Application of composite coating of Nostoc commune Vauch polysaccharides and sodium carboxymethyl cellulose for preservation of salmon fillets

Preparation, characterization of basil essential oil liposomes unidirectional single-conducting water sustained-release pads and their preservation properties to Lateolabrax japonicus fillets

The juice exudation of aquatic products oozes out during storage can influence storage quality. Herein, a novel basil essential oil liposome unidirectional water-conducting sustained-release preservation pads (BEOL/UCSP) were prepared with nylon mesh as water-conducting layer, basil essential oil liposome (BEOL) as sustained-release preservation layer, and diatomite and absorbent-cotton as water-absorbing layer. EL/UCSP, β-CL/UCSP, and BEO/UCSP were prepared after BEOL was replaced by eugenol liposome, β-caryophyllene liposome, and BEO. BEOL are microspheres with bilayer structure, had good storage stability, centrifugal stability, thermal stability, embedding capacity, sustained-release, and oxidation resistance, and the main components of preservatives had a synergistic effect on antibacterial properties. The pads without preservative can initially slow down quality deterioration. BEOL/UCSP can directionally absorb exudate and realize long-term sustained-release of preservative, has excellent antibacterial and antioxidant effect, and extended shelf life of Lateolabrax japonicus fillets from 6.0 days to 12.8 days. The BEOL/UCSP can provide technical theoretical support for preservation materials.

Inhibitory effects of citral on the production of virulence factors in Staphylococcus aureus and its potential application in meat preservation

Foodborne diseases caused by Staphylococcus aureus contamination on meat and meat products has gained increasing attention in recent years, while the pathogenicity of S. aureus is mainly attributed to its virulence factors production, which is primarily regulated by quorum sensing (QS) system. Herein, we aimed to uncover the inhibitory effects and mechanisms of citral (CIT) on virulence factors production by S. aureus, and further explore its potential application in pork preservation. Susceptibility test confirmed the antibacterial properties of CIT against S. aureus, the minimal inhibitory concentration (MIC) was 0.25 mg/mL. Treatment with sub-MICs of CIT reduced the hemolytic activity by inhibiting the production of α-hemolysin, and staphylococcal enterotoxins (SEs) production was significantly inhibited by CIT in both culture medium and pork without affecting bacterial growth. Transcriptomic analysis indicated that the differentially expression genes encoding α-hemolysin, SEs, and other virulence factors were down-regulated after treatment with 1/2MIC CIT. Moreover, the genes related to QS including agrA and agrC were also down-regulated, while the global transcriptional regulator sarA was up-regulated. Data here demonstrated that CIT could inhibited S. aureus virulence factors production through disturbing QS systems. In a challenge test, the addition of CIT caused a remarkable inhibition of S. aureus population and delay in lipid oxidation and color change on pork after 15 days incubation at 4 °C. These findings demonstrated that CIT could not only efficiently restrain the production of S. aureus virulence factors by disturbing QS, but also exhibit the potential application on the preservation of meat products.

Ethyl cellulose/gelatin-carboxymethyl chitosan bilayer films doped with Euryale ferox seed shell polyphenol for cooked meat preservation

This study evaluated the effects of an edible bilayer containing polyphenols from the Euryale ferox seed shell on ready-to-eat cooked beef products, including the physical, mechanical, antioxidant, and antibacterial capabilities. Here, the bilayer films were prepared by layer-by-layer solution pouring using hydrophobic ethyl cellulose (EC) as the outer layer, and hydrophilic gelatin/carboxymethyl chitosan (GC) as the inner layer. By adjusting the proportion of gelatin to carboxymethyl chitosan, the optical, mechanical, and barrier characteristics of bilayer films were markedly enhanced. Extracted polyphenol (EP) from shell of the Euryale ferox seed performed potent antibacterial property against Listeria monocytogenes (L. monocytogenes). The addition of EP to the inner layer of the optimized bilayer film further improved the mechanical and barrier properties of films, and as expected, the film exhibited antioxidant and antibacterial abilities. Additionally, cooked beef and cooked chicken preservation tests indicated that the active bilayer film showed good inhibition of L. monocytogenes and delayed lipid oxidation in ready-to-eat meat products, and significantly delayed the pH, moisture loss, color and texture changes. This study developed multifunctional bilayer active edible films, which has a great potential in the preservation ready-to-eat cooked meat products.

Recent progress in plant-derived polysaccharides with prebiotic potential for intestinal health by targeting gut microbiota: a review

Natural products of plant origin are of high interest and widely used, especially in the food industry, due to their low toxicity and wide range of bioactive properties. Compared to other plant components, the safety of polysaccharides has been generally recognized. As dietary fibers, plant-derived polysaccharides are mostly degraded in the intestine by polysaccharide-degrading enzymes secreted by gut microbiota, and have potential prebiotic activity in both non-disease and disease states, which should not be overlooked, especially in terms of their involvement in the treatment of intestinal diseases and the promotion of intestinal health. This review elucidates the regulatory effects of plant-derived polysaccharides on gut microbiota and summarizes the mechanisms involved in targeting gut microbiota for the treatment of intestinal diseases. Further, the structure-activity relationships between different structural types of plant-derived polysaccharides and the occurrence of their prebiotic activity are further explored. Finally, the practical applications of plant-derived polysaccharides in food production and food packaging are summarized and discussed, providing important references for expanding the application of plant-derived polysaccharides in the food industry or developing functional dietary supplements.

Polymeric Packaging Applications for Seafood Products: Packaging-Deterioration Relevance, Technology and Trends

Seafood is a highly economical product worldwide. Primary modes of deterioration include autolysis, oxidation of protein and lipids, formation of biogenic amines and melanosis, and microbial deterioration. These post-harvest losses can be properly handled if the appropriate packaging technology has been applied. Therefore, it is necessary for packaging deterioration relevance to be clearly understood. This review demonstrates recent polymeric packaging technology for seafood products. Relationship between packaging and quality deterioration, including microbial growth and chemical and biochemical reactions, are discussed. Recent technology and trends in the development of seafood packaging are demonstrated by recent research articles and patents. Development of functional polymers for active packaging is the largest area for seafood applications. Intelligent packaging, modified atmosphere packaging, thermal insulator cartons, as well as the method of removing a fishy aroma have been widely developed and patented to solve the specific and comprehensive quality issues in seafood products. Many active antioxidant and antimicrobial compounds have been found and successfully incorporated with polymers to preserve the quality and monitor the fish freshness. A thermal insulator has also been developed for seafood packaging to preserve its freshness and avoid deterioration by microbial growth and enzymatic activity. Moreover, the enhanced biodegradable tray is also innovative as a single or bulk fish container for marketing and distribution. Accordingly, this review shows emerging polymeric packaging technology for seafood products and the relevance between packaging and seafood qualities.

Application of Xanthan-Gum-Based Edible Coating Incorporated with Litsea cubeba Essential Oil Nanoliposomes in Salmon Preservation

Salmon is prone to be contaminated by Vibrio parahaemolyticus (V. parahaemolyticus), leading to the deterioration of salmon quality and the occurrence of food-borne diseases. In this study, we aimed to develop a novel xanthan-gum-based edible coating embedded with nano-encapsulated Litsea cubeba essential oil (LC-EO) for salmon preservation at 4 °C. First, the results of the growth curves and scanning electron microscopy (SEM) showed that LC-EO displayed potent antibacterial activity against V. parahaemolyticus; the optimal concentration of LC-EO in the liposomes was 5 mg/mL, and the maximal encapsulation efficiency (EE) was 37.8%. The particle size, polydispersity coefficient (PDI), and zeta potential of the liposomes were 168.10 nm, 0.250, and −32.14 mV, respectively. The rheological test results of xanthan-gum-based edible coatings incorporating liposomes showed that the prepared coating was suitable for applying on food surfaces. The results in the challenge test at 4 °C demonstrated that the treatment of 1:3 (liposome: xanthan gum, v/v) coating performed the best preservative properties, the coating treatment delayed the oxidation of salmon, and controlled the growth of V. parahaemolyticus. These findings suggest that the coatings formulated in this study could be used as a promising approach to control V. parahaemolyticus contamination and maintain salmon quality.