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The antioxidant and anti-inflammatory properties of astaxanthin (AST) enable it to protect against oxidative stress-related and inflammatory diseases with a range of biological effects. These activities provide the potential to develop healthier food products. Therefore, it would be beneficial to design delivery systems for AST to overcome its low stability, control its release, and/or improve its bioavailability. This review discusses the basis for AST's various biological activities and the factors limiting these activities, including stability, solubility, and bioavailability. It also discusses the different systems available for the targeted delivery of AST and their applications in enhancing the biological activity of AST. These include systems that are candidates for preventive and therapeutic effects, which include nerves, liver, and skin, particularly for possible cancer reduction. Targeted delivery of AST to specific regions of the gastrointestinal tract, or more selectively to target tissues and cells, can be achieved using targeted delivery systems to increase the biological activities of AST. [ABSTRACT FROM AUTHOR]

Antibacterial delivery emulsions are potential materials for treating bacterial infections. Few studies have focused on the role and mechanism of emulsions in inflammation relief. Therefore, based on our previous analysis, in which the novel and natural Pickering emulsions stabilized by antimicrobial peptide nanoparticles were prepared, the regulation effect of emulsion on inflammasome was explored in silico, in vitro and in vivo. Firstly, the interactions between inflammasome components and parasin I or Pickering emulsion were predicted by molecular docking. Then, the inflammasome stimulation by different doses of the emulsion was tested in RAW 264.7 and THP-1 cells. Finally, in Kunming mice with peritonitis, NLRP3 and IL-1β expression in the peritoneum were evaluated. The results showed that the Pickering emulsion could combine with ALK, casp-1, NEK7, or NLRP3 to affect the assembly of the NLRP3 and further relieve inflammation. LPNE showed a dose–dependent inhibition effect on the release of IL-1β and casp-1. With the concentration of parasin I increased from 1.5 mg/mL to 3 mg/mL, the LDH activity decreased in the chitosan peptide-embedded nanoparticles emulsion (CPENE) and lipid/peptide nanoparticles emulsion (LPNE) groups. However, from 1.5 to 6 mg/mL, LPNE had a dose–dependent effect on the release of casp-1. The CPENE and parasin I-conjugated chitosan nanoparticles emulsion (PCNE) may decrease the release of potassium and chloride ions. Therefore, it can be concluded that the LPNE may inhibit the activation of the inflammasome by decreasing LDH activity, potassium and chloride ions through binding with compositions of NLRP3. [ABSTRACT FROM AUTHOR]

The appeal for environment friendly films with bioactive components to replace synthetic plastic packaging has been increasing in recent years. In this study, ginger essential oil (GEO) nanoemulsion at different levels (0.5%, 1.0%, 1.5%, 2.0%, and 3.0%) were incorporated into fish sarcoplasmic protein (FSP) and chitosan (CH) blend films to evaluate the physical, mechanical, antioxidant, and thermal properties. The water distribution state of films was also determined by NMR transverse relaxation (T2) measurements. The tensile strength (TS) of samples was significantly reduced with increasing GEO nanoemulsion contents (p < 0.05), while the value of elongation at break (EAB) was the highest when the film with 1.0% GEO nanoemulsion. The addition of GEO nanoemulsion enhanced the water barrier properties and affected the water distributions of films, but had negative effects on thermal degradation of films. Scanning electric microscope (SEM) demonstrated the different microstructure at varied levels of GEO nanoemulsion and Fourier transform infrared (FTIR) spectroscopy gave the detailed information about the interactions at molecular level. These results revealed that FSP blended with CH was excellent film-forming material and mixing defined amount of GEO nanoemulsion into film-forming solution enhanced the physical and antioxidant properties of films. [ABSTRACT FROM AUTHOR]

This study examined the effects on conformation and oxidation of myofibrillar protein in largemouth bass by different thawing methods. The conventional thawing, microwave thawing, microwave (MVT) or ultrasound combined with vacuum thawing, microwave or far‐infrared thawing (FMT) combined with magnetic nanoparticles were used in this experiment. The physicochemical changes were analyzed by differential scanning calorimetry and dynamic rheology. The protein structure changes were measured by Raman, intrinsic fluorescence, and second‐derivative ultraviolet spectrometry. The degree of protein aggregation was evaluated by surface hydrophobicity, particle size, and zeta‐potential measurements. Total sulfhydryl content, protein carbonyl content, Ca2+‐ATPase activity, and SDS‐PAGE were used to analyze the degree of protein oxidation. Results showed that MVT and FMT samples had better thermal stability, more stable protein conformation, and a lower degree of protein oxidation. Thus, these two methods would be beneficial to sustain the quality of thawed fillets. Practical Applications: In the market circulation, largemouth bass (Micropterus salmoides) need to be frozen. The thawing methods can directly affect the quality of frozen fish, thus causing the changes in the conformation of the myofibrillar protein in fish, and also affecting the degree of protein oxidation. The results showed that the microwave combined with vacuum and the magnetic nanoparticles combined with far‐infrared thawing had less effect on myofibrillar protein of fish and were a better thawing method. [ABSTRACT FROM AUTHOR]

To evaluate the physicochemical properties and structure of thawed fillets, following six treatments were used: conventional thawing, microwave thawing, microwave or ultrasound combined with vacuum thawing, magnetic nanoparticles combined with microwave or far‐infrared thawing. The thawing loss, cooking loss, pH, color, texture change, water‐holding capacity, and water migration of fish fillets were determined. The total volatile base nitrogen and thiobarbituric acid were used to determine the degree of protein degradation and lipid oxidation. Microscope observations and scanning electron microscope (SEM) were used to observe fiber microstructure. Results indicated that both microwave combined with vacuum thawing and far‐infrared combined with magnetic nanoparticles thawing had desirable physicochemical properties as compared to other thawing methods. The lower total volatile base nitrogen and thiobarbituric acid values had less effect on protein degradation and lipid oxidation of thawing process. Besides, both microwaves combined with vacuum thawing and far‐infrared combined with magnetic nanoparticles thawing samples had no significant difference in immobilized and bond water compared with fresh sample. SEM and microscopic observation showed that the myofibril bundles were arranged regularly and smoothly in microwave combined with vacuum thawing and far‐infrared combined with magnetic nanoparticles thawing samples compared with other thawed methods. Thus, the microwave combined with vacuum thawing and far‐infrared combined with magnetic nanoparticles thawing as potential thawing methods could be used to maintain the quality of thawed fish fillets. Practical Application: Largemouth bass (Micropterus salmoides) is a good source of animal protein. The fish needs to be frozen for circulation because of geographical and seasonal factors, so thawing methods can directly affect the quality of thawed fish. The results showed that the microwave combined with vacuum and the magnetic nanoparticles combined with far‐infrared thawing could better maintain the quality of thawed fish. [ABSTRACT FROM AUTHOR]

The effects on the quality of frozen red sea bream, which were pretreated by soaking in solutions containing trehalose, carboxymethyl chitosan magnetic nanoparticles (CCMN), and glycerin or 0.1% herring antifreeze protein (hAFP), were investigated. In this study, the viscoelastic properties of protein studied with the dynamic rheology, Raman and intrinsic fluorescence spectrometry were used to explore the conformation changes of MFP. Surface hydrophobicity, particle size, and zeta potential were carried out to analyze protein aggregation. Solubility, the content of total sulfhydryl/disulfide bond/carbonyl/dityrosine, and the Ca2+-ATPase activity were measured to explore the degree of protein oxidation. SDS-PAGE was conducted to analyze the protein denaturation. Results showed that the pretreatment of red sea bream with soak solutions could improve the viscoelasticity of fillets protein, stabilize the secondary and tertiary conformation of the MFP, inhibit the protein aggregation and oxidation, and decrease the degree of protein denaturation compared with the control (4 °C thawing), especially the soak solutions containing hAFP could minimize the freeze-thaw damage. To summarize, the hAFP helped to retain the above characteristics of frozen fillets much better than that of conventional cryoprotectants (glycerin) to improve the quality of the frozen product after thawing. [ABSTRACT FROM AUTHOR]

The volatile flavor characteristics of largemouth bass (Micropterus salmoides) fillets thawed by magnetic nanoparticles plus microwave thawing (MNPMT) were compared with those of fresh samples thawed by chill storage thawing (CST) and microwave thawing (MT). The strategies of headspace solid-phase microextraction (HS-SPME), gas chromatography mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O), aroma extract dilution analysis (AEDA), and sensory evaluation were applied to analyze the aroma-active compounds. The results of GC-MS showed that 24 kinds of volatile compounds existed in largemouth bass fillets. Orthogonal partial least squares discriminate analysis (OPLS-DA) (R2Y = 0.979, R2Y = 0.98, Q2 = 0.695) showed ethanol, hexanal, 2,6,10,14-tetramethyl-pentadecane, and (E)-9-octadecenoic acid were responsible for the flavor differences in MNPMT, MT, and CST. In GC-O measurement, 14 kinds of volatile compounds were detected, and MNPMT had similar aroma-active compounds with the fresh sample. The grassy (score = 1.58) and leafy (score = 0.75) odors were weak in MT, but the fishy odors (score = 1.5) were strong. All results showed the MNPMT samples had less changes in aroma composition compared with the fresh sample. [ABSTRACT FROM AUTHOR]

• The two devices of UMT and UIT were assembled by the investigators. • The effects of five thawing methods on protein properties and moisture migration were studied. • UMT and UIT could maintain the quality of the red drum fillets better than controls. The influence of ultrasonics combined with microwave thawing (UMT) and ultrasonics combined with far-infrared thawing (UIT) on the water migration and protein denaturation of red drum were studied. Five treatments were used: ultrasonics thawing (UT), microwave thawing (MT), far-infrared thawing (IT), UIT and UMT were used for thawing red drum filets. Moisture migration and protein aggregation were studied using nuclear magnetic resonance (NMR) and particle size, respectively. Raman spectra and fluorescence spectra were used to study the secondary and tertiary structure of protein. SEM was done to observe the fiber microstructure. The results showed that UMT and UIT can maintained protein stability more than other thawing methods and retained the fiber structure of the muscle. Besides, immobilized water in fiber bundles network also had no significant changes compared with fresh samples. Thus, ultrasonics combined with far infrared or microwave thawing were used to decrease protein denaturation and water migration during the thawing of Red drum fillets. [ABSTRACT FROM AUTHOR]

The effects on the quality of frozen red sea bream which were pretreated by soaking in solutions containing trehalose, chitosan magnetic nanoparticles (CS@Fe3O4 nanoparticles), and glycerin or different concentration herring antifreeze proteins (AFPs) were investigated in this study. The DSC, dynamic rheology, shear force, and TPA were conducted to analyze the physical characteristics. Raman and intrinsic fluorescence spectra were used to measure the protein secondary and tertiary structures. So-ANS and zeta potential were carried out to explore the degree of protein aggregation. Low-field NMR was used to test the water migration, and light microscope was performed to observe the fiber microstructure. Results showed that prior to freezing, the pretreatment of red sea bream samples with soak solutions could minimize drip loss, preserve the meat tenderness and texture, and improve the fish fillet thermal stability and viscoelasticity, and the free water content was decreased while the immobilized water content was increased; the longitudinal and transverse fiber structures were clear and less destructive. Compared with the control, the protein secondary and tertiary structures of samples, among the tested soaking solutions, tended to stability, and the degree of protein oxidation and aggregation was decreased. Therefore, this methodology was proved to be an effective method to inhibit the ice crystal growth and modify ice crystal form in order to improve the quality of the final product, and these effects were amplified with the concentration of AFPs increasingly. [ABSTRACT FROM AUTHOR]

Jelly and confectionery products are high in sugar and calories. Xylitol and stevioside are natural low-calorie sweeteners and they can be used as an alternative; however, their effects on fish gelatin are unknown. The gelatin was extracted from cod skins and added to xylitol or stevioside (0, 2, 6, 10, 14, and 20% (w/v)) to form gel products. This paper investigated how xylitol and stevioside affected the physical and rheological behaviors of fish gelatin, such as color, gel strength, texture profile analysis, storage modulus (G′), loss modulus (G″), and viscosity. Results showed that the change of color and viscosity in gel products were similar when various concentrations of xylitol or stevioside were added to the fish gelatin. But the effects of xylitol/stevioside on texture profile analysis and G′, G″ were different, which might due to the structure variation in xylitol and stevioside. The linear structure of xylitol resulted in ionic interaction, hydrogen bonding, van der Waals forces, and hydrophobic association between xylitol and fish gelatin. Therefore, xylitol is a promising sweetener substitute, which was probably related to its greater solubility and number of –OH groups. [ABSTRACT FROM AUTHOR]

The objectives of this study were to investigate the changes and the relationship between structure and physiochemical properties of low sodium salt substitutes (NaCl partially replaced by KCl, CaCl2, and MgCl2) on grass carp myofibrillar protein gels mediated by microbial transglutaminase during cold-set gels and to provide more information about the gel characteristics. The gel strength, water holding capacity, whiteness, rheological characteristics, differential scanning calorimeter (DSC), and Raman spectra of cold-set gels were determined. The Raman spectra data were fitted to four secondary structures (α-helix, β-sheet, β-turn, and random coil). The gel properties of cold-set gels varied both with the low sodium salt types and incubation time. Myofibrillar protein (MP) gels added with NaCl and KCl had significantly higher water holding capacity than the MgCl2, CaCl2, and control groups. Additionally, the results showed that the gel strength and G’ value increased with the incubating time. No significant difference was detected in whiteness between the NaCl group and partial substituted groups. Cold-set gels added with the same molar amount of NaCl and KCl had fairly similar gel properties. There is a strong correlation between structural properties and gel properties of MP gels determined by DSC during the cold-set gelation process. [ABSTRACT FROM AUTHOR]

Ultrasound assisted vacuum thawing (UVT) or microwave vacuum thawing (MVT) with red seabream fillets were compared to fresh, chill storage thawing, vacuum thawing, microwave thawing and ultrasound thawing. The thermal stability and gelation properties were studied with DSC and dynamic rheology, respectively. Raman spectra before and after H/D isotope exchange and intrinsic fluorescence were used to measure protein secondary and tertiary structure. Low-field NMR was done to measure water migration. The two thawing techniques both retained actin thermal stability and generally retained more stable tertiary structures than the other thawing methods. MVT showed a desirable viscoelasticity of muscle proteins and UVT had a relatively stable secondary structure. There were no significant changes in free water. Thus, UVT and MVT could be used to improve the physicochemical properties of proteins during thawing of fillets. [ABSTRACT FROM AUTHOR]

Optimizing the physicochemical properties of microwave-cooked meat needs a better understanding of the mechanisms responsible for protein changes. This paper explored the causes of aggregation of the denatured fish protein in ready-to-eat food by determining the changes in sarcoplasmic and myofibril proteins, which includes the effects of different microwave power levels (300, 600, and 900 W) and heating times (0-60 s) on the aggregation kinetics and physiochemical properties. The determination of aggregation kinetics that accurately describes microwave cooking characteristics is crucial for the optimization of operating parameters, performance improvement of the cooked food system, and product quality. The aggregation rate and turbidity of proteins increased with increasing microwave power and time. A negative correlation was observed between the protein solubility and microwave power and time. Protein aggregation induced by microwave showed a reliable and reproducible characterization of particle size distributions. At longer microwave heating time or higher microwave power, these protein particles formed larger aggregates. [ABSTRACT FROM AUTHOR]

Abstract: The effects of chitosan coating enriched with lemon and thyme essential oils on the physicochemical, microbiological, and quality changes of grass carp fillets during 2 °C storage were determined during 16 days of storage. The pH, total volatile basic nitrogen, thiobarbituric acid reactive substances, color, texture, sensory quality, total viable count, psychrotrophic bacteria, pseudomonads, Shewanella putrefaciens, Enterobacteriaceae, and lactic acid bacteria counts were analyzed. The results indicated that chitosan coating (1.5%) incorporated with lemon or thyme essential oils (0.5%) maintained higher hardness and retarded the oxidation of lipid and protein. The most effective treatment was chitosan coating (1.5%) enriched with lemon and thyme essential oils (0.25 and 0.25%) together, which maintained the color and texture properties, and reduced the microorganisms counts. The results suggested that the synergized use of lemon and thyme essential oils increased the efficiency of chitosan coating, maintained fish fillets quality and extended its shelf life to 16 days. Practical applications: The commercial value of fresh fish fillets is lost in a few days. Many methods have been used to inhibit the spoilage caused by microorganisms, retard the degradation of protein, and extend the shelf life of fish fillets. As an alternative to chemical and synthetic preservatives, many studies are currently focused on using natural products to improve the quality of fish products. This study reports that chitosan coating incorporated with lemon and thyme essential oils together is a promising edible coating for use in commercial applications for prolonging the shelf life of fish fillets. [ABSTRACT FROM AUTHOR]

Polyphenoloxidase (PPO) from prawns (Penaeus vannamei) was purified by ammonium sulphate precipitation, ion-exchange column, and gel filtration chromatography. The specific activity of PPO increased by 9.51 fold to 575.03 U/mg, and the molecular weight of PPO was 66 kDa. The optimal temperature and pH were around 45°C and 6.8, determined by L-β-(3,4-dihydroxylphenyl) alanine (L-DOPA) as substrate. Km and Vmax values were found to be 2.5 mM and 0.062ΔA/min. The effect of thermal treatment on the activity, conformation, and microstructure of the PPO was investigated. Thermal stability of PPO was measured at 40°C, 50°C, 60°C, 70°C, and 80°C, and the half-life values of PPO were 105, 39.6, 13.4, 8.9, and 3.1 min, respectively. PPO activity slightly decreased at 60°C, while the relative enzyme activity remained 9.4% after 80°C for 10 min. The result of differential scanning calorimetry showed that the denatured temperature of PPO was 65°C. Thermal treatment resulted in the changes in the tertiary structure of PPO, and the λmax of fluorescence spectra was red-shifted with decreasing intensity. Curve-fitting analysis showed that α-helix and β-sheet decreased, but β-turns and random coil increased with increased temperature. Atomic force microscopy revealed that PPO molecules aggregated remarkably at 60°C. Moreover, the formation of large globular aggregates occurred as the temperature increased. [ABSTRACT FROM AUTHOR]

The physical properties and nanostructure of fish skin gelatin with and without whey protein isolate (WPI) were investigated. The addition of low concentrations of WPI (1 and 3%, w/v) into fish gelatin decreased the gel strength and textural properties. The addition of 5% WPI did not significantly influence textural properties but increased the melting and gelling temperatures of fish skin gelatin and improved the appearance of gelatin gels. X-ray diffraction indicated that a higher degree of crystallinity with an ordered structure or ordered structure snippets occurred with increasing WPI concentrations in line with the slight decrease in the loss factor (tan δ) with time sweeps. Fish gelatin had a spherical nanostructure, and a homogeneous nanostructure was observed in gelatin with 3% WPI. The addition of 5% WPI led to large aggregates in gelatin gels. The results indicated that whey protein could affect the nanostructure of fish skin gelatin gels and thus change their gelation properties and texture in food and pharmaceutical applications. [ABSTRACT FROM PUBLISHER]

Changes in the biochemical, nutritional, and sensory properties of the low salt fermented shrimp paste during fermentation were studied. The total volatile base nitrogen (TVB-N) content and total viable counts significantly increased. The pH value significantly decreased, while thiobarbituric acid (TBA) content significantly increased over 14 days. The lightness (L*) value significantly decreased during the initial 7 days of fermentation and significantly increased thereafter. The redness (a*) and yellowness (b*) values and astaxanthin content of the low salt fermented shrimp paste gradually increased during the 30 days of fermentation. C16:0, C18:0, C18:1n9t, C20:1n7c, C20:5n3, and C22:6n3 were the predominant fatty acids, while aspartate, glutamate, alanine, leucine, lysine, arginine, and proline were the predominant amino acids in the shrimp paste. N-containing compounds, such as pyrazine, comprised the majority of the volatile compounds. The results obtained from quantitative descriptive analysis showed that low salt fermentation can improve the flavor of the shrimp paste and is, therefore, a promising method to industrially prepare the shrimp paste. [ABSTRACT FROM PUBLISHER]

The effects of thermal treatment on the ultrastructure and quality of Chilgoza pine nuts stored at near-freezing temperature were investigated. The moisture content of pine nuts was adjusted to 13.3%, compared to the initial 17.3% moisture content. Thermal treatment improved the storage stability. The hydrolysis of lipids was delayed in low-moisture pine nuts, resulting in a significant inhibition of free fatty acid accumulation in pine nuts. Low-moisture pine nuts also showed lower peroxide and thiobarbituric acid (TBA)​ values compared with the control. Ultrastructure characterization revealed that thermal treatment maintained the cell integrity, deferred the degradation of the plasmalemma and protected the internal lipid droplet. Thermal treatment better retained the antioxidant components, including total phenolics and vitamin E, and reduced the activities of lipase and lipoxygenase in pine nuts. These results indicated that thermal treatment could retard the senescence and deterioration of quality in pine nuts stored at a near-freezing temperature. [ABSTRACT FROM PUBLISHER]

Low calorie sweeteners, such as xylitol and stevia, are being used for confectionery gels. Xylitol is digested using the human’s glucose pathway and stevia is a natural low calorie sweetener. However, the microstructure and rheological properties of fish gelatin (FG) confectionery gels with these sweeteners has not been studied. Therefore, the effects of xylitol or stevia at 0, 1, 3, 5, 10 and 20% on the rheological properties and microstructure of FG (6.67% w/w) were studied. The addition of xylitol at low concentrations (i.e., 3–5%) increased the gel strength. However, the gel strength decreased upon further addition of xylitol, likely due to the xylitol preventing gel network formation. The gel strength decreased as stevia increased, which might be attributed to an antagonism that prevents fish gelatin from forming three dimensional network structures. Fourier transform infrared (FTIR) spectroscopy showed that the overall intensities of Amides A, B, I, II, III and the Fingerprint region increased with increasing concentrations of xylitol and stevia, suggesting decreased molecular order. Xylitol had more pronounced effects than stevia, which probably was related to its greater solubility and number of OH groups. [ABSTRACT FROM AUTHOR]

BACKGROUND Collagen has a wide range of applications in food, biomedical and pharmaceutical products. RESULTS The collagens in grass carp ( Ctenopharyngodon idella) skin and swim bladder were extracted using acetic acid and pepsin. Higher yield of pepsin-soluble collagen ( PSC) was obtained from skin (178 g kg−1) than from swim bladder (114 g kg−1). Not surprisingly, yields of PSC from skin and swim bladder were also higher than those of acid-soluble collagen ( ASC) from the same organs (89 and 51 g kg−1). Sodium dodecyl sulfate polyacrylamide gel electrophoresis ( SDS-PAGE) profiles showed that ASC and PSC were type I collagens, with PSC containing a higher proportion of α components than ASC. Fourier transform infrared spectra revealed that ASC and PSC were very similar in their protein secondary structures. Scanning electron micrographs showed that the collagens had a spongy structure, with more pores being obtained in swim bladder than in skin collagens. The collagens showed high solubility in the acidic pH range. However, their solubility decreased in the presence of NaCl at concentrations above 20 g kg−1. CONCLUSION Collagens were successfully extracted from the skin and swim bladder of grass carp. These fish by-products could serve as an alternative source of collagens for a wide variety of applications in the food and nutraceutical industries. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Chinese shrimp waste hydrolysates (CSWHs) with or without xylose were heated with increasing time (0–180 min) at 115 °C, pH 8.0, to explored characteristics of Maillard reaction and the rules for the formation of flavour in hydrolysates. The results suggested that CSWHs could be modified by Maillard reaction and exhibited stronger pleasant flavour than thermal degradation at proper heating time. During Maillard reaction, significant changes in Maillard reaction products (MRPs) were found, such as the accumulation of intermediate/browning/fluorescent products, the presentation of tempting reddish-brown, compared to Thermal degradation products (TDPs). Meanwhile, a series of volatile compounds and amino acids were found in MRPs, and combined with sensory evaluation, the MRPs exhibited strong meaty and seafood aroma as well as umami and mouthfulness taste. Therefore, Chinese shrimp waste could potentially be used to produce flavoring essence with strong enticing flavour and colour. [ABSTRACT FROM AUTHOR]

Compositions and antioxidant properties of protein hydrolysates prepared from four carp skins: black carp, grass carp, silver carp and bighead carp, using pepsin, with a degree of hydrolysis (DH) of 6-15%, were investigated. The yield of freeze-dried hydrolysates was in the range of 54-62 g/100 g (dry skin). The content of protein and ash in four freeze-dried hydrolysates was 72-81% and 8-17%, respectively. All hydrolysates contained high amount of hydrophobic amino acid residues (389-480 residues/1000 residues). Meanwhile, their antioxidant properties were evaluated by in vitro assays. The results revealed that all hydrolysates possessed potent antioxidant activities and showed dose dependency as the activity increased with sample concentration, capable of scavenging 72-88% of DPPH and 61-69% of hydroxyl radicals, respectively, at the highest tested concentration. The hydrolysates exhibited high reducing power and b-carotene-linoleic acid oxidation inhibition. Among the four hydrolysates, the hydrolysate derived from bighead carp skin was superior to others in terms of yield, DH and antioxidant activities. [ABSTRACT FROM AUTHOR]

Several naturally occurring essential oils were evaluated for their effectiveness in maintaining post-mortem quality and extending shelf life of red drum ( Sciaenops ocellatus ). Fresh fish fillets were treated with 4 μl/L clove, cumin and spearmint oils at 10 °C for 2 h and the hardness, pH value, K -value, TCA-soluble peptides, sensory evaluation, biogenic amines and microbiological characteristics determined. The results showed that the fillets treated with spearmint oil significantly maintained tissue hardness when compared to the control. Moreover, spearmint essential oil treatment significantly delayed protein degradation and nucleotide breakdown. The essential oil treatment also inhibited the microbiological properties throughout the storage periods. All the treatments were effective in retarding fish sensory deterioration, exhibited a positive effect, causing low biogenic amines content, especially histamine, putrescine, cadaverine. These results indicate that essential oil treatment might be a potential application for extending the shelf life and maintaining the quality of the red drum. [ABSTRACT FROM AUTHOR]

The combined effects of a novel ε-polylysine/sodium alginate (PLSA) treatment on the sensory and physicochemical characteristics of Japanese sea bass ( Lateolabrax japonicas ) stored at 4 ± 1 °C for 16 days were investigated. Fish pH value, total volatile basic nitrogen, free fatty acids, K -value, thiobarbituric acid reactive substances, colour, texture, microbiological and sensory quality were measured. Sea bass coated with PLSA maintained flesh colour and tissue hardness, and showed the lower microbial counts, including mesophilic, psychrophilic, enterobacteria, lactic acid bacteria and yeasts compared with the control. In addition, PLSA coating also delayed changes in lipid oxidation, protein degradation and nucleotide breakdown. The results also proved that PLSA coating effectively maintained the sensory quality of sea bass during the storage period. The efficiency was better than that of PL or SA treatment alone. Therefore, the PLSA coating can be applied for preservation of the sea bass to extend its shelf life and improve its preservation quality. [ABSTRACT FROM AUTHOR]

Antimicrobial activity of essential oils is widely known, but their application to fish preservation is already limited. The objective was to evaluate the microbiological characteristics and quality changes in turbot ( Scophthalmus maximus) fillets with essential oil fumigation treatments over 20 days stored at 2 ± 1 °C. The turbot fillets were fumigated with a series of concentrations (1, 4, and 8 μL/L) of essential oils of clove, cumin, and spearmint. Changes in the color, texture profile analysis (TPA), peroxide value (PV), 2-thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), trimethylamine nitrogen (TMA-N), microbial characteristics (total viable count, psychrotrophic count, pseudomonads, Shewanella putrefaciens, Enterobacteriaceae, and lactic acid bacteria count) were measured. The results showed the turbot fillets from the control group were the first (day 10) to indicate signs of degradation reaching rejection threshold values for all evaluated parameters. All essential oils could inhibit the oxidation of turbot fillets, and the most effective essential oil was spearmint oil. Fumigated with 4 μL/L spearmint oil maintained the color and texture, retarded the lipid and protein oxidation, and reduced the microorganism counts. Therefore, post-mortem essential oil fumigation treatment has positive effects on improving the quality of refrigerated turbot fillets. [ABSTRACT FROM AUTHOR]

In order to establish an effective freezing method for quality control, the present research evaluated the effects of the different freezing treatments on the quality of Japanese sea bass ( Lateolabrax japonicas ) over a period of 20 days storage at 0 ± 1 °C. Fish pH value, total volatile basic nitrogen (TVB-N), K-value, trimethylamine nitrogen (TMA-N), drip loss, hardness, color, biogenic amines, microbiological characteristics were measured. Sea bass fillets were stored at −18 °C (T1), −55 °C for 24 h and then −18 °C (T2), −55 °C (T3) for 3 months prior to refrigerated storage. T2 showed lower TVB-N, pH value, biogenic amines and drip loss than T3 and T1 did. Significant lower value of bacterial loads, b* value and hardness were observed in T1, T2 and T3 than those of control group. No significant differences were observed among T1, T2 and T3 for TMA-N and a* value. The study demonstrated that Japanese sea bass fillets treated with −55 °C for 24 h and then −18 °C up to 3 months maintain better quality during refrigerated storage. [ABSTRACT FROM AUTHOR]

Highlights: [•] Gum arabic+ergothioneine (GAER) retarded nucleotide breakdown and lipid oxidation. [•] GAER coating delayed protein degradation, reduced microbial growth. [•] GAER coating maintained better texture and sensory quality of red sea bream. [ABSTRACT FROM AUTHOR]

The effect of chitosan-ergothioneine coating (CHER) on the post-mortem quality and shelf life of Japanese sea bass ( Lateolabrax japonicas) stored at 4 ± 1 °C for 16 days was investigated. Four different treatments were used: control without coating, CH with chitosan coating, ER with 0.3 % ergothioneine immersion, and CHER with chitosan containing 0.3 % ergothioneine coating. Sea bass pH value, total volatile basic nitrogen, peroxide value, thiobarbituric acid-reactive substances, biogenic amines, color, texture profile, and microbiological and sensory qualities were measured. The results indicate that treatment with CHER coating inhibited increase of total volatile basic nitrogen, peroxide value, and TBA value; maintained tissue hardness; and reduced microorganism counts, such as Pseudomonas, compared with control treatment. The efficiency was better than that of ER or CH treatment. Furthermore, sea bass treated with chitosan-ergothioneine coating also exhibited a positive effect, causing low biogenic amine content, especially putrescine, cadaverine, and histamine. Sensory evaluation proved the efficacy of chitosan-ergothioneine coating by maintaining the overall quality of sea bass during the storage period. Our study suggests that chitosan-ergothioneine coating might be a promising candidate for maintaining sea bass quality and extending their shelf life. [ABSTRACT FROM AUTHOR]

Changes in quality of low-moisture conditioned pine nuts (Pinus gerardiana) under near freezing temperature storage were investigated. Nuts were adjusted to different moisture content (17.3% ± 0.42, 15.1% ± 0.26, and 13.3% ± 0.24) with 35°C, 20%RH, sealed in air-tight jars and stored at −3 and −1°C for 12 months. In general, free fatty acid content and peroxide value of the nuts increased, while sensory quality decreased during the storage. Low-moisture nuts had lower respiration, free fatty acid content, and peroxide value. Nuts stored at −3°C had less visible mold infection and browning percentage than at −1°C. Low-moisture treatment exerted a slight negative effect on texture, but had significant preservative effects on color, odor, and taste during storage. Overall, integration of low-moisture conditioning and near freezing temperature storage can be a promising non-chemical way for maintaining the postharvest quality and extending shelf-life of pine nuts. [ABSTRACT FROM PUBLISHER]

The functional properties and bioactivities of the pine nut protein isolates (PPI) and its enzymatic hydrolysates (PPH) prepared with Alcalase at 5 %, 10 %, 15 % and 25 % degree of hydrolysis (DH) were studied. The solubility of PPH significantly increased ( p < 0.05) with the increase of the DH, while the foaming capacity of PPH was only improved at a low DH. However, enzymatic hydrolysis reduced the emulsifying capacity of PPH. The DPPH radical scavenging and inhibition of linoleic acid oxidation activities of PPH were significantly improved by a low DH (5 %) compared with those of PPH with a higher DH and the original PPI ( p < 0.05). The reducing power of PPH at all DH decreased in comparison to that of the original PPI. Potent angiotensin-converting enzyme (ACE) inhibitory peptides could be generated by hydrolysis with Alcalase, and the ACE inhibitory activity of PPH increased ( p < 0.05) with the DH. These results revealed that a low degree of enzymatic hydrolysis was appropriate to obtain PPH with improved functional properties and good antioxidant activities, while a high degree of hydrolysis was essential to obtain highly potent ACE inhibitory peptides from PPI. These results suggest that the control of the DH may be an effective strategy to modify specific functional and bioactive properties of PPH, and PPH has potential as a functional food ingredient for related functional and health benefits. [ABSTRACT FROM AUTHOR]

Changes in the content of bioactive components, oxidative stability, and radical scavenging capacity of pine nut oils extracted from kernels roasted for different times (0-60 min) at 150°C were determined. Oil extracted from kernels roasted for 30 min demonstrated the highest oxidative stability. The browning index which indicates extent of Maillard reaction significantly ( p<0.05) increased with roasting. Compared to samples from unroasted kernels, roasting was found to cause an increase in total phenolics and a reduction in the level of total tocopherols. Total carotenoids and total chlorophylls were also reduced by roasting and almost completely diminished in heaver roasting conditions. The highest radical scavenging capacity was detected in oil sample from kernels roasted for 30 min. The improvement of oxidative stability and antioxidant capacity is possibly resulted from the combined action of the neo-formed Maillard reaction products, increased total phenolics, and other remaining bioactive components. [ABSTRACT FROM AUTHOR]

Abstract: To obtain an overall view on gene expression during the early stage (24h) of tomato fruit in response to postharvest UV-C irradiation (4kJ/m2), we performed a microarray analysis by using Affymetrix Tomato Genechip. The results showed that 274 and 403 genes were up- or down-regulated, respectively, more than two folds in postharvest tomato fruit irradiated with UV-C as compared with that in control fruit. The up-regulated genes mainly involve in signal transduction, defense response and metabolism. Conversely, genes related to cell wall disassembly, photosynthesis and lipid metabolism were generally down-regulated. These results opened ways to probe into the molecular mechanisms of the effects of postharvest UV-C irradiation on increased disease resistance, delayed softening, better quality maintenance and prolonged postharvest life in tomato fruit. [Copyright &y& Elsevier]

The present study investigated the effects of CS@Fe 3 O 4 nanoparticles combined with microwave or far infrared thawing on microbial diversity of red seabream (Pagrus major) fillets in terms of thawing loss, pH, TVB-N, classical microbiological enumeration and high-throughput sequencing, and the same parameters were also studied for 24 h after thawing. Four thawing methods were used: microwave thawing (MT), far-infrared thawing (FT), CS@Fe 3 O 4 nanoparticles combined with microwave thawing (CMT) and CS@Fe 3 O 4 nanoparticles combined with far-infrared thawing (CFT). The results showed that CFT and CMT had lower values of pH and TVB-N compared to the FT and MT. Based on conventional microbial count analysis, CFT and CMT samples also maintained lower TVC, pseudomonas and LAB counts. Using high-throughput sequencing analysis, Compared with FT and MT, CFT and CMT samples showed a significant decrease in the proportion of the Pseudomonadaceae flora. However, the proportion of Pseudomonas, Bacillaceae and Thermaceae also increased significantly after 24 h of storage, which indicated that become the predominant microbiota in red seabream (Pagrus major) fillets. • Four thawing methods were studied in red seabream by high-throughput sequencing. • The thawing method of CS@Fe 3 O 4 nanoparticles plus microwave or far infrared was used. • CFT and CMT decreased the community richness and microbial communities bacterial diversity. [ABSTRACT FROM AUTHOR]

The effects of magnetic nanoparticles combined with microwave thawing (MNPMT) and magnetic nanoparticles combined with far-infrared thawing (MNPFT) on the freshness and amines content of red seabream fillets were investigated. Four thawing methods were used: microwave thawing (MT), far-infrared thawing (FIRT), magnetic nanoparticles combined with microwave thawing (MNPMT) and magnetic nanoparticles combined with far-infrared thawing (MNPFT). The quality of the fresh sample, the sample after thawing and thawed sample after being stored for 6 h were compared by measuring the freshness indexes such as the volatile amino nitrogen content, thiobarbituric acid content, pH value, total number of viable colonies, and the food safety evaluation indexes such as the formaldehyde, dimethylamine, trimethylamine and putrescine contents. The results showed that MNPFT and MNPMT can maintain better freshness than microwave and far-infrared thawing, and the increase in amines content was significantly inhibited. • Two methods of combined thawing have been proposed. • Effect of four thawing methods on the freshness and safety was analyzed. • Magnetic nanoparticles plus microwave or far infrared thawing works better. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different thawing methods on the quality of largemouth bass. The viscoelastic properties of proteins in Ultrasonics combined with microwave thawing (UMT) and Ultrasonics combined with far-infrared thawing (UIT) samples were closer to FS, which was an indication of good gelation and gel quality. Zeta potential, Raman spectra before and after H/D isotope exchange were used to measure the protein aggregation and the secondary structure of protein. Fourier transform Raman spectra and Raman spectra have been used to investigate the chemical changes in fish lipid during lipid oxidation. Results indicated that both UMT and UIT showed protein stability and gelation property. Thus, it was proved that UMT and UIT could be potentially used to improve the fish quality during thawing process. • Two novel thawing methods have been proposed. • The effects of five thawing methods on fish quality was studied. • UMT and UIT could maintain the quality of the largemouth bass fillets better. [ABSTRACT FROM AUTHOR]

In this study, docosahexaenoic acid powder-enhanced gelatin-chitosan edible films were prepared by casting, electrospinning and coaxial electrospinning, respectively. The color (CR), transparency (UV), light transmission (UV), mechanical strength (TA-XT), thermal stability (DSC), crystalline structures (XRD), molecular interactions (FTIR), and microstructure (SEM) were assessed in the analytical research. The results of the research showed that the electrospinning process and the coaxial electrospinning process produced a smooth surface visible to by the naked eye and a uniform granular network structure in a unique film-forming manner, thereby exhibiting good water solubility and mechanical properties. In contrast, the casted film was smooth, transparent, and mechanically strong but poorly water soluble. It was also found that the addition of docosahexaenoic acid powder affected the optical, physical and mechanical properties of the film to varying degrees. [ABSTRACT FROM AUTHOR]

BACKGROUND: Water‐free transportation (WFT), as a novel strategy for express delivery of live shrimp (Litopenaeus vannamei), was developed recently. However, air exposure during this transportation arouses a series of abiotic stress to the shrimp. In the present study, the influences of WFT stress on glycolysis and lipolysis metabolism and meat quality (umami flavor and drip loss) were investigated in comparison with conventional water transportation (WT). RESULTS: The results showed that type II muscle fibers with the feature of anaerobic metabolism were dominated in shrimp flesh. In addition, the increments of intracellular Ca2+ was detected in WFT and WT, which then activated the AMP‐activated protein kinase pathway and promoted the consumption of glycogen, as well as the accumulation of lactate and lipolysis, under the enzymolysis of hexokinase, pyruvate kinase, lactate dehydrogenase and adipose triglyceride lipase. Glycogen glycolyzed to latate. Meanwhile, ATP degraded along with glycolysis resulting in the generation of ATP‐related adenosine phosphates such as inosine monophosphate with umami flavor and phosphoric acid. More remarkable (P < 0.05) physiological changes (except lactate dehydrogenase and lactate) were observed in WFT compared to WT. Additionally, the fatty acid profile also slightly changed. CONCLUSION: The transport stress induced significant energy metabolism changes of shrimp flesh and therefore effected the flesh quality. The intensifications of freshness (K‐value) of shrimp flesh were detected as a result of ATP degradation, which were more pronounced after WFT. However, the drip loss of shrimp flesh was more significantly increased (P < 0.05) after WFT compared to WT. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A new fermentation method for kiwi wine was explored by developing the well-known medicinal and edible plant Cyclocarya paliurus (C. paliurus) to create more value with undersized kiwifruits. In this study, the changes in bioactive substances during the C. paliurus–kiwi winemaking process were analyzed on the basis of response surface optimization results, and the antioxidant capacity, aromatic compounds, and sensory quality of the C. paliurus–kiwi composite wine with kiwi wine and two commercial kiwi wines were compared. The results showed that DPPH radical, OH− radical, and ABTS+ scavenging rates remained at over 60.0%, 90.0%, and 70.0% in C. paliurus–kiwi wine, respectively. The total flavonoid content (TFC) and total polyphenol content (TPC) of C. paliurus–kiwi wine were significantly higher than those of the other three kiwi wines. C. paliurus–kiwi wine received the highest score and detected 43 volatile compounds. Ethyl hexanoate, which showed stronger fruity and sweet aromas, was one of the main aroma components of C. paliurus–kiwi wine and different from commercial wines. This wine has a good flavor with a natural and quality feeling of C. paliurus–kiwifruit extract, low-cost processing, and great market potential. [ABSTRACT FROM AUTHOR]

Oxidation of lipid and protein is a major reason of flesh quality deterioration during storage. In this work, cold storage (CS) and flake ice (FI) storage, as traditional strategies for live shrimp (Litopenaeus vannamei) sedation and refrigerated storage, showed remarkable oxidation damage of lipid and protein in shrimp flesh during storage. In contrast, ice slurry (IS), with good heat exchange capacity and contactability, stunned shrimp in a sudden and thus relieved antemortem stress, which resulted in reducing the reactive oxygen species and reactive nitrogen species accumulation, and the oxidation damage risk in flesh. Additionally, IS, as a storage medium acted an oxygen barrier, further inhibited the oxidation of lipid and myofibrillar protein (MP), as revealed by the lower thiobarbituric acid reactive substances level, carbonyl (CO) derives content, total disulfide bond (S–S) content, and the higher total sulfhydryl (SH) content in shrimp flesh during storage, compared with CS and FI. The sodium dodecyl sulfate‐polyacrylamide gel electrophoresis electrophoretogram pattern of MP also suggested better preservation of myosin heavy chain, myosin light chain, actin, and tropomyosin in IS, whereas these proteins degraded in CS and FI. Consequently, IS prevented the formation of cross‐linking caused by oxidation in MP, leading to improved shrimp flesh quality during refrigerated storage, as demonstrated by the better maintained hardness, springiness, and water‐holding capacity compared to CS and FI. [ABSTRACT FROM AUTHOR]

Highlights • Vacuum impregnation AFP minimizes freeze-thaw damage to fish. • hAFP and CS@Fe 3 O 4 nanoparticles have synergistic effect. • They maintain quality to red sea bream during freeze-thaw cycles. Abstract This study examined the effect of herring antifreeze protein (hAFP) combined with chitosan magnetic nanoparticles (CS@Fe 3 O 4), applied through vacuum impregnation, on protein conformation and moisture state of red sea bream during freeze-thaw cycles. DSC and dynamic rheology were used to analyze physicochemical changes. Raman, intrinsic fluorescence and second derivative UV spectrometry were used to explore the structural changes of myofibrillar proteins. Surface hydrophobicity, particle size and zeta-potential were used to analyze protein aggregation and denaturation. AV, POV, and TBA were used to determine the degree of lipid oxidation. LF-NMR and MRI were used to test water migration and distribution. The results indicated that pretreatment of red sea bream through vacuum impregnation with hAFP combined with CS@Fe 3 O 4 solutions could minimize freeze-thaw damage, prevent protein and lipid oxidation. Therefore, these results confirm the importance of hAFP as a valuable food additive in frozen foods. [ABSTRACT FROM AUTHOR]

The effects of partial substitution of NaCl with KCl, MgCl 2 and CaCl 2 on gelation properties of myofibrillar protein (MP) mediated by microbial transglutaminase during the heating process were studied, including texture, color, water-holding capacity, rheological properties, Raman spectra and microstructure. Ranking of chlorinated salts efficiency showed NaCl > KCl > MgCl 2  > CaCl 2 . The NaCl and KCl groups of MP gels exhibited similar water-holding capacity and gel strength. The gel strength was all decreased in the MP gels containing KCl, CaCl 2 and MgCl 2 compared to the NaCl group, while the KCl group reduced the gel strength to a less extent. The rheological properties of NaCl and KCl groups showed significant higher G′ and G″ values compared to the control group. Thus, the utilization of chlorinated salts substitutes is a promising way to reduce sodium content in fish products. These results could be used for references in developing low-sodium meat and fish products. [ABSTRACT FROM AUTHOR]

The freshness of turbot stored at 4 ° C for 18 days was assessed using Quality Index Method (QIM), biochemical, and proteomic methods, respectively. Results showed that the developed QIM scheme for turbot consisted of eight parameters which gave a total of 20 demerit points. QI showed a linear relationship to storage time (QI = 1.175 × t days – 0.395, R 2 = 0.988), and the remaining storage time could be estimated with an accuracy of ±1 day. pH, K values, TVB-N, and TVC increased significantly with storage time, and the shelf-life of turbot was determined to have been 15 days. Seven protein spots of interest were screened form the post mortem muscle proteome during storage, and were identified as: phosphoglucomutase-1, pyruvate kinase, kinesin-1 heavy chain, Troponin T, desmin-like, and actin, respectively. They were considered as the potential freshness markers of turbot, since the abundance changes of those proteins were significantly correlated with QI, K value, TVB-N, and TVC, and associated with the loss of fish quality and freshness. The work could provide useful information enabling the development of new strategies for freshness evaluation based on protein markers. [ABSTRACT FROM AUTHOR]

The combined effect of ultrasonic and alkali pretreatment for the hydrolysis of native collagenous materials and release of ACE inhibitory peptides was investigated. The ultrasonic and alkali pretreatment of pig skin could accelerate the release of the ACE inhibitory peptides from the triple helix of collagen in early stages of hydrolysis. Furthermore, the pretreatment could also accelerate collapse of the triple helix and release more ACE inhibitory peptides during hydrolysis than collagen samples left untreated. Compared to untreated and alkali pretreated samples, the ultrasonic and alkali pretreatment could decrease the thermostability of pig skin significantly (P < 0.05) because the ultrasonic and alkali pretreatment could weaken hydrogen bonds and break parts of covalent bonds in collagen, leading to damage of the triple helical structure in collagen. Therefore, the ultrasonic and alkali pretreatment could damage the triple helical structure of collagen in native collagenous materials and expose more inner sites for subsequent hydrolysis, and it could be a potential way to prepare ACE inhibitory peptides effectively from collagen-rich raw material. [ABSTRACT FROM AUTHOR]

BACKGROUND: The consumption of frozen foods inevitably involves a thawing process. Protein conformation changes during a short thawing process and the quantification of their effects remains challenging. Molecular dynamics simulations can be used to evaluate the conformational changes of protein occurring in food processing. RESULTS: In the present study, four different thawing methods were used [i.e. magnetic nanometer combined with microwave thawing (MT‐Mag), magnetic nanometer combined with radio frequency thawing (RT‐Mag), radio frequency thawing (RT) and microwave thawing (MT)] to change the conformation of myosin heavy chain (MHC). The results obtained showed that, compared with the fresh sample, the hydrogen bond number and radius of gyration of the RT‐Mag and RT groups were less decreased. Visual molecular dynamics STRIDE analysis showed that the content of the α helix was relatively high in the RT‐Mag and MT‐Mag groups. CONCLUSION: These simulation results indicate that RT‐Mag can be used as an effective method for promoting the thawing process of fish and better stabilizing the protein structure. These conclusions provide a theoretical realization for understanding the protein conformational transition during the thawing process and the realization of quantification and also provide guidance for choosing better thawing conditions without loss of nutritional properties. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

An ultra-high-pressure ( UHP) transmission medium with HCl was applied as a pretreatment to extract gelatin. The effects of the acid concentration (0-1% (w/v)) on the gelatinisation of collagen and the properties of gelatin were investigated. An increase in the acid concentration decreased the thermostability of collagen and increased the yield of gelatin (from 64% increased to 80%). The content of the subunit components in the pretreated collagen and the gelatin declined slightly as the acid concentration was increased, resulted in slight decrease ( P > 0.05) in the gel strength (from 435 g decreased to 408 g). The analysis of Fourier transform infrared spectroscopy ( FTIR) spectra showed that the triple-helical structure, secondary structures of the collagen and covalent cross-linking in the collagenous fibres were damaged gradually as the acid concentration was increased. The scanning electron microscopy ( SEM) images showed that the smooth surface of collagen was partly disrupted with microvoids after UHP/1% HCl pretreatment, which may be related to the damage on the covalent cross-linking. [ABSTRACT FROM AUTHOR]

Hyperuricemia (HUA) is a metabolic disorder caused by abnormal uric acid (UA) metabolism, which is a complex physiological process involving multiple organs (liver, kidney, and intestine). Although UA metabolism in the liver and kidneys has been elucidated, only a few studies have focused on the process in the intestine. With our growing knowledge of the effects of gut microorganisms on health, the gut microbiota has been identified as a new target for HUA treatment. In this review, the relationship between HUA and the gut microbiota is elucidated, and anti-hyperuricemia mechanisms targeting the intestine are discussed, such as the promotion of purine and UA catabolism by the gut microbiota, increases in UA excretion by the gut microbiota and its metabolites, regulation of UA absorption or secretion in the intestinal tract by certain transporters, and the intestinal inflammatory response to the gut microbiota. Additionally, probiotics (Bifidobacteria and Lactobacilli) and prebiotics (polyphenols, peptides, and phytochemicals) with UA-lowering effects targeting the intestinal tract are summarized, providing reference and guidance for further research. [ABSTRACT FROM AUTHOR]

In this research, ovalbumin (OVA) and sodium alginate (SA) were used as the materials to prepare OVA-SA composite carriers, which protected and encapsulated the hydrophobic kaempferol (KAE) and the hydrophilic tannic acid (TA). To achieve the purpose of targeted delivery, the TA-Fe3+ coating film was prepared. Results showed that the observation of small diffraction peaks in carriers proved the formation of TA/Fe3+ coating film on the surface of four composite nanoparticles (pOVA, pOVA-SA, pOVA-KAE-SA, and pOVA-KAE-TA-SA). The protein structure of the composite nanoparticles coated with TA/Fe3+ changed, and the order of the changes was pOVA-KAE > pOVA > pOVA-KAE-SA > pOVA-KAE-TA-SA > pOVA-SA. This phenomenon is due to the fact that the chromophore –C=O and the auxo-chromophore –OH are in the opposite position in the benzene ring of TA, and the two substituents have opposite effects and synergize, resulting in the different degrees of redshift of the composite nanoparticle λ max. Additionally, pOVA-SA had the highest α-helix content and the lowest random coils, conferring the protein structure the strongest stability. The coating of TA/Fe3+ increased the system stability and the thermal stability of the composite nanoparticles. Additionally, the carriers were endowed with antioxidant activity, and their antibacterial ability against Staphylococcus aureus and Escherichia coli was pOVA-KAE-TA-SA > pOVA-KAE-SA > pOVA-KAE > pOVA-SA > pOVA based on the difference in antibacterial diameter (D, mm) and square (S, mm2). pOVA-KAE-TA-SA had the strongest antioxidant activity and antibacterial ability, which improved the bioavailability of TA/KAE. These results provide a theoretical basis for the application of OVA-SA composite nanoparticles in the delivery of bioactive compounds. • OVA/SA composite carrier encapsulated KAE and TA was prepared. • The TA-Fe3+ coating film with targeted release was formed. • The protein structure of composite nanoparticles coated with TA-Fe3+ changed. • The coating film increased system and thermal stability of nanocomposites. • pOVA-KAE-TA-SA had the strongest antioxidant activity and antibacterial ability. [ABSTRACT FROM AUTHOR]

This work was aimed to explore the effects of different thawing strategies on the properties of sea bass myofibrillar protein (MP) and organization structure. Results revealed that magnetic nanometer combined with radio frequency thawing (RT-Mag) and magnetic nanometer combined with microwave thawing (MT-Mag) increased the α-helical content and decreased β-sheet content, while RT-Mag had minimal effect on the secondary protein structure. Low-field nuclear magnetic resonance and SEM analysis revealed that RT-Mag and radio frequency thawing (RT) reduced the mobility and loss of immobilized and non-mobile water, had the most compact and ordered network structure. Decreases in the T max and enthalpies were observed in the thawing treatments expect for RT-Mag during the thawing process. The appearance of polymerized protein band of SDS-PAGE indicated that RT-Mag and MT-Mag occurred a mild oxidation. In addition, the changes of particle size indicated that MP pretreated by RT-Mag and MT-Mag had less aggregation and degradation. The UV second derivative showed that the effect of RT-Mag treatment was closer to that of FS, and the improvement effect of protein aggregation and oxidation was better. Therefore, RT-Mag of New thawing method can be used as an alternative method to improve MP performance and meat quality. ● The two new thawing method of RT-Mag and MT-Mag were adopted. ● Protein structure and thermal stability of sea bass thawed by different methods were studied. ● RT-Mag and MT-Mag could improve MP performance and meat quality. [ABSTRACT FROM AUTHOR]

Abstract: Mature-green tomato fruit (Lycopersicon esculentum cv. Zhenfen 202) were exposed to different doses of UV-B irradiation (10, 20, 40 and 80kJ/m2) and stored in the dark at 14°C, 95% RH for up to 37d. Of the four doses, 20 or 40kJ/m2 was most effective in maintaining a high level of firmness and delaying the colour development. Furthermore, 20 or 40kJ/m2 promoted the accumulation of total phenolics and total flavonoids, and enhanced antioxidant capacity during storage, though UV-B irradiation could reduce the ascorbic acid content. A dose of 10kJ/m2 had similar effects but to a lesser extent. The highest dose of 80kJ/m2 resulted in higher lycopene content, but showed negative effects on texture, colour, and other antioxidants. The optimum dose of UV-B for maintaining sensory qualities and enhancing antioxidant capacity was 20 or 40kJ/m2. These results suggest that UV-B irradiation appears to be a useful non-chemical way of maintaining postharvest quality and enhancing antioxidant capacity in tomato fruit. [ABSTRACT FROM AUTHOR]

In this study, microemulsions were fabricated using tomato seed oil, water, Tween 80 and citric acid, and then the physicochemical characteristics and the influence of environmental stress were investigated. The physicochemical properties of the microemulsions were evaluated by transmission electron microscopy (TEM), mean particle diameter, polydispersity index (PDI) and conductivity. The phase diagrams of tomato seed oil/Tween 80/citric acid/water microemulsions were constructed under different pHs and ionic strengths. Storage stability of the systems was investigated at 4, 37 and 65°C, and changes in turbidity and lipid oxidation products were monitored. Nano‐size zeta potential analyzer results demonstrated that the mean particle diameter and polydispersity index of tomato seed oil microemulsions were 14 nm and 0.014. The transition from W/O to O/W could be detected from electrical conductivity and viscosity data with the increasing of water content. The results showed that the microemulsion areas decreased with increasing pH and NaCl concentrations. What is more, the study proved that tomato seed oil microemulsions exhibited a good storage stability. Practical Application: In this study, the preparation of tomato seed oil microemulsion can not only make full use of the nutritional value of tomato seed oil, but also ensure the effective protection of the nutrients contained in it, and improve the problem of adding difficult. By using microemulsion as delivery carrier of tomato seed oil, the application of tomato seed oil in food, cosmetics and other fields could be enhanced. Therefore, the preparation of tomato seed oil microemulsion provides a theoretical basis for production practice. [ABSTRACT FROM AUTHOR]