Thymol Induces Fenton-Reaction-Dependent Ferroptosis in Vibrio parahemolyticus.

Thymol has efficient bactericidal activity against a variety of pathogenic bacteria, but the bactericidal mechanism against Vibrio parahemolyticus (V. parahemolyticus) has rarely been reported. In the current study, we investigated the bactericidal mechanism of thymol against V. parahemolyticus. The Results revealed that 150 µg/mL of thymol had 99.9% bactericidal activity on V. parahemolyticus. Intracellular bursts of reactive oxygen species (ROS), Fe2+accumulation, lipid peroxidation, and DNA breakage were checked by cell staining. The exogenous addition of H2O2 and catalase promoted and alleviated thymol-induced cell death to a certain extent, respectively, and the addition of the ferroptosis inhibitor Liproxstatin-1 also alleviated thymol-induced cell death, confirming that thymol induced Fenton-reaction-dependent ferroptosis in V. parahemolyticus. Proteomic analysis revealed that relevant proteins involved in ROS production, lipid peroxidation accumulation, and DNA repair were significantly upregulated after thymol treatment. Molecular docking revealed two potential binding sites (amino acids 46H and 42F) between thymol and ferritin, and thymol could promote the release of Fe2+ from ferritin proteins through in vitro interactions analyzed. Therefore, we hypothesized that ferritin as a potential target may mediate thymol-induced ferroptosis in V. parahemolyticus. This study provides new ideas for the development of natural inhibitors for controlling V. parahemolyticus in aquatic products.

Quality Changes and Fungal Microbiota Dynamics in Stored Jujube Fruits: Insights from High-Throughput Sequencing for Food Preservation.

Postharvest rot is an urgent problem affecting the storage of winter jujube. Therefore, the development of new technologies for efficient and safe preservation is very important. This study aimed to elucidate the fungal microbiota found on the epidermis of jujube during the storage period using high-throughput sequencing, as well as to monitor the changes in quality indexes throughout this period. Through internal transcribed spacer (ITS) sequencing, we identified two phyla (Basidiomycota and Ascomycota) and six genera (Cryptococcus, Bulleromyces, Sporidiobolus, Alternaria, Pseudozyma, and Sporobolomyces), which potentially contribute to the spoilage and deterioration of jujube, referred to as "core fungal taxa". A high correlation was further found between preservation indices (including decay rate, firmness, and total soluble solids) and the growth of multiple core fungi over time. These findings will provide insights and a theoretical basis for further research on preservation techniques related to biological control during date fruit storage.

Structure, functional and physicochemical properties of lotus seed protein under different pH environments.

BACKGROUND: The present study investigated the structure, functional and physicochemical properties of lotus seed protein (LSP) under different pH environments. The structures of LSP were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Fourier transform infrared spectroscopy (FTIR), zeta potential, particle size distributions, free sulfhydryl and rheological properties. The functional and physicochemical properties of LSP were characterized by color, foaming property, emulsification property, solubility, oil holding capacity, water holding capacity, differential scanning calorimetry analysis and surface hydrophobicity. RESULTS: LSP was mainly composed of eight subunits (18, 25, 31, 47, 51, 56, 65 and 151 kDa), in which the richest band was 25 kDa. FTIR results showed that LSP had high total contents of α-helix and ß-sheet (44.81-46.85%) in acidic environments. Meanwhile, there was more ß-structure and random structure in neutral and alkaline environments (pH 7.0 and 9.0). At pH 5.0, LSP had large particle size (1576.98 nm), high emulsion stability index (91.43 min), foaming stability (75.69%) and water holding capacity (2.21 g g-1), but low solubility (35.98%), free sulfhydryl content (1.95 µmol g-1) and surface hydrophobicity (780). DSC analysis showed the denaturation temperatures (82.23 °C) of LSP at pH 5.0 was higher than those (80.10, 80.52 and 71.82 °C) at pH 3.0, 7.0 and 9.0. The analysis of rheological properties showed that LSP gel had high stability and great strength in an alkaline environment. CONCLUSION: The findings of the present study are anticipated to serve as a valuable reference for the implementation of LSP in the food industry. © 2024 Society of Chemical Industry.

Ferrous gluconate triggers ferroptosis in Escherichia coli: Implications of lipid peroxidation and DNA damage.

Microbial ferroptosis has been proved to combat drug-resistant pathogens, but whether this pattern can be applied to the prevention and control of Escherichia coli remains to be further explored. In this study, ferrous gluconate (FeGlu) showed remarkable efficacy in killing E. coli MG1655 with a mortality rate exceeding 99.9%, as well as enterotoxigenic E. coli H10407 (ETEC H10407) and enterohemorrhagic E. coli O157:H7 (EHEC O157:H7). Bacteria death was instigated by the infiltration of Fe2+, accompanied by a burst of intracellular reactive oxygen species (ROS) and lipid peroxidation. Notably, mitigating lipid peroxidation failed to alleviate death of E. coli. Further findings confirmed that FeGlu induced DNA damage, and ΔrecA mutant showed more sensitive, implicating that DNA damage was involved in the death of E. coli. The direct interaction of Fe2+ with DNA was demonstrated by fluorescent staining, gel electrophoresis, and circular dichroism (CD). Moreover, proteomic analysis unveiled 50 differentially expressed proteins (DEPs), including 18 significantly down-regulated proteins and 32 significantly up-regulated proteins. Among them, the down-regulation of SOS-responsive transcriptional suppressor LexA indicated DNA damage induced severely by FeGlu. Furthermore, FeGlu influenced pathways such as fatty acid metabolism (FadB, FadE), iron-sulfur cluster assembly (IscA, IscU, YadR), iron binding, and DNA-binding transcription, along with α-linolenic acid metabolism, fatty acid degradation, and pyruvate metabolism. These pathways were related to FeGlu stress, including lipid peroxidation and DNA damage. In summary, FeGlu facilitated ferroptosis in E. coli through mechanisms involving lipid peroxidation and DNA damage, which presents a new strategy for the development of innovative antimicrobial strategies targeting E. coli infections.

Ferrous sulphate triggers ferroptosis in Candida albicans and cures vulvovaginal candidiasis in a mouse model.

Candida albicans is the most leading cause of life-threatening fungal invasive infections, especially for vulvovaginal candidiasis (VVC). Resistance and tolerance to common fungicide has risen great demands on alternative strategies for treating C. albicans infections. In the present study, ferroptosis has been proven to occur in C. albicans by directly exposed to FeSO4 via induing hallmarks of ferroptosis, including Fe2+ overload burden, ROS eruption and lipid peroxidation. Transcriptomic profile gave the great hints of the possible mechanism for fungal ferroptosis that FeSO4 disturb pathways associated to ribosome, tyrosine metabolism, triglyceride metabolism and thiamine metabolism, thus mobilizing death-related gene synthesis. Inspired by the results, a FeSO4-loaded hydrogel was prepared as an antifungal agent to treat C. albicans infection. This hydrogel exhibited excellent dressing properties and maintained superior antifungal activity by characterization tests. Besides, mice treated by this composite hydrogel displayed excellent therapeutic efficacy. These results highlighted the potential therapeutic use of FeSO4 as an innovative strategy in treating C. albicans infections by targeting ferroptosis.

Identification of flavor peptides based on virtual screening and molecular docking from Hypsizygus marmoreuss.

Hypsizygus marmoreuss is an under-explored source of flavor peptides that can enhance the flavor of NaCl or MSG, allowing products to be reformulated in line with reduction policies. This study utilized advanced techniques, including UPLC-Q-TOF MS/MS and molecular docking, to identify H. marmoreuss peptides. Sensory evaluations revealed 10 peptides with pronounced umami flavors and seven with dominantly salty tastes. VLPVPQK scored highest for umami intensity (5.2), and EGNPAHQK for salty intensity (6.2). Further investigation influenced by 0.35 % MSG or 0.35 % NaCl exposed peptides with elevated umami and salty thresholds. LDSPATPEK, VVEGEPSLK, and QKLPEKPER had umami-enhancing thresholds of 0.18, 0.18, and 0.35 mM, while LDSPATPEK and VVEGEPSLK had similar thresholds for salt (0.09 mM). Molecular docking revealed that taste receptor proteins interacted with umami peptides through hydrogen, carbon-hydrogen, alkyl, and van der Waals forces. Specific amino acids in the umami receptor T1R1 had roles in bonding with umami peptides through hydrogen and carbon-hydrogen interactions. In conclusion, molecular docking proved to be an effective and efficient method for flavor peptide screening. Further, this study demonstrated that flavor peptides from H. marmoreuss had the capacity to enhance NaCl and MSG flavours and might be useful tools for reformulation, reducing salt and MSG contents.

High-throughput analysis of hazards in novel food based on the density functional theory and multimodal deep learning.

The emergence of cultured meat presents the potential for personalized food additive manufacturing, offering a solution to address future food resource scarcity. Processing raw materials and products in synthetic food products poses challenges in identifying hazards, impacting the entire industrial chain during the industry's further evolution. It is crucial to examine the correlation of biological information at different levels and to reveal the temporal dynamics jointly. Proposed active prevention method includes four aspects: (i) Investigating the molecular-level mechanism underlying the binding and dissociation of hazards with proteins represents a novel approach to mitigate matrix effect. (ii) Identifying distinct fragments is a pivotal advancement toward developing a novel screening strategy for hazards throughout the food chain. (iii) Designing an artificial intelligence model-based approach to acquire multi-dimensional histology data also holds significant potential for various applications. (iv) Integrating multimodal data is a practical approach to enhance evaluation and feedback control accuracy.

Structure, physicochemical properties, and biological activities of protein hydrolysates from Zanthoxylum seed.

BACKGROUND: Zanthoxylum seed, as a low-cost and easily accessible plant protein resource, has good potential in the food industry. But protein and its hydrolysates from Zanthoxylum seed are underutilized due to the dearth of studies on them. This study aimed to investigate the structure and physicochemical and biological activities of Zanthoxylum seed protein (ZSP) hydrolysates prepared using Protamex®, Alcalase®, Neutrase®, trypsin, or pepsin. RESULTS: Hydrolysis using each of the five enzymes diminished average particle size and molecular weight of ZSP but increased random coil content. ZSP hydrolysate prepared using pepsin had the highest degree of hydrolysis (24.07%) and the smallest molecular weight (<13 kDa) and average particle size (129.80 nm) with the highest solubility (98.9%). In contrast, ZSP hydrolysate prepared using Alcalase had the highest surface hydrophobicity and foaming capacity (88.89%), as well as the lowest foam stability (45.00%). Moreover, ZSP hydrolysate prepared using Alcalase exhibited the best hydroxyl-radical scavenging (half maximal inhibitory concentration (IC50 ) 1.94 mg mL-1 ) and ferrous-ion chelating (IC50 0.61 mg mL-1 ) activities. Additionally, ZSP hydrolysate prepared using pepsin displayed the highest angiotensin-converting enzyme inhibition activity (IC50 0.54 mg mL-1 ). CONCLUSION: These data showed that enzyme hydrolysis improved the physicochemical properties of ZSP, and enzymatic hydrolysates of ZSP exhibited significant biological activity. These results provided validation for application of ZSP enzymatic hydrolysates as antioxidants and antihypertensive agents in the food or medicinal industries. © 2023 Society of Chemical Industry.

The structural characteristics and physicochemical properties of mung bean protein hydrolysate of protamex induced by ultrasound.

BACKGROUND: The limited physicochemical properties (such as low foaming and emulsifying capacity) of mung bean protein hydrolysate restrict its application in the food industry. Ultrasound treatment could change the structures of protein hydrolysate to accordingly affect its physicochemical properties. The aim of this study was to investigate the effects of ultrasound treatment on the structural and physicochemical properties of mung bean protein hydrolysate of protamex (MBHP). The structural characteristics of MBHP were evaluated using tricine sodium dodecylsulfate-polyacrylamide gel electrophoresis, laser scattering, fluorescence spectrometry, etc. Solubility, fat absorption capacity and foaming, emulsifying and thermal properties were determined to characterize the physicochemical properties of MBHP. RESULTS: MBHP and ultrasonicated-MBHPs (UT-MBHPs) all contained five main bands of 25.8, 12.1, 5.6, 4.8 and 3.9 kDa, illustrating that ultrasound did not change the subunits of MBHP. Ultrasound treatment increased the contents of α-helix, ß-sheet and random coil and enhanced the intrinsic fluorescence intensity of MBHP, but decreased the content of ß-turn, which demonstrated that ultrasound modified the secondary and tertiary structures of MBHP. UT-MBHPs exhibited higher solubility, foaming capacity and emulsifying properties than MBHP, among which MBHP-330 W had the highest solubility (97.32%), foaming capacity (200%), emulsification activity index (306.96 m2 g-1 ) and emulsion stability index (94.80%) at pH 9.0. CONCLUSION: Ultrasound treatment enhanced the physicochemical properties of MBHP, which could broaden its application as a vital ingredient in the food industry. © 2023 Society of Chemical Industry.

Monitoring of Volatile Compounds of Ready-to-Eat Kiwifruit Using GC-IMS.

Ready-to-eat kiwifruit has gained significant market value in recent years due to its convenience and the increasing consumer demand for healthy ready-to-eat snacks. The volatile compound content (VOC) in ready-to-eat kiwifruit is a crucial factor determining its flavor and aroma. VOC is an important characteristic that positively affects the overall evaluation of ready-to-eat kiwifruit. In this study, we utilized gas chromatography-ion mobility spectrometry (GC-IMS) to investigate changes in the composition of VOCs in ready-to-eat kiwifruit during different storage periods (every 12 h). Our results revealed the presence of 55 VOCs in ready-to-eat kiwifruit, with alcohols, esters, and ketones being the dominant compounds responsible for the aromatic flavor. Among these compounds, methyl caproate, ethyl butyrate, and ethyl propionate provided specific fruit flavors to ready-to-eat kiwifruit, whereas esters played a secondary role. Furthermore, varying trends were observed for different compound types as the storage period increased: alcohols exhibited a decreasing trend, whereas ester products and some sulfur-containing compounds showed an increase. Additionally, fingerprint profiles of volatile compounds were established for each storage period, enabling the identification of characteristic substances. This comprehensive analysis of volatile flavor substances during the ripening of ready-to-eat kiwifruit will greatly contribute to enhancing its sensory quality, consumer appeal, and overall marketability.

Fabrication and 3D printing of Pickering emulsion gel based on Hypsizygus marmoreus by-products protein.

Pickering emulsion gel (PEG) stabilized by the protein extracted from the by-product of Hypsizygus marmoreus, combining with xanthan gum (XG), was formulated as 3D printing ink. Hydrogen bonds are formed in XG/protein hybrid particles. Afterwards, PEG was developed. Results indicated that it has shear-thinning properties. The apparent viscosity, yield stress, Elastic modulus (G') and gel strength increased with the increased XG addition, while the size of emulsion decreased. XG incorporation improved the 3D printing performance with desired self-supporting capability and printing precision if its concentration reached 2.0% (w/v). This study provides ideas for the application of Hypsizygus marmoreus by-products protein in stabilizing PEG used for 3D printing, which has a potential to replace traditional hydrogenated cream for cake decoration.

UPLC-Q-Exactive Orbitrap-MS-Based Untargeted Lipidomic Analysis of Lipid Molecular Species in Spinal Cords from Different Domesticated Animals.

Lipids are crucial components for the maintenance oof normal structure and function in the nervous system. Elucidating the diversity of lipids in spinal cords may contribute to our understanding of neurodevelopment. This study comprehensively analyzed the fatty acid (FA) compositions and lipidomes of the spinal cords of eight domesticated animal species: pig, cattle, yak, goat, horse, donkey, camel, and sika deer. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) were the primary FAs in the spinal cords of these domesticated animals, accounting for 72.54-94.23% of total FAs. Notably, oleic acid, stearic acid and palmitic acid emerged as the most abundant FA species. Moreover, untargeted lipidomics by UPLC-Q-Exactive Orbitrap-MS demonstrated that five lipid classes, including glycerophospholipids (GPs), sphingolipids (SPs), glycerolipids (GLs), FAs and saccharolipids (SLs), were identified in the investigated spinal cords, with phosphatidylcholine (PC) being the most abundant among all identified lipid classes. Furthermore, canonical correlation analysis showed that PC, PE, TAG, HexCer-NS and SM were significantly associated with genome sequence data. These informative data provide insight into the structure and function of mammalian nervous tissues and represent a novel contribution to lipidomics.

Auricularia auricular Adsorbs Aflatoxin B1 and Ameliorates Aflatoxin B1-Induced Liver Damage in Sprague Dawley Rats.

Aflatoxin B1 (AFB1), as a class I carcinogen, poses a substantial health risk to individuals. Contamination of food sources, particularly grains and nuts, with Aspergillus flavus (A. flavus) contributes to the prevalence of AFB1. The impact of global warming has spurred research into the development of AFB1 prevention technologies. While edible fungi have shown potential in detoxifying AFB1, there is a scarcity of literature on the application of Auricularia auricular (A. auricular) in this context. This study aimed to investigate the ability and underlying mechanism of A. auricular mycelia to adsorb aflatoxin B1, as well as evaluate its protective effects on the AFB1-induced liver damage in SD rats. Additionally, the effects of temperature, time, pH, and reaction ratio on the adsorption rate were examined. Combining thermodynamic and kinetic data, the adsorption process was characterized as a complex mechanism primarily driven by chemical adsorption. In SD rats, the A. auricular mycelia exhibited alleviation of AFB1-induced liver damage. The protective effects on the liver attributed to A. auricular mycelia may involve a reduction in AFB1 adsorption in the intestine, mitigation of oxidative stress, and augmentation of second-phase detoxification enzyme activity. The adsorption method for AFB1 not only ensures safety and non-toxicity, but also represents a dietary regulation strategy for achieving effective defense against AFB1.

The Ultrasensitive Detection of Aflatoxin M1 Using Gold Nanoparticles Modified Electrode with Fe3+ as a Probe.

The increasing incidence of diseases caused by highly carcinogenic aflatoxin M1 (AFM1) in food demands a simple, fast, and cost-effective detection technique capable of sensitively monitoring AFM1. Recent works predominantly focus on the electrochemical aptamer-based biosensor, which still faces challenges and high costs in experimentally identifying an efficient candidate aptamer. However, the direct electrochemical detection of AFM1 has been scarcely reported thus far. In this study, we observed a significant influence on the electrochemical signals of ferric ions at a gold nanoparticle-modified glassy carbon electrode (AuNPs/GCE) by adding varying amounts of AFM1. Utilizing ferricyanide as a sensitive indicator of AFM1, we have introduced a novel approach for detecting AFM1, achieving an unprecedentedly low detection limit of 1.6 × 10-21 g/L. Through monitoring the fluorescence quenching of AFM1 with Fe3+ addition, the interaction between them has been identified at a ratio of 1:936. Transient fluorescence analysis reveals that the fluorescence quenching process is predominantly static. It is interesting that the application of iron chelator diethylenetriaminepentaacetic acid (DTPA) cannot prevent the interaction between AFM1 and Fe3+. With a particle size distribution analysis, it is suggested that a combination of AFM1 and Fe3+ occurs and forms a polymer-like aggregate. Nonetheless, the mutual reaction mechanism between AFM1 and Fe3+ remains unexplained and urgently necessitates unveiling. Finally, the developed sensor is successfully applied for the AFM1 test in real samples, fully meeting the detection requirements for milk.

Lentinus edodes Powder Improves the Quality of Wheat Flour Gluten Sticks.

Spicy wheat flour gluten sticks are delicious and affordable puffed snacks for young adults and even minors in China, and have a relatively simple nutritional quality. L. edodes powder (LEP) is rich in nutrients and boasts a variety of biological activities. This study evaluated the effects of different concentrations of LEP addition on the quality of wheat flour gluten sticks. The gelatinization results of the products showed that the peak viscosity decreased from 454 cP to 251 cP; the breakdown value decreased from 169 cP to 96 cP; and the setback value decreased from 381 cP to 211 cP. With the increase in LEP, the radial expansion rate (RER) of L. edodes gluten sticks (LSGS) first increased and then decreased, reaching a maximum value of 1.388 in the 10% LEP group. The oil absorption rate (OAR) of LSGS increased from 5.124% to 14.852% with the increase in the amount of LEP. Additionally, texture profile analysis showed that the hardness value increased from 1148.898 to 2055.492 g; the chewiness value increased from 1010.393 to 1499.233; and the springiness value decreased from 1.055 to 0.612. Through X-ray diffraction (XRD), it was found that the crystal type was transformed from A-type crystal to B-type and V-type crystals. Low field nuclear magnetic resonance (LF-NMR) results showed that the moisture distribution in the products was basically bound water. The scanning electron microscopy (SEM) results showed that, with the increase in the LEP amount, the surface of the products changed from rough to smooth. Sensory evaluation results indicated that the products with 10% LEP helped to maintain better taste and quality of LSGS, with an average score of 7.628, which was the most popular among consumers. This study not only increases the possible raw materials for use in extruded puffed food, but also provides a new possibility for the production of high-quality edible fungi extruded products.

Preparation and characterization of 3D-printed antibacterial hydrogel with benzyl isothiocyanate.

Benzyl isothiocyanate (BITC) is an isothiocyanate of plant origin, especially the mustard family, which has good antibacterial properties. However, its applications are challenging due to its poor water solubility and chemical instability. We used food hydrocolloids, including xanthan gum, locust bean gum, konjac glucomannan, and carrageenan as three-dimensional (3D)-printing food ink base and successfully prepared 3D-printed BITC antibacterial hydrogel (BITC-XLKC-Gel). The characterization and fabrication procedure of BITC-XLKC-Gel was studied. The results show that BITC-XLKC-Gel hydrogel has better mechanical properties by low-field nuclear magnetic resonance (LF-NMR), mechanical properties, and rheometer analysis. The strain rate of BITC-XLKC-Gel hydrogel is 76.5%, which is better than that of human skin. Scanning electron microscope (SEM) analysis showed that BITC-XLKC-Gel has uniform pore size and provides a good carrier environment for BITC carriers. In addition, BITC-XLKC-Gel has good 3D-printing performance, and 3D printing can be used for customizing patterns. Finally, inhibition zone analysis showed that the BITC-XLKC-Gel added with 0.6% BITC had strong antibacterial activity against Staphylococcus aureus and the BITC-XLKC-Gel added with 0.4% BITC had strong antibacterial activity against Escherichia coli. Antibacterial wound dressing has always been considered essential in burn wound healing. In experiments that simulated burn infection, BITC-XLKC-Gel showed good antimicrobial activity against methicillin-resistant S. aureus. BITC-XLKC-Gel is a good 3D-printing food ink attributed to strong plasticity, high safety profile, and good antibacterial performance and has great application prospects.

Changes in quality components and antioxidant activity of peony seed soy sauce during low-salt solid-state fermentation.

BACKGROUND: In this study, the fermentation conditions of peony seed soy sauce (PSSS) koji were optimized by response surface method, and the quality components and antioxidant activity of PSSS were investigated at different low-salt solid-state fermentation stages. RESULTS: Results of response surface method showed that the optimal fermentation conditions were 460.6 g kg-1 water content, 48.6 h culture time, 31.5 °C culture temperature and ratio 2.1:1 (w/w) of peony seed meal:wheat bran, with the highest neutral protease activity (2193.78 U g-1 ) of PSSS koji. PSSS had the highest amino acid nitrogen (7.69 g L-1 ), salt-free soluble solids (185.26 g L-1 ), total free amino acids (49.03 g L-1 ), essential free amino acids (19.58 g L-1 ) and umami free amino acids (16.64 g L-1 ) at 20 days of fermentation. The highest total phenolics were 5.414 g gallic acid equivalent L-1 and total flavonoids 0.617 g rutin equivalent L-1 , as well as the highest DPPH radical scavenging activity (86.19%) and reducing power (0.8802, A700 ) of PSSS fermented at 30 days. Sensory evaluation showed that fermentation of 20 days and 25 days could produce a better taste and aroma of PSSS than 15 days and 30 days. CONCLUSION: PSSS had the highest quality components in the middle of fermentation (20 days) and the highest antioxidant activity in the late fermentation period (30 days). These results demonstrated that peony seed meal could be used to produce high-quality soy sauce with high antioxidant activity. © 2023 Society of Chemical Industry.

Ultrasound-assisted blue light killing Vibrio parahaemolyticus to improve salmon preservation.

Vibrio parahaemolyticus is a typical marine bacterium, which often contaminates seafood and poses a health risk to consumers. Some non-thermal sterilization technologies, such as ultrasonic field (UF) and blue light (BL) irradiation, have been widely used in clinical practice due to their efficiency, safety, and avoidance of drug resistance, but their application in food preservation has not been extensively studied. This study aims to investigate the effect of BL on V. parahaemolyticus in culture media and in ready-to-eat fresh salmon, and to evaluate the killing effectiveness of the UF combined with BL treatment on V. parahaemolyticus. The results showed that BL irradiation at 216 J/cm2 was effective in causing cell death (close to 100%), cell shrinkage and reactive oxygen species (ROS) burst in V. parahaemolyticus. Application of imidazole (IMZ), an inhibitor of ROS generation, attenuated the cell death induced by BL, indicating that ROS were involved in the bactericidal effects of BL on V. parahaemolyticus. Furthermore, UF for 15 min enhanced the bactericidal effect of BL at 216 J/cm2 on V. parahaemolyticus, with the bactericidal rate of 98.81%. In addition, BL sterilization did not affect the color and quality of salmon, and the additive UF treatment for 15 min did not significant impact on the color of salmon. These results suggest that BL or UF combined with BL treatment has potential for salmon preservation, however, it is crucial to strictly control the intensity of BL and the duration of UF treatment to prevent reducing the freshness and brightness of salmon.

Preparation and application of tremella polysaccharide based chrome free tanning agent for sheepskin processing.

The abuse of chrome tanning agent in leather processing has caused great harm to human health and the natural environment. We use tremella polysaccharides (TP), lentinan (LNT) and konjac gum (KG) as raw materials, and sodium periodate as oxidant to prepare the corresponding polysaccharide tanning agent. Tremella polysaccharide was selected as the best tanning agent according to the shrinkage temperature, and the subsequent experiments were carried out. Tremella polysaccharide (TP) as raw material and sodium periodate as an oxidant, dialdehyde tremella polysaccharide (DTP) was prepared and applied in leather tanning. The effects of different oxidation conditions (sodium periodate dosage, temperature, pH, and reaction time) on the shrinkage temperature of DTP tanned leather were studied. The change of shrinkage temperature showed that the dosage of sodium periodate had the greatest influence on the shrinkage temperature. Therefore, the effects of different dosage of sodium periodate on the aldehyde content and molecular weight of DTP were investigated, including the analysis of physical properties and microstructure of tanned leather. In general, the increase of sodium periodate dosage was found to increase the aldehyde content and reduce the molecular weight, which was more conducive to leather tanning.

Blended cumin/Zanthoxylum essential oil improve the antibacterial, fresh-keeping performance and flavor of chilled fresh mutton.

Microbial pollution and fat oxidation are the main factors that induce the deterioration in the quality of chilled fresh mutton. This study evaluated the effects of cumin (Cuminum cyminum) essential oil (CEO), Zanthoxylum essential oil (ZEO), and blended cumin/zanthoxylum essential oil (BEO) on the antibacterial, preservation of freshness, and flavor improvement of chilled fresh mutton. The results show that BEO exerts a good inhibition effect on microbial growth, lipid oxidation, and the formation of TVB-N, as well as slowing down the rate of juice loss under chilled conditions. GC-IMS assay results showed that BEO can enrich the flavor of roasted mutton with a higher level of volatile organic substances, such as ethyl acetate D. In conclusion, BEO treatments were more efficient than single treatments in ensuring the quality of lamb to improve microbiological safety and improve the flavor of roasted lamb stored under chilled conditions. Overall research indicates that BEO is an effective natural addition that can be used to preserve the quality and safety of chilled fresh mutton during storage.