Effects of Chitosan-Grafted-Phenolic Acid Coating on Quality and Microbiota Composition of Vacuum-Packaged Sea Bass (Lateolabrax japonicus) Fillets during Chilled Storage

A konjac glucomannan/ gelatin film integrated with rosemary essential oil and ginger essential oil-loaded bacterial cellulose: Preparation, characterization, and application in sea bass (Lateolabrax maculatus) packaging

In this study, a konjac glucomannan (KGM)/ gelatin (GEL)-based film integrated with ginger essential oil (GEO) and rosemary essence oil (REO)-loaded bacterial cellulose was prepared. The synergistic effects of GEO and REO were evaluated. The physicochemical, mechanical, optical, morphological, antibacterial, antioxidant properties, thermal stability and preservation effects of the composite films were characterized. Results demonstrated that GEO and REO exhibited synergistic antibacterial activity when combined in a 3:1 ratio. FT-IR analysis, scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed good compatibility among the components of the film. Furthermore, the incorporation of EOs enhanced various properties of the active film including mechanical strength, barrier performance, hydrophobicity as well as its antibacterial and antioxidant capabilities while also improving thermal stability. Additionally, the active film containing 0.8 % (w/v) composite essential oils (KGB-0.8) effectively maintained the quality of refrigerated sea bass and extended the shelf-life for another 6 days.

Impact of Incorporating Gallic Acid-Grafted-Chitosan on the Quality Attributes of Refrigerated Chicken Patties

To improve the antimicrobial and antioxidant characteristics of chitosan (CH), a conjugate of gallic acid (GA) and chitosan (GA-g-CH) was synthesized through a radical grafting process. The impact of the addition of GA-g-CH on the quality of chicken patties was investigated during a 15-day period under refrigerated conditions. The microbiological characteristics, encompassing the total viable counts, counts of Pseudomonas spp., and counts of lactic acid bacteria were assessed. Furthermore, the water migration, sensory characteristics, and physicochemical characteristics, including thiobarbituric acid-reactive substances (TBARS), carbonyl content, pH level, water holding capacity (WHC), and color deterioration were also evaluated. The findings suggest that both CH+GA and GA-g-CH addition effectively maintained the quality of chicken patties during cold storage. Nevertheless, GA-g-CH exhibited superior antimicrobial properties and a stronger capacity to inhibit the formation of TBARS and carbonyl compounds. The addition of GA-g-CH also inhibited water migration, maintained a higher WHC, and resulted in superior sensory attributes for a longer duration compared to the other treated samples, thus prolonging the shelf life and retarding the deterioration of fresh chicken patties by 3-6 days during refrigerated storage. The research findings suggest that the incorporation of GA-g-CH exhibits promising potential in maintaining the freshness of ground chicken products during storage.

Effects of chitosan-gentianic acid derivatives on the quality and shelf life of seabass (Lateolabrax maculatus) during refrigerated storage

Chitosan is a natural polymer material with antibacterial, biodegradable and biocompatibility. At present, the research is mainly to enhance the antibacterial and antioxidant activity of chitosan by grafting with phenolic acids to further expand its application in food. In this study, the effect of chitosan-g-gentisic acid graft copolymer (CS-g-GA) on the shelf life of refrigerated seabass (Lateolabrax maculatus) was investigated. The results of microbial analysis demonstrated that GA and CS-g-GA treatment could effectively inhibit the growth of microorganisms. In addition, physicochemical analysis showed that GA and CS-g-GA treatment could reduce the increase of pH value, thiobarbituric acid reactive substances (TBARS), total volatile base nitrogen (TVB-N) and K-value, delay water loss, maintain texture and color, and postpone the decrease of sensory score. Compared with the control sample, CS-g-GA could keep the quality of Lateolabrax japonicus and extend its shelf-life for another 9 days. In summary, CS-g-GA has good application and development prospects for the preservation of seabass.

Effects of slightly acidic electrolyzed water combined with ԑ-polylysine-chitooligosaccharide Maillard reaction products treatment on the quality of vacuum packaged sea bass (Lateolabrax japonicas)

In this study, a new natural preservative, ε-polylysine (ε-PL) and chitooligosaccharides (COS) Maillard reaction products (LC-MRPs), was prepared by Maillard reaction. The preservation effect of LC-MRPs combined with slightly acidic electrolyzed water (SAEW) pretreatment (SM) on vacuum-packed sea bass during refrigerated storage was evaluated. The results showed that after 16 days, SM treatment could effectively inhibit the microbial growth and prevent water migration in sea bass. In addition, the highest water holding capacity (69.79 %) and the best sensory characteristics, the lowest malonaldehyde (MDA) (58.96 nmol/g), trimethylamine (TMA) (3.35 mg/100 g), total volatile basic nitrogen (TVB-N) (16.93 mg N/100 g), myofibril fragmentation index (MFI) (92.2 %) and TCA-soluble peptides (2.16 μmol tyrosine/g meat) were related to SM group. Combined with sensory analysis, we can conclude that the combined treatment of SAEW and LC-MRPs could prolong the shelf-life of sea bass for another 11 days compared with the DW group. Results disclosed that the composite treatment of SAEW and LC-MRPs is a promising technology to improve the shelf-life of vacuum-packed sea bass during refrigerated storage.

Effect of chlorogenic acid grafted chitosan on microbiological compositions of sea bass (Lateolabrax japonicus) fillets: Dominant spoilage bacteria, inhibition activity and membrane damage mechanisms

This study investigated the effect of chlorogenic acid grafted chitosan (CS-g-CA) on the microbiota composition of sea bass (Lateolabrax japonicus), isolated and identified the specific spoilage organisms (SSOs) in the late stage of refrigerated fillets and evaluation of their spoilage potential. Moreover, antibacterial activity and membrane damage mechanism of CS-g-CA against spoilage bacteria was also investigated. Illumina-MiSeq high throughput sequencing results showed that CS-g-CA retarded the growth of Pseudomonas spp., which largely contributed to delaying the quality degradation of sea bass during storage. Then nine spoilage bacteria were isolated and identified from the fillets at the end of storage and inoculated into sterile fish fillets to determine their spoilage capacity. Results showed that fish fillets inoculated with spoilage bacteria exhibited a significant increase in TVB-N, TBA and putrescine content and decreased sensory quality during storage. Subsequently, the inhibitory activity of CS-g-CA against spoilage bacteria was investigated and strains that were more sensitive to the CS-g-CA with a strong spoilage capacity were selected for the study of the inhibition mechanism. Results suggested that CS-g-CA had strong inhibitory activity and led to bacterial death through the mechanism of membrane damage. Overall, this study analyzed the effect of CS-g-CA on the preservation of fish fillets from a microbiological point of view to provide a reference for the anti-bacterial preservation of aquatic products.

Antibacterial and antioxidant properties of phenolic acid grafted chitosan and its application in food preservation: A review

Chitosan is a bio-renewable natural polymeric material. The antibacterial and antioxidant activity of chitosan can be enhanced by grafting with phenolic acids to further expand its application in food. Therefore, this paper focuses on reviewing the structure, antimicrobial and antioxidant activities and their mechanisms with phenolic acid-g-CS, evaluating its cytotoxicity, and describing its application in various food preservation. In general, different reaction mechanisms of phenolic acid-g-CS synthesis lead to different product structures. Compared to chitosan, phenolic acid-g-chitosan exhibited enhanced antibacterial and antioxidant activities. The toxicity assessment showed that phenolic acid-g-CS is not cytotoxic. Moreover, phenolic acid-g-CS has been applied to a variety of food products such as fruits, vegetables and meat with good results. Overall, this review provides a certain reference for subsequent researchers to design phenolic acid-g-CS more rationally and for the subsequent development of phenolic acid-g-CS in food preservation.