It is of great importance to accurately assess the safety risk of chemical contaminants in meat products as one of the causes of food safety problems, which could provide a basis for food safety supervision. Considering the advantages and disadvantages of the existing risk assessment methods, a risk assessment method of chemical contaminants in meat products based on the improved matter-element extension model was proposed, which takes into account the maximum limit of each contaminant and the statistical distribution pattern of sampling results, and selects the detection rate, failure rate, failure degree, mean contents and coefficient of variation of contaminants as risk evaluation indexes. In addition, the weight of each evaluation index was determined by introducing the best-worst method, and the risk level of each contaminant was determined from the asymmetric closeness calculated based on the improved matter-element extension model. Moreover, a case study was conducted with the sampling results of five food additives and four heavy metal elements in meat products in a certain province of China in 2018, and a comparative experiment was conducted with the commonly used Nemerow index evaluation method. The results of both methods showed basically identical rank order of the nine chemical contaminants, and the results of the method developed in this study were distributed at level I–V, while those of the Nemerow index method were concentrated at level III–V. Our method can effectively highlight the difference in the risk of different contaminants, and the results from it comply more with reality, which provide a scientific basis for the development of pollutant sampling plans and the optimization of detection resources.

To investigate the effects of different slaughter ages on the meat quality, intramuscular fat content and muscular long-chain fatty acid content of the Longissimus dorsi (LD) muscle of Xianan cattle (Bos taurus), newborn, 12-month-old and 24-month-old Xianan cattle (three bulls of each age with similar body mass) were slaughtered to measure meat quality indexes of Longissimus dorsi including pH, cooking loss, drip loss and shear force. Oil red O stained sections were prepared and examined. Triglyceride (TG) levels and intramuscular fat content were detected, and the composition of medium-chain and long-chain fatty acids in the muscle was analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that the pH of the LD of 12-month-old cattle was significantly higher than that of newborn cattle (P < 0.05), and the cooking loss of the LD of newborn cattle was significantly higher than that of 24-month-old cattle (P < 0.05). The linoleic acid content in the LD of 24-month-old cattle was significantly higher than that in newborn and 12-month-old cattle (P < 0.01). The arachidonic acid content in the LD of cattle aged 12 and 12 months was significantly higher than that in newborn cattle (P < 0.05). The total polyunsaturated fatty acid (PUFA) content in the LD of 24-month-old cattle was higher than that in newborn and 12-month-old cattle. In this study, there were no significant differences in the drip loss and shear force of the LD among cattle of different ages. In terms of intramuscular fat content and long-chain fatty acid composition, it is suggested that the meat of 24-month-old cattle is more in line with human health standards.

Litsea cubeba essential oil (LCEO) has attracted wide attention as a natural antibacterial material due to its advantages of high safety, no drug resistance and broad-spectrum antibacterial activity. The purpose of this study was to investigate the antibacterial activity of LCEO against Penicillium italicum in citrus fruits and its mechanism. The minimum inhibitory concentration (MIC) of LCEO, and its influence on the mycelial growth, spore germination, release of cell components, extracellular pH and electrical conductivity of Penicillium italicum were determined after LCEO treatment. The changes of the surface morphology of Penicillium italiana mycelia caused by LCEO were observed by scanning electron microscopy (SEM), and the integrity of the spore membrane was detected by propidium iodide (PI) staining. The disease incidence and lesion diameter in citrus fruits infected with Penicillium italicum were determined. The MIC of LCEO against Penicillium italicum was 1.17 mg/mL. LCEO could significantly inhibit the mycelial growth and spore germination of Penicillium italicum, and the inhibition rates of mycelial growth and spore germination were (88.17 ± 0.30)% and (97.78 ± 0.30)% after 1 000 mg/L LCEO treatment, respectively. With an increase in LCEO concentration, the extracellular conductivity and extracellular pH of Penicillium italicum increased gradually, and the leakage of nucleic acid became more serious. SEM observation showed the mycelial linearity was lost, and irreversible morphological changes such as distortion, shrinkage and shriveling appeared on the mycelial surface after LCEO treatment. The higher the concentration of LCEO, the more serious the damage to the integrity and permeability of Penicillium italicum mycelia. The results of PI staining showed that the integrity of the cell membrane of the spores was damaged. In addition, the in vivo experiments showed that the disease incidence and lesion diameter of LCEO-treated citrus fruits decreased significantly compared to the untreated control group (P < 0.05), and the best effect was observed at 4 800 mg/L concentration. LCEO could effectively inhibit the spread of Penicillium italicum in citrus fruits, and it had a good control effect on citrus blue mold.

In order to explore the biological functions of active ingredients in dried ginger, high performance liquid chromatography (HPLC) and mass spectrometry (MS) with selective reaction monitoring/multi-reaction monitoring (SRM/MRM) were used for qualitative and quantitative analysis of active ingredients in dried ginger. The antioxidant and uric acid-lowering activities of dried ginger extract and its active components were determined. The results showed that the most abundant phenylpropanoid components in dried ginger extract were phenylalanine, ferulic acid and p-coumaric acid. All these compounds had significant antioxidant capacity in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging capacity and ferric ion reducing power, and the decreasing order of the antioxidant capacity was ferulic acid > dried ginger extract > p-coumaric acid. In vitro xanthine oxidase inhibition assay showed that all the three drugs had strong uric acid lowering activity, the effect of p-coumaric acid being more pronounced than that of ferulic acid and dried ginger extract. Molecular docking revealed that ferulic acid and p-coumaric acid inhibited xanthine oxidase by the formation of hydrogen bonds, van der Waals force and π-π stacking with amino acid residues in the enzyme. In this study, ferulic acid, p-coumaric acid and ginger extract have good antioxidant capacity and xanthine oxidase inhibitory activity in vitro, and therefore have the potential to be developed into new uric acid-lowering products.

In order to explore the effect of alternating electric field (AEF) assisted freezing on energy metabolism in beef during thawing and aging, bovine Longissimus dorsi muscle samples were assigned to three groups: direct aging at 4 ℃ (control), thawing and then aging at 4 ℃ after 30 days of freezing at −18 ℃ (FA), and thawing and then aging at 4 ℃ after 30 days of AEF assisted freezing −18 ℃ (EA). The changes of muscle pH, adenosine triphosphate (ATP) content, glycogen content, lactic acid content, lactate dehydrogenase activity, hexokinase activity and Ca2+-ATPase activity were analyzed during the aging process. The results showed that as aging time increased, the pH of the OA group initially increased, then decreased and finally increased again, reaching the ultimate pH at the third day of aging. The pH of the FA and EA treatment groups remained relatively constant during aging. For all groups, there was a decreasing trend in ATP content. The ATP content of the OA group decreased from 7 245.43 to 752.38 µmol/g after seven days of aging. The ATP content of the EA group was significantly lower than that of the OA group on day 0 of aging (P < 0.05). The muscle glycogen contents in the FA and EA groups were significantly lower than that in the control group during the entire aging process (P < 0.05), and the lactic acid content, and hexokinase and lactate dehydrogenase activities decreased significantly with aging time (P < 0.05). On day 5 of aging, the glycogen and lactate contents, and lactate dehydrogenase activity in the EA group were significantly lower than those in the FA group (P < 0.05), and the activity of Ca2+-ATPase was significantly higher than that in FA group (P < 0.05), indicating that alternating electric field can accelerate the process of energy metabolism. In conclusion, aging after freezing and thawing can prolong the stiffening time of beef, and AEF assisted freezing effectively can promote energy metabolism, thus improving muscle quality. These findings may provide a basis for the development of new storage and preservation technologies for meat products.

This study investigated the effect of freezing ball milling treatment on the structure, properties and digestibility of waxy rice starch, prepared by alkaline extraction. The effects of treatment time on the particle size distribution, microstructure, crystalline structure, short-range ordered structure, pasting properties, thermodynamic properties and digestibility of waxy rice starch were examined. The results showed that after freezing ball milling treatment, the integrity of starch granules was damaged with cracks appearing on the surface, the particle size tended to increase, and the crystalline structure and short-range ordered structure were severely damaged. The water absorption index increased from 2.15 to 7.31 g/g, and the cold water solubility and swelling power increased significantly from 2.97% and 3.25% to 46.33% and 15.50%, respectively in the 80 min ball milling group compared with untreated samples (P < 0.05). The enthalpy change (ΔH) decreased from 9.33 to 1.79 J/g, and the degree of gelatinization significantly increased (P < 0.05). The birefringence of the starch gradually disappeared with increasing treatment time. The rapidly digestible starch (RDS) content of waxy rice starch increased significantly (P < 0.05), while the contents of resistant starch (RS) and slowly digestible starch (SDS) decreased significantly (P < 0.05). This study provides basic data and references for the production of modified starch products with novel structures and properties.

Bovine β-Lactoglobulin (BLG) induces severe cow’s milk allergy. This research investigated the effect of ultrasound-assisted luteolin (LUT) treatment on the structure and allergenicity of BLG. The structure of the treated BLG was characterized by Fourier transform infrared (FTIR) spectroscopy, circular dichroism (CD) spectroscopy, ultraviolet (UV) absorption spectroscopy and fluorescence spectroscopy, and its allergenicity was evaluated by enzyme-linked immunosorbent assay (ELISA) and cell experiments. It was found that the major interaction force between BLG and LUT was hydrophobic interaction both before and after ultrasonic treatment. Ultrasound-assisted LUT treatment significantly altered the secondary and tertiary structures of BLG, and reduced the IgE-binding ability and the release of interleukin-6, interleukin-4 and histamine from KU812 cells. Therefore, ultrasound-assisted LUT treatment changes the conformational epitope of BLG, reducing its allergenicity, and the best effect can be achieved by secondary ultrasound-assisted LUT treatment.

The inactivation effect of plasma spray reactor on Zygosaccharomyces rouxii in apple juice was studied as a function of plasma discharge voltages, gas flow rate and liquid flow rate, and the morphological changes of the cells and the effect of this treatment on apple juice quality were evaluated. In this study, a plasma spray reactor was used to treat 0.5 L of apple juice for 30 min at a discharge voltage of 21 kV, a gas flow rate of 150 L/h, and a liquid flow rate of 9.0 L/h. The number of osmotolerant yeast cells in apple juice decreased significantly. Plasma spray reactor treatment caused cell rupture, thus resulting in the inactivation of yeast cells. Under the optimal parameters, this treatment increased the pH of apple juice slightly, but did not cause any significant changes in the titratable acid or reducing sugar concentration (P > 0.05) and resulted in no significant changes in the major major volatile compounds in apple juice. This study may provide a reference for the application of plasma spray reactor in apple juice processing.

The effects of different preparation techniques (aqueous enzymatic extraction, aqueous extraction, cold pressing, hot pressing and organic solvent extraction) on the physical and chemical properties, nutritional components and oxidation stability of tiger nut oil from the cultivar ‘Zhongyousha 1’ grown in Xinjiang were investigated. The results showed that organic solvent extraction gave the highest extraction rate (88.31%), and there were significant differences in the physicochemical properties of tiger nut oils prepared by different processes (P < 0.05). Oleic acid accounted for 76.04% of the total fatty acids in the oil prepared by aqueous extraction, which was 1.72–2.34 percentage points higher than that obtained with other preparation processes (P < 0.05). Different preparation techniques had significant effects on the lipid concomitant content and oxidation stability of tiger nut oil (P < 0.05). The oil obtained by organic solvent extraction had the highest contents of tocopherol (370.67 mg/kg), total phenol (168.59 mg/100 g) and phytosterol (271.26 mg/100 g), while the content of squalene was highest (162.04 mg/kg) in the oil obtained by aqueous extraction. The cold pressed oil had the highest oxidation stability index (24.15 h) indicating good oxidation stability. Correlation analysis indicated that the oxidation stability of tiger nut oil was positively correlated with unsaturated fatty acid and oleic acid (r = 0.72, r = 0.48), and the antioxidant capacity (1,1-diphenyl-2-picrylhydrazyl and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging rate) of polar components was significantly positively correlated with total phenol content (r = 0.91, r = 0.96, P < 0.05). The results of principal component analysis (PCA) revealed that the cold pressed oil was similar to the oil obtained aqueous enzymatic extraction, while the oils prepared by organic solvent extraction, hot pressing and aqueous extraction were differentiated well. These results can provide a theoretical basis for the development of high-quality tiger nut oil.

In order to improve the small intestinal digestibility of rice analogues (RA) and to enhance the nutritional value of the product, rice and potato flour blends were used as raw materials to prepare RA by direct extrusion modification using chemical or biological modifiers combined with high-temperature puffing. The internal structure and nutritional characteristics of RA were analyzed. The results showed that potato starch and amylase enhanced the digestive resistance of RA. The tested chemical modifiers mainly affected the structure and physicochemical properties of starch, in turn increasing the apparent viscosity and decreasing the degree of hydrolysis and digestibility of RA. Octenylsuccinic anhydride (OSA) played a promoting role in the initial stage of intestinal digestion. Propylene oxide (HPPO) reduced the particle size and increased the storage modulus (G’) of RA. Sodium trimetaphosphate (STMP) increased the particle size and G’ of RA. α-Amylase promoted the decomposition of large particles, led to even distribution of proteins on the surface of particles, and inhibited digestion. High-temperature expansion promoted starch decomposition in the early stage of intestinal digestion. Digestion results showed that the combinatorial effect of extrusion modification and high-temperature puffing weakened the film-forming capability of potato starch, which effectively inhibited the decomposition of the starch and weakened the digestive reaction when it just entered the intestine.

Resistant dextrin (RD) prepared from corn starch by different processes vary in structure and physicochemical properties and in turn resistance to human digestive enzymes. In this research, the solubility, bond structure, digestibility and morphological structure of RD prepared by three different processes (dry heating, α-amylase, and α-amylase combined with transglycosidase) were characterized so as to explore the relationship between the quality of RD and preparation processes. The results showed that the solubility of all samples prepared was close to 100%, the water activity was less than 0.3, and the stability was good. Further strengthening the reaction conditions changed the structure of RD, resulting in the hydrolysis of α-1,4 bonds to form α-1,6, α-1,2, and β-1,6 bonds, which are the basis for digestive enzyme resistance, and the branching structure of the resulting product was mainly linked by α-1,6 and β-1,6 bonds. The enzymatic treatment changed the starch molecules from an ordered crystal structure to a disordered one, decreasing the crystallinity. After adding transglycosidase, the average branching degree (DB) increased up to 55%, and the resistance to human digestive enzymes was strongest. The results of scanning electron microscopy (SEM) and gel permeation chromatography (GPC) showed that after adding the two enzymes, repolymerization of RD occurred, the molecular weight decreased and the molecular volume increased at the same time, and gaps were formed in the molecules. This study may provide a new idea for researchers engaged in the production of RD with higher quality.

To investigate the effect of low voltage electrostatic field combined with high humidity thawing on the water-holding capacity of frozen lamb meat, lamb hindleg meat after 24 h of postmortem aging was frozen in a refrigerator at −18 ℃ for 24 h and then thawed. The effects of low voltage electrostatic field combined with high humidity thawing (current of 0.2 mA, voltage of 2 500 V, 4 ℃, and relative humidity of 98%) on the thawing rate, water retention, moisture distribution, carbonyl content, total sulfhydryl content, solubility, surface hydrophobicity, protein secondary structure and protein tertiary structure of lamb meat were evaluated in comparison with those of another three thawing methods: refrigerator thawing (4 ℃, and relative humidity of 55%), low voltage electrostatic field assisted thawing (current of 0.2 mA, voltage of 2 500 V, 4 ℃, relative humidity of 55%), and high humidity thawing (4 ℃, and relative humidity 98%). The results showed that among the four thawing methods, low voltage electrostatic field combined with high humidity thawing had the shortest thawing time (519 min), the lowest thawing loss (3.37%), cooking loss (30.60%), carbonyl content (3.85 nmol/mg) and surface hydrophobicity (21.90 μg), relative content of immobilized water (97.96%) closest to that of fresh meat (98.44%), the highest total sulfhydryl content (28.55 nmol/mg) and solubility (29.98%), and the most stable protein secondary and tertiary structures, indicating that this thawing method shortened the thawing time, effectively inhibited protein oxidative denaturation, and reduced the juice loss, and myofibrillar proteins from the treated lamb meat had the highest water hydration capacity and the best water-holding capacity.

Objective: To investigate the protective effects of mannan oligosaccharide (MOS) and partially hydrolyzed guar gum (PHGG) on liver injury induced by long-term alcohol intake in mice. Methods: Mice were randomly divided into control (Ctrl), model (EtOH), positive control (PC, silymarin at 86 mg/(kg·d)), MOS intervention (2 000 mg/(kg·d)) and PHGG intervention (2 000 mg/(kg·d)) groups. A Lieber-DeCarli model of chronic alcoholic liver injury (ALD) was established in this study. After five weeks of feeding, the levels of liver function, oxidative stress and inflammatory factors were measured. Hematoxylin-eosin (HE) staining and oil red O (ORO) staining were used to observe hepatic histopathological alterations. The mRNA and protein expression levels of ileal tight junction proteins (zonula occludens-1 and occludin) were detected by real-time fluorescence quantitative polymerase chain reaction (qPCR) and immunofluorescence staining, respectively. The hepatic lipopolysaccharide (LPS) level was quantitatively determined by enzyme-linked immunosorbent assay (ELISA). Besides, the contents of acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid and caproic acid in fecal samples were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). Results: Supplementation of MOS and PHGG could significantly attenuate hepatic steatosis, lipid accumulation, oxidative stress and inflammation induced by long-term ethanol exposure. Additionally, compared with the EtOH group, MOS and PHGG intake markedly improved liver function and intestinal barrier function, inhibited intestinal LPS leakage, and increased intestinal short-chain fatty acids (SCFAs) levels. Conclusion: Guar gum-derived MOS and PHGG could effectively alleviate chronic ALD in mice by enhancing intestinal integrity and regulating intestinal SCFA levels.

Objective: The effect of tea seed saponin (TSS) combined with aerobic exercise (AE) on lipid metabolism and oxidative stress in mice on a high-fat diet (HFD) was investigated. Methods: Mice were randomly divided into a normal group and a model group. The normal group was fed on a maintenance diet and the model group on the HFD to establish an obesity model. After successful modeling, the mice were further divided into an HFD group, an HFD + TSS group, an HFD + AE group and an HFD + TSS-AE group. The levels of serum lipid metabolism and oxidative stress were determined by commercial kits. Hepatic steatosis was observed by hematoxylin-eosin (HE) staining. The protein levels of adenosine 5’-monophosphate (AMP)-activated protein kinase (AMPK), phosphorylated AMPK (p-AMPK), silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor γ coactlvator 1α (PGC-1α) and peroxisome proliferators-activated receptors γ (PPAR-γ) were detected by Western blot. Results: TSS combined with AE treatment significantly reduced body mass and subcutaneous, epididymal, perirenal and abdominal fat indexes in HFD mice (P < 0.05) and improved blood lipid disorders. The serum levels of total cholesterol (TC), triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) were, respectively, reduced by 27.80%, 75.15%, 78.36% in the HFD + TSS + AE group compared with the HFD group. Hepatic steatosis was significantly improved in the HFD + TSS, HFD + AE and HFD + TSS-AE groups in comparison with the HFD group. The expression level of hepatic p-AMPK was increased by 64.19%, 2.12 times and 2.64 times, SIRT1 by 47.01%, 1.48% and 67.02%, PGC-1α by 2.03 times, 62.93% and 2.10 times, and PPAR-γ in skeletal muscle by 64.08%, 2.12 times and 3.34 times, respectively. After treated by TSS and AE, the serum and liver levels of superoxide dismutase (SOD) and glutathione (GSH) were increased in HFD mice, and serum malondialdehyde (MDA) levels were decreased. Conclusion: TSS combined with AE can reduce fat accumulation and improve lipid metabolism disorders and oxidative stress induced by HFD in mice.

In this study, the structure of a water-soluble polysaccharide named PCP-W from the P. citrinopileatus mycelia was investigated by high performance size exclusion chromatography (HPSEC) and infrared (IR) spectroscopy. To evaluate the in vivo hypoglycemic effect of PCP-W, the fasting blood glucose level, glucose tolerance and fasting insulin level in mice with type 2 diabetes were measured after gavage administration of PCP-W for eight weeks, the quantitative insulin sensitivity check index (QUICKI) was calculated, and the levels of serum lipids and oxidative stress and the activities of hepatic hexokinase (HK) and pyruvate kinase (PK) were detected. The results showed that the molecular mass of PCP-W, containing D-glucopyranose units, was 5 238 Da. PCP-W was composed of mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose and fucose in a molar ratio of 0.003: 0.010: 0.011: 0.015: 0.001: 0.944: 0.013: 0.001. After eight weeks of treatment with PCP-W, the fasting blood glucose level was reduced, the glucose tolerance was improved, the fasting insulin level was increased, and QUICKI was improved in diabetic mice significantly (P < 0.01). In addition, lipid metabolism and oxidative stress levels were improved, and the activities of PK and HK were increased (P < 0.01). Therefore, PCP-W has the potential to act as a hypoglycemic agent.

Iron deficiency anemia (IDA) is a common iron deficiency disease. IDA has become one of the major public health problems worldwide. Our previous studies have shown that Auricularia auricula melanin (AAM) can alleviate IDA, but the mechanism is not clear. In this study, the role of the intestinal microflora in the improvement of IDA by AAM was studied by elimination of gut bacteria using an antibiotic cocktail as well as using metabonomics. The results showed that AAM treatment significantly alleviated anemia symptoms of IDA mice in terms of body mass, hemoglobin concentration, hematocrit, mean erythrocyte volume and platelet count, and this effect was lost when the intestinal flora was eliminated. Totally 76 differential metabolites were identified by metabolnomics analysis. Pathway enrichment analysis identified seven pathways including tryptophan metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, ascorbic and uronic metabolism, glutathione metabolism, tyrosine metabolism, pentose and glucuronate interconversion and steroid hormone biosynthesis. Among these, tryptophan metabolism was most significant. In the presence of intestinal microflora, tryptophan metabolites such as 5-hydroxyindole acetic acid and N-formyl kynurenine were significantly accumulated in IDA mice supplemented with AAM, indicating that AAM could mitigate IDA, which may be related to activation of tryptophan metabolism through the intestinal flora. This study may provides a theoretical basis for further research on the mechanisms by which AAM improves IDA and for the development of anti-IDA products.

In order to investigate the molecular mechanism behind the anti-inflammatory effect of Camellia fascicularis polyphenols (CFP), the anti-inflammatory activity of CFP was evaluated using the zebrafish model and the polyphenol composition was analyzed using ultra-performance liquid chromatography combined with quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Then, the targets of effective ingredients and inflammation-related targets were predicted using the SwissTargetPrediction and DisGeNET databases. The protein-protein interaction (PPI) network was constructed, and gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed using the STRING and DAVID databases. Furthermore, molecular docking and visualization of key components and core proteins were performed using the AutoDockTools and PyMOL software. The results showed that 21 phenolic compounds were identified from Camellia fascicularis and 32 intersection targets were selected. The GO function and KEGG pathway enrichment analysis indicated that CFP exerted anti-inflammatory effects by acting on core targets as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), prostaglandin-endoperoxide synthase 2 (PTGS2) and matrix metallopeptidase 2 (MMP2) through biological processes including positive regulation of cell proliferation, cytoplasm, adenosine triphosphate (ATP) binding, and in turn regulating signaling pathways like arachidonic acid metabolism, hypoxia inducible factor-1 (HIF-1) signaling pathway and platelet activation. Molecular docking results demonstrated excellent binding activity between the key components in CFP and inflammation-related targets. The research could provide a theoretical reference for the development of anti-inflammatory products with polyphenol components of C. fascicularis.

The effect of cold plasma on the composition and diversity of apple surface fungi and endophytes in cold storage was analyzed by high-throughput sequencing. Microbial co-occurrence networks were constructed. The results showed that cold plasma significantly inhibited the elevation of the α diversity of apple surface fungal communities and affected their composition during cold storage, but there were no significant effects of cold plasma on apple endophytic communities. The predominant fungi on the apple surface were unidentified (52.76%), Penicillium (14.70%), Aspergillus (13.80%) and Acremonium (8.33%). Cold plasma reduced the relative abundance of potentially harmful postharvest fungi on the surface of apples such as Penicillium, Aspergillus and Acremonium. The dominant endophytic bacteria of apples were unidentified (80.78%), Staphylococcus (4.23%) and Bacillus (3.13%). Cold plasma decreased the relative abundance of endophytic Staphylococcus, Bacillus and Corynebacterium. The dominant endophytic fungi of apples were unidentified (30.69%), Rhizopus (18.15%), Lysurus (6.56%), Aspergillus (4.38%) and Cutaneotrichosporon (3.26%). Cold plasma caused a significant decrease in the relative abundance of Zygosaccharomyces, Mortierella and Penicillium. The symbiotic networks of surface fungi and endophytic bacteria of ‘Golden Delicious’ apples were more complex, with more key nodes and complex correlations between nodes. Cold plasma could affect the co-occurrence networks of surface fungi and endophytic bacteria, simplifying their structures. But the co-occurrence network of endophytic fungi was simple in structure with less connectivity between nodes.

The present research was undertaken in order to study the effect of exogenous fructose treatment on postharvest softening of apricot fruits. ‘Saimaiti’ apricots were subjected to osmotic treatment in 300 mmol/L fructose solution at 0.05 MPa for 2 min followed by normal pressure for another 5 min before storage at (0 ± 1) ℃. Distilled water was used as control treatment. Fruit hardness, cell membrane permeability, water soluble pectin (WSP), chelate soluble pectin (CSP), Na2CO3 soluble pectin (NSP) and cellulose contents, and polygalacturonase (PG), pectin methyl esterase (PME), β-galactosidase (β-Gal) and cellulase (CEL) activities were determined every seven days during storage, and cell ultrastructure was observed by transmission electron microscopy (TEM). The results showed that exogenous fructose treatment could significantly inhibit the activity of cell wall degrading enzymes and maintain the contents of CSP, NSP, and cellulose, thereby inhibiting the degradation of the cell wall. On day 49 of storage, compared with the control group, the contents of CSP, NSP and cellulose in fructose-treated apricot fruits increased by 31.30%, 10.58%, and 14.30% (P < 0.05). The WSP content and cell membrane permeability of the control group were 1.09 and 1.25 times as high as those in the control group, respectively. Furthermore, this treatment maintained the integrity of organelles and the membrane system, and effectively delayed the decline in fruit hardness.

The purpose of this study was to investigate the effect of carboxymethyl chitosan (CMCS)-induced culture of Cryptococcus laurentii treatment on the resistance to Penicilium italicum in postharvest grapefruits. ‘Rio Red’ grapefruits were dipped in distilled water as a control, CMCS solution, C. laurentii suspension or CMCS-induced C. laurentii suspension. The biocontrol efficacy against green mold and phenylpropane metabolism in the treated grapefruits were analyzed. The results showed that the CMCS-induced C. laurentii treatment significantly reduced the disease incidence and lesion expansion of P. italicum in grapefruits (P < 0.05). CMCS-induced C. laurentii treatment induced an increase in the activities of phenylalanine ammonia lyase (PAL), cinnamic acid 4-hydroxylase (C4H), 4-coumaric acid coenzyme A ligase (4CL), polyphenol oxidase (PPO), peroxidase (POD), β-1,3-glucanase (GLU), and chitinase (CHI), and the contents of total phenols, flavonoids and lignin compared to the control group. Therefore, CMCS can induce increased biocontrol efficacy of C. laurentii. CMCS-induced C. laurentii can enhance the resistance to Penicilium italicum in postharvest grapefruits by increasing phenolpropane metabolism and resistance substance contents, and its effect is more pronounced than those of CMCS and C. laurentii.

As an antioxidant and broad-spectrum antibacterial agent, thymol has some disadvantages such as poor solubility, low stability and strong irritating odor, restricting its application in food preservation. In order to overcome these shortcomings, thymol-containing microcapsules were prepared by the saturated aqueous solution method using thymol as the core material and β-cyclodextrin as the wall material, and the sustained release performance, antibacterial and antioxidant capacity of the microcapsules were evaluated. Meanwhile, its structure was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric (TG) analysis, and its efficacy in preserving strawberry quality was analyzed. The results showed that thymol was successfully embedded in β-cyclodextrin and the thermal stability of the microcapsules was significantly improved. The maximum cumulative amount of thymol released from the microcapsules was 41.16% after 360 min. When used at a dosage of 25 mg, the microcapsules had the strongest antibacterial effect on Escherichia coli and Staphylococcus aureus. At a concentration of 10 mg/mL, it scavenged 81.40% of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The microcapsules reduced the decay incidence and loss rate by 26.34% and 19.63%, respectively on the 10th day of storage compared with the control group, slowed the decrease in hardness and soluble solids content (SSC), and better maintained the appearance, color, texture and flavor. Thymol-containing microcapsules could delay the spoilage, effectively maintain the quality, and prolong the shelf life of strawberry at room temperature.

The sterilization operation in food production is a key process to ensure the safety of food products, and most existing technologies for food sterilization utilizes thermal and/or non-thermal effects. Conventional heat sterilization requires a heat transfer medium, which is completed in a certain period of time at a certain temperature. Electric field processing, a non-conventional food processing technology which utilizes both thermal and non-thermal effects, can reduce the effective temperature threshold and time of conventional heat sterilization, thereby better retaining the nutritional value of foods with less impact on the sensory quality, flavor and color. This paper reviews the principles of ohmic heating sterilization, high-voltage pulsed electric field sterilization and induced electric field sterilization as well as the frontiers and progress in these sterilization technologies in the food industry, discusses the characteristics and differences between the current electric field technologies, and presents an outlook on their future development.

Bitter compounds widely exist in foods and have an important impact on food flavor. The major bitter compounds in foods include amino acids, peptides, polyphenols, alkaloids, and inorganic salts. Bitterness is perceived through binding between bitter compounds and the specific sites of the 25 human bitter taste receptors (hTAS2Rs), which further activates the downstream signal pathway mediated by G protein, converting chemical signals into electrical signals and transmitting them to the brain. Some foods with strong bitterness taste are not well accepted by consumers, so appropriately reducing bitterness in foods can improve consumers’ preference. At present, there are two main methods to reduce the perception of food bitterness: 1) masking bitterness by polymerization/complexation or flavor interaction, and 2) removing bitterness by reducing the content of bitter compounds or changing their structure. In this paper, the bitter compounds in foods, the analytical methods for them, the mechanism of bitterness perception and the methods used to reduce bitterness perception are reviewed in an effort to provide theoretical guidance for food bitterness regulation.

Vinegar is an acidic condiment with a unique taste and fragrance, which is produced by microbial fermentation. Vinegar has rich nutrients and bioactive substances, which can provide a good material basis for the development of functional vinegar. This review summarizes the major progress that has been made in vinegar research in terms of product types, brewing methods, bioactive components and their functional properties in the past decade, and proposes that future development research on functional vinegar should consider the selection and combination of raw materials, the combination and application of microorganisms with customized functions, and the selection of containers and the development of new treatment methods for the aging of vinegar. This review will be helpful for developing new healthy vinegar and novel functional vinegar beverages under the background of ‘One Health’.

The industrial application of free enzyme is limited due to its high cost, poor operational stability and difficult reuse. Immobilization on carrier is an effective way to overcome the limitation. Nanozyme immobilization technology has emerged in the past 10 years, which is an emerging technology with great potential. At present, immobilized enzymes have been widely used in several fields such as food, medical treatment, and environmental treatment. This article systematically summarizes the latest progress in the research and application of immobilized enzymes based on three new nanomaterials (protein-inorganic hybrid nanoflowers, metal organic frameworks and nanogels), comprehensively compares the advantages and disadvantages of the three nanomaterials, analyzes and summarizes their respective applicable enzymes, and finally points out that cascade enzyme immobilization and the development of new immobilized materials are the future trend for the development of immobilized enzymes.

Some serotypes of Escherichia coli (E. coli) such as E. coli O157:H7 can cause serious diseases in humans. Pathogenic E. coli is widespread in primary agricultural products and encounter various environmental stresses during food processing. After a period of adaptation to a weakly acidic environment, it develops an inducible acid tolerance response, which enhances its ability to survive in a strongly acidic environment and may also enhance its resistance to heat, cold, osmotic pressure and antibiotics, posing a great threat to food safety. This article provides an overview of recent progress in research on the inducible acid tolerance response, two-component regulatory system, pH homeostatic system, cell membrane fluidity regulation, macromolecular protection and cross-protection of E. coli, which may provide theoretical guidance for deep understanding of the stress response of E. coli during food processing and for the development of measures for its prevention and control in the future.

Citral is used in the food field because of its lemon-like aroma and antibacterial biological activity. However, due to its sensitivity to acid, oxygen and light, citral is prone to acid-catalyzed cyclization, oxidation and photochemical degradation, reducing its biological activity and consequently limiting its application. Polysaccharide encapsulation is an effective way to improve the physical and chemical stability of citral and delay its degradation. This article reviews the structural properties of citral and its application in food and beverage as a food preservative, summarizes the methods used for encapsulating and stabilizing citral with polysaccharides including emulsion systems, self-assembly, hydrogels and spray drying as well as the current status of the application of these methods to stabilize citral, and finally points out the problems existing in this field and future research directions. This review hopes to provide a theoretical reference for improving the biological activity of citral and expanding its application in the food field.

Metabolic syndrome is a chronic systemic metabolic disorder. The number of patients with this disease is increasing year by year, and its prevalence is affected by age, gender, and dietary habits. Studies have pointed out that metabolic syndrome is closely related to insulin resistance, obesity, oxidative stress, and inflammation. In recent years, it has been found that intestinal flora is closely related to metabolic syndrome through omics methods such as macroeconomics and amplicon sequencing. Probiotics, a strategy to regulate intestinal flora, can improve oxidative stress, reduce the secretion of pro-inflammatory factors, and regulate glucose and lipid metabolism by regulating intestinal flora and its metabolites, thereby alleviating metabolic syndrome. This article systematically summarizes the pathological mechanism of metabolic syndrome and the relationship between intestinal flora and metabolic syndrome, and expounds the key molecular targets and specific signaling pathways by which probiotics mitigate metabolic syndrome. This review hopes to provide a theoretical reference for the development of probiotics as a new strategy for the treatment of metabolic syndrome and the targeted mining of healthy and functional microorganisms with the ability to improve metabolic syndrome.

Acetohydroxy acid synthase (AHAS), a thiamine diphosphate (ThDP)-dependent enzyme, is the key enzyme that catalyzes the first step in the production of branched chain amino acids (BCAA), namely L-valine, L-leucine and L-isoleucine. AHAS is susceptible to feedback inhibition by the end product, BCAA, which inhibits the activity of the enzyme and affects carbon flux to BCAA. Therefore, AHAS is an important target for high-yield production of BCAA, and the modification of AHAS is of great significance. In this review, the structure, catalytic mechanism, and role of AHAS in the BCAA synthesis pathway are introduced. The current research status of the catalytic process of the enzyme and the current molecular modification strategies for AHAS are summarized. Finally, future research directions and modification strategies for the enzyme are proposed.

Deep-frying is a traditional cooking method in China, endowing the product with unique crispy characteristic but also greasiness. High-calorie fried foods can create health risks. Many attempts have been made by researchers to reduce the absorption of oil during the frying process while ensuring the good quality of deep-fried products. This paper reviews the oil-absorbing behavior of deep-fried starch-based products during the frying process and describes several methods to regulate the oil content of deep-fried products. Adding functional ingredients (proteins or starches and a combination of hydrocolloids with the main ingredients of the product) is in line with the current trend of nutritious and low-fat foods. Coating technology, which utilizes natural macromolecules as an oil barrier, has promising applications in the production of low-fat fried foods. In addition, new frying technologies such as vacuum frying, air frying and spray frying are becoming increasingly mature, and can gradually replace traditional frying for the production of low-fat fried products according to the needs of industrial production. All regulatory measures described in this paper can reducing the oil content of different fried products to different degrees, which will provide a scientific and theoretical basis for selecting a suitable measure for oil reduction in different fried starch-based products based on their oil absorption mechanisms, and provide a theoretical reference for the development of low-fat fried products.

Salt content is essential for the quality of aquatic products, especially for the water-holding capacity and textural properties of salted products and the gel properties of surimi-based products. However, the salt content in traditional aquatic products is generally too high to meet consumers’ demand for healthy convenience foods with low salt content. Reducing the salt content will decrease the storage stability, eating quality and processing properties of aquatic products. Therefore, reducing the salt content without sacrificing the quality is an important issue faced by the aquatic product processing industry. The premise and basis of effectively controlling the quality of aquatic products with low salt content is to clarify the effect and mechanism of NaCl on the quality of aquatic products. In the present paper, we review the role of NaCl in the processing and storage of aquatic products and the latest progress of salt reduction technologies from the aspects of NaCl substitution, novel salt reduction technologies, and sodium release/perception enhancement technologies, and we discuss the problems with the processing of salt-reduced aquatic products. The present article may provide valuable information for high-quality processing of lightly salted aquatic products.

Illegal addition has always been a difficult point in the governance of food safety crimes. At present, there has been a high number of criminal cases related to illegal addition, which involve a wide range of criminal objects and a wide variety of additives. According to its manifestation and harmfulness, illegal addition can be divided into ‘prohibited addition’ and ‘restricted addition’. The judicial interpretation No. 24[2021] of the Supreme People’s Court has improved the criminal regulation system for crimes related to illegal food additives, transmitting the concept of scientific regulation and precision crackdown. However, there are still some problems, such as unclear standards for criminal conviction and inconsistent rules for the application of criminal charges. Therefore, we should break the barriers of scientific and technological standards and legal norms between administrative and criminal regulation, make legal fictions based on scientific research, and clearly delimit the boundary between administrative and criminal regulation in a quantitative way on the basis of the fact that the current judicial interpretation is only qualitative. In addition, in the field of criminal regulation, based on the hierarchy, overlap and inclusiveness between articles 140, 143 and 144 of the criminal law, we should further clarify the legal application logic and rules of ‘restricted addition’ and ‘prohibited addition’ cases, as well as cases involving illegal additives whose toxicity is not clear yet.

Deoxyribozymes (DNAzymes), a class of artificial DNA sequences with catalytic activities, have attracted much attention due to their great potential in biosensing. These functional oligonucleotides can not only serve as specific molecular recognition elements, but also report or transduce signals directly through their catalytic activity. In recent years, DNAzyme-based biosensing technology is developing rapidly in the field of food safety. This article provides an overview of catalytic mechanism and biosensing strategy of DNAzymes, and reviews their progress in rapid detection for food safety, with a focus on the scientific literature in the past three years. Finally, we discuss possible future trends and directions of this biosensing technology in the analysis and detection of food samples.

As a key link in the management of grain storage, quality inspection and evaluation has always been a hot research field of much concern among researchers. It plays a vital role in ensuring safe storage and product processing of grain. In order to better carry out relevant work in the future, this paper reviews the progress in research on conventional methods for the detection and evaluation of stored grain quality based on optical, acoustic, dielectric, physicochemical properties and volatile substances, and it also summarizes the application of the current new detection techniques such as strong magnetic field, laser-induced breakdown spectroscopy, nuclear magnetic resonance spectroscopy and scanning electron microscopy in the quality evaluation of stored grains. In addition, it compares and analyzes and the advantages and disadvantages of these techniques. This review concludes with an outlook on future research directions.

Color is one of the most important sensory quality indexes of fermented meat products. Addition of nitrite makes traditional fermented meat products have a good color. However, nitrite can be transformed to N-nitrosamine in the human body, which is a potential carcinogen and can cause health problems. Therefore, it cannot meet the green and safety requirements in food manufacturing. In recent years, the chromogenic effect of microorganisms has been discovered and excavated, indicating the potential to replace nitrite in fermented meat products. In this review, the color conversion mechanism of fermented meat products is introduced in detail, and recent progress in research on the chromogenic mechanism of microorganisms is summarized. The important functions of five key enzymes in microbial color development and two dominant strains used to make fermented meat products are outlined. This review may provide novel ideas for the green and healthy development of fermented meat products.

Patulin, a toxic secondary metabolite of fungi, exists widely and stably in fruits, vegetables, grains, nuts and Chinese medicinal materials. Patulin enters the body through skin contact or food intake, posing a great threat to the health of humans and animals. Previous studies have shown that patulin can induce genotoxicity, immunotoxicity and reproductive toxicity, damaging the intestine, kidney, liver and other organs in the body. The toxic mechanism of patulin involves inducing damage to biological macromolecular structures, oxidative stress injury and cell autophagy as well as damaging intestinal flora homeostasis. In this article, the recent status of patulin contamination in foods is reviewed, with an emphasis on the latest progress in research on the toxicity and mechanism of action of patulin. It is hoped that this review will provide a theoretical basis for patulin detoxification.

Lotus (Nelumbo nucifera Gaertn.) is an abundant edible and medical resource, and the utilizable parts of lotus include leaves, roots, seeds, plumule, seed skins, flowers and seed pots, which contain many bioactive components including polysaccharides, and possess high nutritional value and many pharmacological activities. As an important component in different parts of lotus, polysaccharides have a variety of biological activities, such as antioxidatnt, anti-saccharification, hypoglycemic, immunoregulatory, antibacterial and anti-osteoporosis activities. At present, only scattered information is available on polysaccharides in different parts of lotus, so this paper reviews recent progress in research on the extraction, purification, structural features and biological activity of polysaccharides from different parts of lotus, aim at providing a reference for the comprehensive exploitation and utilization of polysaccharides in different parts of lotus to promote the application of lotus by-products.

Benzalkonium chloride is a quaternary ammonium compound with bactericidal activity, which is widely used in domestic and healthcare settings as well as in food processing environments. It plays an important role in the prevention and control of foodborne pathogens. However, the presence of biofilms or improper use of benzalkonium chloride may enable foodborne pathogens to adapt to bactericides, affecting the tolerance to homologous or heterologous biocidal agents. The review summarizes the relationship between the adaptation of foodborne pathogens to benzalkonium chloride and their tolerance to this biocide. The reasons for the increased tolerance to benzalkonium chloride are explained from the perspectives of the expression of efflux pump genes, cell membrane modification, and the formation of the viable but non-cultivable (VBNC) state. Furthermore, the influence of benzalkonium chloride adaptation on the antibiotic resistance of foodborne pathogens is discussed, and the reasons for the increased antibiotic resistance are summarized from the perspectives of biofilm formation, spontaneous mutations, horizontal gene transfer, and the role of efflux pumps in antibiotic resistance. This review could help understand the mechanism of the adaption of foodborne pathogens to benzalkonium chloride and provide a reference for the rational use of biocides and the prevention and control of foodborne pathogens.

In recent years, the number of patients with diabetes or obesity has increased rapidly, and the glycemic index (GI) of grains has attracted attention. Using GI value to guide the choice of grains is of great significance to the prevention and control of chronic diseases such as diabetes. However, the GI value of grains is influenced significantly by processing methods and is often directly related to measurement methods. Therefore, this paper summarizes the current methods used to determine the GI value of foods as well as their advantages and disadvantages. Thereafter, this review also analyzes the effects of different processing methods on the GI values of grains and their products, and explains the possible mechanism for changes in the GI value of grains from the perspective of the interaction between various components in grains caused by processing methods. This paper is expected to provide an effective basis for the prediction of changes in the GI value of grains and the selection of processing methods, and also provide a reference for the research and development of grain products with low GI value.

In recent years, the interactions of various food components have often been used to improve the functional properties of food systems. Proteins, polyphenols, and starches are widespread and play crucial roles in food systems. Their ternary systems are usually accompanied by complex reactions. The interactions of these components can endow foods with excellent properties and produce functional effects. Understanding the interaction mechanism of proteins, polyphenols and starches is of great significance to the development and application of their ternary systems in foods. Their interactions play a positive role in the development and modification of resistant starch, the development of emulsion-based delivery systems and the preparation of nanoparticle complexes. This paper discusses and summarizes the interactions between proteins, polyphenols, and starches in food systems and their effect on the functional properties of these components, which may provide theoretical guidance for the application of protein-polyphenol-starch ternary food systems.

Sugar esters are non-ionic biosurfactants. In comparison to traditional surfactants, sugar ester biosurfactants have superior emulsifying, antibacterial, and biodegradable properties, and are widely utilized in foods, cosmetics, medicine, and other sectors. Compared to sucrose esters, the most investigated sugar esters, lactose esters (LEs) exhibit superior physicochemical and biological properties and have more promising applications. This article focuses on recent advances in the manufacture of LEs using chemical and biological methods, as well as their application as emulsifiers and antibacterial materials. The application potential of LEs in the fields of bacterial photodynamic inactivation and photodynamic therapy is summarized. In addition, some problems with the preparation and application of LEs as well as their future prospects are discussed in order to provide a reference for intensive research and development of LEs.

Methionine is the only essential sulfur-containing amino acid required for the human body and is involved in important metabolic pathways including protein synthesis, transsulfuration, and one-carbon metabolism. However, in recent years, a large number of studies have shown that restricting dietary methionine intake exerts many physiological functions beneficial to body health. This article comprehensively summarizes the benefits of methionine restriction (MR) including promoting gut health, prolonging lifespan, reducing lipid accumulation and body mass, increasing insulin sensitivity, ameliorating diabetes, atherosclerosis and other cardiovascular diseases, improving learning and memory function, and anti-tumor and anti-cancer effects, as well as the effects of MR on bone and skeletal muscle function and protein synthesis. In addition, the strengths and weaknesses of five MR strategies including protein-restriction diet, vegan diet, diet formulation based on monomeric amino acid, oral methioninase, and injection of recombinant methioninase are reviewed in this article. It also discusses future major research directions, which may provide a theoretical reference for the development and application of new foods containing low levels of methionine and the realization of the health functions of MR.

Konjac glucomannan is a water-soluble, nonionic high-molecular-mass polysaccharide with good water-holding, film-forming, gelation, and biocompatibility properties. Among the many studies on konjac glucomannan-based composite materials, the studies of physically modified composite films have attracted much attention and shown promising applications in the field of new food packaging materials. In this review, the molecular structure and properties of konjac glucomannan are outlined, with a special focus on the types, morphological and structural characteristics, intermolecular interactions of the blending components, formation mechanism and functional properties of konjac glucomannan-based physically modified composite films and recent progress in their application.

Ionizing radiation is a type of energy released by atoms in the form of electromagnetic waves (X-rays and γ-rays) or particles (α, β, or neutrons) with energy greater than 12 eV sufficient to ionize atoms or molecules. Ionizing radiation can directly attack DNA, proteins, lipids and other biological macromolecules in the body, or indirectly damage cells by ionizing water molecules to produce a large number of free radicals, which in turn can cause damage to the human blood system, immune system, reproductive system and nervous system. Radioprotective agents are drugs that can reduce the systemic or local damage of ionizing radiation to the body when applied before or early after irradiation, thus contributing to the recovery of the damage. However, chemically synthesized radioprotective agents have deficiencies such as high research costs and toxic side effects. Therefore, the research and development of radioprotective agents derived from natural products has a promising future. In order to provide a reference for the research and development of new radiation protection agents based on active natural products, this paper introduces the mechanism of ionizing radiation damage to the human body and its hazards, and mainly discusses recent progress in research on the radiation protection effects of active natural products such as polysaccharides, polyphenols and peptides, and presents the problems of current research.

Reasonable, effective and rapid food safety detection methods are of great significance for ensuring food safety. As a new fluorescent carbon based nanomaterial, carbon quantum dots (CQDs) exhibit the advantages of large Stokes shift, good photostability, adjustable emission wavelength and photochemical stability. In addition, CQDs have excellent biocompatibility, and their chemically modified surface can be coupled with antibodies, nucleic acids and other macromolecules without changing their biological properties. The use of CQDs fluorescence detection technology can improve the sensitivity, shorten the detection time, reduce the detection limit, and save human and material resources. Therefore, CQDs can be considered to be one of the most powerful carbon nanomaterials in sensor research. In this paper, the structure, classification and fluorescence mechanism of carbon dots are reviewed, with emphasis on recent progress in green synthesis based on CQDs and the application of CQDs as fluorescent probes in food safety detection, in order to provide new ideas for the synthesis of CQDs and the development of rapid food safety detection technologies.