A sodium alginate bilayer coating incorporated with green propolis extract as a powerful tool to extend Colossoma macropomum fillet shelf-life

Edible Coatings for Fish Preservation: Literature Data on Storage Temperature, Product Requirements, Antioxidant Activity, and Coating Performance-A Review

Fresh fish is among the most nutritive foodstuffs, but it is also the most perishable one. Therefore, huge efforts have been made to find the most suitable tools to deliver fish of the highest quality to exigent consumers. Scientific studies help the industry to exploit the newest findings to scale up emerging industrial technologies. In this review article, the focus is on the latest scientific findings on edible films used for fish coatings and storage. Since today's packaging processing and economy are governed by sustainability, naturality underpins packaging science. The synthesis of edible coatings, their components, processing advantages, and disadvantages are outlined with respect to the preservation requirements for sensitive fish. The requirements of coating properties are underlined for specific scenarios distinguishing cold and freezing conditions. This review raises the importance of antioxidants and their role in fish storage and preservation. A summary of their impact on physical, chemical, microbiological, and sensory alterations upon application in real fish is given. Studies on their influence on product stability, including pro-oxidant activity and the prevention of the autolysis of fish muscle, are given. Examples of lipid oxidation and its inhibition by the antioxidants embedded in edible coatings are given together with the relationship to the development of off-odors and other unwanted impacts. This review selects the most significant and valuable work performed in the past decade in the field of edible coatings whose development is on the global rise and adheres to food waste and sustainable development goals 2 (zero hunger), 3 (good health and well-being), and 12 (responsible consumption and production).

Alginate-based active and intelligent packaging: Preparation, properties, and applications

Alginate-based packaging materials have emerged as promising alternatives to conventional petroleum-based plastics due to their biodegradability, renewability, and versatile functionalities. This review provides a comprehensive analysis of the recent advances in the development and application of alginate-based films and coatings for food packaging. The composition and fabrication methods of alginate-based packaging materials are discussed, highlighting the incorporation of various functional compounds to enhance their physicochemical properties. The mechanisms of action and the factors influencing the release and migration of active compounds from the alginate matrix are explored. The application of alginate-based packaging materials for the preservation of various food products, including meat, fish, dairy, fruits, and vegetables, is reviewed, demonstrating their effectiveness in extending shelf-life and maintaining quality. The development of alginate-based pH-sensitive indicators for intelligent food packaging is also discussed, focusing on the colorimetric response of natural pigments to spoilage-related pH changes. Furthermore, the review highlights the challenges and future perspectives of alginate-based packaging materials, emphasizing the need for novel strategies to improve their performance, sustainability, and industrial adoption.

Development and characterization of bilayer chitosan/alginate cling film reinforced with essential oil based nanocomposite for red meat preservation

With a goal to finding suitable alternatives to plastic packaging in the food industry, we developed a multifunctional bio-based active packaging film to enhance the shelf life of red meat. A chitosan/alginate (Chi + Alg) bilayer film was developed through layer-by-layer (LBL) assembly and an active material i.e. lemongrass nanoemulsion with silver nanoparticles-based nanocomposite (NC1) was loaded into the alginate layer to improve the quality of the bio-based film (Chi + Alg + NC1). The Chi + Alg + NC1 film was characterized in terms of its microstructure, mechanical strength, thermal stability, and antimicrobial activity. Scanning electron microscopy (SEM) revealed a film (22.5 ± 1.44 μm thickness) with a smooth and even surface and a cross-sectional structure. The incorporation of NC1 improves the quality of the film by enhancing its mechanical strength and thermal stability. FT-IR spectra showed the successful interaction between chitosan and alginate in the LBL assembly and the incorporation of NC1 in the alginate layer. The red meat preservation test demonstrated that the shelf life improved when the meat was covered with the fabricated bio-based film. The color of the meat was retained for up to 7 days compared to that of the control (Chi alone and Chi + Alg). Additionally, a reduction in the microbial count in the Chi + Alg + NC1 film was observed, corroborating the shelf-life improvement. In addition to its inherent antimicrobial properties, NC1 induced hydrophilic properties to the film, which further aids in its antimicrobial activity against E. coli. These findings suggest that Chi + Alg + NC1 film could be a potent alternative to plastic packaging and can be used as a cling film to prolong the shelf life of red meat.

Activity and safety evaluation of natural preservatives

Synthetic preservatives are widely used in the food industry to control spoilage and growth of pathogenic microorganisms, inhibit lipid oxidation processes and extend the shelf life of food. However, synthetic preservatives have some side effects that can lead to poisoning, cancer and other degenerative diseases. With the improvement of living standards, people are developing safer natural preservatives to replace synthetic preservatives, including plant derived preservatives (polyphenols, essential oils, flavonoids), animal derived preservatives (lysozyme, antimicrobial peptide, chitosan) and microorganism derived preservatives (nisin, natamycin, ε-polylysine, phage). These natural preservatives exert antibacterial effects by disrupting microbial cell wall/membrane structures, interfering with DNA/RNA replication and transcription, and affecting protein synthesis and metabolism. This review summarizes the natural bioactive compounds (polyphenols, flavonoids and terpenoids, etc.) in these preservatives, their antioxidant and antibacterial activities, and safety evaluation in various products.

Shelf-life extension of Pacific white shrimp (Litopenaeus vannamei) using sodium alginate/chitosan incorporated with cell-free supernatant of Streptococcus thermophilus FUA 329 during cold storage

Seafood is highly perishable and has a short shelf-life. This study investigated the effect of chitosan and alginate (CH-SA) coating combined with the cell-free supernatant of Streptococcus thermophilus FUA329 (CFS) as a preservative on the quailty of white shrimp (Litopenaeus vannamei) refrigerated at 4° for 0, 3, 6, 9, 12, 15 days. Freshly shrimps were randomly divided into four groups: the CFS group (400 mL); the CH-SA group (1% chitosan/1% alginate); the CFS-CH-SA group (1% chitosan/1% alginate with 400 mL CFS) are treatment groups, and the control group (400 mL sterile water). The CFS-CH-SA coating effectively suppressed microbial growth total viable count and chemical accumulation (pH, total volatile basic nitrogen, thiobarbituric acid reactive substance) compared with the control. Additionally, the CFS-CH-SA coating improved the texture and sensory characteristics of shrimp during storage. The coated shrimp exhibited significantly reduced water loss (p < 0.05). The combination of CH-SA coating with CFS treatment can extend the shelf life of shrimp. PRACTICAL APPLICATION: Recently, edible films have received more consideration as a promising method to enhance the shelf life of seafood. The presence of Lactic acid bacteria metabolites in edible films reduces spoilage and improves consumer health. Our findings encourage the application of edible coating incorporated with cell-free supernatant of Streptococcus thermophilus FUA 329 to design multifubctional foods and preserve the qualities of shrimp.

Effects of vitamin C combined with sodium alginate on serum biochemistry, oxidative stress, gill tissue morphology, and muscle quality of pearl gentian grouper during waterless transport

This research examined the effects of sodium alginate (SA) and vitamin C (Vc) soaking of pearl gentian grouper before waterless transportation from the perspectives of serum parameters, oxidative stress, muscle quality, and gill tissue morphology. After the fish reached semi-dormancy with a cooling rate of 3 °C/h, fish (420 ± 25 g) were distributed to 4 treatments as follows: S1 group (50 mg/L Vc and 0.1% SA were added), S2 group (50 mg/L Vc and 0.3% SA were added), S3 group (50 mg/L Vc and 0.5% SA were added), and control group (without soaking in protective fluid). After oxygenated packaging, samples were taken at 0, 8, and 16 h of waterless transportation and 12 h after rehydration, respectively. It was found that after 16 h of waterless transport, compared with the control group, cortisol, glucose, blood urea nitrogen (BUN), uric acid (UA), creatinine (CREA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels were significantly decreased (p < 0.05), while albumin, lysozyme (LZM), muscle pH, and total free amino acid (TFAA) contents were significantly elevated (p < 0.05) in the S3 group. Moreover, by gill tissue microscopy, it was found that the protective solution of group S3 did not cause serious deleterious morphological changes to the gill epithelium. The results showed that the grouper was soaked by protective fluid before waterless could maintain surface moisture, reduce gill and kidney function and oxidative stress damage, and maintain the stability of muscle quality. This study provides a novel transportation method for waterless preservation, which helps to reduce transportation costs and improve transportation efficiency.

Development and Analysis of Silver Nitroprusside Nanoparticle-Incorporated Sodium Alginate Films for Banana Browning Prevention

Banana (Musa acuminate) has been popular among consumers worldwide due to its rich nutrients and minerals. However, bananas are highly susceptible to the physical and biological factors that lead to postharvest loss during transportation and storage. In this work, novel sodium alginate (SA) films incorporated with silver nitroprusside nanoparticles (AgNNPs) were prepared to extend the shelf life of bananas through antibacterial and antioxidant coating. The results exhibited that AgNNPs were cubical and that their size was <500 nm, with metal composition being Ag and Fe. Additionally, the incorporation of AgNNPs in the SA film was seen in FE-SEM and zeta analysis, with an average size of about 365.6 nm. Furthermore, the functional and crystalline properties of AgNNPs were assessed through FTIR and XRD. Transmittance testing of the SA-AgNNPs films confirmed they have good UV barrier properties. SA-AgNNPs films exhibited excellent high antibacterial activity against foodborne pathogens including L. monocytogenes, S. enterica, and E. coli at the concentration of 500 µg/mL. Moreover, during the storage of bananas, SA-AgNNPs nanocomposite coatings act as a barrier to microbial contamination and slow down the ripening of bananas. As a result, compared with SA-coated and uncoated bananas, SA-AgNNPs-coated bananas exhibited the lowest weight loss and lowest total bacterial colonies, thus greatly extending their shelf life. Particularly when coated with SA-AgNNPs films, total bacterial colonies (TBC) in the banana peel and pulp were as low as 1.13 × 103 and 51 CUF/g on the ninth day of storage, respectively. Our work offers an efficient strategy to improve the quality of bananas during the postharvest period, with extensive applications in fruit preservation and food packing.

Food-grade delivery systems of Brazilian propolis from Apis mellifera: From chemical composition to bioactivities in vivo

Brazilian propolis from Apis mellifera is widely studied worldwide due to its unique chemical composition and biological properties, such as antioxidant, antimicrobial, and anti-inflammatory. However, although many countries produce honey, another bee product, the consumption of propolis as a functional ingredient is linked to hydroethanolic extract. Hence, other food uses of propolis still have to be incorporated into food systems. Assuming that propolis is a rich source of flavonoids and is regarded as a food-grade ingredient for food and pharmaceutical applications, this review provides a theoretical and practical basis for optimising the bioactive properties of Brazilian propolis, encompassing the extraction processes and incorporating its bioactive compounds in the delivery systems for food applications. Overall, pharmacotechnical resources can optimise the extraction and enhance the chemical stability of phenolic compounds to ensure the bioactivity of food formulations.

Starch nanoparticles containing phenolic compounds from green propolis: Characterization and evaluation of antioxidant, antimicrobial and digestibility properties

This study investigated the production of nanoparticles through nanoprecipitation using cassava and potato starches as carriers to stabilize phenolic compounds (PC) from green propolis extract (PE). Additionally, the antioxidant and antimicrobial activities of PC stabilized with starch nanoparticles (SNPs), as well as their release under gastrointestinal conditions were investigated. PE exhibited antioxidant and antibacterial properties, especially PE3 (PE produced using sonication by 20 min and stirring at 30 °C for 24 h) had the highest concentrations of p-coumaric acid, rutin, kaempferol and quercetin. SNPs displayed bimodal distribution with particle size lower than 340 nm. The stabilization of PC increased surface charge and hydrophobicity in SNPs. Moreover, SNPs containing PC from PE exhibited antibacterial activity against Listeria monocytogenes, at a concentration of 750 mg/mL. Low release of PC was observed from the nanoparticles when exposed under simulated gastrointestinal conditions. These nanomaterials could be used as natural ingredients with antioxidant and antimicrobial properties.

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

The spoilage of fish products and the growth of pathogenic bacteria cause great economic loss and serious harm to human health, so fish preservation is very important issue. In this study, Nostoc commune Vauch polysaccharides (NVP) was added into sodium carboxymethyl cellulose (CMC) to form a mixed coating to prepare an active packaging material. The antibacterial and antioxidant activities of NVP, physicochemical properties of the mixed coating, and preservative effects of the coating on salmon fillets were evaluated. The results showed that NVP had good antibacterial and antioxidant activities. Physical characterization of the coating solution showed that when the ratio of NVP to CMC was 1:3, the coating had the best dispersion, denser structure and strongest hydrogen bond. On this basis, NVP/CMC coating can significantly prolong the shelf life of salmon fillets during cold storage by reducing pH, improving the color and texture, delaying the oxidation of fat and protein, inhibiting the growth of microorganisms. At the same time, the coated salmon fillets had good sensory acceptance. The results showed that the edible coating has a broad application prospect in the preservation of fish products.

Development and characterization of sodium alginate/tea tree essential oil nanoemulsion active film containing TiO2 nanoparticles for banana packaging

To improve the postharvest quality and reduce the anthracnose of bananas, the sodium alginate (SA)/tea tree essential oil nanoemulsion (TEON) based bilayer films incorporated with different contents of TiO₂ nanoparticles were fabricated in this work. The developed TEON presented satisfactory DPPH scavenging activity (65.5 ± 1.8%) and antifungal capability (90.5 ± 5.8%). The microscopy images of the cross-section of the films indicated that the bilayer films with well-cross-linked were developed successfully. Notably, the addition of a certain content of TiO₂ to SA greatly improved the UV blocking and water vapor and oxygen barrier properties of the developed film. However, the barrier property of the film was decreased when the TiO₂ content further increased to 4.0 mg/100 mg of SA. The retention of TEO under visible and UV light in the bilayer film was respectively prolonged to 24 days and 32 h when the addition of TiO₂ content was 2.0 mg/100 mg of SA. Finally, the postharvest quality and anthracnose of banana fruits were significantly improved by SA-TiO₂ + SA-TEON film-forming solution treatments. Results from the present work might open up new insights into the approaches of postharvest quality improvement of bananas.

Applications of Alginate-Based Nanomaterials in Enhancing the Therapeutic Effects of Bee Products

Since the ancient times, bee products (i.e., honey, propolis, pollen, bee venom, bee bread, and royal jelly) have been considered as natural remedies with therapeutic effects against a number of diseases. The therapeutic pleiotropy of bee products is due to their diverse composition and chemical properties, which is independent on the bee species. This has encouraged researchers to extensively study the therapeutic potentials of these products, especially honey. On the other hand, amid the unprecedented growth in nanotechnology research and applications, nanomaterials with various characteristics have been utilized to improve the therapeutic efficiency of these products. Towards keeping the bee products as natural and non-toxic therapeutics, the green synthesis of nanocarriers loaded with these products or their extracts has received a special attention. Alginate is a naturally produced biopolymer derived from brown algae, the desirable properties of which include biodegradability, biocompatibility, non-toxicity and non-immunogenicity. This review presents an overview of alginates, including their properties, nanoformulations, and pharmaceutical applications, placing a particular emphasis on their applications for the enhancement of the therapeutic effects of bee products. Despite the paucity of studies on fabrication of alginate-based nanomaterials loaded with bee products or their extracts, recent advances in the area of utilizing alginate-based nanomaterials and other types of materials to enhance the therapeutic potentials of bee products are summarized in this work. As the most widespread and well-studied bee products, honey and propolis have garnered a special interest; combining them with alginate-based nanomaterials has led to promising findings, especially for wound healing and skin tissue engineering. Furthermore, future directions are proposed and discussed to encourage researchers to develop alginate-based stingless bee product nanomedicines, and to help in selecting suitable methods for devising nanoformulations based on multi-criteria decision making models. Also, the commercialization prospects of nanocomposites based on alginates and bee products are discussed. In conclusion, preserving original characteristics of the bee products is a critical challenge in developing nano-carrier systems. Alginate-based nanomaterials are well suited for this task because they can be fabricated without the use of harsh conditions, such as shear force and freeze-drying, which are often used for other nano-carriers. Further, conjunction of alginates with natural polymers such as honey does not only combine the medicinal properties of alginates and honey, but it could also enhance the mechanical properties and cell adhesion capacity of alginates.