerns.

Preparation and Characterization of a Pectin Membrane-Based Optical pH Sensor for Fish Freshness Monitoring.

In a simple and instant procedure for detecting fish freshness, a hydrogel and hydrophilic pectin matrix membrane was used successfully as an optical pH sensor by immobilizing the chromoionophore ETH 5294 (CI), which is very selective and sensitive for the membrane. The Pe/CI optical pH sensor exhibited excellent linearity between pH 5 and pH 9, with a sensor response time of 5 min and reproducibility of 1.49% relative standard deviation (RSD). The sensor showed response stability for 15 days and a response reduction of 8.6%. The sensor's capability was demonstrated by the detection of fish freshness for 17 days at 4 °C.

Survey of mislabelling across finfish supply chain reveals mislabelling both outside and within Canada.

Seafood has become one of the most heavily traded food commodities in the era of globalization. International seafood supply chains are complex and contend with many difficulties in bringing an enormous variety of products to market. A major challenge involves accurately labelling products such that they comply with a diverse set of regulatory frameworks, ranging from country-of-origin through to the final point of consumer sale. Thanks to DNA barcoding, seafood mislabelling is now recognized as a global problem, with potentially negative impacts on human health, economy and the environment. Mislabelling can result from species misidentification, use of inappropriate common names, incomplete and/or out-dated regulatory frameworks, or through market substitution. While prior studies have focused primarily on retail and food service establishments, this study used barcoding to assess rates of finfish mislabelling at multiple points in the supply chain within Ontario, Canada. A total of 203 specimens from 12 key targeted species were collected from varied importers, registered processing plants and retailers in Southern Ontario and identified using DNA barcoding. Species identity of samples was used to assess conformity of labelling against the Canadian Food Inspection Agency's (CFIA) Fish List, which revealed an overall mislabelling rate of 32.3% among targeted species. The mislabelling rate was significantly different between samples collected from importers and retailers. Among the mislabelled samples were seven samples that originated from US and were properly labelled according to US Food and Drug Administration (FDA) Seafood List. This study evaluated the integrity of chain of custody documents and identified discrepancies in 43 samples (21.4%). Implementing seafood traceability throughout the supply chain and harmonizing labelling regulations between countries can help to ensure industry compliance in a globalized market, while sampling at multiple points in the supply chain can help to reveal causes.

Avaliação das condições higiênico-sanitárias e de manipulação dos pescados comercializados no mercado da produção de Maceió-AL / Evaluation of hygienic-sanitary conditions and handling of fish marketed on the Maceió-AL production market

Pescado compreende os peixes, crustáceos, moluscos, quelônios e mamíferos de água doce ou salgada usados na alimentação humana. O Brasil é um dos líderes em produção de pescado, porém o consumo é considerado baixo no País. O consumo inferior pode ser desencadeado pelo custo, mas também pela baixa qualidade dos pescados, causada pela falta de boas práticas durante a manipulação e as condições físicas dos locais de comercialização. Neste sentindo, o objetivo deste trabalho foi avaliar as condições higiênico-sanitárias dos pescados que são comercializados no mercado da produção na cidade de Maceió-Alagoas, a fim de identificar os riscos que possam comprometer a qualidade do pescado e em consequência à saúde do consumidor. Foram entrevistados cerca de 17 manipuladores, abordados de maneira aleatória e realizado a coleta de dados sobre o nível de conhecimento dos manipuladores relacionado as boas práticas de manipulação. Posteriormente foi analisado o armazenamento do pescado, fonte de água, higiene dos boxes, descarte de resíduos, presença de animais no local e uniformes de acordo com a RDC 216/2004. Após as avaliações observacionais, constatou-se que as características avaliadas não correspondem aos padrões exigidos pela legislação, bem como, os manipuladores desses produtos, desconhecem as regras básicas de boas práticas de manipulação dos alimentos.

Avaliação das condições higiênico-sanitárias e estruturais da comercialização de pescado nas feiras livres de Palmas - TO / Evaluation of the hygienic-sanitary and structural conditions of the fish marketing in the free fairs of Palmas - TO

O objetivo deste estudo foi avaliar as condições higiênico-sanitárias da comercialização de pescado em feiras livres em Palmas – TO. Foi aplicada a lista de verificação, adaptada da RDC n° 275, da ANVISA, avaliando-se uma série de itens divididos em 9 blocos. A feira do Aureny I apresentou o maior índice de inconformidades (66%), em relação à feira da 1112 sul (61%) e a feira da 304 sul (52%). A comercialização de pescado apresenta índices críticos de inadequação à legislação, devido a que os feirantes desconhecem as Boas Práticas de Manipulação e as instalações físicas não foram projetadas para contribuir a uma comercialização em condições higiênico-sanitárias adequadas. É necessária a capacitação dos manipuladores em Boas Práticas de Fabricação, visando a comercialização de pescado em condições higiênico-sanitárias satisfatórias.

Avaliação das condições higiênico-sanitárias na comercialização de pescado no mercado do peixe no município de São Luís - MA / Evaluation of sanitary conditions on fish marketing in the fish market in the municipality of São Luís - MA

A demanda de pescado tem crescido devido às mudanças de hábitos alimentares da população, sendo frequente a comercialização em feiras e mercados públicos. Contudo, os hábitos irregulares como a falta de atenção ao manipular e armazenar o pescado pode desencadear graves problemas à saúde pública. Este trabalho teve como objetivo avaliar as condições higiênicos sanitários da comercialização de pescado no Mercado do Peixe de São Luís - MA. Foi utilizado o método observacional direto e aplicação de check list fundado na RDC nº 275 do Ministério da Saúde. Os resultados evidenciaram algumas desconformidades relacionadas ao manejo de resíduos, vestimenta dos manipuladores e resfriamento de pescado, não atendendo os padrões de higiene e acondicionamento para comercialização de pescado.

Acellular Fish Skin Grafts for Management of Split Thickness Donor Sites and Partial Thickness Burns: A Case Series.

METHODS: Ten patients having split-thickness skin grafting for burn injury were treated with the fish skin xenografts. RESULTS: There were no adverse reactions noted on the use of the fish skin grafts. No patient had any reaction to the fish skin and there was a zero incidence of infection. The handling of the fish skin was excellent, a robust and pliable xenograft that was easy to apply.The quality of donor site healing was judged to be good in all cases. Both the analgesic effect noted and the relatively short average times until 100% re-epithelialization are promising. We also illustrate two cases where the dressing was used to treat superficial burns.