Geographical identification of Chinese wine based on chemometrics combined with mineral elements, volatile components and untargeted metabonomics.

Identifying the geographic origin of a wine is of great importance, as origin fakery is commonplace in the wine industry. This study analyzed the mineral elements, volatile components, and metabolites in wine using inductively coupled plasma-mass spectrometry, headspace solid phase microextraction gas chromatography-mass spectrometry, and ultra-high-performance liquid chromatography-quadrupole-exactive orbitrap mass spectrometry. The most critical variables (5 mineral elements, 13 volatile components, and 51 metabolites) for wine origin classification were selected via principal component analysis and orthogonal partial least squares discriminant analysis. Subsequently, three algorithms-K-nearest neighbors, support vector machine, and random forest -were used to model single and fused datasets for origin identification. These results indicated that fused datasets, based on feature variables (mineral elements, volatile components, and metabolites), achieved the best performance, with predictive rates of 100% for all three algorithms. This study demonstrates the effectiveness of a multi-source data fusion strategy for authenticity identification of Chinese wine.

Enhanced photodynamic inactivation against Escherichia coli O157:H7 provided by chitosan/curcumin coating and its application in food contact surfaces.

Sterilisation technologies are essential to eliminate foodborne pathogens from food contact surfaces. However, most of the current sterilisation methods involve high energy and chemical consumption. In this study, a photodynamic inactivation coating featuring excellent antibacterial activity was prepared by dispersing curcumin as a plant-based photosensitiser in a chitosan solution. The coating generated abundant reactive oxygen species (ROS) after light irradiation at 420 nm, which eradicated ≥99.999 % of Escherichia coli O157:H7. It was also found that ROS damaged the cell membrane, leading to the leakage of cell contents and cell shrinkage on the basis of chitosan. In addition, the production of ROS first excited the bacterial antioxidant defence system resulting in the increase of peroxidase (POD) and superoxide dismutase (SOD). ROS levels exceed its capacity, causing damage to the defence system and further oxidative decomposition of large molecules, such as DNA and proteins, eventually leading to the death of E. coli O157:H7. We also found the curcumin/chitosan coating could effectively remove E. coli O157:H7 biofilms by oxidative of extracellular polysaccharides and proteins. All the contributors made the chitosan/curcumin coating an efficient detergent comparable with HClO.

Effects of purple potato anthocyanins on the in vitro digestive properties of starches of different crystalline types.

This study explored the potential of purple potato anthocyanins (PPAs) in regulating the digestive properties of starches of various crystalline types. In vitro digestion experiments indicated that PPAs inhibit the hydrolysis of rice starch (A-type) better than that of garden pea starch (C-type) and potato starch (B-type). Further structural assessment of different PPA-starch systems showed that PPAs and starch likely interact through non-covalent bonds, resulting in structural changes. Microstructural changes observed in the starches were consistent with the in vitro digestion results, and the chain length and proportions of short/long chains in amylopectin molecules affected the binding strengths and interaction modes between PPAs and starch. Hence, the three starches differed in their PPA loading efficiency and digestibility. These discoveries contribute to a deeper understanding of the mechanisms underlying the inhibition of starch digestibility by PPAs. They can aid the formulation of value-added products and low-glycemic-index foods.

Apple pectin-based active films to preserve oil: Effects of naturally branched phytoglycogen-curcumin host.

Pectin has excellent film-forming properties, but its functional properties need to be enhanced. Therefore, we constructed naturally branched phytoglycogen (PG) nanoparticles to solubilize curcumin (CCM) and further enhance the properties of apple pectin-based active films. The size of the PG spherical particles ranged from 30 to 100 nm with some aggregates. The branch density of the PG was 6.02 %. These PG nanoparticles increased the solubility of CCM nearly 1742-fold and a nanosized phytoglycogen-curcumin (PG-CCM) host was formed via hydrogen bonding and hydrophobic interaction. This host promoted the formation of pectin-based films with a dense structure and increased their tensile strength to 23.51 MPa. The coefficient to water vapor permeability, oxygen permeability and carbon dioxide permeability were all decreased indicating their barrier performance were improved. Among them, the oxygen permeability coefficient decreased most, from 1.14 × 10-7 g·m-1·s-1 to 0.8 × 10-7 g·m-1·s-1. Also, the transmittance of the active film at 280 nm and 660 nm decreased to 0.65 % and 72.10 %. Antioxidant and antibacterial properties were significantly enhanced (P < 0.05). And the results showed this film was an excellent oil packaging material. The active film incorporating PG-CCM host can replace heat-sealed plastic bags/pouch made from polyethylene and polypropylene synthetic plastics, and solve the problem that plastic packaging is difficult to degrade and cannot be squeezed clean. This provides a new conceptual framework for developing pectin-based active films by incorporating of PG and CCM.

Fusing hyperspectral imaging and electronic nose data to predict moisture content in Penaeus vannamei during solar drying.

The control of moisture content (MC) is essential in the drying of shrimp, directly impacting its quality and shelf life. This study aimed to develop an accurate method for determining shrimp MC by integrating hyperspectral imaging (HSI) with electronic nose (E-nose) technology. We employed three different data fusion approaches: pixel-, feature-, and decision-fusion, to combine HSI and E nose data for the prediction of shrimp MC. We developed partial least squares regression (PLSR) models for each method and compared their performance in terms of prediction accuracy. The decision fusion approach outperformed the other methods, producing the highest determination coefficients for both calibration (0.9595) and validation sets (0.9448). Corresponding root-mean square errors were the lowest for the calibration set (0.0370) and validation set (0.0443), indicating high prediction precision. Additionally, this approach achieved a relative percent deviation of 3.94, the highest among the methods tested. The findings suggest that the decision fusion of HSI and E nose data through a PLSR model is an effective, accurate, and efficient method for evaluating shrimp MC. The demonstrated capability of this approach makes it a valuable tool for quality control and market monitoring of dried shrimp products.

Characterization, antioxidant activity and potential application fractionalized Szechuan pepper on fresh beef meat as natural preservative.

The pericarp of Szechuan pepper is rich in phenols and alkylamides, making it a potential source of antioxidant compounds. Despite being recognized as the primary antioxidants in Szechuan pepper, there is still limited knowledge about their application in real food systems. This study aims to identify, separate, and apply polyphenol and alkylamide fractions derived from Szechuan extracts to beef meat. Using HPLC-MS2, we identified 5 phenols and 11 alkylamides in Szechuan extracts. The quality of the minced meat was evaluated based on color, thiobarbituric acid reactive substances (TBARS), conjugated dienes, carbonyl content, Sulfhydryl content, microbiological content, and total volatile basic nitrogen content (TVB-N). Compared to the polyphenol fraction (1.25 mg/mL), alkylamide fraction (25 mg/mL), and control samples, beef samples incorporated with the polyphenol fraction (6.25 mg/mL) significantly reduced carbonyl content, TBARS, and TVB-N values at the end of storage. Furthermore, they exhibited a significant slowdown in microbial development, improved meat color stability, and preserved pH. Therefore, the use of Szechuan pepper fractions as natural preservatives in meat and meat products is an important area of research and has the potential to enhance the safety and quality of meat products.

Extracellular volume fraction as a potential predictor to differentiate lung cancer from benign lung lesions with dual-layer detector spectral CT.

Background: Extracellular volume (ECV) fraction has been used in cardiovascular diseases, pancreatic fibrosis, and hepatic fibrosis. The diagnostic value of ECV for focal lung lesions remains to be explored. The aim of this study was to evaluate the feasibility of ECV derived from a dual-layer detector computed tomography (DLCT) to differentiate lung cancer (LC) from benign lung lesions (BLLs). Methods: Retrospectively, 128 consecutive patients with pathologically confirmed LC (n=86) or BLLs (n=42) were included. Conventional computed tomography (CT) characteristics and spectral CT parameters were assessed. All patients' hematocrits were measured to correct contrast volume distributions in blood while calculating ECV. After performing logistic regression analysis, a conventional CT-based model (Model A), DLCT-based model (Model B), combined diagnostic models (Model C), and an ECV-based model (Model D) were developed. The diagnostic effectiveness of each model was examined using the receiver operating characteristic (ROC) curve and their corresponding 95% confidence intervals (CIs). The area under the curve (AUC) of each model was compared using the DeLong test. Results: Certain conventional CT features (such as lesion size, lobulation, spiculation, pleural indentation, and enlarged lymph nodes) differed significantly between the LC and BLL groups (all P<0.05). Statistical differences were found in the following DLCT parameters (all P<0.05): effective atomic number (Zeff) (non-enhancement), electron density (ED) (non-enhancement), ECV, iodine concentration (IC), and normalized iodine concentration (NIC). Models A, B, C, and D had AUCs of 0.801 [95% confidence interval (CI): 0.721-0.866], 0.805 (95% CI: 0.726-0.870), 0.925 (95% CI: 0.865-0.964), and 0.754 (95% CI: 0.671-0.826), respectively. The AUC of Model D (ECV) showed no significant difference from that of Models A and B (DeLong test, P>0.05). Conclusions: The ECV derived from DLCT may be a potential new method to differentiate LC from BLLs, broadening the scope of ECV in clinical research.

Effects of quinoa flour (Chenopodium Quinoa Willd) substitution on wheat flour characteristics.

Quinoa is a pseudo-cereal with great nutritional and functional qualities, serving as an excellent substitution to develop quinoa-containing foods. This study aimed to explore the influence of quinoa flour substitution on quality characteristics of wheat flour (WF). WF was substituted with different level of quinoa core flour, ground quinoa whole flour and recombined quinoa whole flour. Increasing levels of quinoa flour in WF declined dough swelling index, while increased falling number of composite flours. Besides, quinoa flour substitution considerably decreased the chemical forces of gluten in composite flours. The proportions α-helix and ß-sheets reduced, while the random coil proportion increased in gluten secondary structure. SEM images revealed that the gluten network structure was severely damaged. Our findings indicated that substitution of WF with quinoa flours was promising to be developed as an ingredient for food products.

Simultaneous determination of six α-dicarbonyl compounds in traditional Chinese medicines using high-performance liquid chromatography-fluorescence detector with pre-column derivatization.

A reliable method for determination of six α-dicarbonyl compounds in traditional Chinese medicines was first developed and validated by high-performance liquid chromatography-fluorescence detector with pre-column derivatization. α-Dicarbonyl compounds in traditional Chinese medicines were extracted and derivatized with 2,3-diaminaphthalene. The derivatization procedure of six α-dicarbonyl compounds was confirmed by high-resolution mass spectrometry. The limits of quantitation for six α-dicarbonyl compounds ranged from 3.70 × 10-3 to 2.21 × 10-2  µM. The established method showed good linearity (regression coefficient > 0.9990), precision (relative standard deviation < 3.37%), and high recovery (97.8%∼113.1%). The developed method was successfully applied to detect the six α-dicarbonyl compounds in traditional Chinese medicines. The result exhibited six α-dicarbonyl compounds was found in the 15 kinds of traditional Chinese medicines, which suggested us that the determination of α-dicarbonyl compounds should be paid more attention in the quality control of traditional Chinese medicines.

The mediating role of psychological capital in the relationship between job stress and professional identity in Chinese medical interns.

BACKGROUND: Adaption to clinical work during the internship can induce several stressors among medical students, especially in the context of the coronavirus disease 2019 (COVID-19) pandemic. Particularly, job stress could be linked to the development of psychological traits and the formation of the professional identity of medical interns. OBJECTIVE: This study aimed to explore the relationship between job stress, psychological capital, and professional identity through a mediation analysis of Chinese medical interns. METHODS: A descriptive cross-sectional study was conducted in 30 hospitals and clinics in China from June 2021 to March 2022. A total of 665 medical interns filled out questionnaires related to demographic questions, psychological capital, job stress, and professional identity. Data analysis was executed using the IBM SPSS version 22.0 software and its add-in PROCESS Windows version 4.0. RESULTS: The findings indicated a statistically significant mediating effect of psychological capital between job stress and professional identity. Job stress and job stress combined with psychological capital accounted for 5.3% and 37.9%, respectively, of the variance in professional identity. The bootstrapping method corroborated the significance of the indirect effect of job stress through psychological capital (95% bootstrap CI = -4.7921, -2.4345). CONCLUSION: The current findings underscore the need for increased attention on improving the psychological capital of medical interns.

Evaluation of Ultra-High-Pressure Sterilization in Terms of Bactericidal Effect, Qualities, and Shelf Life of 'Xinli No. 7' (Pyrus sinkiangensis) Pear Juice.

In this study, ultra-high-pressure sterilization (UHPS) of Xinli No. 7 juice (XL7) was explored and optimized. A challenge to implement UHPS in juice as a full alternative to thermal treatment could be represented by the adoption of a pressure level of up to 500 MPa for 20 min at one cycle followed by the packaging in aseptic conditions. It was found that UHPS and HS treatments could effectively kill the microorganisms in XL7 juice but HS treatment would inevitably lose the nutritional quality in the juice, while UHPS treatment could better maintain the glyconic acid content, functional components, and antioxidant activity and reduce Browning degree and improve the stability of XL7 juice. The deterioration rate of UHPS and HS-treated XL7 juice increased with the increased storage temperature. The predicted shelf life of UHPS and HS-treated XL7 juice was 68 and 41 days at 4 °C, respectively. Collectively, UHPS treatment combined with low-temperature storage might be an effective way to prolong the shelf life of XL7 juice.

Rosmarinic Acid-Grafted Dextran/Gelatin Hydrogel as a Wound Dressing with Improved Properties: Strong Tissue Adhesion, Antibacterial, Antioxidant and Anti-Inflammatory.

Designing a strong tissue adhesive and multifunctional hydrogel dressing for various skin injuries is still a significant challenge. Based on the bioactive activities of rosmarinic acid (RA) and its catechol structure being similar to dopamine, RA-grafted dextran/gelatin hydrogel (ODex-AG-RA) was designed and systemically characterized in this study. The ODex-AG-RA hydrogel exhibited excellent physicochemical properties, including fast gelation time (61.6 ± 2.8 s), strong adhesive strength (27.30 ± 2.02 kPa) and enhanced mechanical properties (1.31 × 104 Pa of G'). The examination of hemolysis and co-culturing with L929 cells showed the strong in vitro biocompatibility of ODex-AG-RA hydrogels. The ODex-AG-RA hydrogels exhibited a 100% mortality rate against S. aureus and at least 89.7% against E. coli in vitro. In vivo evaluation for efficacy in skin wound healing was carried out in a rat model of full-thickness skindefect. The amount of collagen deposition and CD31 on wounds in the two ODex-AG-RA-1 groups on day 14 was 4.3 times and 2.3 times of that in the control group, respectively. Furthermore, the mechanism of ODex-AG-RA-1 for promoting wound healing was proved to be related to its anti-inflammatory properties by adjusting the expression of inflammatory cytokines (TNF-α and CD163) and reducing the level of oxidative stress (MDA and H2O2). Overall, this study demonstrated the wound-healing efficacy of RA-grafted hydrogels for the first time. ODex-AG-RA-1 hydrogel, due to its adhesive, anti-inflammatory, antibacterial and antioxidative activities, was a promising candidate as a wound dressing.

Soy Protein/Polyvinyl-Alcohol (PVA)-Based Packaging Films Reinforced by Nano-TiO2.

This work was investigated to prepare a reinforcing composite packaging film composited of soy protein/polyvinyl alcohol (PVA) and nano-TiO2. First, different film compositions were designed by the particle size of nano-TiO2, concentration of nano-TiO2, concentration of polyvinylpyrrolidone (PVP, a dispersing agent for nano-TiO2), and pH of film casting solution. Then, the film composition that yielded the optimal physical properties was identified using orthogonal array design single-factor experiments, considering its physical properties, including tensile strength, elongation, water absorption, water vapor transmission, oxygen permeation, thermal property, and film morphology. The results displayed that the optimal film composition was (1) soy protein/PVA film with 2.5 wt% nano-TiO2, (2) 30 nm nano-TiO2 particle size, (3) 1.5 wt% PVP, and (4) pH 6.0 of film-forming solution. It yielded tensile strength of 6.77 MPa, elongation at break rate of 58.91%, and water absorption of 44.89%. Last, the films were characterized by scanning electron microscope (SEM) and differential scanning calorimetry (DSC). SEM analysis showed that compared with the film without TiO2, the film containing TiO2 has a smoother surface, and DSC determined that adding nano-TiO2 can improve the thermostability of soy protein/PVA film. Therefore, the film prepared in this paper is expected to provide a new theoretical basis for use in the packaging industry.

Changes in vinegar quality and microbial dynamics during fermentation using a self-designed drum-type bioreactor.

The bioreactor based on solid-state fermentation technology has been developed for vinegar production, standardization of fermentation process and stabilization of vinegar quality. The microbial community diversity, and volatile compounds of six cultivars of vinegar samples fermented in a self-designed solid-state fermentation bioreactors were investigated using Illumina MiSeq platform and gas chromatography mass spectrometry (GC-MS) technology. The correlations between the richness and diversity of microbiota and volatile profiles, organic acids, as well as physicochemical indicators were explored by R software with the coplot package. The findings indicated that Acetobacter, norank-c-Cyanobacteria, and Weissella played key roles during fermentation process. Norank-f-Actinopolyporaceae, norank-c-Cyanobacteria, Pediococcus, and Microbacterium had significant correlations with the physicochemical characteristics. The most common bacterial species were associated with a citric acid content, whereas the least number of bacterial species correlated with malic acid content. Findings could be helpful for the bioreactor optimization, and thus reaching the level of pilot scale and industrialization.

Nanocellulose-enhanced smart film for the accurate monitoring of shrimp freshness via anthocyanin-induced color changes.

Smart films allow consumers to visually determine food freshness. We aimed to improve the surface contact area of gas permeation in anthocyanin (AH)-induced smart films by introducing nanocellulose (NC) prepared by sulfuric acid (CNSA), citric acid (CNCA), and TEMPO (CNF) to improve their sensitivity. The film matrix was composed of PVA. The structure, functionality, and sensitivity of films were compared. The results showed that films incorporating CNSA and CNCA had larger surface areas and stronger intermolecular interactions. Sensitivity tests showed a color change from blue-violet to yellow in PVA/AH-CNSA and -CNCA films at 131 ppm of ammonia, occurring within 4 min of exposure. Shrimp freshness was further monitored using the films, with three stages of shrimp freshness (fresh, sub-fresh, and spoiled) differentiated clearly via distinct color changes. A strong correlation between freshness indexes and color parameters was established. The PVA/AH-CNSA and -CNCA films are suitable for real-time monitoring seafood freshness.

Microwave-assisted enzymatic hydrolysis as a novel efficient way to prepare porous starch.

To shorten the preparation time of porous starch while simultaneously ensuring its adsorption performance, we treated corn starch with a combination of microwave and complex enzymatic (α-amylase and amyloglucosidase) hydrolysis. Specifically, we investigated the effect of microwave and enzymatic hydrolysis on the structure, physicochemical properties, and adsorption capability of the prepared porous starch. The results showed that the porous starch prepared by combined treatment had denser pores, no new groups were produced in the porous starch, the relative crystallinity, gelatinization temperature, and solubility increased, while the gelatinization enthalpy and swelling power decreased. Compared to enzymatic hydrolysis, the combined treatment yielded starch samples with a larger specific surface area and pore capacity, and the adsorption performance was significantly improved, with water and oil absorption rates increasing from 110.99 % and 133.11 % to 128.29 % and 143.3 %, respectively. These findings indicate that the synergistic processing of microwave and enzymatic hydrolysis has great potential as a productive and rapid method for the preparation of porous starch.

Preparation and characterization of type 3 resistant starch by ultrasound-assisted autoclave gelatinization and its effect on steamed bread quality.

In this study, we aimed to establish an innovative and efficient preparation method of potato resistant starch (PRS). To achieve this, we prepared type 3 resistant starch (RS3) from native potato starch (PS) using an ultrasonic method combined with autoclave gelatinization and optimized by the response surface method to study the structure and properties of potato RS3 (PRS3) and its effect on the quality of steamed bread. Under optimal treatment conditions, the PRS3 content increased from 7.5% to 15.9%. Compared with PS, the B-type crystal structure of PRS3 was destroyed, and the content of hydroxyl groups was increased, but no new chemical groups were introduced. PRS3 had a rougher surface and a lower crystallinity, gelatinization temperature, viscosity, setback value, and breakdown value. The low content (5%) of PRS3 had a stable viscosity and was easily degraded by bacteria, which can improve the quality of steamed bread to a certain extent. When the PRS3 content was over 10%, it competed with the gluten protein to absorb water, which reduced the contents of ß-turn and α-helix in the dough, increased the contents of ß-fold, and weakened the structure of the gluten network. It also decreased the specific volume and elasticity of the steamed bread and increased the spreading rate, hardness, and chewiness. Steamed bread prepared with a flour mixture containing 5% PRS3 was similar to the presidential acceptance of control flour. In this study, a new sustainable and efficient PRS3 preparation method was established, which has certain guiding significance for the processing of Functional steamed bread with high-resistant starch.

Quantitative analysis of Chinese steamed bread staling using NIR, MIR, and Raman spectral data fusion.

For efficient and comprehensive detection of the staling degree of Chinese steamed bread (CSB), staled CSB samples stored for 0-16 days were prepared and analyzed using near-infrared (NIR), mid-infrared (MIR), and Raman spectroscopy combined with data fusion. Among three data fusion schemes, decision-level fusion achieved the best performance when quantifying the CSB staling degree according to the soluble starch amylose fraction, relative crystallinity, and hardness, with determination coefficients and root mean square errors for the validation set in the range of 0.928-0.986 and 0.015-1.290, respectively. The relative percent deviation values of the three indicators increased to 8.362, 4.735, and 3.617, respectively. These results indicate that the combination of NIR, MIR, and Raman spectroscopy as a decision-level fusion scheme can achieve efficient, comprehensive, and accurate quantification of the staling degree of CSB. This research has important applications for food quality, safety, and shelf-life evaluations.

Effects of ultrasonic-microwave combination treatment on the physicochemical, structure and gel properties of myofibrillar protein in Penaeus vannamei (Litopenaeus vannamei) surimi.

The objective of this study was to evaluate the effects of single ultrasound (360 W, 20 min), single microwave (10 W/g, 120 s) and ultrasonic-microwave combination treatment on shrimp surimi gel properties. The structure and physicochemical properties of myofibrillar protein (MP) were also determined. Low-field nuclear magnetic resonance showed that the fluidity of water molecules and the moisture content decreased, the stability and water holding capacity (WHC) increased after single ultrasound, single microwave and ultrasonic-microwave combination treatment. Compared with the traditional water bath treatment, ultrasound and microwave treatment reduced the total sulfhydryl content and promoted the formation of intermolecular disulfide bonds and hydrophobic interactions, which improved the compactness of the network structure of shrimp surimi gel. Moreover, Fourier transform infrared spectroscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that these treatments not only inhibited the degradation of MP, but also decreased the α-helix content and increased the ß-sheet content. The three treatments also significantly reduced the particle size and decreased the solubility of MP. Overall, the effect of ultrasonic-microwave combination treatment was superior to that of either single treatment.