Scaling up parameters for shelf-life extension of Atlantic Salmon (Salmo salar) fillets using superchilling and modified atmosphere packaging

Significantly Different Lipid Profile Analysis of Litopenaeus vannamei under Low-Temperature Storage by UPLC-Q-Exactive Orbitrap/MS

Low-temperature storage is one of the most important preservation methods for aquatic product storage. However, the effects of low-temperature storage on the lipid profiles of shrimp are unclear. Herein, UPLC-Q-Exactive Orbitrap/MS combined with LipidSearch software was applied to analyze the effect of three low storage temperatures (4 °C, -2 °C, and -18 °C) on the lipidomics of Litopenaeus vannamei. A total of 15 lipid classes were analyzed, and PC, PE, DG, and TG accounted for vast majority of peak areas. Furthermore, 531 individual lipid variables enriched in 12 metabolic pathways were identified via bioinformatics analysis methods. A total of 56 significantly different lipid molecular species (55 belonging to PC, PE, DG, and TG) were selected as potential biomarkers of lipid oxidation via correlational analysis between physical properties (texture and color) and individual lipid variables. The results indicated that the three low storage temperatures caused different effects on the lipidomics profile of L. vannamei, and PC, PE, DG, and TG could become potential focuses in further studies of lipid oxidation in L. vannamei.

Understanding the role of atmospheric cold plasma (ACP) in maintaining the quality of hairtail (Trichiurus Lepturus)

Impacts of atmospheric cold plasma (ACP) on the properties of muscle protein and performance of extracted crude enzyme of hairtail (Trichiurus Lepturus) fish have been evaluated. A decrease in extracted crude enzyme activity with increasing the ACP treatment time has been found, and the highest reduction (p < 0.05) value of 0.035 units/mg proteins was obtained after 240 s. A considerable increase in the carbonyl content in the treated sample for about three times higher than the control sample was found, and a decrease of total sulfhydryl content to 0.34 nmol/mg protein. Texture profile analysis, water holding capacity, and the color properties of the muscle protein improved significantly in the samples treated with ACP. SDS-PAGE pattern showed an increase in the band intensity of cross-linked myosin heavy chains and actin proteins. Based on these outcomes, ACP could play a significant role as a promising non-thermal method to prolong the shelf-life of hairtail fish.

Characterisation of Biologically Active Hydrolysates and Peptide Fractions of Vacuum Packaging String Bean (Phaseolus vulgaris L.)

The aim of the study is to characterise biologically active hydolysates and peptide fractions obtained from vacuum-packed string beans (Phaseolus vulragis L.) (PB). Unpacked beans were a control sample. The influence on human squamous carcinoma cell line SCC-15 (ATCC CRL-1623) was determined. Packed bean (PB) and unpacked bean (UB) extracts were found to exert no effect on the tongue squamous carcinoma cells. The results of the study indicated that the packing process contributed to the retention of protein, soluble dietary fibre, and free sugar (2.36, 3.5, and 1.79 g/100 d.m., respectively). PB was characterised by higher antioxidant activity (expressed as neutralisation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS ABTS•+) and 2,2-diphenyl-1-picrylhydrazyl (DPPH·) free radicals) as well as Fe2+ chelation and reducing power (IC50 = 54.56, 0.46, 3.85 mg mL-1; 0.088 A700/peptide content, respectively) than the UB samples before hydrolysis. The hydrolysis process enhanced these properties. The IC50 value of lipase and α-amylase inhibitory activity of the hydrolysates obtained from UB was reduced. The PB and UB fractions exhibited a certain level of antimicrobial activity against S. aureus and E. coli. Candida albicans were not sensitive to these peptide fractions.

Effect of low-temperature preservation on quality changes in Pacific white shrimp, Litopenaeus vannamei: a review

Shrimp has been widely accepted as an excellent resource for white meat due to its high-protein and low-fat content, especially low cholesterol. However, shrimps are highly perishable during preservation and retailing procedures due to the activities of enzymatic proteolysis, lipid oxidation, and microbial degradation. With increasing knowledge of and demands for safety, nutrition, and freshness of shrimp products, energy efficient, quality, maintained, and sustainable preservation technologies are needed. Low-temperature preservation, a practical processing method for improving the shelf life of food products, is widely used in the aquatic industry. This review focuses on the effects of low-temperature preservation on the quality changes in Litopenaeus vannamei. It considers physicochemical properties, sensory evaluation, melanosis assessment, and microbiological analysis. The perspectives of non-protein-based techniques on quality analysis of shrimps during preservation are also discussed. © 2019 Society of Chemical Industry.

Development of shelf life kinetic model for fresh rainbow trout (Oncorhynchus mykiss) fillets stored under modified atmosphere packaging

The sensory, chemical (based on the thiobarbituric acid, total volatile basic nitrogen and trimethylamine), and microbial quality (based on the total viable count and lactic acid bacteria count) of the rainbow trout stored under modified atmosphere packaging (MAP) conditions was evaluated. Four different gas combinations, including P₁ (80% CO₂, 10% N₂, 10% O₂), P₂ (60% CO₂, 20% N₂, 20% O₂), P₃ (60% CO₂, 40% N₂, 0% O₂), and P₄ (40% CO₂, 30% N₂, 30% O₂), were used. Also, the fish packages were stored at four constant temperatures (including 0, 5, 10, and 15 °C) for 12 days. The absence of oxygen in P₃ and high concentration of carbon dioxide in P₁ extended the shelf life by delaying the chemical, microbial, and sensory spoilage. Over the storage time of trout fillets in MAP, the rate of chemical reactions significantly increased while the sensory scores decreased. Based on the Arrhenius kinetic modeling for the spoilage reactions of the sensory (total acceptance) and chemical (total volatile basic nitrogen) indices, the shelf life was extended for P₃ and succeedingly, for P₁ packaging.

Seafood spoilage microbiota and associated volatile organic compounds at different storage temperatures and packaging conditions

Seafood comprising of both vertebrate and invertebrate aquatic organisms are nutritious, rich in omega-3 fatty acids, essential vitamins, proteins, minerals and form part of healthy diet. However, despite the health and nutritional benefits, seafood is highly perishable. Spoilage of seafood could be as a result of microbial activity, autolysis or chemical oxidation. Microbial activity constitutes more spoilage than others. Spoilage bacteria are commonly Gram negative and produce off odours and flavours in seafood as a result of their metabolic activities. Storage temperature, handling and packaging conditions affect microbial growth and thus the shelf-life of seafood. Due to the complexity of the microbial communities in seafood, culture dependent methods of detection may not be useful, hence the need for culture independent methods are necessary to understand the diversity of microbiota and spoilage process. Similarly, the volatile organic compounds released by spoilage bacteria are not fully understood in some seafood. This review therefore highlights current knowledge and understanding of seafood spoilage microbiota, volatile organic compounds, effects of storage temperature and packaging conditions on quality of seafood.

Efeito da embalagem com atmosfera modificada associada ao ácido ascórbico na vida útil de filés de tilápia-do-nilo (Oreochromis niloticus)

Resumo A presente pesquisa teve por objetivo avaliar o efeito da embalagem com atmosfera modificada associada ao ácido ascórbico na vida útil de filés de tilápia-do-nilo, bem como determinar o tratamento mais eficaz para sua conservação. Para tanto, filés desta espécie foram submetidos a quatro tratamentos distintos: T1 (controle) em aerobiose, T2 (1% de ácido ascórbico + 80% CO2 + 20% O2), T3 (1% de ácido ascórbico + 100% CO2) e T4 (1% de ácido ascórbico + vácuo), posteriormente, as amostras foram acondicionadas a 4 ± 1 °C e submetidas às análises microbiológicas, físico-químicas e sensoriais em diferentes intervalos. Os tratamentos T3 e T4 foram mais eficazes na inibição do desenvolvimento de bactérias psicrotróficas bem como de micro-organismos do grupo coliformes, nas amostras analisadas, ao longo do tempo, não sendo detectada a presença de Clostridium sulfito redutores nos filés de ambos os tratamentos. Entretanto, pelos resultados das análises de pH, bases nitrogenadas voláteis totais e substâncias reativas ao ácido tiobarbitúrico, o tratamento T4 sobressaiu sobre T3, mantendo as características de frescor inalteradas por mais tempo. Os resultados das análises sensoriais demonstraram redução nas médias de todos os atributos avaliados em função do tempo, sendo significativamente afetadas em função do período de armazenamento (p<0,05). A avaliação sensorial delimitou a vida útil das amostras, sendo o tratamento T4 o que manteve melhores médias durante maior período de tempo, 18 dias. Correlacionando-se os resultados das análises microbiológicas, físico-químicas e sensoriais, conclui-se que o tratamento T4 (1% de ácido ascórbico + vácuo) mostrou-se mais eficaz, sendo, portanto, o mais indicado para conservação do filé de tilápia-do-nilo refrigerado.