Given that the conventional blockchain model for the fruit and vegetable supply chain has the problems of insufficient depth of traceability information, insufficient data correlation, and low query efficiency, a graph blockchain model was proposed in this study. Firstly, the graph theory was used to improve the block data structure of the traditional blockchain and change the storage structure of the sequence table in the traditional blockchain structure into a graph structure that can facilitate the storage of in-depth traceability information for associated storage of deep traceability information. Then, the mapping relationship between physical block data and graph block chain model was established through a graph block chain mapping model, and according to the logical structure of the fruit and vegetable supply chain, the graph block data structure was established. Customized design of smart contracts for graph blockchain data storage, query and authority management was performed to ensure the reliability of supply chain data. Finally, the graph blockchain model was developed based on the XuperChain platform and its performance was experimentally compared with that of the traditional blockchain. The results showed that the graph blockchain allows deep traceability of the fruit and vegetable supply chain and greatly improves the efficiency of data query, which can provide a new method and idea for the traceability information storage and fast query of the fruit and vegetable supply chain based on blockchain.

The differences in quality properties between 40 major oil and feed soybean varieties in four major production areas of China were analyzed. Ten key quality indexes of soybean for each purpose were determined. One-way analysis of variance (ANOVA) and principal component analysis (PCA) were carried out, and a model was proposed using combination weighting method in order to select the quality characteristics of soybeans for different purposes and the superior soybean production areas and varieties. Significant differences in all quality properties except color, odor and carbohydrate content were found among varieties and production areas (P < 0.01 or P < 0.001). In the PCA, crude fat content, vitamin E (VE) content, impurity content, damage ratio, moisture content, and phospholipid content were extracted by factor analysis as key quality characteristics of oil soybean. For feed soybean, seven key quality characteristics including 7S/11S protein, protein dissolution ratio, crude fat content, protein content, impurity content, damage ratio, and soybean isoflavone content were identified. Using the proposed model, top 10 oil and feed soybean varieties with the highest comprehensive score and their major production areas were selected. Using cluster analysis, the oil and feed soybeans were assigned into five and nine groups with similar quality characteristics, respectively. This study provides a theoretical basis for quality evaluation of soybeans from different major production areas in China and specialty soybean variety selection.

The contents, structures, physicochemical properties and functional characteristics of soluble dietary fiber (SDF), insoluble dietary fiber (IDF) and total dietary fiber (TDF) from the peel and pomace of Nanfeng tangerine, Zigui navel orange and Shatian pomelo were compared and analyzed. The results showed that TDF contents in citrus peel and pomace ranged from 19.96­ to 44.26 g/100 g, and IDF/SDF ratios in tangerine peel, tangerine pomace and pomelo pomace were the closest to the recommended dietary ratio (2:1). All dietary fiber samples had obvious characteristic structures of polysaccharides, but their monosaccharide compositions and microstructures were different. Citrus pomace dietary fiber exhibited superior physicochemical properties and functional characteristics to peel dietary fiber, with pomelo pomace dietary fiber showing the best overall performance. Notably, pomelo pomace SDF had a water-holding capacity (WHC) of 28.46 g/g, a water swelling capacity (WSC) of 29.07 mL/g, an oil-holding capacity (OHC) of 3.38 g/g, a cholesterol adsorption capacity (CAC) of 22.56 mg/g, a nitrite ion adsorption capacity (NIAC) of 911.59 µg/g, a glucose adsorption capacity (GAC) of 2.64 mmol/g, and a glucose dialysis retardation index (GDRI) of 28.78% (15 minutes). In conclusion, citrus peel and pomace are good sources of high-quality dietary fiber and can be used as functional food components. This study can provide a theoretical basis for further refining the application of citrus dietary fiber and improving the added value of citrus by-products.

This study was carried out in order to clarify the antifungal activity and mechanism of the essential oil of Litsea cubeba against Candida albicans. The major components of the essential oil were analyzed, and changes in the cell morphology, surface hydrophobicity, surface charge, intracellular nucleic acid and protein leakage of Candida albicans isolated from contaminated pickles were evaluated after being treated with the essential oil. The results showed that the major components of Litsea cubeba essential oil were citral, limonene, and citronellal. The minimum inhibitory concentration (MIC) was 0.25 mg/mL, and the minimum bactericidal concentration (MBC) was 1 mg/mL. The addition of Litsea cubeba essential oil to yeast extract peptone dextrose (YPD) medium delayed cell growth, impaired cell membrane integrity, and increased cell membrane permeability, indicating that Litsea cubeba essential oil has good membrane permeability, and can disrupt cell structure, disorder cell membrane permeability, and result in leakage of intracellular materials, thus leading to cell death. This study provides a theoretical basis for the application of Litsea cubeba essential oil to inhibit the growth of Candida albicans during the storage of fermented vegetable juice and dairy products.

This study aimed to systematically elaborate on the inhibitory mechanism of metal-binding antimicrobial peptide SIF4 on the respiratory and energy metabolism of Escherichia coli. By analyzing changes in the metabolic activity, individual and synergistic respiratory inhibition rate, cytoplasmic membrane ion channel ATPase and intracellular ATP level of E. coli after being treated with SIF4, the effects of SIF4 on the cell metabolic activity, respiratory metabolic pathway, cytoplasmic membrane ion channel ATPase and intracellular ATP biosynthesis were studied. Results showed that the metabolic activity of E. coli decreased significantly with increasing dose of SIF4 (P < 0.05), and decreased by 70.41% in the 2 × minimal inhibitory concentration (MIC) group compared with the control group. SIF4 had good inhibitory effect on the respiration of Escherichia coli, with an inhibition rate of (19.387 ± 0.168)% and (25.222 ± 0.326)% at MIC and 2 × MIC, respectively. The synergistic respiratory inhibition rate of SIF4 combined with iodoacetic acid was the lowest ((19.982 ± 0.133)%), indicating that SIF4 could exhibit high antimicrobial activity mainly by inhibiting the glycolysis pathway of E. coli. The activities of cytoplasmic membrane ion channel Na+K+-ATPase and Ca2+Mg2+-ATPase decreased after treatment with SIF4, and this effect was positively correlated with SIF4 dose and treatment time, but weaker than that of the positive control Triton X-100. As SIF4 dose and treatment time increased, the intracellular ATP concentration decreased significantly, and after 12 h, the intracellular ATP concentration in the 2 × MIC group was significantly lower than that in the control group but higher than that in the positive control group (P < 0.05). All results confirmed that SIF4 could exhibit high antimicrobial activity against E. coli by interfering with respiratory metabolism, weakening cytoplasmic membrane ion channel ATPase activity and inhibiting the biosynthesis of intracellular ATP, which can provide theoretical support for the biocontrol of foodborne E. coli.

Objective: To investigate the effects of electron beam irradiation on the physicochemical properties and antioxidant activity of non-waxy and waxy proso millet. Methods: waxy (‘Yushu 1’) and non-waxy (‘Yumi 2’) proso millet were subjected to electron beam irradiation at different doses of 0 (control), 2, 4, 6, 8, and 10 kGy and were evaluated for physicochemical properties, bioactive substances and antioxidant capacity. Results: After electron beam irradiation, the color, starch content, ash content, phenolic content and antioxidant activity of non-waxy and waxy proso millet changed significantly (P < 0.05), while the physical properties, moisture content and protein content did not (P > 0.05). In addition, electron beam irradiation treatment significantly increased the contents of total phenols and total flavonoids, antioxidant activity and individual phenolic contents in non-waxy and waxy proso millet; the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity increased up to 78.01% and 70.22%, and the 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cation scavenging capacity increased up to 61.51% and 50.57%, respectively. The contents of gallic acid, caffeic acid, resveratrol, catechin and kaempferol in proso millet extract increased, while the contents of protocatechuic acid and epicatechin remained relatively stable. The correlation analysis suggested that the total phenolic content had a significantly positive correlation with the contents of catechin and quercetin (P < 0.01), the total flavonoid content had a significantly positive correlation with the contents of rutin and gallic acid (P < 0.01), and the antioxidant activity was positively correlated with the catechin content. Compared with the control, proso millet treated with electron beam irradiation exhibited stronger antioxidant properties and higher phenolic contents, which would be worthy of further research and development.

In order to improve the drying rate and rehydration of tilapia meat, the freeze-drying characteristics and quality changes of blanched or steamed fish meat were analyzed. The effect of heat pretreatment on the quality of freeze-dried fish meat was elucidated by considering the denaturation degree of myofibrillar protein, water distribution and microstructural changes in fish meat during the drying process. The results showed that heat pretreatment could effectively improve the drying rate of tilapia meat, shortening the drying time by nine hours compared with the control group; blanching was more effective than steaming. The rehydration temperature range for tilapia meat was expanded by heat pretreatment, and good rehydration was observed at 50–80 ℃. The rehydration temperature for the control samples was 80 ℃, and the rehydration rate of the 10 min heat treatment group was more than 60%, indicating that the dried product can be rapidly rehydrated. The hardness of the rehydrated fish meat was similar to that of cooked fresh fish meat, and it had good mouthfeel. Heat pretreatment caused significant denaturation of myofibrillar protein and consequently changes in water distribution and a conspicuous increase in the peak area of transverse relaxation time T23, indicating that the increase in free water content after heat treatment is an important reason for the increase in freeze-drying rate. The experimental results can provide technical support for the development of ready-to-eat dried fish products that are suitable for rehydration.

In this study, soybean protein isolate (SPI) and blueberry anthocyanins (BANs) complex (HPPM-SPI-BANs) treated by high power pulsed microwave (HPPM) was prepared, and its physicochemical properties and biological activity were evaluated. The effect of HPPM treatment on the functional properties and biological activity of SPI was studied. In addition, the effect of partial replacement of egg white protein by HPPM-SPI-BANs on the baking quality and storage properties of cake was evaluated. The results indicated that HPPM treatment significantly improved the solubility of HPPM-SPI-BANs by 2.11 folds, and improved the foaming and emulsifying properties (P < 0.05). The antioxidant activity was also significantly improved compared with SPI and SPI-BANs complex without HPPM treatment. Moreover, the addition of HPPM-SPI-BANs inhibited water loss during cake baking and improved the hardness and chewiness of cake. The 2,2-diphenyl-1-picryhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power of cake with HPPM-SPI-BANs increased by 4.56 and 3.79 folds, respectively, and the aging rate constant k decreased to 0.12. Accordingly, HPPM-SPI-BANs plays an important role in improving the shelf life quality of cake.

Objective: To investigate the chemical composition and anti-inflammatory mechanism of Coregonus peled oil (CPO). Methods: CPO was extracted by ultrasonic homogenization and its major chemical components were detected. In addition, its fatty acid (FA) composition was analyzed by gas chromatography-mass spectrometry (GC-MS). Macrophage RAW264.7 cells were cultured as an inflammation model and stimulated with lipopolysaccharides (LPS). Cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The accumulation of succinate was detected by liquid chromatography tandem mass spectrometry (LC-MS/MS). The concentration of nitric oxide (NO) and the activity of inducible nitric oxide synthase (iNOS) in the supernatant were measured by commercial kits. Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the supernatant. The expression levels of CD68, CD86, Arg1, CD206, YM1 and HIF-1α were detected by quantitative real-time polymerase chain reaction (qPCR), and their protein expression levels were determined by Western blotting. Results: The major chemical constituents of CPO were palmitoleic acid, oleic acid, eicosapntemacnioc acid (EPA), and docosahexaenoic acid (DHA). CPO significantly inhibited the production of NO, iNOS, IL-6, TNF-α, and IL-1β as well as their gene expression levels. CPO blocked NF-κB activation by inhibiting the degradation of inhibitor α of NF-κB (IκBα) and decreasing p65 nuclear translocation in LPS-induced RAW264.7 cells. In addition, CPO promoted macrophage polarization from M1 to M2 types by inhibiting the phosphorylation of signal transducer and activator of transcription 1 (STAT1). The content of succinate and the expression levels of hypoxia-inducible factor-1α (HIF-1α) gene and protein indicated that CPO could inhibit the production of IL-1β by inhibiting the accumulation of succinate. Conclusion: The anti-inflammatory mechanism of CPO may be due to the inhibition of the NF-κB, STAT1, and succinate/HIF-1α signaling pathways.

The objective of this work was to investigate the protective effect and underlying mechanism of a bioactive peptide from coix seeds (Coix lacryma-jobi) on high glucose-injured human umbilical vein endothelial cells (HUVEC). HUVEC injured by 30 mmol/L glucose were treated with different concentrations of the peptide and were evaluated for the secretion of nitric oxide (NO) by the nitrate reductase method. The content of reactive oxygen species (ROS) was detected by flow cytometry. Cell apoptosis was detected by Annexin V-FITC/PI double staining. Quantitative real-time polymerase chain reaction (qPCR) was applied to detect the expression of inflammation-related genes. The results showed that NO secretion was decreased by 28.72% (P < 0.05), ROS secretion was increased by 96.19% (P < 0.05), and the expression of the ICAM-1, IL-6, MCP-1 and VCAM genes was significantly increased in HUVEC induced by high glucose compared with the normal control group. The prolongation of high glucose treatment time significantly increased the apoptosis rate of HUVECs, and after 14 days, the apoptosis rate of HUVECs was 1.61 times higher than that in the normal control group. Treatment with the peptide at all concentrations increased NO secretion, decreased ROS content and the expression of inflammatory genes and reduced cell apoptosis. In summary, the coix seed biopeptide possesses a protective effect on high glucose-injured HUVEC. 

Caffeic acid phenethyl ester (CAPE), a natural polyphenol derived from propolis, has a good regulatory effect on lipid metabolism, but its molecular mechanism is not clear. In the present study, the ameliorative effect of CAPE on lipid metabolism in oleic acid-induced HepG2 human liver cancer cells and its mechanism at the cellular level were investigated. The results showed that compared with the high fat group, lipid accumulation in the cells was significantly improved after CAPE intervention, and a total of 3 270 differentially expressed genes (DEGs) were selected at the transcriptomic level; 1 351 of them were up-regulated and the rest were down-regulated. The functional annotation analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database showed that the DEGs caused by CAPE intervention were significantly annotated to lipid metabolism-related pathways. The KEGG signaling pathway enrichment analysis showed that the HIF-1α pathway and the fatty acid catabolism pathway were significantly enriched. The expression levels of gene HIF-1α, PPARα, CPT1A and FABP5 were 1.326, 1.661, 2.039 and 2.598 times higher in the CAPE group than the high fat group. It is suggested that CAPE can improve lipid metabolism disorder in oleic acid-induced cells possibly by reducing oxidative stress and regulating the PPARα and fatty acid oxidative catabolic pathways. This study provides a theoretical reference for future research on the molecular mechanism of lipid metabolism regulation by CAPE and the regulation of lipid metabolism disorder induced by a high-fat diet.

Objective: To investigate the effect and possible mechanism of Rosa roxburghii fruit polyphenols (RRP) on hypertension induced by NG-nitro-L-arginine methyl ester (L-NAME) in mice. Methods: RRP with a purity of 68% was prepared in the laboratory. L-NAME was used to induce a mouse model of hypertension, and the mice were divided into four groups: model, positive control (captopril), low-dose RRP, and high-dose RRP. All mice were killed and dissected for measurement of organ indexes. Mice not treated with L-NAME served as a control group. The serum was collected to determine the levels of nitric oxide (NO), endothelin-1 (ET-1), renin, angiotensin II (Ang II), aldosterone (ALD), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α). The levels of oxidative stress markers including malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were assayed in kidney and liver tissues, and heart and kidney tissues were stained with hematoxylin and eosin (HE) for pathological observation. Results: Compared with the blank group, the model group showed a significant increase in blood pressure; serum NO concentration significantly decreased (P < 0.05), serum IL-6 and TNF-α levels significantly increased (P < 0.05), and serum ET-1, renin, Ang II, and ALD levels significantly increased (P < 0.05). MDA levels in kidney and liver tissues significantly increased (P < 0.05), and SOD and GSH-Px activities significantly decreased (P < 0.05). Compared with the model group, blood pressure significantly increased in the positive control group and the low- and high-dose RRP groups (P < 0.05). Serum NO levels significantly increased (P < 0.05), and serum IL-6, TNF-α, ET-1, renin, Ang II, and ALD levels significantly decreased (P < 0.05). MDA levels in kidney and liver tissues significantly declined (P < 0.05), and GSH-Px activity significantly increased (P < 0.05). Conclusion: RRP has an obvious hypotensive effect, possibly by increasing NO bioavailability, improving endothelial cell dysfunction, inhibiting the over-activation of the renin angiotensin aldosterone system, and reducing inflammation and oxidative stress.

Objective: The objective of this study is to evaluate the cytoprotective activity and potential mechanism of hawthorn bioactive polyphenols (HBPs) using human bronchial epithelial (16HBE) cells exposed to benzo(a)pyrene (BaP). Methods: HBPs were isolated by activity-guided separation, and their cytotoxicity was assessed by the methyl thiazolyl tetrazolium (MTT) method. The cytoprotective activity of HBPs against BaP-induced injury in 16HBE cells was determined by the cell counting kit-8 (CCK-8) method. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the effect of HBP-1 on BaP-induced inflammatory factors such as tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-18, IL-10, IL-6 and reactive oxygen species (ROS) in 16HBE cells. Flow cytometry was utilized to explore the effect of HBP-1 on BaP-induced apoptosis in 16HBE cells. Western blotting was conducted to examine the effect of HBP-1 on protein expression related to the aryl hydrocarbon receptor (AhR) and nuclear factor kappa-B (NF-κB) signaling pathways in BaP-induced 16HBE cells. Results: A total of 10 bioactive phenolic compounds were isolated from hawthorn. Among them, HBP-1 exhibited the most significantly cytoprotective activity against BaP-induced inflammatory injury in 16HBE cells. HBP-1 significantly inhibited the oversecretion of IL-1β, IL-18 and TNF-α and the increase in ROS level and BaP-induced apoptosis in 16HBE cells. Western blotting results indicated that HBP-1 could inhibit the activation of the AhR and NF-κB signaling pathways in 16HBE cells induced by BaP. Conclusion: HBP-1 is able to inhibit BaP-induced oxidative stress and excessive production of inflammatory cytokines in 16HBE cells by suppressing the activation of the AhR and NF-κB signaling pathways, highlighting the cytoprotective effect of HBP-1 against BaP-induced damage.

Objective: To explore the protective mechanism of Auricularia auricula melanin (AAM) on iron deficiency anemia (IDA) induced ulcerative colitis (UC) in mice. Methods: Forty-five Kunming male mice were randomly divided into blank control group, model group, and AAM group (n = 15 each). The mice from all groups except the blank control one were provided with a low-iron diet to establish an IDA-induced UC model. After two weeks, AAM was administered by gavage to the mice from the AAM group for three weeks, whereas those from the model group continued receiving the low-iron diet. The effects of AAM on anemia indexes, colonic inflammation characteristics, oxidative stress, inflammatory factor expression levels and inflammatory signaling pathways in UC mice were evaluated. Results: Compared with the model group, the symptoms of anemia in the AAM group were alleviated. The body mass returned to the normal level, and the colonic pathological score was significantly reduced (P < 0.000 1). In addition, the total antioxidant capacity (TAC) and superoxide dismutase (SOD) activity in the colon of mice from the AAM group were significantly enhanced compared with the model group (P < 0.000 1), and the levels of malondialdehyde (MDA), hydroxyl radical (·OH), and superoxide anion radical (O2-·) were significantly decreased (P < 0.000 1, P < 0.01, P < 0.001), indicating that AAM could enhance antioxidant capacity and attenuate oxidative damage in mice. Further mechanistic studies showed that intervention with AAM significantly regulated protein expression associated with Toll-like receptors-4/nuclear factor-kappa B (TLR4/NF-κB) signaling pathway, significantly down-regulated the gene expression of the pro-inflammatory cytokine tumor necrosis factor (TNF-α) (P < 0.01), and significantly increased the gene expression level of the anti-inflammatory cytokine interleukin-10 (IL-10) (P < 0.05). Conclusion: Auricularia auricula melanin may regulate oxidative stress and inhibit the TLR4/NF-κB signaling pathway, thereby reducing intestinal mucosal ulcer, oxidative stress injury and inflammatory cell infiltration in colon tissue, and finally alleviating IDA-induced UC in mice.

In order to study the effect of hot air treatment before or after minimal processing on the quality preservation of fresh-cut apples, ‘Red Fuji’ apples (Malus pumila Mill.) were treated with hot air at 70 ℃ before or after minimal processing and stored at 4 ℃. The mass loss rate, respiratory intensity, browning index, total soluble solids (TSS) content, titratable acid (TA) content, polyphenol oxidase (PPO) activity, total phenolic content (TPC), antioxidant capacity and microbial growth in fresh-cut apples were determined during storage, and the flavor and aroma components were analyzed by an electronic tongue and an electronic nose. The results showed that during 0–12 days of storage, hot air treatment before or after minimal processing effectively inhibited the respiration rate, ethylene release, browning index, and microbial growth, reduced the mass loss rate significantly (P < 0.05), increased the soluble solid content, total phenol content and antioxidant capacity significantly (P < 0.05), and delayed the flavor deterioration of fresh-cut apples compared with the control group. Hot air treatment after minimal processing exhibited better preservation effect.

Riboflavin (vitamin B2), a safe and non-toxic food additive, plays an important physiological role in plant growth, development and stress resistance. In this study, we investigated the effects of exogenous riboflavin on the postharvest quality maintenance of pak choi (Brassica rapa subsp. chinensis). Pak choi was treated at postharvest with different concentrations of riboflavin (0, 200, 400, 600, and 800 μmol/L) and evaluated for color, chlorophyll content, chlorophyll metabolism-related gene expression and antioxidant enzyme activity. The results showed that 400 μmol/L riboflavin treatment effectively maintained the quality of postharvest pak choi, mainly by 1) reducing the expression of chlorophyll catabolism-related genes (BrNYC1, BrPPH, BrPAO, and BrSGR1/2) to delay chlorophyll degradation, 2) reducing the total bacterial count on the surface of pak choi leaves to reduce pathogenic spoilage, and 3) upregulating the expression of antioxidant enzyme genes (BrPOD, BrSOD and BrCAT) and enhancing the antioxidant enzyme activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) to increase antioxidant activity. In addition, riboflavin treatment maintained high levels of antioxidants (ascorbic acid and total phenolics), thereby increasing the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and reducing the production of malondialdehyde (MDA). These findings are helpful to understand how riboflavin affects the postharvest quality of leafy vegetables, which is of reference significant for improving the postharvest commercial value and quality of leafy vegetables.

The quality and physiological changes of ‘Luli’ and ‘Gala’ apples during low-temperature storage were explored to provide a theoretical basis for the storage and preservation of new mid-early ripening apple varieties. The results showed that the hardness, soluble solids content and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of ‘Gala’ and ‘Luli’ apples showed a downward trend during cold storage and the shelf life period. After 90 days of storage, the hardness of ‘Gala’ apples decreased by 56.3%, while that of ‘Luli’ apples decreased only by 30.7%. Compared with ‘Gala’ apples, ‘Luli’ apples had lower polyphenol oxidase and lipoxygenase activities and higher contents of total phenols, flavonoids and chlorogenic acid during storage. During low temperature storage, the contents of individual phenolics in ‘Luli’ apples decreased, and the contents of chlorogenic acid, epicatechin, hypericin, and ferulic acid decreased most in the first 15 days, but did not significantly change during the shelf life period. The contents of catechins, p-coumaric acid, rutin, and caffeic acid in ‘Gala’ apples increased slightly after 15 days of low temperature storage and then decreased, but decreased gradually during the shelf life period. The contents of all phenolics decreased during the shelf life period. The major aroma components in ‘Gala’ and ‘Luli’ apples were aldehydes, alcohols and esters, among which 3-methyl-2-buten-1-ol, isoamyl benzoate, nonanal, 2-amino-6-methylbenzoic acid, 1-methyldibenzofuran and diisobutyl phthalate were only detected in ‘Luli’ apples. During low-temperature storage, the relative contents of aldehydes in both varieties decreased, while the relative contents of alcohols and esters showed an increasing trend. The relative content of alcohols in ‘Luli’ apples decreased during the shelf life period, while the opposite trend was observed for ‘Gala’ apples. In conclusion, ‘Luli’ apples exhibited higher fruit hardness, antioxidant capacity and phenol content during low-temperature storage and the shelf life period, and the overall storage quality was better than that of ‘Gala’ apples.

Fresh wet bean thread, which is made from rice and beans by heat treatment after soaking in water and grinding, has some problems such as poor water-holding capacity (WHC), fast water loss and hard texture during storage. In order to delay the quality changes of fresh wet bean thread during storage, the effects of adding 0, 0.2%, 0.4%, 0.6%, 0.8% and 1.0% (m/m, on a dry basis) soluble soybean polysaccharide (SSPS) on the hardness, water content, moisture migration, total plate count, acidity, color, and microstructure of fresh wet bean thread were evaluated during storage at 25 and 4 ℃. The results showed that for each storage temperature, the addition of SSPS had little effect on the shelf life of fresh wet bean thread. However, the addition of SSPS enhanced the binding strength between water and starch, made fresh wet bean thread exhibit a porous honeycomb structure, reduced the water loss rate, increased the WHC, and consequently decreased the hardness. Additionally, SSPS delayed the rate of color change of fresh wet bean thread at 4 ℃. Fresh wet bean thread with 0.8% SSPS had strong WHC and small water loss rate and overall hardness during storage at 25 and 4 ℃. The color was stable and the overall whiteness was high during storage at 4 ℃. Therefore, the addition of 0.8% SSPS can effectively improve the WHC and reduce the hardness of fresh wet bean thread during storage, which will provide a theoretical basis for improving the storage quality and market development of fresh wet bean thread.

Nattokinase (NK), a serine protease, can be used as a thrombolytic agent. Compared with clinical thrombolytic drugs (urokinase and streptokinase), NK has the advantages of low price, high thrombolytic efficiency, oral administration, and no toxic side effect, making it an ideal natural thrombolytic agent. At present, commercial thrombolytic NK products have the problems of low activity and bioavailability, which enter the bloodstream to exert thrombolytic effects through the oral and gastrointestinal digestion and absorption system. The gastrointestinal tract (GIT) environment (strong acidity, pepsin and trypsin) can destroy the spatial structure of NK, leading to a decrease or loss of its thrombolytic activity. The construction of functional vectors for NK delivery using natural biomaterials such as lipids, polysaccharides, and proteins can effectively avoid these adverse factors in the digestive system, enhancing the stability of NK, and improving its biological activity and bioavailability in the body. Beginning with an overview of the structural and functional properties of NK, this paper summarizes recent progress in research on functional vectors for NK delivery in order to provide a theoretical basis and technical support for efficient and stable thrombolytic NK products.

Prepared aquatic products have recently shown a momentum of rapid development due to its convenience and easy availability. With the characteristics of high protein content, high water content, and neutral pH, prepared aquatic products are susceptible to oxidation, microorganisms, and endogenous enzymes, leading to flavor deterioration. With the continuous development of the prepared aquatic products industry, understanding the mechanism of flavor deterioration in prepared aquatic products is of great significance for their quality maintenance and flavor regulation. In this context, the mechanism of flavor deterioration in prepared aquatic products is reviewed herein from the perspectives of protein oxidation, lipid oxidation, microorganisms, and endogenous enzymes. Furthermore, the methods for the flavor regulation of prepared aquatic products through processing techniques, exogenous additives, and packaging methods are discussed. We expect that this review will provide a reference for the flavor maintenance of prepared aquatic products and the development of the prepared food industry.

In recent years, breeding work and planting techniques pursuing high yield and disease resistance, and post-harvest treatments such as low-temperature storage have caused a great decline in tomato flavor quality. How to improve the flavor quality of tomato is an urgent problem to be solved. The flavor quality of tomato mainly involves sweet and sour taste and aroma, which is closely related to sugars, organic acids and volatile flavor substances in the fruit, and losses of volatile flavor substances are the key factor causing the deterioration of tomato flavor quality. In this paper, the flavor composition of tomato, the synthesis pathways of tomato flavor compounds and the factors affecting tomato flavor are systematically reviewed in order to provide theoretical guidance for improving the flavor quality of tomato.

Foods contain a variety of macromolecules such as proteins as well as trace flavor compounds and the binding effect between aroma compounds and the protein matrix has an important impact on the release and perception of the overall flavor of foods. In this paper, we systematically review the mechanism, determination methods, mathematical models and influential factors of the binding effect between proteins and aroma compounds, and summarize the binding interactions between proteins and aroma compounds including non-covalent bonding, covalent bonding and mass transfer effect, and presents a systematic comparison of the application of multispectral techniques such as fluorescence, circular dichroism and Fourier transform infrared spectroscopy to the investigation of the protein-aroma compound binding effect. Moreover, we summarize several common theoretical models and emerging molecular docking and molecular dynamics simulation methods available for research on the binding interactions between proteins and aroma compounds, and review the influential factors of the release and retention of aroma compounds bound to the protein matrix from three perspectives: protein, aroma compounds and food ingredients. Furthermore, we discuss the major problems existing in the current research and put forward some suggestions for future research directions in order to provide a scientific basis and reference for the controllable release of aroma compounds bound to proteins in foods.

During the aqueous enzymatic extraction of vegetable oils, a stable emulsion is often formed, which greatly limits the extraction of oil. The structure and properties of the interfacial membrane formed by interfacial proteins, phospholipids and carbohydrates affect the stability of the emulsion. Interfacial proteins are one of the most important components of the interfacial membrane, and their quantity, structure and properties have a significant impact on the properties and stability of the emulsion, and demulsification of the emulsion is the key to increasing the oil content. This article briefly introduces the major components, properties and influential factors of the emulsion, reviews the effects of interfacial protein concentration, structure and properties on the stability of the emulsion, and summarizes the demulsification mechanism of the emulsion from the perspective of changes in interfacial proteins, in order to provide a theoretical reference for future research on the demulsification of the emulsion during the aqueous enzymatic extraction of plant oils.

Erythritol, a natural sweetener, is widely used in the food, medicinal and chemical industries because of its advantages of low calorie, good stability and high food safety. Yarrowia lipolytica is widely used as an efficient fermentation strain for erythritol production. However, the current research on erythritol production by Yarrowia lipolytica concentrates on control of the fermentation process and metabolic pathway regulation and has bottlenecks in the yield of erythritol and the fermentation process. On this basis, this article reviews recent progress in research on erythritol production by Yarrowia lipolytica from three aspects: fermentation substrate utilization, fermentation process control and metabolic pathway modification by genetic engineering. This review is expected to provide a reference for breaking the bottlenecks in erythritol production by Yarrowia lipolytica.

Advanced glycation end products (AGEs) are a series of stable compounds generated by the nonenzymatic reaction of reducing sugars with proteins, lipids or nucleic acids. It has been found that the excessive accumulation of AGEs in the body can easily cause various chronic diseases such as diabetes, atherosclerosis, Alzheimer’s diseases and cardiovascular diseases. Finding methods to suppress the formation of AGEs is of great significance for ensuring human health. This article summarizes the types, structures, formation process, pathogenesis, and in vivo metabolic pathways of AGEs, with a focus on the methods and mechanisms for the inhibition of AGEs. This review will provide a theoretical basis for controlling the formation of AGEs.

As an environmental-friendly renewable polymer material, nanocellulose (NCC) has great application potential and ecological benefits. In this paper, we introduce the structural properties and preparation techniques of NCC, give an overview of the methods used to characterize and modify NCC, and elaborate on the latest advances in the application of food industry. Additionally, we use bibliometrics to analyze and summarize the research hotspots in the NCC field. It is expected that the green and efficient production of NCC and the development of functional composites for different purposes will be research priorities in the future.

Vinegar is traditionally produced by fermentation with a mixed system composed of naturally inoculated microorganisms. The complex microbial communities in the fermentation system are crucial to the formation of vinegar flavor. Studies on the microbial communities and their interactions are helpful to reveal the relationship between microorganisms and the quality of vinegar and are of great significance for targeted regulation of microorganisms in the fermentation process, productivity enhancement and vinegar quality improvement. Therefore, recent studies on the microbial diversity and the interactions among core functional microorganisms in the traditional fermentation process of vinegar are reviewed in this paper. Moreover, the positive effects of the interaction among core functional microorganisms on the flavor of vinegar are discussed. Finally, the problems existing in the current research are summarized. This review is expected to provide a reference for targeted regulation of vinegar quality.

As a novel and rapid detection technique, surface-enhanced Raman spectroscopy (SERS) has many advantages such as simple sample pretreatment, rich spectral information, high sensitivity, rapidity, easy operation, and immunity to interference from water molecules. Hence, SERS has been considered a powerful tool and a research hotspot for food safety rapid detection. This article reviews the development, enhancement mechanism, and detection modes of SERS, and summarizes the latest progress in the detection of common mycotoxins in foods by SERS. Moreover, its problems to be solved and future trends are discussed. It is hoped that this review can provide a reference for future research and development of SERS technology for rapid detection of mycotoxins.

Curdlan has unique gel properties and special triple helix conformation, and curdlan gel has great application potential in the fields of food and biomedicine because of its water-retention capacity, thickening capacity, film-forming capacity, freeze-thaw stability, pH stability. Curdlan hydrogels with physicochemical properties and application fields can be prepared by different methods. In addition, combination with other substances can improve gel properties and impart unique functional properties to hydrogels. In this paper, the preparation methods, gel properties, and gelation mechanism of curdlan hydrogels, as well as recent progress in research on curdlan-based composite hydrogels are reviewed. Meanwhile, an overview of the application of curdlan-based hydrogels in food and biomedical fields is provided. This review is expected to provide a reference for further research and application of curdlan-based hydrogels.

Protein tyrosine phosphatase 1B (PTP1B), a potential target for the treatment of type 2 diabetes and obesity, plays a key negative regulatory role in the insulin and leptin signaling pathways. Natural products, with structural diversity, can affect different targets and pathways to exert their unique preventive and therapeutic effects on diabetes or its complications. Various food-derived natural products have been reported for their PTP1B inhibitory activity in recent years. This article mainly overviews recent progress in understanding the mechanism of action of PTP1B and food-derived natural PTP1B inhibitors, which will hopefully provide a theoretical rationale for further research on PTP1B inhibitors and the development of new PTP1B inhibitors or hypoglycemic functional foods.

Thrombotic disease refers to the disease caused by thrombosis and thromboembolism. In recent years, the global incidence and mortality rates of thromboembolic diseases has increased significantly, posing a serious threat to human life and health. Since ancient times, anticoagulant has been an important way to prevent and treat thrombotic diseases. However, anticoagulant tolerance and side effects have appeared in its clinical applications. Food-derived bioactive peptides have the advantages of high bioavailability and safety and are very promising in the prevention and treatment of thrombotic diseases. This paper summarizes the sources, preparation, purification, identification, anticoagulant activity and mechanisms of food-derived antithrombotic peptides in order to provide a reference for the future development of food-derived antithrombotic peptides and new anticoagulants.

Pseudomonas, an important spoilage bacterium in animal-derived foods as well as fruits and vegetables in the cold chain, can cause huge economic losses to the food industry. The food spoilage ability of Pseudomonas is closely related to the formation of biofilm, which can enhance the survival and adaptability to the food processing and storage environment of Pseudomonas, causing persistent contamination. However, a systematic review of the biofilm formation of Pseudomonas and its mechanism is still lacking at present. This article describes the contamination status of Pseudomonas in fresh foods, analyzes the biofilm formation and extracellular matrix composition of Pseudomonas, and elucidates the major regulatory factors of the biofilm formation of Pseudomonas such as cyclic diguanylate, quorum sensing system and small RNAs. We believe that this review will provide a theoretical reference for uncovering the mechanism of food spoilage caused by Pseudomona and controlling its biofilm contamination.

Most natural plant protein molecules are spherical, and the excessively compact structure limits the nutrition and functionality of plant proteins. Spherical plant protein molecules can be transformed into plant protein fiber by various techniques such as molecular self-assembly, screw extrusion, shearing, wet spinning, electrospinning and solution blow spinning. Plant protein fiber is characterized by a high aspect ratio, clear molecular orientation, high mechanical strength, and strong functionality, and can be directly eaten, used as food additives or used to encapsulate active substances, which greatly expands the application of plant proteins in the food field and improves the added value of plant proteins. However, the addition of poisonous and harmful chemical reagents, and the morphological defects, poor stability, low yield and high production cost of plant protein fiber limit its wide popularization and industrial production. This article reviews the techniques for the preparation of plant protein fiber and its application in the food field, analyzes its advantages, disadvantages and limitations, and proposes future directions.

Mycotoxins are natural potent toxins commonly found at low concentrations in foods. Mycotoxin contamination not only causes economic losses, but also endangers human health. Because mycotoxins are stable and difficult to degrade, they are difficult to remove during food processing, so it is urgent to develop efficient removal technologies for mycotoxins. Photocatalytic degradation technology, a green and economically advanced oxidative sterilization and disinfection technology, has the advantages of environmental friendliness, mild reaction, and high catalytic degradation efficiency. It has been gradually applied to the degradation of mycotoxins. In this article, the basic principle of photocatalytic degradation of mycotoxins is briefly described, and the recent progress in the application of different semiconductor materials to degrade mycotoxins are systematically summarized. Moreover, future prospect are discussed.

At present, China’s food inspection and testing mainly concentrate in food processing, packaging and sale, so that supervision over the food production process is lacking, and the regulation of the large number of production and operation entities and of the intertwining of various risks is ineffective. The cost of controlling food quality and safety by means of inspection and testing is high, and a large amount of data has not been fully utilized, causing lack of effective support for quality control in food processing. This article summarizes the current status of research on food inspection and quality control in China, analyzes the existing problems and puts forward some suggestions such as strengthening the ability to analyze and mine data, finding the law of food safety risks, targeted detection of high-risk indicators according to the law, improving the detection efficiency and the risk control ability, and guiding the monitoring and management of food safety risks. Research on quality control in food processing by comprehensive application of test data can promote the development of quality control in food processing, which can in turn improve the level of risk control and ensure food safety.

It is a worldwide technical problem to avoid the waste of food resources caused by storage conditions not meeting the requirements. On this basis, the preparation and application of green and environmentally friendly degradable nanocellulose-based antimicrobial films have received widespread attention. This paper systematically introduces the common preparation methods of nanocellulose-based composite films and the latest progress in their applications in fruit and meat preservation. The mechanism of action of nanocellulose-based composite films in food preservation is described, and their advantages such as high mechanical strength, degradability, and biocompatibility over traditional antimicrobial films are analyzed. Moreover, the application potential of nanocellulose-based films in food preservation is discussed.

Sea cucumber, an important marine food and medicinal resource, contains polysaccharides, which are one of the most important active substances in it. Sulfate groups play an important role in the biological activity of polysaccharides, and sea cucumber sulfated polysaccharides may specifically affect the growth of certain intestinal microorganisms and the production of related metabolites due to their different chemical structures, which contribute to the variable health promoting effects. As a complex ecosystem of the human body, the intestinal flora plays an irreplaceable role in life activities such as nutritional metabolism. Sea cucumber sulfated polysaccharides can be used as prebiotics to alleviate diseases caused by intestinal flora disorder by regulating its composition. This review article summarizes the structures of sea cucumber sulfated polysaccharides, with a focus on the latest progress in research on their influence on glycolipid metabolism through the gut microbiota. These studies will contribute to a better understanding of the health promoting mechanism of sea cucumber sulfated polysaccharides and provide a scientific basis for their application in functional foods.

Gastrodia elata Bl. is used for both culinary and medicinal purposes. It contains a variety of bioactive components such as gastrodin, parishin, p-hydroxybenzyl alcohol, polysaccharides, and has good health-promoting functions such as improving memory, helping sleep, and anti-epilepsy effect. At present, much progress has been made in the research on bioactive components in Gastrodia elata Bl. and their biological activity, but a systematic summary is lacking. Therefore, this article summarizes the basis for the application of Gastrodia elata Bl. in common foods and health foods, and reviews recent progress in research on major bioactive components in Gastrodia elata Bl. and their pharmacological effects and action mechanisms. We anticipate that this review will provide a reference for the reasonable application of Gastrodia elata Bl. in the food field and further research on its health benefits.

γ- and δ-lactones are important flavor compounds, which are widely used in foods and daily chemical flavors. Due to the chiral centers in the molecules, the aroma characteristics of the two enantiomers of each of the lactones are quite different, which makes them have different purposes in the formulation of flavors and fragrances. In this paper, the natural sources, chemical structures, aroma characteristics and preparation methods of common chiral γ- and δ-lactones in foods are reviewed in order to provide a comprehensive understanding of chiral lactones and provide a reference for the development of new methods for their preparation.

As one of the most popular beverages in the world, tea is highly susceptible to mold contamination during its planting, processing, and distribution. Toxigenic fungi produce mycotoxins under suitable conditions, and humans drinking tea may be at risk of ingesting mycotoxins. In this review, we briefly describe the sources, types, and hazards of mycotoxins in tea, summarize the current status of mycotoxin contamination in tea, discuss the advantages and disadvantages of mycotoxin detection technologies, and outline the prevention and control measures for mycotoxins in tea. This article is expected to provide a reference for the quality control of tea.

Green biodegradable food contact materials have been increasingly used, but they may contain degradation products from raw materials and additives, impurities, newly formed compounds and pollutants. These non-intentionally added substances, many of which are unknown, can migrate into foods. In order to ensure the safety of consumers, it is necessary to identify these substances and evaluate their health risks. This article summarizes non-intentionally added substances in biodegradable food contact materials and their possible sources, outlines the latest sample pretreatment methods and high-resolution mass spectrometry for the analysis of non-intentionally added substances, and describes the application of the threshold of toxicological concern approach in the health risk assessment of non-intentionally added substances. Moreover, this article proposes that bioassays are effective supplements to conventional risk assessment methods. It is hoped that this review will provide a reference for research on the safety of biodegradable food contact materials.

Microbes can cause food spoilage and waste, and even cause diseases posing a threat to human health. Being different from the traditional sterilization technology, photodynamic inactivation is a non-thermal physical sterilization technology based on the biological activity of natural antibacterial substances under light. It is characterized by remarkable microbial killing efficacy, simple operation, low cost, environmental friendliness, and can well maintain food flavor, color and nutritional value. This paper mainly summarizes the principle of photodynamic inactivation, outlines the major microorganisms in foods and the mechanism of photodynamic inactivation of microorganisms, and reviews the current status of the application of photodynamic inactivation in foods. We believe that this review will provide theoretical support for the application of photodynamic inactivation in the food field.

Food-derived bioactive peptides (FBPs), a class of short-chain amino acid peptides produced by the hydrolysis of natural food proteins, have a variety of excellent functional activities and may play an important role in promoting human health and preventing the development of chronic diseases. However, FBPs generally suffer from bitter taste, high hygroscopicity, poor stability and low bioavailability, which restricts their application in food and medicine fields. A delivery system is commonly used for the encapsulation, protection and delivery of bioactive components. Therefore, choosing a suitable delivery system for FBPs is important for improving the stability and bioavailability of FBPs. This article reviews the major challenges facing the application of FBPs in the food industry, with a focus on the types, characteristics, advantages and disadvantages of FBP delivery systems, and discusses the current problems and future research directions of FBP delivery systems, in order to provide new ideas and guidance for the design, preparation and research of FBP delivery systems.

As a member of the European Union, Portugal is always a leader in food safety management. Portugal exerts strong government supervision over food safety, gives full play to the regulatory role of non-governmental bodies in the food safety chain, and ensures food safety in an all-round way through efficient industry associations, strict enterprise autonomy and diverse consumer supervision, thereby effectively improving the food safety level in the country. In this paper, the food safety governance mode of Portugal is introduced from three aspects: the government, industries and consumers. At the government level, the Economic and Food Safety Administration (ASAE) is the only competent department of food safety governance in Portugal, which has a clear division of labor with other government organizations and performs its duties, providing a solid institutional guarantee for food safety in Portugal. At the industry level, Portugal has established mature industry associations with diverse responsibilities to make up for the government’s deficiencies in food safety governance and Portuguese food enterprises have been able to ensure food safety in the whole production process through the hazard analysis and critical control point (HACCP) system. At the consumer side, the Portuguese Consumer Protection Association, a non-profit private-owned public welfare organization completely independent of the government, speaks for consumers and defends their rights. This provides a good paradigm for the transformation of food safety governance in China from traditional single government governance to social co-governance, which is of reference significance.

Postbiotics are dead bacteria without vital signs and their metabolites. Since many substances in postbiotics are still biologically active and are safer and more stable than probiotics, they are widely used in the prevention and treatment of various diseases. In recent years, many studies have shown that postbiotics can ameliorate obesity by regulating lipid metabolism, which are expected to be a new strategy for the prevention and treatment of obesity. This article introduces the harms and possible pathogenesis of obesity, illustrates the potential mechanism by which postbiotics regulate diseases, and reviews the role of postbiotic bacteria and their metabolites in obesity regulation. This article is expected to provide references for future research on the application of postbiotics in obesity management.