Repurposing fish waste into gelatin as a potential alternative for mammalian sources: A review

Mammalian gelatin is extensively utilized in the food industry because of its physicochemical properties. However, its usage is restricted and essentially prohibited for religious people. Fish gelatin is a promising alternative with no religious and social restrictions. The desirable properties of fish gelatin can be significantly improved by various methods, such as the addition of active compounds, enzymes, and natural crosslinking agents (e.g., plant phenolics and genipin), and nonthermal physical treatments (e.g., ionizing radiation and high pressure). The aim of this study was to explore whether the properties of fish gelatin (gel strength, melting or gelling temperature, odor, viscosity, sensory properties, film-forming ability, etc.) could be improved to make it comparable to mammalian gelatin. The structure and properties of gelatins obtained from mammalian and fish sources are summarized. Moreover, the modification methods used to ameliorate the properties of fish gelatin, including rheological (gelling temperature from 13–19°C to 23–25°C), physicochemical (gel strengths from ∼200 to 250 g), and thermal properties (melting points from ∼25 to 30°C), are comprehensively discussed. The relevant literature reviewed and the technological advancements in the industry can propel the development of fish gelatin as a potential alternative to mammalian gelatin, thereby expanding its competitive market share with increasing utility.     

Role of lipid deterioration on the quality of aquatic products during low-temperature storage: a lipidomics-based study using large yellow croaker (Larimichthys crocea)

This work investigated the effects of different storage periods (0 day, 90 days, 120 days) on the quality of large yellow croaker oil. The lipomics of large yellow croaker oil was quantitatively detected by GC-MS, the content of triglyceride in large yellow croaker oil reached 52.56% at 0 day. With the extension of storage time, the content of large yellow croaker oil components decreased gradually. Differential lipid histogram clearly indicates that the extension of the storage period will affect the change of fish oil, due to the rise in the temperature of large yellow croaker oil; the color of the hot map is bright from the dark. Additionally, the fatty acid composition and volatile components were measured. At 120 days, the decomposition rate of lipid molecular in large yellow croaker oil is increased by oxidation of unsaturated fatty acids, and its oxidised metabolite produced small substance such as aldehydes, ketones, alcohols, and acids. During storage, the waxy, fat, and floral flavour in the oil aroma of large yellow croaker oil decreased gradually, while the yeast flavour and oil flavour increased gradually. These results provide insights for the study of lipid transformation and quality of large yellow croaker oil during different storage.     

The antibacterial activity and antibacterial mechanism of the tea polyphenol liposomes/lysozyme–chitosan gradual sustained release composite coating

To obtain long-lasting preservation materials, the tea polyphenol liposomes (TP-Lips)/lysozyme (LZM)–chitosan (CS) composite coating with the gradual sustained property was prepared by tape casting method. These coatings were characterised, and their physicochemical properties were measured. Meanwhile, the antibacterial mechanisms of coatings were studied using the spoilage bacteria of aquatic products (Shewanella putrefaciens and Pseudomonas fluorescens) as target strains. Compared with CS coating, the incorporation of TP-Lips makes the cracks and granular matter of the coatings increase. Except for the oxygen permeabilities (OP) and carbon dioxide permeabilities (CDP), the rest of the physicochemical properties are decreased, including tensile strength (Ts), elongation at break (EB) and light transmittance (T). Antibacterial mechanisms indicate that TP and LZM have a synergistic antibacterial effect. The slow-release system composed of liposomes and coating prolongs the action time of TP and LZM. Hence, the TP-Lips/LZM-CS coating could be a hopeful material in food preservation field with excellent antibacterial properties.     

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

A scale-up parameter to ensure optimal conditions for packaging Atlantic Salmon (Salmo salar) fillets using superchilling and a modified atmosphere system for different compositions of CO₂:N₂ gas mixture, product weight, and g/p ratio; utilizing an integrated mathematical model for MAP systems at equilibrium was determined: the solubility. High correlation between the measured solubility and the theoretical solubility estimated with the model (r² > 0.98). Also, an experimental validation based on bacteriological, sensory and physical–chemical analysis was done. Modeling will allow develop new products estimating the appropriate design parameters to ensure the shelf-life extension and to avoid package collapse.     

液相色谱法检测鱼类肝脏中天然维生素A北大核心CSCD

为了准确测定鱼类肝脏中维生素A(维生素A_(1)、维生素A_(2))含量,对样品预处理方法(水浴皂化法、室温皂化法、直接提取法)和检测方法(正相色谱法、反相色谱法)进行筛选,并应用于9种经济鱼类肝脏中维生素A的测定。结果表明:维生素A_(1)、维生素A_(2)标准品用反相色谱法检测分离效果良好,且在各自线性范围内线性关系良好,R^(2)均大于0.99;水浴皂化法维生素A含量显著高于室温皂化法及直接提取法(p<0.05),且维生素A_(1)平均回收率为104.52%,维生素A_(2)平均回收率为90.94%;在9种鱼中,除了淡水鱼乌鳢和大口黑鲈外,其他淡水、海水鱼类肝脏中维生素A总含量均达200μg/100 g以上,其中海水鱼龙趸石斑鱼肝脏中维生素A总含量最高,达到14413.78μg/100 g。水浴皂化法结合反相色谱法精密度良好,适用于鱼类肝脏中维生素A的分析测定。