Search

Selenium-enriched edible fungi are rich in selenium polysaccharides, selenoproteins, selenium polypeptides and other bioactive components. However, the selenium forms and organic selenium transformation rate of selenium-enriched edible fungi are affected by several factors, such as species, selenium biotransformation methods and cultivation techniques. Subsequently, edible fungi show different biological activities and mechanisms of action. Therefore, it is particularly important to study the forms, distribution, absorption and transformation of selenium in edible fungi. The paper reviews the proportion of different forms of selenium in total selenium, the process of absorption and transformation of different selenium forms, the threshold of total selenium, the present selenium-enriched technology and the industrial problems of representative selenium-enriched edible fungi. The immunological activity, antitumor activity and antioxidant activity of different selenium forms in selenium-enriched edible fungi are also discussed in this paper. This review is expected to provide a reference basis for the precise selenium enrichment of edible fungi, to serve as a scientific support for the development of highly active different forms of selenium, and to propose directions for the development of selenium-enriched edible fungi.

Abstract Patulin (PAT) is a common mycotoxin in moldy fruits that causes gastrointestinal injury if accidentally ingested. Some studies have reported the symptoms of intestinal injury caused by PAT. However, the effects of PAT on the gut microbiota and gut metabolism remain to be investigated, which is important for clarifying the toxicological mechanisms. Thus, C57/BL6J mice were gavaged once with 0, 1, 4, and 16 mg/kg body weight PAT, and the small intestinal and colonic contents were collected. The 16S rRNA sequencing and targeted and untargeted metabolomics were applied to assess the alterations in microbiota and metabolism, respectively. The results showed that Mycoplasma, Dubosiella, and Enterorhabdus were jointly affected by acute PAT exposure in the small intestinal and colonic contents. Some inflammation‐related bacteria, such as Mycoplasma in the small intestine and Mycoplasma, Alistipes, Eubacterium_coprostanoligenes_group, and Candidatus_saccharimona in the colon, increased with increasing doses of PAT. In metabolic results, amino acids decreased and bile acids elevated in both intestinal contents; lipids increased in the small intestinal contents but decreased in the colonic contents. PAT mainly affected host amino acid and lipid metabolism; it also downregulated microbial tryptophan metabolism and short‐chain fatty acid levels (mainly in the colon), which could be explained by the decrease of Bacteroides and Lactobacillus. These influences in microbial abundances and metabolic levels persisted after PAT and its products were cleared. These results fill a gap in the effects of PAT on the gut microbiota and provide a theoretical basis for elucidating the toxic mechanism of mycotoxins.

Plant-based fermentations provide an untapped source for novel biotechnological applications. In this study, a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes. Polysaccharides were extracted from fermented and non-fermented L. edodes and purified via DEAE-52 and Sephadex G-100. The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR, HPGPC, HPAEC, SEM, GC-MS and NMR. The results revealed that probiotic fermentation increased the molecular weight from 1.16 × 104 Da to 1.87 × 104 Da and altered the proportions of glucose, galactose and mannose, in which glucose increased from 45.94 % to 48.16 %. Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns. Furthermore, their immunomodulatory activities were evaluated with immunosuppressive mice. NF-LEP and F-LEP improved immune organ indices, immunoglobulin (IgG and IgM) and cytokines concentrations; restored the antioxidation capacity of liver; and maintained the balance of gut microbiota. F-LEP displayed better moderating effects on the spleen index, immunoglobulin, cytokines and the diversity of gut microbiota than NF-LEP (200, 400 mg/kg). Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides, which helps to enhance their biological activity and promote their wide application in food, medicine and other fields.

Abstract Agaric is a dual‐purpose fungus for medicine and food, which is considered a healthcare product. However, in cultivation and production, agaric is contaminated by a variety of molds, resulting in a decline in quality and yield. Fusarium, as one of the poisonous filamentous fungi, seriously threatens the healthy development of the agaric industry and even affects human health. Therefore, it is necessary to establish timely and accurate identification and rapid detection of pathogens and crops. In this study, the visible near infrared hyperspectral imaging was used to obtain the image and spectral information, and the best classification model was selected and established to quickly distinguish Fusarium oxysporum from Fusarium verticillioides, which was also successfully applied for the preliminary identification of agaric infection. This approach could provide a nondestructive manner for rapid identification and detection of pathogenic fungi contamination in agaric.

In this paper, the drying efficiency of natural drying, hot air and vacuum microwave on Auricularia auricula were systematically investigated, and the changes of physicochemical properties of Auricularia auricula and the degradation effect of quinolones (enrofloxacin, ciprofloxacin) were also evaluated. The results showed that the drying time of Auricularia auricula was greatly shortened to 150 min with the hot air drying (80 ℃) and 15 min with vacuum microwave (2.4 kW) compared with the natural drying. With the treatments of hot air drying and vacuum microwave drying, there was no significant effect on the content of crude protein, fat, fiber and ash in Auricularia auricula, and the total sugar content decreased by 1.34% and 2.28%, respectively. The physicochemical indexes still met the National Standard requirements. In addition, the degradation rates of enrofloxacin and ciprofloxacin during natural drying were 16.32% and 14.22%, while that of hot air drying were 35.37% and 32.39%, and vacuum microwave drying were 36.11% and 33.19%, respectively. The results indicated that there was no significant difference in antibiotic degradation between the two treatments. Therefore, vacuum microwave drying exhibits the advantages of less treatment time and effect on the physicochemical indexes, higher drying efficiency and better antibiotic degradation effect, which provides a new idea for the drying and quality control of edible fungi.

Mycotoxin contamination has become a major food safety issue and greatly threatens human and animal health. Patulin (PAT), a common mycotoxin in the environment, is exposed through the food chain and damages the gastrointestinal tract. However, its mechanism of enterotoxicity at the genetic and metabolic levels remains to be elucidated. Herein, the intestinal histopathological and biochemical indices, transcriptome, and metabolome of C57BL/6 J mice exposed to different doses of PAT were successively assessed, as well as the toxicokinetics of PAT in vivo. The results showed that acute PAT exposure induced damaged villi and crypts, reduced mucus secretion, decreased SOD and GSH-Px activities, and enhanced MPO activity in the small intestine and mild damage in the colon. At the transcriptional level, the genes affected by PAT were dose-dependently altered in the small intestine and fluctuated in the colon. PAT primarily affected inflammation-related signaling pathways and oxidative phosphorylation in the small intestine and immune responses in the colon. At the metabolic level, amino acids decreased, and extensive lipids accumulated in the small intestine and colon. Seven metabolic pathways were jointly affected by PAT in two intestinal sites. Moreover, changes in PAT products and GST activity were detected in the small intestinal tissue but not in the colonic tissue, explaining the different damage degrees of the two sites. Finally, the integrated results collectively explained the toxicological mechanism of PAT, which damaged the small intestine directly and the colon indirectly. These results paint a clear panorama of intestinal changes after PAT exposure and provide valuable information on the exposure risk and toxic mechanism of PAT.

Abstract Akebia fruit is a plant used for both medicinal and edible purposes. In recent years, due to the rich phytochemical composition with bioactive effects, Akebia fruit has attracted increasing attention on its composition analysis, active ingredients identification, and product applications. For example, the protein, sugar, amino acids, and vitamin C content of the pulp is higher than that of ordinary fruit. The seeds are not only processed into edible oil, it is also rich in protein and have the potential to be developed into a new resource with beneficial effects on human health. However, the research on the understanding of Akebia as a plant fruit is relatively lacking. In this review, an overview of Akebia fruit from food perspectives, including extraction methods and phytochemicals, bioactive functions, and various applications, were summarized. Finally, based on the current status and existing challenges, the prospect and future development direction of Akebia fruit were discussed.

Although Vibrio parahaemolyticus has become the most common pathogen in fresh and frozen seafood, its virulence changes have often been ignored during the processing of seafood. To investigate these potential risks, we used frozen Penaeus chinensis as examples, and the most virulent factors of V. parahaemolyticus, including amounts, VBNC status, toxins TDH and TRH, and virulence genes tdh and trh, were determined. Bacterial quantities were significantly reduced during drain and sprinkling phases, but caused by different factors. By SYTO9 and PI staining showed that washing was the main reason for the bacterial reduction at the drain phase, while the strain entering VBNC state was another reason at sprinkling phase. Their hemolysis toxicity, produced by TDH and TRH, became stronger after inoculation on shrimp, and could be detected throughout the process. Moreover, tdh and trh also exhibited trends similar to that of the hemolysis toxicity test. tdh was almost to a two-fold expression level during ice-glazing phase, while trh only express at a low level, less than half of the expression level before inoculation. These results demonstrated that the strains were not dead during freezing process, but became VBNC cells, which still produced and accumulated toxins, especially TDH, the most virulent factor.

Abstract Dysbiosis of the gut microbiota and metabolic disorders contributes to the occurrence of diabetes mellitus. Polyphenols reduce the risk of type II diabetes mellitus (T2DM) by inhibiting α‐glucosidase. Mulberry leaf Fu tea (FM) is a kind of tea obtained by the fermentation of Eurotium cristatum, which is polyphenol‐enriched and has a distinctive aroma, but its antidiabetic mechanism is unclear. In this study, we investigated the polyphenols in the aqueous extract of FM through HRLC‐MS and verified its inhibitory effect on α‐glucosidase in vitro test and finally studied its effect on gut microbiota and short‐chain fatty acids (SCFAs) in diabetic mice. The findings demonstrated that FM supplementation considerably altered gut microbiota abnormalities in diabetic mice, maintained the balance of microflora, encouraged the growth of beneficial microorganisms (Coriobacteriaceae UCG‐002, Dubosiella, Lactobacillus, and Bifidobacterium), and increased levels of acetic acid, propionic acid, and butyric acid. In conclusion, FM can regulate gut microbiota and SCFAs to ameliorate or alleviate T2DM caused by HFD‐STZ. Therefore, FM can also be used as postbiotics to improve T2DM.

Food safety evaluation, which aims to reflect food safety status, is an important part of food safety management. Traditional food evaluation methods often consider limited data, and the evaluation process is subjective, time-consuming, and difficult to popularize. We developed a new food safety evaluation system that incorporates simple qualification degrees, food consumption, project hazard degrees, sales channels, food production regions, and other information obtained from food safety sampling and inspection to reflect the food safety situation accurately, objectively, and comprehensively. This evaluation model combined the statistical method and the machine learning method. The optimal distance method was used to calculate the basic qualification degree, and then expert elicitation via a questionnaire and the factor analysis of mixed data method (FADM) was applied to modify the basic qualification degree so as to obtain the food safety index, which indicates food safety status. Then, the effectiveness of this new method was verified by calculating and analyzing of the food safety index in region X. The results show that this model can clearly distinguish food safety levels in different cities and food categories and identify food safety trends in different years. Thus, this food safety evaluation system based on the FADM quantifies the real food safety level, screens out cities and food categories with high food safety risks, and, finally, helps to optimize the allocation of regulatory resources and provide technical and theoretical support for government decision-making.

Abstract Ethyl carbamate (EC) is a kind of genotoxic and carcinogenic substance and potentially harmful to human health. In this study, simple and effective removal of EC from liquor samples by using the magnetic mesoporous adsorbent (Fe3O4@COFs) was investigated. Gas chromatography and triple quadrupole tandem mass spectrometry (GC‐MS/MS) was used to monitor the whole of adsorption process. The results showed that the adsorbent has high efficiency and fast adsorption capacity. Under the optimized adsorption parameters, pseudo‐first‐order and pseudo‐second‐order kinetic models were employed to reveal the underlying sorption mechanism. Results indicated that the adsorption of EC on Fe3O4@COFs is more consistent with the pseudo‐second‐order model. Furthermore, an effective method for the adsorption and detection of EC was successfully developed, which exhibited good linearity with R2 ranging from 0.9954 to 0.9998, satisfactory recoveries in the range of 86.9%–116.2%, and the relative standard deviations (RSD) was lower than 5.8%. Fe3O4@COFs showed good stability and excellent performance in removing EC from liquor samples. It is expected that the proposed magnetic COFs hold great promise for liquor sample pretreatment and be extended for application in other fields.

Jujube contains abundant cyclic adenosine monophosphate (cAMP) and the ultrasonic-assisted pectinase extraction (UAPE) conditions for obtaining the maximum cAMP yield from jujube were optimized. Orthogonal array design was applied to evaluate the effects of 4 variables by UAPE on cAMP yield. The results showed that the optimal cAMP yield (783.0 μg/g) was derived at ratio of liquid to solid 5 mL/g, ratio of pectinase to raw material 1.5 %, time 60 min and temperature 40 °C. Moreover, the effect of cAMP on the anti-allergic function of action induced by immunoglobulin E (IgE) and its meschanism was investigated through establishing the sensitized cell model in rat basophilic leukemia (RBL-2H3) cells using dinitrophenylated (DNP)-bovine serum albumin (BSA)-IgE. The results showed that cAMP interfered with sensitized cells, effectively inhibited the occurrence of basophil degranulation in dose dependence, and significantly reduced the activity of β-hexosamindase (β-hex), at the optimal concentration of 50 μg/mL. The level of anti-inflammatory factor interleukin-10 (IL-10) was promoted and the content of pro-inflammatory factor tumor necrosis factor-α (TNF-α) was suppressed by cAMP. In addition, influx of intracellular Ca2+ was repressed effectively. Our results demonstrate that jujube cAMP regulated the cytokine balance in the allergy pathway through blocking the influx of extracellular Ca2+, with the prevention of allergy symptoms.

Abstract Osteoporosis is characterized by decreased bone mass, microarchitectural deterioration, and increased bone fragility. High-fat diet (HFD)-induced obesity also results in bone loss, which is associated with an imbalanced gut microbiome. However, whether HFD-induced obesity or HFD itself promotes osteoclastogenesis and consequent bone loss remains unclear. In this study, we developed HFD-induced obesity (HIO) and non-obesity (NO) mouse models to evaluate the effect of HFD on bone loss. NO mice were defined as body weight within 5% of higher or lower than that of chow diet fed mice after 10 weeks HFD feeding. NO was protected from HIO-induced bone loss by the RANKL /OPG system, with associated increases in the tibia tenacity, cortical bone mean density, bone volume of cancellous bone, and trabecular number. This led to increased bone strength and improved bone microstructure via the microbiome-short-chain fatty acids (SCFAs) regulation. Additionally, endogenous gut-SCFAs produced by the NO mice activated free fatty acid receptor 2 and inhibited histone deacetylases, resulting in the promotion of Treg cell proliferation in the HFD-fed NO mice; thereby, inhibiting osteoclastogenesis, which can be transplanted by fecal microbiome. Furthermore, T cells from NO mice retain differentiation of osteoclast precursors of RAW 264.7 macrophages ex vivo. Our data reveal that HFD is not a deleterious diet; however, the induction of obesity serves as a key trigger of bone loss that can be blocked by a NO mouse-specific gut microbiome.

Abstract Alicyclobacillus acidoterrestris (A. acidoterrestris), a kind of spore‐forming bacterium, could causes spoilage of fruit juices, which results in pecuniary losses to the industry. Unfortunately, the conventional methods used to identify this bacterium are laborious and complex. In this work, copper‐based metal‐organic frameworks (Cu‐MOFs) with intrinsic peroxidase‐like activity were fabricated by a self‐assembly method. Based on the properties of Cu‐MOFs, a colorimetric assay was developed for the detection of guaiacol, a characteristic metabolite of A. acidoterrestris and chromogenic substrate of peroxidase. Under optimal conditions, an excellent linear relationship was achieved over a range of guaiacol (0.01–0.4 mM), with a limit of detection (LOD) as low as 0.003 mM. This biosensor also showed a satisfactory sensing performance towards guaiacol, allowing the identification of A. acidoterrestris with high selectivity in a real sample. This present study provides a new perspective for the exploration of more sensitive and convenient methods for A. acidoterrestris detection.

Abstract Mycotoxins are the secondary metabolites of fungi in food and can be toxic to people. Therefore, developing simple, sensitive, and specific detection methods to detect mycotoxins in food is essential for ensuring food safety. Fluorescent aptasensors for the detection of mycotoxins in food have developed rapidly. They are simple and fast with high affinity and specificity. However, fluorescent aptasensors have not yet been applied in officially approved standards so far. This review elucidates fluorescent aptasensors for mycotoxin detection, including principles, constituted elements, types, and applications. Screening results of aptamers and each aptamer sequence used in fluorescent aptasensors are summarized to facilitate further research for later studies. We also focused on fluorescent probes, nanomaterials, and other strategies in the process of constructing fluorescent aptasensors. We then discuss current challenges and future perspectives in fluorescent aptasensors for mycotoxin detection.

Burkholderia gladioli pv. cocovenenans is a serious safety issue in black fungus due to the deadly toxin, bongkrekic acid. This has triggered the demand for an efficient toxigenic phenotype recognition method. The objective of this study is to develop an efficient method for the recognition of toxin-producing B. gladioli strains. The potential of multilocus sequence typing and a back propagation neural network for the recognition of toxigenic B. cocovenenans was explored for the first time. The virulent strains were isolated from a black fungus cultivation environment in Qinba Mountain area, Shaanxi, China. A comprehensive evaluation of toxigenic capability of 26 isolates were conducted using Ultra Performance Liquid Chromatography for determination of bongkrekic acid and toxoflavin production in different culturing conditions and foods. The isolates produced bongkrekic acid in the range of 0.05–6.24 mg/L in black fungus and a highly toxin-producing strain generated 201.86 mg/L bongkrekic acid and 45.26 mg/L toxoflavin in co-cultivation with Rhizopus oryzae on PDA medium. Multilocus sequence typing phylogeny (MLST) analysis showed that housekeeping gene sequences have a certain relationship with a strain toxigenic phenotype. We developed a well-trained, back-propagation neutral network for prediction of toxigenic phenotype in B. gladioli based on MLST sequences with an accuracy of 100% in the training set and an accuracy of 86.7% in external test set strains. The BP neutral network offers a highly efficient approach to predict toxigenic phenotype of strains and contributes to hazard detection and safety surveillance.

Considerable progress has been achieved in the bioaccumulation and transformation of selenium (Se)-enriched lactic acid bacteria (LAB). However, research on the effects of Se on the structure and probiotic potential of LAB is relatively limited. In this study, six industrial LAB strains, including Lactobacillus plantarum 21,805, Lactobacillus paracasei 20,241, Lactobacillus fermentum 21,828, Lactobacillus casei 23,185, Lactobacillus acidophilus 6064, and Lactobacillus plantarum 6076, were cultured in De Man, Rogosa, and Sharpe (MRS) medium containing Se for three generations. High-Se LAB was screened based on bacterial biomass, viable bacterial count, and Se content. Their structural characteristics were analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results indicated that LAB growth was influenced by the Se environment, with high Se (20 μg/mL) inhibiting it. At a Se concentration of 10 μg/mL, LAB maintained integrity and exhibited a high Se enrichment ability, with a Se enrichment of 4.88 ± 0.39 mg/g. The intracellular Se existed in an amorphous or non-crystalline form. Furthermore, Se-enriched LAB exhibited enhanced probiotic properties, including tolerance to simulated gastrointestinal fluids, acid resistance, bile salt resistance, and hydrophobicity. Therefore, Se-enriched LAB are expected to develop new functional foods or dietary supplements for human and animal consumption.

Asparagus root (AR) is utilized globally as a traditional herbal medicine because it contains various bioactive compounds, such as polyphenols, flavonoids, saponins, and minerals. The composition profiles of AR are strongly affected by its botanical and geographical origins. Although minerals and heavy metals are minor constituents of AR, they play a crucial role in determining its quality and efficacy. A comprehensive classification of AR, its phytochemistry, and its pharmacology were reviewed and interpreted herein. Potentially eligible articles (in English) were identified through an electronic search of the Web of Science database (2010–2022) and Google (2001–2022). We used the primary search term “Asparagus roots” combined with the words “pharmacology,” “bioactive compounds,” “physicochemical properties,” and “health benefits” to find the relevant literature. We screened the titles, keywords, and abstracts of the publications obtained from the database. A full copy of the article was obtained for further assessment if deemed appropriate. Different asparagus species might potentially be used as herbal medicines and functional foods. Phytochemical studies have revealed the presence of various bioactive compounds as valuable secondary metabolites. The dominant class of bioactive compounds in AR is flavonoids. Furthermore, AR displayed significant pharmacological effects, such as antioxidant, antimicrobial, antiviral, anticancer, anti-inflammatory, and antidiabetic effects, as shown in animal and human studies. This review provides a valuable resource to enable a thorough assessment of the profile of Asparagus root as a functional ingredient for the pharmaceutical and food industries. In addition, it is anticipated that this review will provide information to healthcare professionals seeking alternative sources of critical bioactive compounds.

This study aimed to evaluate the application of encapsulated L. plantarum and eugenol as potential biocontrol agents in sliced apples. The combined encapsulated L. plantarum and eugenol treatment was more effective than separate encapsulated L. plantarum and eugenol treatments, with regards to browning inhibition and consumers panel test. The application of encapsulated L. plantarum and eugenol reduced the decline of the physicochemical qualities of the samples, and improved the ability of antioxidant enzymes to scavenge reactive oxygen species. Furthermore, reductions in the growth of L. plantarum of only 1.72 log CFU/g were observed after 15 days of storage at 4 °C for samples treated with encapsulated L. plantarum and eugenol. Results suggest the combined encapsulated L. plantarum and eugenol appears to be a promising method to protect fresh-cut apples from food-borne pathogens while maintaining the visual appearance.

Several of the fungal species associated with Fuzhuan brick tea (FBT) are considered as potential probiotics, but few studies have investigated the probiotic properties of these fungi. Here, we isolated 18 fungal strains from two types of FBT and identified these strains based on internal transcribed spacer (ITS) fragment sequence similarity to reference strains (sequence similarity > 98%). Of the 18 strains, 10 tolerated simulated human digestive conditions for sufficient periods in vitro: pH 2-3, 0.3%-0.5% (m/V) bile salts, and artificial gastrointestinal juices. We then measured the antimicrobial activity of the remaining 10 strains against 5 enteropathogenic bacteria and tested the bacteriostatic effects of the thalli and fermentation broth extracts. Of the 6 strains with strong bacteriostatic effects, we eliminated Eurotium cristatum S-9 due to its low hydrophobicity of (26.12 ± 0.35)%. Finally, 2 exhibited good adhesion abilities to human cells (> 100%). Notably, 2 strains can survive in vivo, because they can be isolated from C57BL/6 mice feces. Thus, 2 strains, Aspergillus cristatus H-1 and A. cristatus H-5, are herein identified as promising candidate probiotic strains. It may be put forward a novel research focus on evaluating potential probiotic fungi from FBT.

Ochratoxin A (OTA) is a secondary metabolite of several fungi and widely exists in various species of foods. The establishment of effective methods for OTA reduction is a key measure to ensure food processing and human health. This article reviews the current research of OTA reduction by biological approaches, summarizes the characteristics and efficiency of them, and evaluates the transformation pathways and metabolites safety of each degradation technology. The shortcomings of various methods are pointed out and future prospects are also proposed. Biological methods are the most promising approaches for OTA control. The defect of them is the long processing time and the growth of microbial cells may affect the product quality. Therefore, the control of OTA contamination should be conducted according to the food processing and their product types. Besides, it is significant for the exploitation of new strains, enzyme and novel adsorbents.

Abstract Juice spoilage caused by Alicyclobacillus acidoterrestris has troubled the global manufacturers for many years. Most approaches have failed to detect this bacterium with desirable sensitivity and selectivity because of their inherent drawbacks. In this work, carbon dots (CDs) with bright fluorescence were prepared which can be quenched by the HRP‐catalyzed oxidation product of p‐phenylenediamine, via inner filter effect. Therefore, an unlabeled fluorescence ELISA strategy incorporating CDs as signal reporter was developed for the detection of A. acidoterrestris in apple juice. This approach showed excellent performance on target identification with enhanced specificity, achieving a limit of detection of 3.2 × 102 CFU/mL. It is expected that this method could provide a reliable way for timely identification of A. acidoterrestris, effectively warning against the emergence of juice spoilage incidence.

Abstract Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium genera. It is hepatotoxic, nephrotoxic and carcinogenic. The growing contamination of OTA in wine and grape juice is a great threat to human. In this study, different enzymes were screened for the detoxification of OTA in wine and grape juice. The results indicated that seven enzymes had OTA degradation capacity in the buffer, and the degradation rate of carboxypeptidase A (CPA), lipase, pancreatin and thermolysin were 100%, 100%, 75.72%, and 73.45%, respectively. In grape beverages, pancreatin and CPA showed the most promising result with OTA degradation of 53.24% and 61.56% at 37°C. The LC‐MS/MS analysis further indicated that OTA produced nontoxic OTα and phenylalanine under treatment with three enzymes (carboxypeptidase A, lipase, and pancreatin). Furthermore, pancreatin and CPA had a clarifying effect on wine and grape juice, but had a slight effect on the organic acids and flavor components of them. It suggested that pancreatin and CPA could be used for OTA degradation in grape beverages.

Over the last few years, smartphone-based sensors present a rapid development in the field of point-of-care (POC) testing owing to the properties of ubiquity and convenience. Considering the test accuracy and sensitivity, kinds of external devices were equipped on smartphones for a better on-site medical diagnosis. However, some devices were not easily fabricated or obtained. The compatibility and practicality of the equipped devices may often be overlooked in the process of application. This review pays attention to the application of smartphone independent detections for the POC testing, especially in the cases that were performed only by build-in sensors and analysis algorithms of smartphones, as well as some universal and compatible tools. Four types of build-in sensor systems, including optical sensors, sound sensors, electrochemical sensors, and other sensors, were mainly introduced to improve the public cognition and understanding of smartphone sensors. At last, a brief perspective on scientific challenges and prospects was discussed, aiming to open new ways for exploiting smartphone-based POC or home healthcare.

To address the potential risks to food safety, headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS) were used to analyze the volatile organic compounds (VOCs) generated from chilled chicken contaminated with Staphylococcus aureus during early storage. Together with the KEGG database, we analyzed differential metabolites and their possible biotransformation pathways. Orthogonal partial least squares discriminant analysis (OPLS-DA) was applied to characterize VOCs and identify biomarkers associated with the early stage of chicken meat contamination with S. aureus. The results showed 2,6,10,15-tetramethylheptadecane, ethyl acetate, hexanal, 2-methylbutanal, butan-2-one, 3-hydroxy-2-butanone, 3-methylbutanal, and cyclohexanone as characteristic biomarkers, and 1-octen-3-ol, tetradecane, 2-hexanol, 3-methyl-1-butanol, and ethyl 2-methylpropanoate as potential characteristic biomarkers. This provides a theoretical basis for the study of biomarkers of Staphylococcus aureus in poultry meat.

Abstract Quinoa is a pseudo‐cereal that is rich in protein and an ideal source of antihypertensive peptides. In this study, quinoa flour was fermented with Lactobacillus paracasei CICC 20241 via solid fermentation to produce antihypertensive peptides. The peptides were isolated and purified by ultrafiltration and gel chromatography, and then identified by liquid chromatography−tandem mass spectrometry. A total of 91 peptides were identified. In addition, five potential angiotensin‐converting enzyme (ACE) inhibitory peptides were synthesized with reference to in silico analysis. Among them, NIFRPFAPEL and AALEAPRILNL had the greatest inhibitory effect, with an IC50 of 49.02 and 79.72 µM, respectively. Inhibition dynamics and molecular docking indicated that NIFRPFAPEL formed eight hydrogen bonds with ACE residues Tyr523, Arg522, Glu384, Glu143, Glu123, Thr92, Tyr62, and Trp59. NIFRPFAPEL exerted a competitive inhibitory effect by interacting with residues Tyr523 and Glu384 of pocket S1. AALEAPRILNL exerted a noncompetitive inhibitory effect by forming eight hydrogen bonds with the inactive ACE site residues Ser516, Glu403, Ser355, Glu143, ARG124, and Asn70. These results confirmed that quinoa is a potential material for antihypertensive functional foods, while NIFRPFAPEL and AALEAPRILNL could be used for the development of antihypertensive functional foods or drugs.

A. acidoterrestris has been identified as the target bacterium in fruit juice production due to its high resistance to standard heat treatment. Multiple studies have shown that cold plasma can effectively inactivate pathogenic and spoilage microorganisms in juices. However, we are aware of only a few studies that have used cold plasma to inactivate A. acidoterrestris. In this study, the inactivation efficacy of cold plasma was determined using the plate count method and described using a biphasic model. The effects of the food matrix, input power, gas flow rate, and treatment time on inactivation efficacy were also discovered. Scavenging experiments with reactive oxygen species (•OH, •O2−, and 1O2), scanning electron microscopy (SEM), Raman spectra, as well as an in vitro toxicology assay kit, were used to determine the inactivation mechanism. According to the plate count method, a maximum reduction of 4.14 log CFU/ mL could be achieved within 7 s, and complete inactivation could be achieved within 240 s. The scavenging experiments showed that directly cold plasma-produced singlet oxygen plays the most crucial role in inactivation, which was also confirmed by the fluorescence probe SOSG. The scanning electron microscopy (SEM) and Raman spectra showed that the cold plasma treatment damaged the membrane integrity, DNA, proteins, lipids, and carbohydrates of A. acidoterrestris. The plate count results and the apple juice quality evaluation showed that the cold plasma treatment (1.32 kV) could inactivate 99% of A. acidoterrestris within 60 s, with no significant changes happening in apple juice quality, except for slight changes in the polyphenol content and color value.

Abstract Quercetin, a dietary flavonol, has been used as potential ingredient in food supplements to promote health. Its health effects are closely related to its bioavailability and further depend on its absorption, metabolism and excretionin vivo. Here, we systematically summarized the absorption and metabolism of quercetin in human intestine, liver, and kidney, highlighting the transport and metabolic pathways, intermediate metabolites, and circulation channels involving quercetin. The bioactivities of quercetin on theintestine, liver, and kidney were also considered. In general, except for passive diffusion, different transporters (e.g., SGLT1,OATPs, and MRPs) participate in the transport of quercetin and its metabolites across biological barriers. Quercetin undergoes phase II metabolism after absorption by the intestine and is finally excreted into bile through liver or urine through kidney. Quercetin can protect the intestinal barrier and modulate the microflora. Moreover, its antioxidant, anti‐inflammatory, and anti‐fibrotic activities protect the liver and kidney.

Cinnamic acid (CA) is a safe and effective antimicrobial agent. The objective of this study was to reveal the antibacterial mechanism of CA against a food-derived Pseudomonas fragi 38-8, from the aspects of bacterial growth kinetics, cell membrane homeostasis, cell microstructure, and transcription. The minimum inhibitory concentration (MIC) of CA against P. fragi 38-8 was 0.25 mg/ml. CA retarded bacterial growth and induced a series of cell membrane changes. After CA treatment, cell membrane homeostasis was destroyed, which was evidenced by cell membrane depolarization, intracellular pH reduction, and intracellular ATPase activity decrease. Field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), and confocal laser scanning fluorescence microscope (CLSM) realized the visualization of cell microstructure changes, showing cell death and morphological changes, such as cell rupture, shrinkage, and hollowness. RNA sequencing analysis further confirmed the effects of CA to the cell membrane, because of the significant enrichment of differentially expressed genes (DEGs) related to membrane. The results of the phenotype tests and RNA-seq both focused on cell membrane damage, which showed that CA exerted antibacterial effect mainly by acting on cell membrane.

Ractopamine, as a feed additive, has attracted much attention due to its excessive use, leading to the damage of the human nervous system and physiological function. Therefore, it is of great practical significance to establish a rapid and effective method for the detection of ractopamine in food. Electrochemical sensors served as a promising technique for efficiently sensing food contaminants due to their low cost, sensitive response and simple operation. In this study, an electrochemical sensor for ractopamine detection based on Au nanoparticles functionalized covalent organic frameworks (AuNPs@COFs) was constructed. The AuNPs@COF nanocomposite was synthesized by in situ reduction and was characterized by FTIR spectroscopy, transmission electron microscope and electrochemical methods. The electrochemical sensing performance of AuNPs@COF-modified glassy carbon electrode for ractopamine was investigated using the electrochemical method. The proposed sensor exhibited excellent sensing abilities towards ractopamine and was used for the detection of ractopamine in meat samples. The results showed that this method has high sensitivity and good reliability for the detection of ractopamine. The linear range was 1.2–1600 μmol/L, and the limit of detection (LOD) was 0.12 μmol/L. It is expected that the proposed AuNPs@COF nanocomposites hold great promise for food safety sensing and should be extended for application in other related fields.

Fuzhuan brick tea (FBT) is a unique post-fermented tea product, naturally co-fermented by microorganisms, and has gained global popularity due to its potential health benefits for humans. Considerable efforts have been made toward elucidating the microbial diversity within FBT, but an understanding of the underlying FBT community interactions and functions remains poorly studied. Consequently, the microbial communities of two types of FBT, originating from Hunan and Shaanxi provinces, were investigated using comparative shotgun metagenomic sequencing and functional annotations. Metagenomic analysis indicated that two communities shared similar taxonomic and functional attributes. Two samples shared 486 genera, in which Pseudomonas contributed most to the abundant functions within the two samples. The carbohydrate active enzyme functions of the communities primarily comprised GH (32.92%), GT (26.8%), CEs (20.43%), and AAs (18.04%). Furthermore, the overall metabolic pathways encoded by the metagenomes were largely associated with carbohydrate and amino acid metabolism, with nine metabolic pathways that were differential between two groups including penicillin and cephalosporin biosynthesis. Significantly, a total of 35 potential probiotics were inferred, with Pseudomonas putida being the most abundant inferred probiotic (80%) within the FBT communities. This study provides new insights into FBT microbial communities on their potential functions and roles in FBT characteristics.

Alicyclobacillus acidoterrestris (A. acidoterrestris), a spore-forming bacterium, has become a main challenge and concern for the juices and acid beverage industry across the world due to its thermo-acidophilic characteristic. Thymoquinone (TQ) is one of the active components derived from Nigella sativa seeds. The objective of this study was to investigate antibacterial activity and associated molecular mechanism of TQ against A. acidoterrestris vegetative cells, and to evaluate effects of TQ on A. acidoterrestris spores and biofilms formed on polystyrene and stainless steel surfaces. Minimum inhibitory concentrations of TQ against five tested A. acidoterrestris strains ranged from 32 to 64 μg/mL. TQ could destroy bacterial cell morphology and membrane integrity in a concentration-dependent manner. Field-emission scanning electron microscopy observation showed that TQ caused abnormal morphology of spores and thus exerted a killing effect on spores. Moreover, TQ was effective in inactivating and removing A. acidoterrestris mature biofilms. These findings indicated that TQ is promising as a new alternative to control A. acidoterrestris and thereby reduce associated contamination and deterioration in the juice and acid beverage industry.

Due to the misuse of pathogen-infected food, human beings continue to face serious diseases and even deaths. Thus, researchers from all walks of life concern on prevention, detection, and resistance for pathogenic bacteria. It is necessary to develop and explore a fast, cost-effective, portable, and efficient detection technology for pathogens. Recently, electrochemical sensors have been widely used for food safety analysis, due to their increasingly high sensitivity and selectivity. In particular, researchers have made significant breakthroughs on signal enhancement strategies, quantitative methods, and miniaturization of the instrument, which can be used as a reference to food safety analysis. Moreover, a device integrating facile working procedures, miniaturization, and automation must be indispensable. In order to meet the needs of People’s Daily life, household device and point-of-care (POC) testing need to be combined with electrochemical sensing technology. In this review, the state of the art in electrochemical sensing for recognition and rapid detection of foodborne pathogenic bacteria is summarized from perspectives of common foodborne pathogens, especially focusing on real-time monitoring, lab-on-a-chip, and photoelectrochemical platform applied in food and medical treatment fields. Furthermore, the limitations and prospects of recognition elements, active nanomaterials, and optical materials, that are essential components in sensing systems on future research directions, were evaluated.

Antiallergic activities of Lactobacillus plantarum (L. plantarum) prepared from kimchi as orally administered probiotics were examined in type I peanut allergy mice models. Oral administration with L. plantarum restored the deteriorated profile of enteric flora in mice sensitized with peanut allergen and attenuated allergic symptoms, including diarrhea scores, clinical scores, serum specific immunoglobulin E (IgE) and histamine production. The mRNA expression of interleukin-10 and interferon-γ was suppressed and enhanced, respectively by L. plantarum administration. Thus, L. plantarum probably promoted anti-allergic activities via modulating enteric flora, intestinal cytokines mRNA expression in type I allergic mice, resulting in alleviation of allergic symptoms, including serum specific IgE and clinical hypersensitivity scores.

Since the outbreak of coronavirus disease-19 (COVID-19), cold-chain food contamination caused by the pathogenic severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has attracted huge concern. Cold-chain foods provide a congenial environment for SARS-CoV-2 survival, which presents a potential risk for public health. Strengthening the SARS-CoV-2 supervision of cold-chain foods has become the top priority in many countries. Methodologically, the potential safety risks and precaution measures of SARS-CoV-2 contamination on cold-chain food are analyzed. To ensure the safety of cold-chain foods, the advances in SARS-CoV-2 detection strategies are summarized based on technical principles and target biomarkers. In particular, the techniques suitable for SARS-CoV-2 detection in a cold-chain environment are discussed. Although many quarantine techniques are available, the field-based quarantine technique on cold-chain food with characteristics of real-time, sensitive, specific, portable, and large-scale application is urgently needed.

Patulin (PAT) is a toxic fungal metabolite, and oxidative damage was proved to be its important toxicity mechanism. Selenium nanoparticles (SeNPs) were prepared by reducing sodium selenite with chitosan as a stabilizer and used for preventing PAT-induced liver, kidney and gastrointestinal damage. SeNPs have good dispersibility, in vitro antioxidant activity, and are much less cytotoxic than sodium selenite. Cell culture studies indicated that SeNPs can effectively alleviate PAT-induced excessive production of intracellular ROS, the decline of glutathione peroxidase activity, and the suppression of cell viability. Evaluation of serum biochemical parameters, histopathology, oxidative stress biomarkers and activities of antioxidant enzymes in a mouse model showed that pre-treatment with SeNPs (2 mg Se/kg body weight) could ameliorate PAT-induced oxidative damage to the liver and kidneys of mice, but PAT-induced gastrointestinal oxidative damage and barrier dysfunction were not recovered by SeNPs, possibly because the toxin doses suffered by the gastrointestinal as the first exposed tissues exceeded the regulatory capacity of SeNPs. These results suggested that a combination of other strategies may be required to completely block PAT toxicity.

Probiotic strain Eurotium cristatum was isolated from Chinese Fuzhuan brick-tea and tested for its in vitro activity against aflatoxigenic Aspergillus flavus. Results indicated that E. cristatum can inhibit the radial growth of A. flavus. Furthermore, this inhibition might be caused by E. cristatum secondary metabolites. The ability of culture filtrate of strain E. cristatum against growth and aflatoxin B1 production by toxigenic A. flavus was evaluated in vitro. Meanwhile, the influence of filtrate on spore morphology of A. flavus was analyzed by scanning electron microscopy (SEM). Results demonstrated that both radial growth of A. flavus and aflatoxin B1 production were significantly weakened following increases in the E. cristatum culture filtrate concentration. In addition, SEM showed that the culture filtrate seriously damaged hyphae morphology. Gas chromatography mass spectrometry (GC/MS) analysis of the E. cristatum culture supernatant revealed the presence of multiple antifungal compounds. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis showed that the expression of aflatoxin biosynthesis-related genes (aflD, aflQ, and aflS) were down-regulated. Importantly, this latter occurrence resulted in a reduction of the AflS/AflR ratio. Interestingly, cell-free supernatants of E. cristatum facilitated the effective degradation of aflatoxin B1. In addition, two degradation products of aflatoxin B1 lacking the toxic and carcinogenic lactone ring were identified. A toxicity study on the HepG2 cells showed that the degradation compounds were less toxic when compared with AFB1.

The osmotolerant Zygosaccharomyces rouxii is known for its trait to survive in extreme high sugar environments. This ability determines its role in the fermentation process and leads to yeast spoilage in the food industry. However, our knowledge of the gene expression in response to high sugar stress remains limited. Here, we conducted RNA-sequencing (RNA-seq) under different sugar concentrations of the spoilage yeast, Z. rouxii, which exhibit extremely high tolerance to sugar stress. The obtained differentially expressed genes (DEGs) are significantly different to that of the Saccharomyces cerevisiae, which is sensitive to extreme high sugar stress. Most of the DEGs participated in the “glucan synthesis,” “transmembrane transport,” “ribosome,” etc. In this work, we also demonstrated that the gene ZYRO0B03476g (ZrKAR2) encoding Kar2p can significantly affect the growth of Z. rouxii under high sugar stress. In addition, we combined with a previous study on the genome sequence of Z. rouxii, indicating that several gene families contain significantly more gene copies in the Z. rouxii lineage, which involved in tolerance to sugar stress. Our results provide a gene insight for understanding the high sugar tolerance trait, which may impact food and biotechnological industries and improve the osmotolerance in other organisms.

Chitosan is widely used as a natural preservative of fruits and vegetables, but its poor mechanical and water resistances have limited its application. Therefore, in this study, we prepared chitosan composite films by incorporating different amounts of nano-zinc oxide (nano-ZnO) to improve the mechanical properties of chitosan. We also assessed the antibacterial activity of these films against selected microorganisms. The addition of nano-ZnO improved the tensile strength (TS) and elongation at break (EAB) of the chitosan films and reduced their light transmittance. TS and EAB increased from 44.64 ± 1.49 MPa and 5.09 ± 0.38% for pure chitosan film to 46.79 ± 1.65 MPa and 12.26 ± 0.41% for a 0.6% nano-ZnO composite film, respectively. The ultraviolet light transmittance of composite films containing 0.2%, 0.4%, and 0.6% nano-ZnO at 600 nm decreased from 88.2% to 86.0%, 82.7%, and 81.8%, respectively. A disc diffusion test showed that the composite film containing 0.6% nano-ZnO had the strongest antibacterial activity against Alicyclobacillus acidoterrestris, Staphylococcus aureus, Escherichia coli, and Salmonella. In a 15-day preservation study, chitosan composite films containing 0.6% nano-ZnO maintained the soluble solid content of cherry tomatoes, effectively inhibited their respiration, and exhibited good antibacterial properties against the selected microorganisms. Overall, the prepared chitosan nano-ZnO composite film showed a good preservation effect on cherry tomatoes.

Spices are susceptible to contamination by aflatoxin B1 (AFB1) and ochratoxin A (OTA), which are both mycotoxins with high toxicity and carcinogenicity. In this study, we aimed to develop an immuno-chromatographic strip test for the simultaneous quantification of AFB1 and OTA in spices by spraying the coupled antigens AFB1–ovalbumin (AFB1–OVA) and OTA–ovalbumin (OTA–OVA) on a nitrocellulose membrane. The test strip had high sensitivity, good specificity, and strong stability. The detection limits of these two mycotoxins in Chinese prickly ash, pepper, chili, cinnamon, and aniseed were 5 μg/kg. The false positivity rate was 2%, and the false negativity rate was 0%. The maximum coefficient of variation was 4.28% between batches and 5.72% within batches. The average recovery rates of AFB1 and OTA in spices were 81.2–113.7% and 82.2–118.6%, respectively, and the relative standard deviation (RSD) was 1 and OTA in spices. This method would allow the relevant regulatory agencies to strengthen supervision in an effort to reduce the possible human health hazards of such contaminated spices.

Sugar content and bacterial contamination levels are important indicators for the health and safety of food, respectively. Therefore, it is important to construct a method that can detect both glucose and bacterial activity. Herein, natural compounds (gallic acid and glucose oxidase) were assembled into nanozyme (GOx@GA-Fe (ii)) for mild cascade detection. The nanozyme catalyzes glucose to produce hydrogen peroxide, which is then converted to ·OH and oxidized colorless TMB from blue oxidized TMB. Under the optimal conditions, the method has a good linear relationship in the glucose concentration range of 1–500 μM (R2 = 0.993) with minimum detection concentration of 0.43 μM. Based on the glucose consumption of bacteria metabolism, the cascade reaction was then applied to detect the viability of 5 common bacteria. As such, a cascade method based on a natural self-assembled nanozyme was fabricated to monitor the quality of food.

In this study, Vidal grape must was fermented using commercial Saccharomyces cerevisiae F33 in pure culture as a control and in mixed culture with five indigenous non-Saccharomyces yeast strains (Hanseniaspora uvarum QTX22, Saccharomycopsis crataegensis YC30, Pichia kluyveri HSP14, Metschnikowia pulcherrima YC12, and Rhodosporidiobolus lusitaniae QTX15) through simultaneous fermentation in a 1:1 ratio. Simultaneous fermentation inhibited the growth of S. cerevisiae F33 and delayed the time to reach the maximum biomass. Compared with pure fermentation, the contents of polyphenols, acetic esters, ethyl esters, other esters, and terpenes were increased by R. lusitaniae QTX15, S. crataegensis YC30, and P. kluyveri HSP14 through simultaneous fermentation. S. crataegensis YC30 produced the highest total aroma activity and the most abundant aroma substances of all the wine samples. The odor activity values of 1 C13-norisoprenoid, 3 terpenes, 6 acetic esters, and 10 ethyl esters improved significantly, and three lactones (δ-decalactone, γ-nonalactone, and γ-decalactone) related to coconut and creamy flavor were only found in this wine. Moreover, this sample showed obvious “floral” and “fruity” note odor due to having the highest amount of ethyl ester aromatic substances and cinnamene, linalool, citronellol, β-damascenone, isoamyl ethanoate, benzylcarbinyl acetate, isobutyl acetate, etc. We suggest that simultaneous fermentation of S. crataegensis YC30 with S. cerevisiae might represent a novel strategy for the future production of Vidal icewine.

In the food industry, microbiological safety is a major concern. Mycotoxin patulin represents a potential health hazard, as it is heat-resistant and may develop at any stage during the food chain, especially in apple-based products, leading to severe effects on human health, poor quality products, and profit reductions. The target of the study was to identify and characterize an excellent adsorbent to remove patulin from apple juice efficiently and to assess its adsorption mechanism. To prevent juice fermentation and/or contamination, autoclaving was involved to inactivate bacteria before the adsorption process. The HPLC (high-performance liquid chromatography) outcome proved that all isolated strains from kefir grains could reduce patulin from apple juice. A high removal of 93% was found for juice having a 4.6 pH, 15° Brix, and patulin concentration of 100 μg/L by Lactobacillus kefiranofacien, named JKSP109, which was morphologically the smoothest and biggest of all isolates in terms of cell wall volume and surface area characterized by SEM (Scanning electron microscopy) and TEM (transmission electron microscopy). C=O, OH, C–H, and N–O were the main functional groups engaged in patulin adsorption indicated by FTIR (Fourier transform–infrared). E-nose (electronic nose) was performed to evaluate the aroma quality of the juices. PCA (Principal component analysis) results showed that no significant changes occurred between control and treated juice.

As natural occurring antimicrobial substances, phenolic compounds have been used to inhibit various bacteria. Stenotrophomonas maltophilia 4–1, a strain isolated from food, exhibited spoilage potential in vitro with proteolysis and lipolysis at 25°C. The present study evaluated the antibacterial properties of 13 polyphenols on S. maltophilia 4–1, and selected 6 compounds (ferulic acid, p-coumaric acid, caffeic acid, chlorogenic acid, (−)-epigallocatechin, and phloretin) for binary combination treatments. The results revealed that antibacterial activities of polyphenols were structure-dependent, and cinnamic acid showed strong inhibitory effects, with a minimum inhibitory concentration (MIC) of 0.125 mg/mL. Importantly, we did not observe any obvious synergistic effects across all binary combinations. The antibacterial mechanism of cinnamic acid was related to membrane damage, caused by the loss of cell membrane integrity and alteration of cell morphology. These findings suggest that cinnamic acid is a promising candidate for the control of spoilage bacteria in food.

Constructing MOFs-composite catalyst with satisfactory catalytic efficiency as well as low cost still presents a major challenge. In this work, a low-cost modular photocatalyst with controllable activity is facilely fabricated by embedding ZIF-8 nanocrystal clusters with ammonium tetrathiomolybdate (ATTM) (donated as ZIF-MS). The embedded ATTM molecules can not only serve as photocatalytic sites but also alter the nucleation and morphology of the resulted ZIF-MS, showing controllable activity for catalytic application. Under the optimized proportion of precursors, 576.52 nm ZIF-MS nanocrystal cluster composed of 24.70 nm grain, showing high activity and size selectivity for the photocatalytic degradation of environmental pollutants, was obtained. The combination of size-selectivity of structure-tunable ZIFs with high photocatalytic activity of embedded noble-free inorganic photocatalytic agent makes these ZIF-MS ideal candidates for photocatalytic applications. Keywords: Ammonium tetrathiomolybdate, MOFs, Photocatalysis, Controllable catalyst, Size-selectivity

Alicyclobacillus acidoterrestris is a major putrefying bacterium that can cause pecuniary losses in the global juice industry. Current detection approaches are time-consuming and exhibit reduced specificity and sensitivity. In this study, an immunoproteomic approach was utilized to identify specific biomarkers from A. acidoterrestris for the development of new detection methods. Cell surface-associated proteins were extracted and separated by 2-D (two-dimensional) gel electrophoresis. Immunogenic proteins were detected by Western blot analysis using antisera against A. acidoterrestris. Twenty-two protein spots exhibiting immunogenicity were excised and eighteen of the associated spots were successfully identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF MS). These proteins were observed to be involved in energy and carbohydrate metabolism, transmembrane transport, response to oxidative stress, polypeptide biosynthesis, and molecule binding activity. This is the first report detailing the identification of cell surface-associated antigens of A. acidoterrestris. The identified immunogenic proteins could serve as potential targets for the development of novel detection methods.

The antioxidant capacity (AC) and antioxidant activity (AA) of three flavonols (FLV), aglycones and their glycosylated derivatives were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays in various solvents. Findings confirmed that the glycosylation at the 3-position (3-glycosylation) always decreased the AC under most conditions due to substitution of the 3-position hydroxyl group and glycoside disruption in the molecular planarity. The 7-glycosylated derivatives did not have the above effects, thus generally exhibited ACs similar to their aglycones. Glycosylation decreased the AA of kaempferol and isorhamnetin for both assays in methanol, 3-glycosylation inhibited quercetin AA in the ABTS assay. In the DPPH assay, the AA of 3-glycosylated quercetin was significantly higher than quercetin. Using LC–MS/MS analysis, we found that quercetin and quercetin-7-glucoside underwent dimerization during the antioxidant reaction, potentially leading to a decline in AAs. However, 3-glycoside substitution may have hindered dimer formation, thereby allowing the FLVs to retain strong free radical scavenging abilities.

Penicillium expansum, as a main postharvest pathogen of fruits, can secrete patulin (PAT), causing fruit decay and health problems. In this study, the antifungal test, SEM (scanning electron microscope) observation, transcriptional profile, PAT biosynthesis, and physiological characters of P. expansum exposed to cinnamaldehyde and citral combination (Cin/Cit) were evaluated. Cin/Cit could inhibit the mycelial growth and spore germination of P. expansum in a dose-dependent manner. Besides, Cin/Cit caused spores and mycelia wrinkled and depressed by SEM observation. Gene expression profiles of P. expansum were conducted by RNA sequencing (RNA-seq) in the presence or absence of Cin/Cit treatment. A total of 1713 differentially expressed genes (DEGs) were obtained, including 793 down-regulated and 920 up-regulated genes. Most of the DEGs participated in the biosynthesis of secondary metabolites, amino acid metabolism, and oxidation-reduction process, etc. Cin/Cit induced the dysfunction of the mitochondrial membrane, causing the potential influence on energy metabolism and reactive oxidative species production. The changes of superoxide dismutase (SOD) and catalase (CAT) activities combing with the increase of hydrogen peroxide content indicated the oxidative stress on P. expansum induced by Cin/Cit, which corresponded well with the transcriptional results. Moreover, both the RNA-seq data and the qRT-PCR showed the remarkable down-regulation of genes included in the PAT biosynthetic pathway under the Cin/Cit treatment. These findings provided more useful information about the antifungal mechanism of Cin/Cit against P. expansum at molecular and gene levels and suggested that Cin/Cit is a potential candidate to control P. expansum.