Sodium erythorbate, stable chlorine dioxide, and gellan gum glazing for shelf life extension of commercial peeled shrimp ( Litopenaeus vannamei ) during frozen storage

Advancements in Gellan Gum-Based Films and Coatings for Active and Intelligent Packaging

Gellan gum (GG) is a natural polysaccharide with a wide range of industrial applications. This review aims to investigate the potential of GG-based films and coatings to act as environmentally friendly substitutes for traditional petrochemical plastics in food packaging. GG-based films and coatings exhibit versatile properties that can be tailored through the incorporation of various substances, such as plant extracts, microorganisms, and nanoparticles. These functional additives enhance properties like the light barrier, antioxidant activity, and antimicrobial capabilities, all of which are essential for extending the shelf-life of perishable food items. The ability to control the release of active compounds, along with the adaptability of GG-based films and coatings to different food products, highlights their effectiveness in preserving quality and inhibiting microbial growth. Furthermore, GG-based composites that incorporate natural pigments can serve as visual indicators for monitoring food freshness. Overall, GG-based composites present a promising avenue for the development of sustainable and innovative food packaging solutions.

Spectrophotometric- and LC/MS-Based Lipidomics Analyses Revealed Changes in Lipid Profiles of Pike Eel (Muraenesox cinereus) Treated with Stable Chlorine Dioxides and Vacuum-Packed during Chilled Storage

Spectrophotometric- and liquid chromatography/mass spectrometry (LC/MS)-based lipidomics analyses were performed to explore the changes of lipid profiles in pike eel (Muraenesox cinereus) under stable chlorine dioxides (ClO₂) and vacuum-packed treatment during chilled storage. The peroxide value (PV) and malondialdehyde (MDA) content in ClO₂ treated and vacuum-packaged (VP) samples were significantly reduced compared to simple-packaged (SP) samples during whole chilled storage. The LC/MS-based lipidomics analyses identified 2182 lipid species in the pike eel muscle classified into 39 subclasses, including 712 triglycerides (TGs), 310 phosphatidylcholines (PCs), 153 phosphatidylethanolamines (PEs), and 147 diglycerides (DGs), among others. Further, in comparison with fresh pike eel (FE) muscle, 354 and 164 higher and 420 and 193 lower abundant levels of differentially abundant lipids (DALs) were identified in SP samples and VP samples, respectively. Compared with the VP batch, 396 higher and 404 lower abundant levels of DALs were identified in the SP batch. Among these, PCs, PEs, TGs, and DGs were more easily oxidized/hydrolyzed, which could be used as biomarkers to distinguish FE, SP, and VP samples. This research provides a reference for controlling lipid oxidation in fatty fish.

Processing Technology and Quality Change during Storage of Fish Sausages with Textured Soy Protein

The addition of textured soy protein (TSP) to surimi products extends the supply of fish protein and improves nutritional and sensory properties, which has attracted considerable research interest. In this study, a single-factor experiment and orthogonal experiment were used to determine the optimal process conditions and to assess the quality indicators of fish sausages during frozen storage. The results indicated that the optimal process conditions were as follows: the addition of 15% TSP, 8% potato starch, and 5% lard oil, resulting in a gel strength of 1894.32 g·cm. During storage of the formulation-optimized fish sausages for 180 days, the water-holding capacity, whiteness, texture properties, and gel strength of the fish sausages all decreased, whereas cooking loss, thawing loss, thiobarbituric acid reactive substances value, and total volatile base nitrogen value all increased. Consequently, TSP is beneficial to improve the gel strength and sensory score of fish sausages. The quality of fish sausages with added TSP was acceptable after storage at -18 °C, for 120 days.

Deciphering the virulent Vibrio harveyi causing spoilage in muscle of aquatic crustacean Litopenaeus vannamei

The muscle of aquatic crustaceans is perishable and susceptible to environmental contamination. Vibrio harveyi is a widely occurring pathogen in aquatic animals. Here, bath treatment with a virulent V. harveyi strain (which was added directly in the rearing water to imitate environmental contamination) isolated from the muscle of the whiteleg shrimp, Litopenaeus vannamei, caused the muscle of Li. vannamei to display a whitish-opaque appearance due to microscopic changes including muscle lysis, muscle fiber damage and microbial colonization. When administered orally by incorporating this isolate in feed (which is an imitation of infection via natural route), rather than direct invasion followed by colonization in the muscle, this isolate indirectly stimulated severe muscle necrosis in Li. vannamei via steering the enrichment of two important (human) pathogens, V. cholerae and V. vulnificus, and one environmental bacterium Pseudomonas oleovorans, based on the meta-taxonomic analyses. In addition to the scientifically proven viral diseases, our research proved that bacterial agents are also capable of causing muscle spoilage in crustaceans via changing the microbial composition, and that the crustaceans might be exploited as the wide-spectrum sensitive bio-detector to indicate the extent of microbial contamination.

Effect of Stable Chlorine Dioxide and Vacuum-Packing Treatments on the Physicochemical and Volatile Flavor Properties of Pike Eel (Muraenesox cinereus) during Chilled Storage

The effects of vacuum-packaging and stable chlorine dioxide treatments on the quality of pike-eel fillets were investigated during chilled storage for a period of up to 10 days. The results reveal that the sensory scores, total volatile basic nitrogen (TVB-N) content, total viable count (TVC), malondialdehyde (MDA) content, and the myofibrillar protein (MP) content of pike-eel fillets with different packing treatments all decreased significantly over 10 days of storage. However, the vacuum-packaging and stable chlorine dioxide pretreatment showed positive effects on the protein stability of pike-eel samples. Compared with the simple packaging (SP) and vacuum packing (VP) treatments, the combination treatments (CP) significantly inhibited the rapid increases in the TVB-N content, TVC values, and MDA content. Moreover, the comparative stability in the MP and its carbonyl content were maintained. Furthermore, our volatile organic compounds (VOCs) analysis confirmed that the combined packaging treatments significantly hindered protein and lipid oxidation, inhibited the growth of spoilage bacteria, and maintained the volatile flavors of pike-eel samples during chilled storage.

Effects of Glazing with Preservatives on the Quality Changes of Squid during Frozen Storage

This study aimed to investigate the effects of glazing with sodium polyacrylate (SP) and D-sodium erythorbate (DSE) on the quality changes of squid during frozen storage. Frozen squid samples were randomly divided into seven groups: (1) CK (unglazed); (2) WG (distilled water-glazed); (3) SG (0.1% SP -glazed); (4) SG-1DSE (0.1% SP with 0.1% DSE -glazed); (5) SG-3DSE (0.1% SP with 0.3% DSE-glazed); (6) SG-5DSE (0.1% SP with 0.5% DSE-glazed); (7) WG-1DSE (0.1% DSE-glazed). The efficacy of the different coatings was evaluated using various indicators, such as water holding capacity (WHC), pH value, low field nuclear magnetic resonance (LF-NMR), color, malondialdehyde (MDA) content value, free amino acids (FAAs) content, intrinsic fluorescence intensity (IFI) and the total sulfhydryl content (SH) content. Intrinsic fluorescence intensity (IFI) and low field nuclear magnetic resonance (LF-NMR) were used as fast monitoring techniques to monitor changes in quality of squid samples. The results showed that compared with the CK and WG groups, coating with either SG or DSE alone resulted in reduced rate of moisture loss (p < 0.05), lipid oxidation (p < 0.05) protein degradation (p < 0.05) and prolonged its shelf-life. The combination of glazing treatment with SG and DSE (groups SG-1DSE, SG-3DSE and SG-5DSE) further improved the protective effects of coating, particularly in the SG-3DSE group. Therefore, the glazing of SG-3DSE is recommended to be used to control the quality of frozen squid and to prolong its shelf-life during frozen storage.