To investigate the water-binding mechanism of fresh sweet potato residue, the water distribution in starch processing residues from 10 varieties of sweet potato was determined by low-field nuclear magnetic resonance (LF-NMR), and the correlation between water states and major organic components was analyzed. Then, the causal relationship was verified through enzymatic hydrolysis experiments. The results showed that three or four states of water were found in the 10 varieties of fresh sweet potato residues, namely compound (T21, 0.658–2.310 ms), immobilized (T22, 7.055–21.550 ms), entrapped (T23, 377.410–705.480 ms) and free flowing water (T24, 705.480–3 764.936 ms). The percentage of entrapped water in sweet potato residues was the highest (93.59% on average), followed by immobilized water (5.15% on average). The percentages of compound water and free flowing water were only 0.85% and 0.41%, respectively. The percentage of entrapped water was significantly positively correlated with the contents of pectin, dietary fiber, and insoluble dietary fiber. The amount of water discharged from sweet potato residues significantly increase after being hydrolyzed by pectinase, but did not significantly change after being hydrolyzed by cellulase, hemicellulase or lignin peroxidase. Under scanning electron microscopy (SEM), it was observed that most of starch particles were encapsulated or bound to cell wall debris. This study can provide a theoretical basis for the development of an efficient dehydration technology for sweet potato residues.

In order to improve the accuracy and efficiency of predictive modeling of the starch content of Huangshui, a byproduct of Baijiu production by solid-state fermentation, spectral information of Huangshui was collected using a Fourier transform near-infrared (FTIR) spectrometer and preprocessed by first derivative. Based on the preprocessed spectra, a predictive model for the starch content of Huangshui was developed using partial least squares regression (PLSR), and its performance was evaluated by determination coefficient (R2) and root mean square error of prediction (RMSEP). As the original spectra contained a lot of redundant information, in order to effectively improve the detection accuracy and to optimize the modeling efficiency, the advantages of different feature extraction methods were combined. Finally, it was found that the PLSR model established by using the spectral features extracted by competitive adaptive reweighted sampling (CARS) combined with the successive projections algorithm (SPA) was significantly better than the model built without feature extraction or using single feature extraction. The results showed that the R2 and RMSEP of the model established using CARS were 0.965 4 and 0.201 2%, while those obtained using CARS-SPA were 0.973 8 and 0.174 8%, respectively. The spectral dimension reduced from 2 203 to 126 after the combination of CARS with SPA, which improved both the prediction accuracy and the modeling efficiency. The method proposed in this study provides an effective means to optimize near-infrared spectral quantitative modeling of starch in Huangshui.

In this study, co-pigmentation with tannin combined with microencapsulation was used to improve the stability of Vitis davidii Foex. anthocyanin. Anthocyanin microcapsules were prepared by vacuum freeze drying using maltodextrin with different dextrose equivalent (DE) values as the wall material. The results showed that the co-pigmented anthocyanin microcapsules with maltodextrin DE12 had the highest encapsulation efficiency of (99.23 ± 0.31)% and the best hygroscopicity and thermal stability. Scanning electron microscopy (SEM) showed that the surface morphology of all four microcapsules was glassy structure. The co-pigmented anthocyanin microcapsules had higher L* and a* values but lower b* value than the unco-pigmented ones. Differential scanning calorimetry (DSC) analysis showed that the co-pigmented anthocyanin microcapsules with maltodextrin DE12 had higher thermal denaturation temperature and thermal stability. Fourier transform infrared spectroscopy (FTIR) confirmed successful microencapsulation of co-pigmented anthocyanin with maltodextrin. The co-pigmented anthocyanin microcapsules with maltodextrin DE12 had good sustained release performance and strong antioxidant capacity. After simulated gastric digestion, the percentage of anthocyanins released from the microcapsules was only (56.84 ± 0.02)%. After simulated intestinal digestion, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the microcapsules was (50.15 ± 0.38)%. Moreover, the degradation kinetics of the microcapsules followed first-order kinetics model and the microcapsules had good storage stability. Microencapsulation could effectively reduce the loss of anthocyanins during the pasteurization of V. davidii Foex. grape juice.

The purpose of this study was to explore the non-covalent interactions between three major polyphenols (chlorogenic acid, caffeic acid and ferulic acid) in coffee and β-lactoglobulin (β-LG) at different pH values and their effects on protein structure by multispectroscopic techniques and molecular docking. The results showed that all three coffee polyphenols statically quenched the fluorescence of β-lactoglobulin under two pH conditions. At pH 7.4 and 298 K, the quenching constants (Ksv) of chlorogenic acid, caffeic acid and ferulic acid for β-lactoglobulin were 6.53 × 104, 3.16 × 104 and 3.09 × 104 L/mol with 1.20, 1.02 and 1.14 binding sites and energy transfer efficiency of 34.55%, 24.56% and 21.35%, respectively. At pH 3.0 and 298 K, the Ksv were 7.18 × 104, 5.24 × 104 and 7.12 × 104 L/mol with 1.28, 1.18 and 1.25 binding sites and energy transfer efficiency of 34.70%, 30.42% and 29.65%, respectively. The results of circular dichroism showed that the α-helix content of β-LG decreased and the β-sheet content increased at pH 7.4, and the β-sheet content increased and the random coil content decreased at pH 3.0. The results of molecular docking showed that the three polyphenols could bind to the hydrophobic pocket of β-lactoglobulin mainly through hydrogen bonds, van der Waals force and hydrophobic interaction. This study preliminarily revealed the interaction mechanism between β-lactoglobulin and chlorogenic acid, caffeic acid and ferulic acid in coffee milk beverage under different pH conditions.

To explore the formation pattern of 5-hydroxymethylfurfural (5-HMF) and the safety of dried longan during processing and storage, this study monitored the changes in 5-HMF content during drying and storage at different temperatures. The changes in the contents of reducing sugar, total acid and total free amino acid and browning degree during processing were determined and their correlation with 5-HMF content was analyzed. Moreover, the safety of dried longan was analyzed using in vitro simulated digestion experiments and a Caco-2 cell model. The results showed that as the drying temperature increased above 85 ℃, the 5-HMF content significantly increased (P < 0.05). The 5-HMF content was positively correlated with the total acid content and browning degree, but negatively correlated with the contents of total free amino acid and reducing sugar. During storage at different temperatures (4, 25, and 37 ℃), the 5-HMF level first increased and then decreased with storage time, and showed different increasing trends under different storage conditions. At 25 ℃, the 5-HMF content began to decline earliest and was lower overall. The 5-HMF content briefly increased during oral digestion, but significantly decreased during gastric and intestinal digestion. The water extract of dried longan inhibited the absorption of 5-HMF and counteracted the cytotoxicity of 5-HMF at 24 mmol/L to Caco-2 cells. These results indicated that optimizing the drying and storage conditions of dried longan can reduce the content of 5-HMF. In the case of normal consumption, the human digestive tract can reduce 5-HMF in dried longan, improving its safety for consumption.

Thermally resistant peptides were obtained from enzymatical hydrolysis of Hongqu rice distiller’s grains and evaluated for its effect on resistance to thermally induced oxidative stress in Saccharomyces cerevisiae. Various proteases were screened for the survival rate of S. cerevisiae under heat stress. The enzymatic hydrolysis conditions were optimized based on the yield of thermally resistant peptides, and the peptides were identified by mass spectroscopy and its antioxidant activity was investigated. The expression of genes in the pentose phosphate pathway and the contents of intracellular coenzyme, glutathione (GSH) and reactive oxygen species (ROS) were analyzed to explore the protective effects of the peptides on S. cerevisiae from heat-induced oxidative stress. The results indicated that the optimal enzymatic hydrolysis conditions were as follows: Hongqu rice distiller’s grains/water ratio 1:10, hydrolysis temperature 50 ℃, hydrolysis time 3 h, protamex dosage 3 000 U/g, and pH 8.5. Under these conditions, the yield of thermally resistant peptides was 62.44%, and the survival rate of S. cerevisiae in the presence of the prepared peptides under heat stress was 73.97%, which was 22.76% higher than that of the control group (pure water). Sequence identification showed that 16 out of the top 20 most abundant peptides had hydrophobic amino acid contents of over 50%. The peptides exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation radical scavenging activity with a half-maximal effective concentration (EC50) of 4.53 and 1.82 mg/mL, respectively, indicating good antioxidant activity. Besides, the thermally resistant peptides upregulated gene expression in the pentose phosphate pathway, elevated NADH kinase activity, increased GSH content by 5.74 times, and restored intracellular ROS to almost the same level as before heat stress treatment, thus enhancing resistance to heat-induced oxidative stress in S. cerevisiae.

In order to improve soy sauce koji making technology and to stabilize its quality, high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the microbial community succession and the changes of total acid, moisture, protease, glucoamylase, amylase and volatile flavor substances during the fermentation of soy sauce koji, and the correlation between microbial community succession and volatile flavor substances was investigated. The results showed that 10 bacterial genera with relative abundance greater than 1% including Weissella, Staphylococcus and Lactobacillus, and three fungal genera with relative abundance greater than 1% including Kodamaea, Aspergillus and Candida were identified, with Weissella, Kodamaea and Aspergillus being dominant throughout the whole fermentation period. With the increase in fermentation time, the moisture content decreased, the total acid content and the activities of protease, amylase and glucoamylase increased, and the total content of volatile flavor substances showed an increasing trend, reaching 4 381.31 μg/100 g at the end of fermentation (48 h). Correlation analysis showed that dominant microorganisms, such as Weissella, Lactobacillus and Kodamaea, affected the activities of protease, glucoamylase and amylase, and significantly influenced the formation of various volatile flavor substances, such as alcohols, aldehydes, esters, acids and pyrazines. This study provides a scientific basis and theoretical foundation for the improvement of the quality of soy sauce koji and the development of koji making technology.

The purpose of this study was to investigate the alleviating effect of Akkermansia muciniphila ONE (AKK ONE) on high-cholesterol diet-induced hypercholesterolemia in mice. Four-week gavage of AKK ONE was found to improve blood lipid levels in hypercholesterolemic mice. Specifically, it significantly reduced the contents of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in serum and liver, increased the content of high-density lipoprotein cholesterol (HDL-C), alleviated liver damage, reduced the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bile acid (TBA), and improved fasting blood glucose levels and glucose tolerance. Further analysis of intestinal flora and metabolites showed that AKK ONE significantly increased the abundance of Faecalibaculum, Oscillospira, Bacteroides and Akkermansia in the intestine of mice, increased the contents of short-chain fatty acids (SCFAs) including acetic acid, isobutyric acid and valeric acid, and regulated the composition of intestinal bile acids (BAs) especially secondary BAs. In summary, AKK ONE improved high cholesterol diet-induced hypercholesterolemia by regulating the abundance of intestinal flora, especially increasing the abundance of SCFAs-producing bacteria, thereby increasing the contents of fecal SCFAs and enhancing the transformation of cholesterol into BAs. This study provides a new insight into the relationship between next-generation probiotics and intestinal flora and metabolites, which will serve as the basis for the potential application of AKK ONE in alleviating hypercholesterolemia.

Objective: To investigate the protective effect of fermented Lycium barbarum polysaccharides (FLBP) on the intestine in an aging mouse model. Methods: The aging model was established by continuous subcutaneous injection of 1 000 mg/(kg mb · d) D-galactose in the back of the neck, followed by gavage of low (150 mg/(kg mb · d)) and high (300 mg/(kg mb · d)) doses of FLBP. After 10 weeks, body mass, organ indexes, serum inflammatory markers and anti-inflammatory indicators including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and IL-10 levels, intestinal permeability, intestinal barrier damage biomarkers such as lipopolysaccharide (LPS) and lipopolysaccharide binding protein (LBP) contents, the histological structure of the colon, colonic mucin 2 (Muc2) expression, intestinal flora composition and fecal short-chain fatty acid contents were detected and analyzed. Results: High-dose FLBP antagonized D-galactose-induced growth retardation and thymus atrophy, decreased the serum levels of TNF-α, IL-1β and IL-6 and significantly increased serum IL-10 levels in the aging mice (P < 0.05). Furthermore, FLBP significantly ameliorated colonic barrier damage in mice, as evidenced by a significant decrease in intestinal permeability, LPS and LBP contents (P < 0.05), alterations in colonic tissue structure, and a significant increase in MUC2 secretion (P < 0.05). Meanwhile, FLBP regulated the gut microbiota composition by changing the α- and β-diversity, increasing the relative abundance of the beneficial bacteria norank_f_Muribaculaceae and Lactobacillus, and decreasing the relative abundance of the harmful bacteria Atopostipes and Jeotgalicoccus, and increasing the fecal contents of acetic acid, propionic acid, valeric acid and isobutyric acid significantly (P < 0.05). Conclusion: High-dose FLBP reduced circulating pro-inflammatory cytokine levels and enhanced anti-inflammatory function in aging mice, which might be related to improving colonic barrier function, regulating the intestinal flora composition, and increasing the levels of beneficial SCFAs in the intestinal tract of mice. This study provides a theoretical reference for the application of FLBP as a functional food ingredient for intestinal health.

Objective: To investigate the antioxidant effect of peptides from Argopecten irradians and its protective effect and mechanism against ethanol-induced alcoholic liver injury in mice. Methods: A. irradians peptides were prepared by two-step enzymatic hydrolysis followed by membrane separation. The in vitro antioxidant activity of A. irradians peptides, the activating effects on superoxide dismutase (SOD) and alcohol dehydrogenase (ADH) and the potential to promote alcohol metabolism were evaluated. The protective effect and mechanism against alcoholic liver injury in mice were investigated by measuring the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum, and the activities of ADH, acetaldehyde dehydrogenase (ALDH), glutathione peroxidase (GSH-Px), catalase (CAT) and SOD and malondialdehyde (MDA) content in the liver of a mouse model of acute alcoholism. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze the peptide sequences. PeptideRanker and AnOxPePred 1.0 tools were used to predict the potential biological activity of peptides and conduct molecular docking analysis of the peptide with the strongest antioxidant activity to ALDH. Results: Peptides with molecular mass between 200 and 1 000 Da constituted approximately 70.38% of the total peptides. Antioxidant amino acids accounted for 68.75% of the total amino acids. In vitro experiments showed that the half maximal inhibitory concentration (IC50) values of A. irradians peptides were 19.43, 4.53 and 2.19 mg/mL in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging and Fe2+ chelating assays, respectively. At 5 mg/mL, the hydrolysate of A. irradians activated SOD and ADH by 19.83% and 18.18%, respectively, demonstrating good antioxidant activity and anti-alcoholic potential. In vivo experimental results showed that A. irradians peptides significantly reduced the levels of ALT and AST in mouse serum, enhanced the activity of ADH, ALDH, GSH-Px, SOD and CAT, and reduced the content of MDA. Using PeptideRanker and AnOxPePred 1.0 tools, 44 identified peptides were screened, and 6 of them met the criteria for molecular docking screening. Molecular docking revealed that they had strong binding capacity to ALDH. Among them, DQPHFPF and YSTHPHF formed 7 and 3 hydrogen bonds with ALDH, respectively, which could be activated through molecular interactions with ALDH. Conclusion：This study provides a theoretical reference for the application of peptides products from A. irradians for curing alcohol and protecting liver.

In order to study dynamic changes and variations in aroma between single- and double- petal jasmine flowers (Jasminum sambac) during the opening process, headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS) was used for qualitative and quantitative analysis of jasmine aroma components at different opening periods. The results showed that phenylacetaldehyde, methyl anthranilate, methyl benzoate, α-farnesene, benzyl acetate were the major aroma components of jasmine flower. The contents of aroma components such as β-ethyl phenylacetate, methyl anthranilate, α-stigmasterol and α-farnesene in single-pedal jasmine flowers initially increased and subsequently decreased during the opening process, and so did the contents of aroma components such as benzyl acetate, cis-3-hexenyl benzoate and benzyl benzoate in double-petal jasmine flowers, being higher at the end than in the beginning of the opening period. In addition, benzaldehyde, phenylacetaldehyde, and β-ethyl phenylacetate were the key substances responsible for the fresh and clean aroma of single-pedal jasmine flowers, while hexyl benzoate, cis-3-hexenyl benzoate, and α-farnesene were the key substances contributing to the strong floral aroma of double-petal jasmine flowers. This study provides a basis for the application of single-pedal jasmine flowers in jasmine tea production.

To investigate the distribution of flavor components in Luzhou-flavor base baijiu from different aged cellars, the aroma components in 18 samples of Luzhou-flavor base baijiu from three cellars of different ages were identified and quantified by direct injection (DI), liquid-liquid extraction (LLE) or vortex-assisted surfactant-enhanced emulsification liquid-liquid microextraction (VSLLME) combined with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The differences in flavor among different base baijiu samples was analyzed by chemometrics methods such as principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and Spearman’s correlation coefficient. The results suggested that 151, 154 and 159 volatile compounds were identified in base baijiu from freshly prepared cellar and those aged over 30 and 100 years. In total, 148 aroma compounds were common to the three base baijiu, accounting for 93.1% of the total number of identified compounds. The quantitative analysis of 61 major aroma compounds showed that the concentrations of ethyl caproate, ethyl butyrate, hexanoic acid, butyric acid and acetic acid in base baijiu from each cellar exceeded 100 mg/L. The concentration of ethyl caproate was the highest, ranging from 1 156.4 to 2 142.2 mg/L. Chemometric results indicated that the flavor similarity of base baijiu between the new and over-30-year-old cellars was higher when compared with the cellar aged over 100 years. This findings further strengthen the baijiu industry’s conventional knowledge of the influence of cellar age on the flavor of Luzhou-flavor baijiu.

To reveal the chemical composition profile of Camellia ptilophylla, a rare natural low-caffeine tea variety, non-targeted metabolomics based on high-resolution mass spectrometry (HR-MS) was employed to identify the metabolite composition of green tea and black tea from C. ptilophylla and C. sinensis var. assamica. Additionally, the metabolomic differences between the two types of tea and between the two tea varieties were analyzed using principal component analysis (PCA), cluster analysis (CA), and orthogonal partial least squares-discriminant analysis (OPLS-DA). Differential metabolites were identified using standards and database. A total of 152 metabolites were identified in the four tea samples, the major ones being flavonoids (42%). These metabolites were categorized into four clusters. The metabolomic difference between C. ptilophylla and C. sinensis var. assamica was more pronounced than that between green and black teas. Notably, 24 metabolites including theasinensin B isomers, theobromine and 14 flavonoids such as tetrahydroxyxanthone and epitheaflagallin 3-O-gallate, which were more abundant in C. ptilophylla green tea than in C. sinensis green tea, were considered as the characteristic metabolites of C. ptilophylla green tea. In black tea from C. ptilophylla, 40 characteristic metabolites were identified including 25 flavonoids such as gallocatechin-3,5-digallate, tetrahydroxyxanthone and dihydromyricetin; 4 tannins such as theaflavin 3-gallate, theasinensin A isomers and theaflavin 3,3’-digallate; and theobromine. This study provides a reference for further exploration of bioactive compounds in C. ptilophylla.

In this study, headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) and odor activity value (OAV) analysis were used to investigate the changes in aroma components of Baiyaqilan oolong tea before and after roasting. The results showed large differences in the types and contents of aroma components in Baiyaqilan tea before and after roasting. The major aroma components before roasting included geraniol, dehydrolinalool, cis-bergamotene, phenylethanol, phenylacetaldehyde, cis-jasmone and geranyl acetone. The major aroma components after roasting included geraniol, dehydrolinalool, oxopholone, cis-jasmone, geranylacetone, cis-coumarin, phenylethanol, phenylacetaldehyde, safranal, trans-2-decenal, oxoisophorone, cis-bergamotene, cosmene, cis-linalool oxide, and 2-pentylfuran. The changes in aroma of Baiyaqilan tea after roasting were attributed to mechanisms such as volatilisation of low-boiling substances, conversion of α-lonone, thermal decomposition of glycosides, oxidation of alcohols, peroxidative decomposition of lipids, and conversion of terpenes and alcohols, resulting in the production of oxopholone, cis-linalool oxides, and 2-pentylfuran as well as a substantial increase in the contents of safranal, trans-2-decenal and cosmene. In summary, this study revealed that the roasting process produced aroma components, altering the aroma profile of oolong tea, and for the first time it was found that the roasting process could lead to the production of the key aroma components including oxopholone. These results provide a reference for in-depth understanding of the effect of the roasting process on the aroma components of oolong tea.

To understand the composition and dynamic changes of primary metabolites in ‘Fuhong’ plum fruits during refrigeration, the primary metabolite profile of ‘Fuhong’ plum fruits stored at 4 ℃ for 0, 30, and 60 days was analyzed using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Differential metabolites were selected by orthogonal partial least squares-discriminant analysis (OPLS-DA) and subjected to pathway enrichment analysis. The results showed that a total of 573 metabolites were identified, including sugars, organic acids, amino acids and their derivatives, lipids, and nucleotides. There was a significant difference in primary metabolite profile between the three storage times, and 95 differential metabolites at day 30 vs. 0, 99 differential metabolites at day 60 vs. 30, and 173 differential metabolites at day 60 vs. 0 were identified. The pathway enrichment analysis showed that the major metabolic pathways with a significant difference included linoleic acid metabolism, unsaturated fatty acid biosynthesis, propionic acid metabolism, sulfur metabolism, purine metabolism, nucleotide metabolism, cysteine and methionine metabolism. This study provides a theoretical basis for the quality evaluation and postharvest preservation of ‘Fuhong’ plum fruits.

In order to investigate the composition and changing pattern of metabolites during the brewing process of goji wine, this study analyzed the changes of metabolites at three stages (pretreatment, primary fermentation and aging) during the brewing process using the widely targeted metabolomics based on ultra-high performance liquid chromatography-electrospray-triple quadrupole linear ion trap-tandem mass spectrometry (UPLC-ESI-QTRAP-MS/MS). The results showed that a total of 1 092 metabolites, including 195 flavonoids, 193 phenolic acids, 174 alkaloids, 121 lipids, 85 organic acids, 80 amino acids and their derivatives, 48 nucleotides and their derivatives, 45 lignans and coumarins, 35 terpenoids, 10 steroids, and 106 other substances were identified during the brewing process of goji wine. Volcano plots identified 260, 619 and 130 differential metabolites for the pretreatment, primary fermentation and aging stages, respectively. These differential metabolites were dominated by lipids, phenolic acids, flavonoids and alkaloids. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the lysine degradation pathway, the valine, leucine and isoleucine biosynthesis pathways, the phytohormone signal transduction pathway, and the flavonoid biosynthesis pathway were significantly enriched during the brewing process of goji wine. This study provides data support for understanding the changes of metabolites during the brewing process of goji wine, and provides a theoretical basis for optimizing the brewing process of goji wine and developing goji-based functional products.

This study used widely targeted and targeted metabolomics based on headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) to analyze the non-volatile metabolites, volatile metabolites, and major quality components in congou black teas produced from the high-aroma black tea cultivars ‘Jinmudan’ and ‘Jinguanyin’, and it explored the differences in chemical characteristics between the two teas. The results showed that a total of 1 318 non-volatile metabolites were identified in the two teas, and the differential metabolites between them were most enriched in flavonoid-related synthesis pathways. Among them, catechins and quercetin-3-O-glucoside were significantly upregulated in ‘Jinmudan’ black tea, while chrysin and apigenin-7-O-neohesperidoside were significantly upregulated in ‘Jinguanyin’ black tea. A total of 759 volatile compounds were identified, among which 12 compounds, including β-ionone, geraniol, decanal and methyl benzoate, were the key aroma components of both teas. The results of relative odor activity value (ROAV) analysis indicated that aroma components such as indole, δ-decanolactone, trans-nerolidol, phenylacetaldehyde and jasmonone responsible for floral, fruity and milky aroma characteristics were more abundant in ‘Jinmudan’ black tea, which may be the key compounds contributing to the floral, fruity and peach-like aromas of ‘Jinmudan’ black tea. Aroma components such as methyl salicylate, (Z)-3-hexenol, and hexanol responsible for fresh and floral aromas were more abundant in ‘Jinguanyin’ black tea, which may be the key compounds contributing to its long-lasting aroma. The results of this study are helpful to elucidate the flavor and quality characteristics of ‘Jinmudan’ and ‘Jinguanyin’ black tea, providing a scientific basis for the development of black tea products from the excellent high-aroma tea cultivars ‘Jinmudan’ and ‘Jinguanyin’.

In order to systematically reveal the differences in flavor quality among green, yellow and black vine teas, processed from the young stems and leaves of Ampelopsis grossedentata by different techniques, sensory evaluation, physicochemical analysis and headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) were used to analyze the quality of green, yellow and black vine teas. Sensory evaluation results showed that yellow vine tea was covered by a silver white powder, and its infusion had a bright yellow color, strong fruity aroma and mellow taste; green vine tea had a yellowish-green color, and its infusion had a bright greenish-yellow color, strong stir-fried aroma and slightly bitter taste; black vine tea had a reddish-brown color, and its infusion had a bright orange-red color, strong floral and fruity aroma, and mellow taste. Taste composition analysis showed that the contents of soluble sugar, water extract, and dihydromyricetin were all higher in green vine tea than in yellow and black vine teas, while the content of free amino acids in black vine tea was the highest. A total of 56 volatile components were identified in the three vine teas, with hydrocarbons being dominant in green and yellow vine teas while alcohols being dominant in black vine tea. 1,1,6-trimethyl-1,2-dihydronaphthalene, stigmasterol, lauryl alcohol and linalool were closely related to the stir-fried aroma of green vine tea, while phenylacetaldehyde, naphthalene, 2-pentylfuran, P-umbelliferyl hydrocarbons, and n-tetradecane were closely related to the fruity aroma of yellow vine tea, and phenylacetaldehyde, methyl salicylate, 1,1,6-trimethyl-1,2-dihydronaphthalene contributed to the floral and fruity flavor of black vine tea.

This study aimed to compare the effects of optimal medium-high pressure coupled with heat treatment (OPH), optimal ultra-high pressure treatment (OP) and traditional two-stage heat treatment (H) on the quality characteristics of Nemipterus virgatus sausages during a refrigerated storage period of 60 days. During storage, changes in freshness indexes such as total bacterial count, total volatile basic nitrogen (TVB-N) content, thiobarbituric acid (TBA) value, pH and conductivity were determined as well as gel properties such as gel strength, water-holding capacity, whiteness and textural properties. The results showed that the total bacterial count, TVB-N content, TBA, conductivity and cooking loss of sausages increased gradually with storage time, while the sensory score, water-holding capacity, whiteness, gel strength, and textural properties progressively decreased. The pH increased first and then decreased. On the 60th day of refrigeration, TVB-N content was 14.04% and 27.12% lower and TBA value was 11.76% and 23.73% lower in the OPH treatment group than in the H and OP treatment groups, respectively. Additionally, the gel strengths of the H, OPH, and OP treatment groups were 2 365.82, 3 229.36 and 1 905.53 g·cm, respectively, and their water-holding capacities were 71.25%, 74.03% and 68.86%, respectively. In summary, OPH treatment was able to better maintain the quality of fish sausages and slow down flavor changes during refrigerated storage.

This study was carried out in order to investigate the effect of high-voltage electrostatic field (HVEF) treatment on the quality of fermented Engraulis japonicus. E. japonicus protein hydrolysate (EJPH) was inoculated with Lodderomyces elongisporus and fermented for different periods of time with different electric field action and intervention times. The fermentation conditions were optimized based on amino nitrogen content and sensory evaluation scores. Furthermore, the effect of HVEF treatment on the pH, total acid concentration and flavor of fermented EJPH was explored. The free amino acid composition of fermented EJPH was analyzed and its nutritional quality was evaluated based on essential amino acids. Its flavor composition was analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that when the fermentation time was 15 days, electric field intervention time was 40 h after inoculation, and electric field treatment time was 30 min, the flavor and quality of the fermentation product were the best. Its amino nitrogen content was 0.72 g/100 mL, and the fermentation product had a strong fresh aroma along with a fruity aroma. The total amount of free amino acids was 54.798 mg/mL. The contents of umami and sweet amino acids were higher and the content of bitter amino acids was lower in the fermentation product than in the control group without HVEF treatment. The essential amino acids index (EAAI) value of the fermentation product with HVEF treatment was 71.07, indicating good nutritional quality. The HS-SPME-GC-MS results showed that compared with the control group, the HVEF group showed increased contents of aroma-active substances such as acids, alcohols and esters, and decreased contents of unpleasant flavor compounds such as straight-chain saturated aldehydes and fuel oil. Therefore, under appropriate conditions, HVEF treatment can improve the flavor quality of fermented E. japonicus.

This research investigated the impacts of various drying methods, including hot-air drying, hot-air-microwave drying, heat-pump drying, vacuum-freeze drying, microwave-vacuum drying, and multi-stage hot-air drying, on the physicochemical properties, antioxidant capacity and flavor profile of Lentinus edodes powder (LEP). The results demonstrated that vacuum-freeze-dried LEP was superior to LEP produced using the other drying methods in terms of physicochemical properties such as water absorption index, expansion ratio, and color. Moreover, vacuum-freeze-dried LEP had the highest total phenolic content (1.345 mg/g) and strongest antioxidant capacity in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging capacity. In contrast, microwave-dried LEP showed the lowest antioxidant capacity. Analysis by electronic nose and gas chromatography-ion mobility spectrometry (GC-IMS) revealed that the major volatile compounds in the six LEPs included sulfur-containing compounds, aldehydes, alcohols, ketones, and esters, and there were significant differences in the aroma profiles of these LEPs. Notably, heat-pump-dried LEP exhibited the highest levels of alcohols and esters. Hot-air-dried LEP exhibited the highest levels of aldehydes. Vacuum-freeze drying was conducive to retaining aroma compounds. The results of electronic tongue analysis indicated that hot-air-microwave dried LEP had high umami and low bitterness. These findings could provide a theoretical foundation for the development and application of LEP as a food ingredient.

To study the relationship between oxidative stress and mitochondrial damage during post-slaughter chilling, M. longissimus dorsi from Tan sheep was treated with the antioxidant N-acetyl-L-cysteine (NAC) solution or physiological saline and stored at 0–4 ℃. After 0, 2, 4, 6 and 8 days, the opening degree of mitochondrial permeability transition pore (MPTP), membrane potential, reactive oxygen species (ROS) content, complex I, II, III and IV activities, the activities of succinate dehydrogenase (SDH), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) content were determined, and the mitochondrial structure of myoblasts was observed under transmission electron microscopy (TEM). The results showed that the opening degree of MPTP in both the NAC and control groups gradually increased (P < 0.05) during the postmortem maturation process, and so did the ROS and MDA levels (P < 0.05). The mitochondrial membrane potential and the activities of complexes I, II, III and IV, SDH, CAT, SOD and GSH-Px showed a gradual decreasing trend (P < 0.05). It can be concluded that oxidative stress occurred in the muscle tissue of Tan sheep after slaughter, resulting in a significant increase in ROS content. Excessive ROS, exceeding the ability of the antioxidant defense system to scavenge it, could lead to an imbalance in the redox system, which could in turn accelerate the increase of ROS levels, thereby triggering the opening of MPTP and a decrease in the mitochondrial membrane potential, finally resulting in serious mitochondrial damage. However, NAC alleviated this phenomenon. Increased ROS levels impaired the normal operation of the mitochondrial electron transport chain, thus leading to increased mitochondrial damage. In addition, the lipid oxidation product MDA also damaged the function and structure of mitochondria, causing mitochondrial structural damages such as swelling and deformation, and finally leading to biological dysfunctions.

In this study, the mechanism of film formation through glutathione-induced lysozyme interface assembly was verified by spectroscopic methods, and the formed film was characterized by ellipsometry. N-(1-pyrenyl)maleimide (NPM) staining demonstrated that reduced glutathione broken the disulfide bonds of lysozyme leading to release of free sulfhydryl groups. Together, tryptophan fluorescence spectroscopy and lysozyme activity assay verified that the disulfide bond Cys6-Cys127 in lysozyme was broken. In addition, the unfolded lysozyme was found to still have antibacterial activity. The lysozyme film was transparent and colorless. Atom force microscopy (AFM) and transmission electron microscopy (TEM) revealed that it was composed of lysozyme aggregates with a uniform, smooth and dense surface. The results of X-ray photoelectron spectroscopy (XPS) and laser confocal Raman spectroscopy (LCRS) indicated that the lysozyme nanofilm might possess interfacial adhesion. The results of ellipsometry showed that the maximum thickness of the film was approximately 900 nm, and did not increase without limit with the increase in incubation time or the concentration of the reactants. Its stiffness value, elastic modulus and hardness were 29.32–34.21 μN/nm, 24.00–27.93 GPa, and 0.44–0.49 GPa, respectively, which were in the strength range of the protein film. The three-phase contact angle of the film was around 70°, indicating good hydrophilicity. Its thermal stability was high, and no degradation occurred at 200 ℃. The preparation of the lysozyme nanofilm provides a good idea and reference for the construction of novel edible coatings.

In this study, the optimal conditions for inducing the spore germination of Alicyclobacillus acidoterrestris were determined, and the effect of spore induction pretreatment on the quality of ultra-high pressure (UHP) treated ‘Hanfu’ apple juice was explored. Meanwhile, the changes of nutritional quality and volatile flavor during storage were investigated. The results showed that the optimal induction conditions were as follows: activation temperature of 41 ℃, activation time of 15 min, L-alanine concentration of 38 mmol/L, induction temperature of 40 ℃, and induction time of 20 min. Induced spore germination of A. acidoterrestris combined with UHP treatment reduced the microbial load of ‘Hanfu’ apple juice to less than 1 (lg(CFU/mL)), and improved the phenolic content and total antioxidant capacity compared with UHP treatment. Electronic tongue analysis showed that the taste of ‘Hanfu’ apple juice subjected to the combined UHP treatment was well preserved during refrigeration. Compared with UHP treatment, the combined treatment significantly increased the types and amount of aroma compounds as determined by solid phase microextraction (SPME) coupled to gas chromatography-mass spectrometry (GC-MS). This study provides an important theoretical basis for the cold sterilization of ‘Hanfu’ apple juice and provides a new idea for the industrial application of ‘Hanfu’ apple deep processing.

The purpose of this study was to construct a vanadium carbide-based immunochromatographic assay for the sensitive detection of T-2 toxin in maize. Vanadium carbide nanosheets (VCNSs) were synthesized by ultrasonic-assisted liquid phase exfoliation, and conjugated with T-2 monoclonal antibody (T-2-mAb) as a signal probe. Based on the competition principle, the T-2 toxin in samples competed with the T-2 antigen on the test (T) line for binding to the black VCNSs-mAb probe. As a result, the T-line value was inversely proportional to T-2 toxin concentration. The best experimental conditions and the standard curve were established based on color development in the T-line of the blank test strip (signal value > 800, detected using an MD-600 reader) and the inhibition rate of 0.5 and 1.5 ng/mL T-2 toxin. The results showed that the linear range of the proposed method was between 0.14 and 0.78 ng/mL, the visual detection limit was 0.25 ng/mL, the cut-off value was 1.5 ng/mL, and the half maximal inhibitory concentration (IC50) was 0.344 ng/mL. The sensitivity was 6.6 times higher than that of the traditional colloidal gold test strip. In addition, the assay did not cross-react with five other common mycotoxins. Moreover, the recoveries for real maize samples ranged from 92.8% to 117.2% with coefficients of variation (CV) of less than 9.13%, and the detection limit of 5.06 μg/kg. In summary, this method is characterized by simple operation, rapid sensitivity and low cost, which enables on-site rapid detection of T-2 toxin in cereals.

A method for the determination of trimetazidine and clomiphene in animal-derived foods was developed by mixed-mode reversed-phase strong cation exchange solid phase extraction cleanup followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Samples were extracted with 0.5% (V/V) formic acid in acetonitrile, and purified on a mixed-mode reversed phase strong cation exchange column (PRiME MCX). The chromatographic separation was performed on a Waters ACQUITY UPLC HSS T3 column by gradient elution using a mobile phase composed of acetonitrile and 0.1% formic acid. The analytes were detected in the positive ion mode using multiple reaction monitoring (MRM). Quantification was performed by the internal standard method. The results showed that good linearity was observed for trimetazidine and clomiphene in the concentration range of 0.3–100.0 ng/mL with determination coefficients (R2) > 0.999. The average recoveries of this method ranged from 93.4% to 112.1%, with relative standard deviations (RSDs) of 0.68%–4.81% (n = 6). The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.1 and 0.3 μg/kg, respectively. The developed method is sensitive, stable, practical, and suitable for the determination of trimetazidine and clomiphene in animal-derived foods, which can provide effective technical support for food safety assurance for sports events.

In this study, a highly sensitive and selective electrochemical aptamer sensor (6-mercapto-1-hexanol (MCH)/Apt/AuNPs/rGO-PANi) for acetamiprid (ACE) was prepared based on Au nanocomposites (AuNPs)/reduced graphene oxide (rGO)-polyaniline (PANi). The morphology and structure of the synthesized nanomaterial and the interface of different electrodes were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and scanning electron microscopy (SEM)/ energy dispersive X-ray spectrometry (EDX). The electrochemical properties of different electrodes were studied by cyclic voltammetry and electrochemical impedance spectroscopy, and it was found that the AuNPs/rGO-PANi modified electrode showed a large electrochemical active area and excellent electrochemical properties, which could provide an ideal platform for aptamer fixation and electrochemical sensing of ACE. Under optimal conditions, the linear range of MCH/Apt/AuNPs/rGO-PANi for ACE detection was 1.0–100 000.0 ng/L, and the detection limit was 0.15 ng/L at a signal-to-noise (RSN) of 3. A 100-fold excess of common co-existing pesticides did not significantly interfere with the detection of ACE. The prepared aptamer sensor was applied to the detection of cucumbers and sweet potato leaves with recoveries ranging from 94.5% to 98.5%. The accuracy of the developed method was verified by liquid chromatography-mass spectrometry (LC-MS).

The oil body is an organelle that stores oil in oil crop seeds. The presence of a phospholipid-protein membrane on its surface allows for the dispersion of oil bodies in water, resulting in the formation of a stable water-in-oil emulsion. Oil bodies hold immense potential in the food industry due to its exceptional physicochemical stability and emulsifying properties. The extraction and stability of oil bodies has always been a research hotspot, driven by the need for enhanced extraction efficiency and applicability. There are diverse extraction methods and conditions for plant oil bodies, which can be generally classified into three categories: water extraction, solution extraction, and enzyme-assisted extraction. The choice of extraction methods depends on plant sources and applications. The stability of oil bodies is assessed from physical, chemical, and biological aspects. This comprehensive review summarizes the commonly employed evaluation methods with the aim of encouraging further research and application of oil bodies.

Glycosidase is an indispensable enzyme in the sugar industry. It is difficult to maintain the stability of natural glycosidase during long-term high-temperature sugar conversion, limiting its application in industrial production. Numerous studies have shown that protein engineering is an important means for enhancing the thermal stability of glycosidase. This article systematically reviews the latest advances in using protein engineering to improve the thermal stability of glycosidase, and dissects the directed evolution, rational design, and semi-rational design strategies used in protein engineering. It also evaluates the effectiveness of these strategies in enhancing the thermal stability of glycosidase and their potential industrial application value, and presents the advantages, limitations and challenges of each strategy. Finally, it suggests that different strategies should be jointly used to improve the thermal stability of glycosidase and gives an outlook on future research directions with a view to promoting the synergistic improvement of the thermal stability and activity of glycosidase.

Food bioactive compounds, such as polyphenols, carotenoids, functional proteins and unsaturated fatty acids, have been used as important ingredients of functional foods due to their diverse biological activities. However, the low aqueous solubility, poor stability and limited bioavailability of these compounds limit their applications in the food industry. The preparation of delivery carriers from natural food macromolecules offers a promising approach to enhance the solubility, stability, and bioavailability of bioactive compounds. As a novel delivery system, intelligent responsive delivery carriers enable precise targeted and controlled release of bioactive compounds, thus improving their bioavailability. In addition, the delivery carriers have the capacity to effectively improve the added nutritional value, enhance the sensory properties, and extend the shelf life of functional foods. This review summarizes the functional properties of food bioactive compounds, the challenges in their application and their steady-state delivery strategies, with a particular emphasis on the common intelligent responsive delivery carriers and their mechanisms of action. Finally, this article discusses the application of these delivery carriers in functional foods, and provides an outlook on future research on bioactive compound delivery systems.

Probiotics are defined as a group of active microorganisms that are safe, non-pathogenic and beneficial to host health, and Bifidobacterium is one of the most studied intestinal probiotics. In recent years, research on the metabolites and health-promoting mechanisms of Bifidobacterium has attracted attention. This probiotic is able to utilize nutrients through fermentation to produce different types of beneficial metabolites such as short-chain fatty acids, phenolics, amino acids, and vitamins. A series of complex metabolic processes are involved in the production of these advantageous metabolites, which have a favorable effect on host health and show promise for applications in probiotic preparations and food additives. Bifidobacterium fermented products are progressively being utilized in the development of probiotic drinks, yogurt and functional foods. Therefore, this article briefly describes the production pathways, health benefits and application of beneficial metabolites of Bifidobacterium, aiming to provide a reference for the development and application of Bifidobacterium metabolites in the food, pharmaceutical and nutraceutical fields.

Whole-wheat foods are rich in various nutrients. Long-term consumption of whole-wheat foods can prevent chronic metabolic diseases, which has become a new trend in the healthy transformation of the grain industry. However, a standard system for whole-wheat foods is currently lacking, so product quality in the market is uneven. Consequently, developing a rapid and accurate method for authenticity identification and quantitative detection of whole-wheat foods is important for standardizing the market order. In this review, we briefly introduce the definition, standards and current detection status of whole-wheat foods, set forth the basis for the use of the whole wheat marker alkylresorcinols for the quality evaluation of whole-wheat foods, and summarize the quantitative detection methods of alkylresorcinols. Finally, we give an outlook on the future prospects and advantages of nanomaterials and bionics technology in the detection of whole-wheat foods, aiming to provide scientific references for the authenticity discrimination and quantitative analysis of whole-wheat foods.

Whey protein contains a wide range of bioactive components and has been found to have various functional properties including immunoenhancing, antibacterial, antiviral, anticancer, antidiabetic, muscle loss-preventing, and skin-protecting effects. However, as a high-quality dietary protein that can benefit human health, its application in health foods is restricted by particular product types and insufficient innovation. Therefore, this article provides a systematic and comprehensive review of the composition, digestion, absorption, metabolism, and functions of whey protein and its application in health products in China. This review hopes to improve the public’s understanding of the nutritional value of whey protein, broaden its application scope as a health product, and promote its applications in functional foods and clinical formulations and consequently the high-quality development of the health industry.

Monitoring of food chemical hazards (FCHs) is crucial to ensure food quality and safety. Non-targeted screening (NTS) is an effective technique to identify a wide range of potential and unknown FCHs using high performance liquid chromatography/high performance gel chromatography-high resolution mass spectrometry (HPLC/HPGC-HRMS) platforms with strong separation capability, high mass resolution and high mass accuracy. However, the development and application of NTS methods are still challenging due to the wide variety of FCHs, the large amount of acquired data, and the cumbersome analysis process. Selecting an appropriate data acquisition mode and an effective non-targeted data analysis strategy are essential to successfully identify potential and unknown FCHs. This paper reviews the data acquisition modes, analysis processes and strategies involved in NTS and the application of NTS for FCHs screening in the past five years, in order to promote the development of NTS methods for FCHs and to provide support for the early warning of risk factors in foods and food safety monitoring.

As dietary habits and the quality of life change, the incidence of non-alcoholic fatty liver disease has increased year by year and has become one of the major public health problems in the world. Due to the complexity of the disease, no drug has been approved for its treatment. Propolis is a natural gelatinous product with extensive pharmacological activities, which can be used in clinical treatment of coronary heart disease, diabetes, hypertension, hyperlipidemia and other diseases. Studies have shown that propolis and its phenolic compounds have pharmacological activities such as hypolipidemic, antioxidant and anti-inflammatory effects, making them promising in alleviating non-alcoholic fatty liver disease. Therefore, this article reviews recent studies on propolis and its phenolic compounds in alleviating non-alcoholic fatty liver disease in order to provide a theoretical reference for research on the alleviative effect of propolis on non-alcoholic fatty liver disease.

The use of organochlorine and organophosphorus pesticides has been prohibited due to their highly toxicity. In recent years, pyrethroids (PYRs) have been widely used in agricultural production and the environment due to their high efficiency and stability, but the residual hazards caused by their frequent use have become increasingly prominent. 3-Phenoxybenzoic acid (3-PBA) is one of the major metabolites of PYRs, which is an environmental estrogen with great potential harms. Pesticide residues have seriously affected people’s production and life, which has attracted extensive attention from researchers. PYRs and 3-PBA degrading bacteria have been widely reported, and microbial and enzymatic degradation is recognized as an effective method for reducing or removing pesticide residues from agricultural products and the environment. The continuous development of genetic engineering and molecular biology technology provides a new way to explore methods for reducing pesticide residues. In this article, we summarize the basic properties and residual hazards of PYRs and 3-PBA, and we review the current status of PYRs residues in agricultural products and the environment as well as recent progress in research on the modes of microbial metabolism and the mechanisms of microbial adsorption and degradation of PYRs. Moreover, we give an outlook on enzymes degrading PYRs and their genetic engineering in order to provide a reference for solving the problem of pesticide residues in agricultural products and the environment.

Wine is a complex solution system generated by physical, chemical and biological transformation of grape berries. Traditional methods for wine authenticity identification and quality control are cumbersome and time-consuming, and therefore cannot meet the needs of mass production. Spectroscopic techniques can simplify the procedure of wine analysis, shorten the analysis time, and enable simultaneous analysis of multiple components. Therefore, spectroscopic techniques have been widely used to assess wine quality and identify the geographical origin, variety, age and authenticity of wine. Furthermore, the combination of spectroscopic techniques and chemometrics allows the identification or modeling of key chemical markers, providing rapid, accurate, non-destructive and real-time detection for wine analysis and quality control. In this article, we summarize the theoretical basis for the application of ultraviolet-visible (UV-Vis), infrared, fluorescence and Raman spectroscopy for wine analysis. Furthermore, we review the current status of the application of spectroscopic techniques in conjunction with chemometrics for wine traceability, quality control and authenticity identification. Finally, we discuss the challenges that spectroscopic techniques face when applied in practice and propose possible solutions to these challenges.

Colorectal cancer is a heterogeneous disease of the intestinal epithelium characterized by the accumulation of genetic mutations and the dysregulation of immune responses. The occurrence of colorectal cancer is the result of a combination of environmental, genetic and other factors. Among environmental factors, dietary factors are closely related to the occurrence of colorectal cancer. Dietary factors play an important role in regulating the intestinal microbiota. In addition, the composition and metabolism of the intestinal microbiome are important contributors to the development of colorectal cancer. Specific intestinal microorganisms such as Fusobacterium nucleatum have been shown to be closely correlated with the occurrence of colorectal cancer. Regulating gut microbiota has emerged as a potential means of preventing and treating colorectal cancer. In order to provide a theoretical reference for the clinical treatment of colorectal cancer, this article reviews the intervening effects of probiotics, next-generation probiotics and their metabolites on colorectal cancer, with a focus on the current status of research on the biological effects of various metabolic secretion products of probiotics, including cell-free supernatants, extracellular polysaccharides, short-chain fatty acids, bacteriocins, bacterial enzymes, bile acids and tryptophan metabolites on colorectal cancer.

Immunochromatographic assay (ICA) has been widely used in various fields for its economy, simplicity, sensitivity and specificity. The application of colloidal gold nanoparticles in ICA has limitations in quantification and interference resistance. Fluorescent nanomaterials have become an important signal label in ICA due to their excellent optical properties. This article briefly describes the preparation and properties of fluorescent nanolabels, such as quantum dots, up-conversion nanoparticles, time-resolved fluorescent microspheres, and persistent luminescence nanoparticles. The focus of this review is the application of fluorescence immunochromatography in the detection and analysis of foodborne pathogens, mycotoxins, pesticides, veterinary drugs, antibiotics, hormones, endocrine disruptors, heavy metals and other food hazards. The combined use of fluorescence immunochromatography with smartphones is also discussed. It is hoped that this review can provide a reference for food safety detection and on-site and real-time monitoring.

As one of the five basic tastes, umami taste is an important sensory attribute of meat as well as an important index to evaluate the quality of meat. The umami taste of meat mainly comes from the umami substances in meat, such as amino acids, nucleotides and peptides. Umami substances have gradually become a research hotspot in the field of food umami science due to their characteristics of improving food flavor and enhancing people’s appetite. In order to provide a reference for theoretical research and practical application of meat umami substances, this article summarizes the classification, taste formation mechanism and influential factors of meat umami substances as well as the methods for the detection of the major umami substances in meat.