The preservation effect of CGA-Gel combined with partial freezing on sword prawn (Parapenaeopsis hardwickii)

Preparation of curcumin-loaded chitosan/polyvinyl alcohol intelligent active films for food packaging and freshness monitoring

To fulfill the current need for intelligent active food packaging. This study incorporated the curcumin inclusion complexes (CUR-CD) into chitosan/polyvinyl alcohol polymer to develop a new intelligent active film. The structures of films were analyzed by Fourier-transform infrared (FT-IR), scanning electron microscope (SEM), and so on. The CP-Cur150 film displays exceptional mechanical properties, water vapor barrier, and UV blocking capabilities as demonstrated by physical analysis. The CP-Cur150 film exhibited free radical scavenging rates on 2,2-diazo-di-3-ethylbenzothiazolin-6-sulfonic (ABTS) (98 %) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (87 %). Additionally, it showed inhibitory effects on Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), reducing live colony counts by approximately 2.7 and 1.3 Log10 CFU/mL, respectively. The films were used to monitor the shrimp's freshness in real time. With the spoilage of shrimp, the film exhibited clear color fluctuations, from light yellow to red. In addition, the evaluation of the impact of films on pork pH, total volatile basic nitrogen, and total bacterial counts demonstrated that the CP-Cur150 film displayed the most significant effectiveness in preserving freshness, thereby extending the shelf life of pork.

Effect of konjac glucomannan-based preservation pads on quality changes in refrigerated large yellow croaker (Pseudosciaena crocea)

The purpose of this study was to evaluate the preservation effects of konjac glucomannan (KGM)/oregano essential oil (OEO) Pickering emulsion-based pads (K/OPE pads) on large yellow croaker (Pseudosciaena crocea) fillets stored at 4 °C. The K/OPE pads were fabricated using a freeze-drying technique. The homogeneous distribution of the OEO Pickering emulsions in the KGM matrix was observed using scanning electron microscopy. Fourier transform infrared spectroscopy confirmed that the OEO emulsions were encapsulated in the KGM and there was hydrogen bonding interaction between them. Compared with the KGM pads, the K/OPE pad groups demonstrated enhanced antioxidant and antimicrobial properties. When the content of OPE was increased from 20 % to 40 %, the antioxidant performance of the K/OPE pads increased from 48.09 % ± 0.03 % to 86.65 % ± 0.02 % and the inhibition range of Escherichia coli and Staphylococcus aureus increased to 13.84 ± 0.81 and 16.87 ± 1.53 mm, respectively. At the same time, K/OPE pads were more effective in inhibiting the formation of total volatile alkaline nitrogen and the production of thiobarbituric acid-reactive substances, thereby helping in reducing water loss and maintaining the muscle tissue structure of fish fillets for a longer storage time. Consequently, these K/OPE40 pads extended the shelf life of the fish fillets by an additional 4 days and delayed spoilage during refrigerated storage. The findings suggest that the K/OPE pads can effectively safeguard the quality of refrigerated large yellow croaker fillets, presenting their potential as an active packaging material in the fish preservation industry.

Inhibitory effects of glutathione peroxidase on microbial spoilage of crayfish (Procambarus clarkii) during refrigerated storage

The variety of enzyme-based biological preservatives is limited. This study evaluated the effects of glutathione peroxidase (GSH-Px) on the quality of crayfish during refrigerated storage by measuring the pH, total volatile basic nitrogen, trimethylamine, and microbial contamination in crayfish muscle simulation system. The results revealed that 0.3% GSH-Px (CK3) not only suppressed the degradation of nitrogenous substances but also decreased the contamination levels of total viable, Enterobacteriaceae, and Pseudomonas counts (P < 0.05). Furthermore, the populations of Lactococcus, Aeromonas, and Massilia differed in the CK3 group compared to the other groups (P < 0.05) at the end of the storage (day 15). Moreover, the principal coordinate analysis showed that the colony composition of CK3 stored for 15 days was similar to that of the control group stored for 10 days. Therefore, GSH-Px exhibits antibacterial activity against Gram-negative bacteria and has good application potential in freshwater aquatic product preservation.

Tandem Mass Tag-based proteomic analysis of protein changes in superchilled crayfish (Procambarus clarkii) presoaked with carrageenan oligosaccharides

To assess the effectiveness of carrageenan oligosaccharides (COs) in enhancing superchilling storage of crayfish, the physicochemical features of muscle and protein abundance in the refrigerated sample (RS), superchilled sample (SS) and COs soaked superchilled sample (CS) were evaluated. Microstructural and SDS-PAGE analyses suggested that CS exhibited fewer pores, with a microstructure and protein subunits distribution more similar to RS. Tandem Mass Tags quantitative proteomic analysis revealed 66 up-regulated differentially abundant proteins (DAPs) in the CS vs. SS batch, including myosin light chain 2, neural cadherin, integrin beta, lectin-like protein, toll-1, reticulon-1, and moesin/ezrin/radixin homolog 1, which facilitate cells adhesion and maintain membrane/cytoskeleton integrity. Eukaryotic Clusters of Orthologous Groups results confirmed that COs treatment increased the stability of crayfish myofibrillar proteins by up-regulating DAPs, which were concentrated in functional categories such as "posttranslation modification, protein turnover, chaperones", "signal transduction mechanisms", "energy production and conversion", and "cytoskeleton".

Growth Reduction of Vibrionaceae and Microflora Diversity in Ice-Stored Pacific White Shrimp (Penaeus vannamei) Treated with a Low-Frequency Electric Field

A novel storage technique that combines the low-frequency electric field (LFEF) and ice temperature was used to extend the shelf life of Pacific white shrimp (Penaeus vannamei). The study investigated the effect of LFEF treatment on the quality and microbial composition of Penaeus vannamei during storage at ice temperature. The results showed that the LFEF treatment significantly extended the shelf life of shrimp during storage at ice temperature. The total volatile base nitrogen (TVB-N) and pH of samples increased over time, while the total viable count (TVC) showed a trend of first decreasing and then increasing. Obviously, shrimp samples treated with LFEF had a lower pH, TVB-N and TVC values than the untreated samples (p < 0.05) at the middle and late stages of storage. LFEF treatment increased the diversity and altered the composition of the microbial communities in Penaeus vannamei. Additionally, the treatment led to a decrease in the relative abundance of dominant spoilage bacteria, including Aliivibrio, Photobacterium and Moritella, in Penaeus vannamei stored at ice temperature for 11 days. Furthermore, correlation analysis indicated that TVB-N and pH had a significant and positive correlation with Pseudoalteromonas, suggesting that Pseudoalteromonas had a greater impact on shrimp quality. This study supports the practical application of accelerated low-frequency electric field-assisted shrimp preservation as an effective means of maintaining shrimp meat quality.

Effect of low-voltage electrostatic field-assisted partial freezing on large yellow croaker protein properties and metabolomic analysis during storage

BACKGROUND

Large yellow croaker is highly perishable during storage because of high protein and moisture content. The degradation of the fish is mainly attributed to microbial growth and enzyme activity, so it is important to find an efficient storage method to extend its shelf life.

METHODOLOGY

This study investigated the effect of a low-voltage electrostatic field combined with partial freezing treatment on the physicochemical properties of myofibrillar protein (MP) and metabolomic analysis of large yellow croaker during preservation. The samples in chilled storage (C), partial freezing storage (PF) and 6 kV/m low-voltage electrostatic field partial freezing storage (LVEF-PF) were analyzed during an 18 day storage period.

RESULTS

In comparison with the C and PF groups, LVEF-PF delayed the oxidation of MP by inhibiting the formation of carbonyl groups (2.25 nmol/mg pro), and maintaining higher sulfhydryl content (29.73 nmol/mg pro). Fourier transform infrared (FTIR) spectroscopy and fluorescence spectroscopy analysis also demonstrated that the LVEF-PF treatment maintained the stability of the protein structure by increasing the a-helix ratio (19.88%) and reducing the random coil ratio (17.83%). Scanning electron microscopy showed that, compared with the LVEF-PF group, there was more degeneration and aggregation of MP in the C and PF groups after 18 days' storage. The results of untargeted metabolomic analysis showed that 415 kinds of differential metabolites were identified after storage, and the difference levels of differential metabolites were least between the samples treated with LVEF-PF stored on the ninth day and the fresh samples. The main differential metabolic pathways during storage were amino acid metabolism and lipid metabolism.

CONCLUSION

The LVEF-PF treatment could maintain the stability of myofibrillar protein in large yellow croaker during storage. These results showed a potential application of the LVEF-PF method for aquatic product preservation. © 2023 Society of Chemical Industry.

Antibacterial properties of hexanal-chitosan nanoemulsion against Vibrio parahaemolyticus and its application in shelled shrimp preservation at 4 °C

Vibrio parahaemolyticus has been considered as the leading pathogen associated with seafood-borne disease. Hexanal possesses antibacterial property but the hydrophobicity and volatility limit its application. The purpose of this study was to prepare hexanal-chitosan nanoemulsion (HCN), investigate its antibacterial ability against V. parahaemolyticus, and examine the combination of HCN with sodium alginate coating on the quality attributes of shrimp during cold storage. The mean droplet size of HCN fabricated by ultrasonic emulsification was 91.28 nm. HCN showed regular spherical shape and exhibited good centrifugation stability and storage stability at 4 °C. HCN exerted anti-V. parahaemolyticus effect with the minimum inhibitory concentration and minimal bactericidal concentration of both 5 mg/mL. Furthermore, HCN induced morphological changes and destroyed bacterial membrane, resulting in cell death. The results of preservation test showed that HCN alone and its combination with sodium alginate coating effectively retarded the quality deterioration and microbial spoilage of shelled shrimps during refrigerated storage. Comparatively, the combination treatment exhibited better preservation effect. The present study suggested that HCN prepared by ultrasonic emulsification is an effective alternative to control V. parahaemolyticus contamination in seafood and also shows great application potential in the quality maintaining of seafood during cold storage.

The stable co-pigmented roselle anthocyanin active film extended shelf life of Penaeus vannamei better: Mechanism revealed by the TMT-labeled proteomic strategy

In order to investigate the influences of modified RAE-based film on shrimp quality, the proteomic approach was performed to elucidate preservation mechanism. Results showed that the modified RAE-based film kept better shrimp quality compared with natural RAE-based film in terms of determined biochemical parameters and estimated shelf-life. Totally, 49 differentially abundance proteins (DAPs) were identified compared with shrimp without packaging. Bioinformatics analysis demonstrated that the modified RAE-based film could maintain functional DAPs which were mainly distributed in the binding, catalytic activity, etc., and metabolic signaling pathways like melanogenesis signaling pathway were remarkably enriched. Meanwhile, there were 25 DAPs showing close relationship with quality traits, and some of them, such as myosin chains, troponin I and heat shock protein were considered as the potential biomarkers to evaluate shrimp quality deterioration. In conclusion, this study revealed the preservation mechanism of modified RAE-based active film on shrimp quality at the protein molecular level.

Effect of three culture patterns on quality changes of crayfish meats during partial freezing storage

The quality changes and main metabolites of rice-crayfish (DT), intensive crayfish (JY), and lotus pond crayfish (OT) under three culture patterns during partial freezing were studied. Compared with the DT and JY groups, the OT samples had higher thiobarbituric acid reactive substances (TBARS), K values and color values. The microstructure of the OT samples deteriorated most obviously during storage, and they had the lowest water-holding capacity and the worst texture. Furthermore, differential metabolites of crayfish under different culture patterns were identified by UHPLC-MS, and the most abundant differential metabolites of the OT groups were found. The main differential metabolites include alcohols polyols and carbonyl compounds; amines; amino acids, peptides, and analogues; carbohydrates and carbohydrate conjugates; fatty acids and conjugates. In conclusion, based on the analysis of existing data, the OT groups were considered to be the most serious deterioration during partial freezing compared with the other two culture patterns.

Effect of low voltage electrostatic field combined with partial freezing on the quality and microbial community of large yellow croaker

The effect of low voltage electrostatic field combined with partial freezing (LVEF- PF) treatment on storage quality and microbial community of large yellow croaker was studied. Three different methods including chilled (C), partial freezing (PF) and 6 kV/m electrostatic field combined partial freezing storage were used to preserve large yellow croaker for 18 days. Total viable counts (TVC), sensory evaluation, and physiochemical index including pH, total volatile basic nitrogen (TVB-N), K value and centrifugal loss were examined. During storage, the large yellow croaker was susceptible to microbial growth and spoilage. However, LVEF-PF treatment was found to be effective in enhancing sensory quality, inhibiting microbial growth, and maintaining myofibril microstructure. Low field nuclear magnetic resonance showed that LVEF-PF treatment reduced the migration of immobilized water to free water. At 18th day, the TVC value of LVEF-PF, PF and chilled group were 3.56 log CFU/g, 5.11 log CFU/g, 7.73 log CFU/g, respectively. Therefore, from the results of TVB-N and TVC value, the shelf life of LVEF-PF group was at least 3 days longer than PF group, and 6 days longer than the chilled group. High-throughput sequencing showed that the microbial community diversity significantly decreased during storage. The predominant bacteria in chilled, PF, LVEF-PF group at 18th day were Pseudomonas, Psychrobacter and Shewanella, respectively, and the relative abundance of spoilage bacteria such as Pseudomonas and Psychrobacter were reduced by LVEF-PF treatment, that corresponding with lower values of TVB-N and TVC value. LVEF-PF treatment could be used as a new processing and storage method to delay deterioration and prolong shelf life of large yellow croaker.

Real-Time Monitoring of the Quality Changes in Shrimp (Penaeus vannamei) with Hyperspectral Imaging Technology during Hot Air Drying

Hot air drying is the most common processing method to extend shrimp’s shelf life. Real-time monitoring of moisture content, color, and texture during the drying process is important to ensure product quality. In this study, hyperspectral imaging technology was employed to acquire images of 104 shrimp samples at different drying levels. The water distribution and migration were monitored by low field magnetic resonance and the correlation between water distribution and other quality indicators were determined by Pearson correlation analysis. Then, spectra were extracted and competitive adaptive reweighting sampling was used to optimize characteristic variables. The grey-scale co-occurrence matrix and color moments were used to extract the textural and color information from the images. Subsequently, partial least squares regression and least squares support vector machine (LSSVM) models were established based on full-band spectra, characteristic spectra, image information, and fused information. For moisture, the LSSVM model based on full-band spectra performed the best, with residual predictive deviation (RPD) of 2.814. For L*, a*, b*, hardness, and elasticity, the optimal models were established by LSSVM based on fused information, with RPD of 3.292, 2.753, 3.211, 2.807, and 2.842. The study provided an in situ and real-time alternative to monitor quality changes of dried shrimps.

The Biological Activity Mechanism of Chlorogenic Acid and Its Applications in Food Industry: A Review

Chlorogenic acid (CGA), also known as coffee tannic acid and 3-caffeoylquinic acid, is a water-soluble polyphenolic phenylacrylate compound produced by plants through the shikimic acid pathway during aerobic respiration. CGA is widely found in higher dicotyledonous plants, ferns, and many Chinese medicine plants, which enjoy the reputation of “plant gold.” We have summarized the biological activities of CGA, which are mainly shown as anti-oxidant, liver and kidney protection, anti-bacterial, anti-tumor, regulation of glucose metabolism and lipid metabolism, anti-inflammatory, protection of the nervous system, and action on blood vessels. We further determined the main applications of CGA in the food industry, including food additives, food storage, food composition modification, food packaging materials, functional food materials, and prebiotics. With a view to the theoretical improvement of CGA, biological activity mechanism, and subsequent development and utilization provide reference and scientific basis.

Eugenol-chitosan nanoemulsion as an edible coating: Its impact on physicochemical, microbiological and sensorial properties of hairtail (Trichiurus haumela) during storage at 4 °C

Effects of the eugenol-chitosan nanoemulsion as an edible coating on the quality of hairtail (Trichiurus haumela) during storage at 4 °C were evaluated. For all samples, such parameters as pH, thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), water holding capacity (WHC), electrical conductivity (EC), total bacteria count (TVC) and sensory were examined periodically. The results demonstrated that eugenol-chitosan nanoemulsion coating showed better preservative effects than chitosan nanoemulsion alone. Therefore, a coating based on eugenol-chitosan nanoemulsion could be regarded as an effective food-grade biopreservative to maintain the quality of hairtail fish and prolong its shelf life during chilled storage.

Effect of locust bean gum-sodium alginate coatings incorporated with daphnetin emulsions on the quality of Scophthalmus maximus at refrigerated condition

In this study, the microbiological, physicochemical, and flavor changes of turbot (Scophthalmus maximus) coated with a composite active coating of locust bean gum (LBG) and sodium alginate (SA) supplemented with daphnetin emulsions (0.16, 0.32, 0.64 mg·mL^-1) were determined during 18 days of refrigerated storage (4 ± 1 °C). Results showed that LBG-SA coatings containing 0.32 mg·mL^-1 daphnetin emulsions could significantly lower the total viable count (TVC), psychrophiles, Pseudomonas spp. and H₂S-producing bacteria counts, and inhibit the productions of off-flavor compounds including the total volatile basic nitrogen (TVB-N), trimethylamine (TMA) and ATP-related compounds. 32 volatile compounds were identified by solid phase microextraction combined with gas chromatography-mass spectrometer method (SPME-GC/MS) during refrigerated storage and the treated turbot samples significantly lowered the relative content of fishy flavor compounds. Further, the LBG-SA coatings containing daphnetin could also delay the myofibril degradation of the turbot samples. These results indicated that the LBG-SA coatings with 0.32 mg·mL^-1 daphnetin were a potential alternative way to improve the quality of turbot during refrigerated storage.