A novel superchilling storage - ice glazing (SS-IG) approach using biopolymer-based composite hydrogel to delay microbiological spoilage and organic oxidation of preserved tilapia

A frontier exploration of ancient craftsmanship: Effects of various tea products in traditional Chinese cuisine "tea flavored beef"

Modern science often overlooks to reveal the scientific essence of traditional crafts to promote their inheritance and development. In this work, five different types of tea products were prepared using the same variety of tea leaves referring to traditional methods. The analysis of their components and activities indicated that the processing reduced total catechin contents (from 172.8 mg/g to 48.2 mg/g) and promoted the synthesis of theaflavins (from 17.9 mg/g to 43.4 mg/g), reducing antioxidant and antimicrobial abilities of the resulting tea products. On this basis, the tea products were applied to "tea flavored beef" to reveal long-term effects. Within 15 days of storage, tea treatment showed remarkable antimicrobial and antioxidant activities on the beef. Also, the declines of sensory scores and texture of the treated beef were significantly suppressed. Meanwhile, protein degradation in the beef was inhibited, limiting the contents of various biogenic amines within relatively low levels.

Mechanisms of polyphenols on quality control of aquatic products in storage: A review

Aquatic products are easily spoiled during storage due to oxidation, endogenous enzymes, and bacteria. At the same time, compared with synthetic antioxidants, based on the antibacterial and antioxidant mechanism of biological agents, the development of natural, nontoxic, low-temperature, better-effect green biological preservatives is more acceptable to consumers. The type and molecular structure of polyphenols affect their antioxidant and antibacterial effectiveness. This review will describe how they achieve their antioxidant and antibacterial effects. And the recent literature on the mechanism and application of polyphenols in the preservation of aquatic products was updated and summarized. The conclusion is that in aquatic products, polyphenols alleviate lipid oxidation, protein degradation and inhibit the growth and reproduction of microorganisms, so as to achieve the effect of storage quality control. And put forward suggestions on the application of the research results in aquatic products. We hope to provide theoretical support for better exploration of the application of polyphenols and aquatic product storage.

Effect of tea polyphenols on chitosan packaging for food preservation: Physicochemical properties, bioactivity, and nutrition

Chitosan packaging has been widely studied for food preservation, the application of which is expanded by the incorporation of tea polyphenols. This paper reviews the influence of tea polyphenols incorporation on chitosan-based packaging from the perspectives of physicochemical properties, bioactivity used for food preservation, and nutritional value. The physicochemical properties included optical properties, mechanical properties, water solubility, moisture content, and water vapor barrier property, concluding that the addition of tea polyphenols improved the opacity, water solubility, and water vapor barrier property of chitosan packaging, and the mechanical properties and water content were decreased. The bioactivity used for food preservation, that is antioxidant and antimicrobial properties, is enhanced by tea polyphenols, improving the preservation of food like meat, fruits, and vegetables. In the future, efforts will be needed to improve the mechanical properties of composite film and adjust the formula of tea polyphenols/chitosan composite film to apply to different foods. Besides, the identification and development of high nutritional value tea polyphenol/chitosan composite film is a valuable but challenging task. This review is expected to scientifically guide the application of tea polyphenols in chitosan packaging.

The application of ice glazing containing D-sodium erythorbate combined with vacuum packaging to maintain the physicochemical quality and sweet/umami non-volatile flavor compounds of frozen stored large yellow croaker (Pseudosciaena crocea)

Ice glazing containing 0.3 % D-sodium erythorbate (DSE), combined with vacuum packaging, was used as a method to maintain the quality of large yellow croaker during frozen storage. This study aimed to assess various aspects, including water properties (water holding capacity and moisture distribution), protein-related characteristics (secondary and tertiary structure of myofibrillar protein), freshness indicators (K value and total volatile base nitrogen (TVB-N)), and non-volatile flavor compounds (free amino acids (FAAs) and nucleotides) in samples stored for 300 days at -23 °C. The results showed that vacuum packaging had a significant inhibitory effect on the growth of ice crystal. Notably, it successfully maintained the cross-sectional area of nearly all ice crystals below 20,000 μm2, effectively curtailing water loss. Simultaneously, the combination of vacuum packaging with the complex ice glaze effectively mitigated the degradation of IMP and free amino acids, maintaining low levels of K value (12.85 %) and TVB-N (11.28 mg N/100 g) throughout the 300-day frozen storage, retaining first-class freshness. Among the various treatment modalities assessed, the combined application of vacuum packaging and 0.3 % DSE-infused ice glazing emerged as the most effective in terms of preservation outcomes. This efficacious combination shows promising potential for the frozen storage of aquatic products and is therefore recommended for practical implementation.

Using maltodextrin and state diagrams to improve thermal transitions in tilapia fillet (Oreochromis spp.)

BACKGROUND

Tilapia (Oreochromis spp.) in the form of frozen fillets is one of the fishes with the highest commercial production levels worldwide. However, protein denaturation, membrane rupture, and lipid oxidation are commonly observed in fillets when stored at standard commercial freezing temperatures for long periods. This study proposes, for the first time, the use of maltodextrin and state diagrams to define processing strategies and suitable storage temperatures for fresh and dehydrated tilapia fillets. Differential scanning calorimetry (DSC) was used to study the effect of maltodextrin weight fractions (W MD ) of 0, 0.4, and 0.8 on the thermal transitions of tilapia fillets as a function of solid mass fractions (W s ).

RESULTS

The glass transition temperature curve (T g vs . W s ) and characteristic parameters of maximal freeze concentration (T g ' ,T m ' ,W s ' ) of tilapia increased significantly with the addition of maltodextrin. Using developed state diagrams, freezing and storage temperatures of -22 °C, -15 °C, and -10 °C (P < 0.05) for long-term preservation were defined for tilapia fillets produced withW MD of 0, 0.4, and 0.8.

CONCLUSION

Maltodextrin is an excellent alternative as a cryoprotectant and drying aid to increase the thermal parameters of tilapia fillets by achieving frozen storage temperatures above the standard commercial freezing temperature of -18 °C. © 2023 Society of Chemical Industry.

Preparation of an Antimicrobial and Antioxidant Bio-Polymer Film and Its Application as Glazing Shell for Postharvest Quality of Fresh-Cut Apple

The aim of this work is to glazing a modified bio-polymer shell as substitute of peel to keep the postharvest quality of fresh-cut fruits. In this study, chitosan as backbone of the shell was modified by addition of the functional extracts obtained from Zanthoxylum, in which 12 kinds of main identified bio-active components consisted of over 55% of the total extracts. The introduction of the extracts improved physic and mechanical properties of the shell, and endowed it with significant antimicrobial and antioxidant activity. Accordingly, the modified chitosan was used as the substitute of peel to preserve fresh-cut apples. Results exhibited that such treatments obviously delayed the decline process of overall postharvest quality of the preserved apple samples throughout all the storage period, represented by the variations in physical, chemical, and microbial properties of the apple samples were significantly inhibited. The overall observations revealed promising potential of the bio-polymer shell in food application.

Effects of incorporation with clove (Eugenia caryophyllata) essential oil (CEO) on overall performance of chitosan as active coating

This research is focused on improving performance of chitosan based functional material by introducing active additive. A series of assays revealed incorporation with clove essential oil (CEO) significantly improved the physical, chemical and antimicrobial performance of chitosan. In this work, the prepared chitosan-CEO film (CH-CEO) showed varieties in color parameters, mechanical strength and water vapor permeability. Moreover, chitosan was endowed with significant antioxidant and antimicrobial activities, thereby it was used as protective coatings for fresh-cutting apple tubes at ~1 °C. Results demonstrated the treatment slowed down the quality deterioration process of preserved apple samples, especially for firmness and color. As well, CH-CEO coating reduced microbial counts in the preserved apple samples and inhibited the varieties in the chemical properties. The overall observations revealed that CH-CEO film has remarkable potential as an antioxidant and antimicrobial material, especially as an active coating for fresh-cutting foods during storage.

Impact of glazing based on chitosan-gelatin incorporated with Persian lime (Citrus latifolia) peel essential oil on quality of rainbow trout fillets stored at superchilled condition

In this research, a new ice-glazing based on chitosan-gelatin (Ch-Gl) incorporated with Persian lime peel essential oil (LEO), and superchilled storage was established to assess the microbial, physicochemical, and sensory quality of rainbow trout fillets. The fillets were immersed in distilled water (control), Ch-Gl, Ch-Gl + 1% LEO, and Ch-Gl + 2% LEO to form glazing layer on the surface, then stored at -1.4 °C for 30 days. All treatments delayed the growth of total mesophilic bacteria, total psychrotrophic bacteria, Enterobacteriaceae, and lactic acid bacteria compared to control during the storage period. The treatments also retarded the increase in the contents of total volatile nitrogen, conjugated dienes, thiobarbituric acid reactive substances, protein carbonyls, pH, and electric conductivity during storage. The freshness indexes i.e. K and F_r values were improved in treated groups compared to control group. The combined treatments (Ch-Gl + 1% or 2% LEO) were more effective than Ch-Gl alone to inhibit the microbial growth, retard the physicochemical deterioration, and improve freshness indexes in the fillets. It can be concluded that ice-glazing based on Ch-Gl incorporated with LEO, and superchilled storage is effective to enhance the quality and shelf-life of rainbow trout fillets.