In this research, the critical micelle concentrations (CMC) of various minor components (phospholipids, oleic acid, β-sitosterol and diglyceride (DAG)) in stripped flaxseed oil were determined, and the effects of the formation of reverse micelles on the oxidative stability of the flaxseed oil and the antioxidant activity of α-tocopherols were studied. The results showed that phospholipid (DOPC) was an important component for the formation of reverse micelles, and its critical micelle concentration was 125 μmol/kg oil. Compared with the control group, the addition of low concentrations (< CMC) of microcomponents had no significant effect on the thermal stability of flaxseed oil. But the formation of reverse micelles could reduce the initial oxidation temperature (~12%) and oxidation induction time (~33%) of the oil, and increase the concentrations of hydroperoxide (~36%), propionaldehyde (~13%) and hexanal (~200%) during storage, showing pro-oxidant activity. Compared with the control group, α-tocopherol inhibited the oxidation of oil, but the formation of reverse micelles exhibited higher oxidation product concentration, reducing the antioxidant activity of α-tocopherol. Therefore, controlling the formation of reverse micelles in flaxseed oil is beneficial to improve its oxidative stability, and can provide a new strategy and approach for the steady-state control of oil rich in n-3 polyunsaturated fatty acids (PUFA).

In this study, milk fat model systems with different solid fat contents were formulated using anhydrous milk fat as an ingredient and were used separately to prepare emulsions. The oral coalescence and tribological properties of the emulsions were measured and sensory evaluation was also performed. The results showed that the milk fat model systems (F10–F85) were found to have solid fat contents of 10%–85%. The average diameter of fat globules in the emulsions (E10–E85) was about 4 μm. After simulated oral processing, the particle size of the emulsions increased, and the highest increase was observed in E40. The friction coefficient μ20 of the emulsion first decreased and then increased with increasing solid fat content, and the friction coefficient μ20 of emulsion E40 was the smallest (0.04 ± 0.01). The overall creaminess of the emulsion first increased and then decreased with increasing solid fat content, and the score of E40 was the highest (8.06 ± 0.73). The oral smoothness and mouth coating attributes of the emulsion were most correlated with the overall creaminess perception, and E40 had the highest correlation. At the middle and late stages of oral processing, the most dominant sensory attributes of the emulsion were oral smoothness and mouth coating. In addition, the dominance rate of oral smoothness and mouth coating of E40 were the highest. This study will provide a theoretical basis for the development of low-fat dairy products with whole milk taste.

The contents of three advanced glycation end products (AGEs), namely (Nε-carboxymethyllysine (CML), Nε-carboxyethyllysine (CEL) and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) in commercial baked, deep-fried, dried and canned fish products were determined, and their relationships with components in processed fish products were analyzed. A method for the determination of AGEs by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with an ACQUITY UPLC BEH amide column was established, and applied to determine the content of AGEs in 65 commercial samples of processed fish products. The results showed MG-H1 was more abundant than CEL and CML in processed fish products. The content of MG-H1 was twice to 11 times higher than that of CEL and twice to 20 times higher than that of CML. The contents of the AGEs in canned fish were higher when compared to those in the other types of fish products. The contents of glyoxal (GO) and methylglyoxal (MGO) were relatively high in deep-fried fish products. Furthermore, a positive correlation between the contents of the three AGEs (r ≥ 0.54, P < 0.001) was found by principal component analysis (PCA) and correlation analysis. The contents of these AGEs were positively correlated with the content of lipids, but negatively correlated with the content of proteins. The content of MG-H1 was positively correlated with the content of MGO in baked and dried fish products.

In order to explore the effect of antifreeze protein (AFP) on the water-holding capacity and texture of frozen scallop (Patinopecten yessoensis) adductor muscle, muscle samples were vacuum-impregnated in aqueous solutions containing each of the three antifreeze agents, 0.2 g/100 mL AFP, 3.0 g/100 mL sodium pyrophosphate and 3.0 g/100 mL trehalose. The yield, centrifugal loss, texture, color, moisture distribution and mobility, ice crystal morphology and microstructural structure of these samples were detected. The results showed that the hardness, cohesiveness and brightness of proton density images of the AFP group were in agreement with those of the fresh sample, and were significantly higher than those of the sodium pyrophosphate and trehalose groups. Compared with the other groups, the yield, springiness and shear force of the AFP group were significantly increased, and T21 relaxation time was significantly shortened (P < 0.05). As observed by optical microscopy and scanning electron microscopy (SEM), the ice crystals in the AFP group were small and spherical, and the muscle fiber structure was clear and complete. The average cross-sectional area of ice crystals was 65.06% lower than that in the blank group, treated with NaCl. This study confirmed that AFP can adsorb onto the surface of ice crystals to inhibit their growth and modify their shape. It is more effective than sodium pyrophosphate and trehalose in regulating the water-holding capacity and texture of frozen scallop muscle and thus can be considered as an effective means to control the quality of frozen products.

In this work, pepsin-solubilized collagen (PSC) was extracted from the body wall of sea cucumber, and its degradation and structural changes during heat treatment were studied. It was found that the denaturation temperature of PSC was 35.3 ℃. When PSC was heated at 40–70 ℃, the triple helix structure was coiled, and the α-helix structure was severely damaged; but after cooling, a strong gel system could still be formed by intermolecular hydrogen bonding and disulfide bonding interactions. When the heating temperature exceeded 70 ℃, the α-peptide chain of PSC began to be gradually degraded into small polypeptides, and the intermolecular cross-linking effect was too poor to form a gel system.

In the present study, a water-in-oil-in-water (W/O/W) multiple emulsion was prepared with soyasaponin as an ingredient of the inner water phase (W1), soybean protein as an ingredient of the outer water phase (W2), and corn oil as the oil phase (O) via a two-step emulsification method. The effects of three different types of soybean protein: soybean protein isolate (SPI), 7S and 11S proteins on the overall stability, particle size characteristics, potential characteristics, microstructure, rheological properties, interfacial tension and long-term stability of the emulsion were investigated. Results indicated that the turbiscan stability index (TSI) value of the emulsion showed an upward trend over time and the particle size was concentrated around 6 μm. The absolute potential of the SPI-stabilized emulsion was the highest (?30.2 mV). The system exhibited pseudo-plastic shear thinning behavior, and had the highest viscosity (0.029 Pa·s). After 15 days of storage, all emulsions showed a creaming phenomenon, and the TSI of the SPI-stabilized emulsion was the smallest (21.51). The stability of the 1% SPI-stability emulsion was better than that of the emulsion stabilized with 1% 11S or 7S.

In this study, the key factors affecting the physical and chemical properties of beeswax oleogels and margarine based on beeswax oleogels were explored. Oleogels were prepared using corn oil as the oil phase and beeswax as the oleogelator, and different small-molecular-mass emulsifiers (Span 40, lecithin), and were mixed with water and emulsified to prepare margarine. The oil-holding capacity of the two oleogels were over 95%, suggesting good oil-holding capacity. Emulsifier concentration and storage temperature affected the hardness of oleogels. With the increase in emulsifier concentration and the decrease in storage temperature, the hardness of oleogels decreased. Considering the texture characteristics and oil-holding capacity of beeswax oleogels, the beeswax oleogel with 1% emulsifier under cold storage conditions had the best comprehensive properties. Besides, emulsifier concentration and storage temperature also had an impact on the rheological properties of margarine: with the increase in emulsifier concentration and the decrease in storage temperature, the viscoelasticity and stability of margarine was enhanced. In addition, the addition of emulsifier greatly improved the water-holding capacity of margarine. Overall, the margarine with 2% emulsifier under cold storage conditions had the best comprehensive properties. The oleogels and margarine prepared in this study could be used as good substitutes for butter and cream to provide consumers with healthier food ingredients.

This study aimed to determine the oxidation by hydroxyl free radicals of the myosin head (S1) and tail (Rod) from porcine myofibrillar protein (MP) hydrolyzed by trypsin and to investigate the effect of clove extract on protein oxidation sites. To this end, unoxidized MP, oxidized MP and oxidized MP bound to clove extract were analyzed by one-dimensional electrophoresis, two-dimensional electrophoresis and mass spectrometry (MS). The results of one-dimensional electrophoresis showed that clove extract had a better protective effect on the S1 site. The small fragments generated by the decomposition of Rod and S1 were cross-linked to actin mainly through disulfide bonds. The results of two-dimensional electrophoresis and MS confirmed that subunits or fragments of major MP components such as myosin or actin were produced after MP oxidation, and the addition of clove extract effectively controlled the generation of these fragments, confirming the inhibitory effect of clove extract on protein oxidation at the molecular level. The MS identification of the peptides showed that the main amino acid sites modified by MP oxidation induced by hydroxyl radicals were methionine and cysteine. This study shows that the addition of clove extract in meat processing and storage can improve the functional properties of meat products.

In this study, a pH responsive carboxymethyl agarose-polydopamine (CMA-PDA) hydrogel carrier was developed. Carboxymethyl agarose (CMA) was synthesized by replacing the hydroxyl groups of agarose with chloroacetic acid and was characterized by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). Then, the CMA-PDA hydrogel was prepared, and its rheological and texture properties were characterized. The results showed that the gel strength, hardness and viscoelasticity of the hydrogel were increased by the addition of PDA. Doxorubicin (DOX) was used as a model to study the release behavior of the hydrogel at pH 2.0, 6.2, 6.8 and 7.4. The results showed that the hydrogel had good pH responsiveness and the release rate was significantly higher at pH 2.0 than at other pH levels. Moreover, the hydrogel had no cytotoxicity on L929 cells. This study proves that CMA-PDA hydrogel has good biocompatibility, pH responsive and slow release properties, and can be used as a potential carrier for bioactive substance delivery.

In this work, we explored the effects of white sugar and butter on sensory quality, specific volume, volume, texture and volatile flavor substances of bread made with a mixed starter culture of Saccharomyces cerevisiae and Lactobacillus plantarum. The results showed that addition of white sugar and butter could significantly improve the appearance, color, organizational structure, elasticity, smell and taste of bread, increasing bread volume by 13.80%, and decreasing hardness and elasticity by 35.35% and 37.91%, respectively. Principal component analysis (PCA) performed on electronic nose data showed that breads with sugar alone and in combination or with neither of them were clearly discriminated according to their volatile flavor components. Addition of white sugar and butter significantly changed the volatile flavor substances in bread samples, and had a significant impact on nitrogen oxides, sulfur compounds, aromatic compounds, aromatic hydrocarbons, methane and ethanol. The results of gas chromatography-ion mobility chromatography (GC-IMS) showed that addition of white sugar and butter significantly affected the type and concentration of volatile flavor substances in bread samples, significantly increasing the contents of methyl acetate, isoamyl acetate, ethyl caproate and furfural. These esters were not only volatile flavor substances, but also major aroma substances produced during fermentation. In conclusion, white sugar and butter play an important role in improving the eating quality of bread.

This study established a food-grade Bacillus subtilis expression system for a maltopentaose-forming amylase derived from Bacillus megaterium STB10 (BmMFA). The enzymatic properties and product synthesis pattern of the expressed enzyme were studied. Results showed that BmMFAse exhibited excellent catalytic activity, and the enzymatic activity in the fermentation supernatant of B. subtilis was 196.57?U/mL. The optimal reaction temperature and pH of BmMFA were 50 ℃ and pH 7.0, respectively, and BmMFAse could adapt to a wide pH range. The action pattern of BmMFA was found to tend to be endo-type. BmMFAse showed superior product specificity, and the maltopentaose content in maltodextrin hydrolyzed by BmMFAse for 24?h was over 42%. The substrate conversion rate and the relative content of maltopentaose as the major product were higher using amylopectin as the substrate for BmMFA than amylose. This study provides a theoretical basis for the efficient production of maltopentaose.

This study aimed to establish a method for rapid screening of dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides from white beer. The amino acid sequences of polypeptides were identified by ultrahigh performance liquid chromatography-quadrupole electrostatic field orbitrap high-resolution mass spectrometry (UPLC-Q-Orbitrap-MS2) with the De novo software. In total 68 polypeptides were determined with high confidence, and their biological activity was evaluated using Peptide Ranker. Of these, four were selected for their scores greater than 0.5 to predict their potential DPP-IV inhibitory activity. Meanwhile, another 13 peptides with DPP-IV inhibitory activity were selected according to previous reports. The absorption, metabolism and toxicity of these 17 peptides were predicted and they were evaluated by molecular docking. Finally, two potential DPP-IV inhibitory peptides, VPFPHTP and LAKLQR, were selected. The molecular docking results showed that both peptides could bind DPP-IV tightly by hydrogen bonding and hydrophobic interaction. The peptides were found to have obvious in vitro DPP-IV inhibitory activity.

Five-month-old captive Hulunbuir sheep (Baerhu and short-fat-tailed, n = 10 for each) were selected to study the effect of important gene networks related to fat metabolism on fat distribution and fatty acid profile. The results showed that the relative mRNA expression of the fat mass and obesity associated (FTO) and methyltransferase 3 (METTL3) genes in longissimus dorsi and triceps brachii, the relative mRNA expression of the AMP-activated proteinkinase (AMPK) gene in triceps brachii, biceps femoris and subcutaneous fat, and the relative mRNA expression of the carnitine palmitate transferase (CPT1) gene in longissimus dorsi, subcutaneous fat and tail fat were significantly higher in Baerhu sheep than in short-fat-tailed sheep (P < 0.05), and the proportion of saturated fatty acids in longissimus dorsi and biceps femoris, the proportion of polyunsaturated fatty acids in subcutaneous and tail fat, and the proportion of monounsaturated fatty acids in tail fat of Baerhu sheep were significantly higher than those in short-fat-tailed sheep (P < 0.05). The relative mRNA expression of the acetyl-CoA carboxylase (ACC) gene in muscle, and FTO, METTL3, PPARγ (peroxisome proliferators-activated receptor γ) and ACC in subcutaneous fat, the content and mass of intramuscular fat, total carcass fat mass, carcass fat percentage, the proportion of polyunsaturated fatty acids in longissimus dorsi and the proportion of saturated fatty acids in tail fat were significantly lower in Baerhu sheep than in short-fat-tailed sheep (P < 0.05). In conclusion, the differential expression of this gene network can affect fat metabolism and energy metabolism of different strains of Hulunbuir sheep to a certain extent and consequently fat distribution and fatty acid profile.

Six commercial lactic acid bacteria (LAB) including Lactobacillus plantarum 90 (Lp), L. casei 37 (Lc), L. paracasei 01 (Lpc), L. acidophilus 85 (La), Bifidobacterium lactis 80 (Bla) and L. helveticus 76 (Lh) were separately used to ferment hawthorn juice. The effect of lactic acid bacteria fermentation on physicochemical properties (pH, total soluble solids, and titratable acidity), phenolic compounds, antioxidant activity, color and volatile flavor components and sensory quality of hawthorn juice were investigated. The results showed that hawthorn juice regulated acidity to pH 4.70 was an excellent substrate for LAB. The growth of the six LAB strains in it was not obviously different. At the end of fermentation, the viable cell count was still higher than 8.5 (lg(CFU/mL)), and good fermentation performance was observed as manifested by lactic acid production exceeding 2.6 mg/mL. Bla and Lh fermentation significantly increased total phenols, but they had no significant influence on total flavonoids. In contrast, La, Lc and Lpc fermentation significantly reduced total flavonoids (P < 0.05), while they showed no significant effect on the total phenol content. In addition, the antioxidant activity of hawthorn juice was enhanced by fermentation with Lpc, Bla and Lh (P < 0.05), as evidence by the strong 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation-scavenging capacity (about 49.0%) and Fe3+ reducing antioxidant power (FRAP, about 25.0 mmol/L). Correlation analysis suggested that the antioxidant activity was negatively correlated with the contents of p-coumaric acid, chlorogenic acid, quercetin and epicatechin. Lactic acid fermentation greatly increased the number and amount of volatile components in hawthorn juice, resulting in the formation 17 new alcohols and 17 new esters and reducing the content of aldehydes. The sensory evaluation results showed that lactic acid bacteria fermentation improved the aroma, taste and flavor of hawthorn juice. The juice fermented by Bla had the best overall sensory quality, followed by Lh. Compared with any other lactic acid bacteria, Bla fermented juice had stronger antioxidant properties, was richer in aroma substances, and possessed good organoleptic quality, and thus could be worthy of further research and development.

Proteomic profiles of whey proteins from bovine colostrum, bovine mature milk, goat colostrum and goat mature milk were obtained by high resolution mass spectrometry. By partial least square discriminant analysis, it was observed that bovine colostrum and mature milk were more similar in protein composition than goat colostrum and mature milk, and nine proteins with high abundance in goat milk could be regarded as protein markers to distinguish among these four milk samples. Bioinformatics analysis showed that most of the high-abundance proteins in goat milk were related to immune responses and metabolic processes, which indicates that goat milk helps newborns develop an immune system against microbial infection. These results provide an in-depth understanding of proteins from goat milk and its products, and are of great significance for the nutritional improvement of breast milk substitutes as well as the development of breast milk substitutes.

In this study, scanning electron microscopy (SEM) and single-cell Raman spectroscopy (SCRS) were used to analyze the differences in the cellular morphology and intracellular macromolecular compounds of Lactobacillus delbrueckii subsp. bulgaricus ND02 in the normal and viable but non-cultivable (VBNC) states. The SEM results showed that the VBNC cells, with a wrinkled surface, were shorter and thicker than the normal ones. The Raman spectra of the VBNC cells were significantly different from those of the normal cells, mainly in terms of 12 peaks, such as 1 673, 1 650, 1 459, 1 030, and 1 005?cm-1, reflecting changes in intracellular biomacromolecules such as proteins and nucleic acids. It was shown that L. delbrueckii subsp. bulgaricus ND02 could adapt to adverse environments by regulating the metabolism of proteins, nucleic acids and lipids when induced to enter into VBNC state. The results also confirmed that single-cell Raman spectroscopy can allow non-destructive label-free detection of macromolecules inside normal and VBNC cells of L. delbrueckii subsp. bulgaricus ND02.

In this study, we evaluated the feasibility of using a mixed starter culture of Streptococcus thermophiles (St), Lactobacillus bulgaricus (Lb) and Lactobacillus kefiranofaciens subsp. kefiranofaciens ZW3 to make ropy yogurt without any added thickener or emulsifier. St + Lb was used as a control. The results showed that L. kefiranofaciens subsp. kefiranofaciens ZW3 shortened the fermentation time, improved water-holding capacity, reduced whey syneresis, increased viscosity, improved rheological properties, and enhanced hardness, gumminess, chewiness, cohesiveness and resilience of yogurt compared with the control group. The results of electronic nose analysis and sensory evaluation showed that ZW3 increased the contents of volatile flavor components and improved the flavor and taste of yogurt without any food additives.

In this study, metatranscriptomics was used to analyze the diversity, succession and differentially transcribed genes of the active microbial community in fermented grains during the main fermentation period of Chinese strong-flavor baijiu (at days 3, 7 and 25). The results showed that the active microbial community was composed of 6 kingdoms, 124 phyla, 195 classes, 2 824 genera, and some unknown or unidentifiable species. The identifiable organisms were mainly composed of bacteria and fungi. As fermentation proceeded, the relative content of fungi decreased from 42.8% to 0.01%, and the content of bacteria increased from 17.7% to 56.3%. Firmicutes and Ascomycota were the major phyla that drove changes in the composition of bacterial and fungal communities, respectively. The numbers of differentially expressed genes among three fermentation times were 6 895 (3 d vs 7 d), 2 640 (7 d vs 25 d) and 6 124 (3 d vs 25 d), respectively. During the fermentation process, the number of down-regulated differential genes was significantly greater than that of up-regulated differential genes. From days 3 to 7 of fermentation, the up-regulated differential genes were significantly enriched in the metabolism of sugars and alcohols. During the whole major fermentation period, the down-regulated differential genes were mainly enriched in cell parts or related biological processes. The results of this study will provide basic data and theoretical support for in-depth understanding of the solid-state brewing mechanism of Chinese strong-flavor baijiu.

In this study, the structure and diversity of microbial community in Jiang-flavor Daqu processed using highland barley, purple wheat or pure wheat as raw material under the same conditions were analyzed using the Illumina platform, and intergroup separation was investigated and marker microorganisms were identified by multivariate statistical analysis. The results showed that Ascomycetes, Firmicutes, and Actinomycetes were the absolute dominant phyla in each of the three Daqu samples. The bacterial community in pure wheat Daqu (XMQ) was dominated by the genera Kroppenstedtia, Virgibacillus, Lactobacillus, and Weissella. The bacterial community in purple wheat Daqu (ZMQ) was dominated by the genera Kroppenstedtia, Virgibacillus, uncultured_bacterium_f_Bacillaceae, Bacillus, and Scopulibacillus. The bacterial community in QKQ was dominated by Lactobacillus, Weissella, and Thermoactinomyces. Thermoascus and Debaryomyces were dominant fungal genera in all samples. Meanwhile, Byssochlamys, Monascus, Kazachstania, and Torulaspora were dominant fungal genera in XMQ. Monascus, Aspergillus, and Rasamsonia were dominant fungal genera in ZMQ. Kazachstania, Torulaspora, and Thermomyces were dominant fungal genera in QKQ. In addition, principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal partial least squares discriminant analysis (OPLS-DA) revealed a clear separation between the three Daqu samples, and out of the dominant genera, 10 significantly differential bacterial genera and nine significantly differential fungal genera were obtained by linear discriminant analysis as key biomarkers to discriminate among Daqu produced from different raw materials. The results of this study lay a theoretical foundation for the quality improvement of Jiang-flavor Daqu.

This study aimed to understand the difference in metabolites of three major jujube cultivars from north Shaanxi, in order to provide a reference for quality analysis and functional evaluation of jujube fruit. The metabolites in Qingjian Muzao, Jiaxian Youzao and Yanchuan Goutouzao were determined and compared by wildly targeted metabonomics based on ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and multivariate statistical analysis. A total of 462 metabolites, belonging to 15 categories, were identified across the three cultivars, and a significant difference in the contents of metabolites was observed among them. Totally 36 differential metabolites between Jiaxian Youzao and Qingjian muzao were identified. In addition, 193 and 204 differential metabolites were identified in Yanchuan Goutouzao compared with qingjian Muzao and Jiaxian Youzao, respectively. KEGG pathway enrichment analysis of the differential metabolites indicated that amino acid metabolism and phenylpropanoid biosynthesis pathway were more active in Yanchuan Goutouzao, while flavonoid biosynthesis pathway was more active in Qingjian Muzao and Jiaxian Youzao. Amino acids such as tryptophan, phenylalanine, tyrosine, histidine, valine, threonine, leucine, isoleucine, sinapic acid, p-coumaric acid and cinnamic acid, as well as phenolic acids such as syringin were accumulated in larger quantities in Yanchuan Goutouzao, while flavonoids such as myricitrin, astragalin, aromadendrine, 4,2’,4’,6’-tetrahydroxychalcone and butin were accumulated in larger quantities in Qingjian Muzao and Jiaxian Youzao. At the metabolic level, it was found that qingjianmuzao had a closer genetic relationship with Jiaxian Youzao, but further relationship with Yanchuan Goutouzao. Qingjianmuzao and Jiaxian Youzao had higher medicinal value, while Yanchaun Goutouzao had more prominent nutritional quality and taste.

In this study, the microbial diversity of flowering cabbage incisions during cold storage, with special reference to the dynamic changes in the relative abundance of microflora, was analyzed by high-throughput sequencing. Flowering cabbage samples stored for 0, 7 and 14 days were collected, and the composition and abundance of microflora in the three samples were investigated and compared by analyzing the sequences of bacterial 16S rRNA and fungal internal transcribed spacer (ITS). The dominant fungal phyla were Basidiomycota, Ascomycota and unclassified Fungi during the whole storage time. The dominant bacterial phyla were Firmicutes and Proteobacteria during the early storage period, while Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes became dominant during the middle and late storage periods. Microbial diversity data showed that the diversity of fungi was higher than that of bacteria. The results of this study can provide theoretical support for future development of antibacterial agents and preservation technologies for flowering cabbage.

In this study, the bacterial?community?structure?and diversity in five samples of bacteria-fermented Sojae Semen Praeparatum produced in different areas of Enshi Prefecture were investigated using high-throughput sequencing on the Illumina PE250 platform. The results showed that the microbial composition of Sojae Semen Praeparatum was diverse. A total of 17 phyla, 24 classes, 43 orders, 78 families, 152 genera and 93 species were identified. Among them, the core dominant phylum were Firmicutes, followed by Proteobacteria, Cyanobacteria and Actinobacteria. The dominant genera were Bacillus thermoamylovorans and Bacillus smithii. The composition of dominant genera in the five samples was the same, but the relative abundance was quite different. There was a significant difference in the composition and relative abundance of the other minor genera.

Objective: The effect of fermentation by Lactobacillus (L. delbrueckii subsp. bulgaricus and L. plantarum subsp. plantarum) on the nutrient components of the fermented supernatant of Porphyra haitanensis and its antioxidant activity and inhibitory activities on key enzymes of glycolipid metabolism (α-glucosidase and pancreatic lipase) were investigated in this study. Methods: The contents of total phenols and total flavonoids in the fermented supernatant were analyzed by using the Folin-Ciocalteu and sodium nitrite-aluminum nitrate methods, respectively. The primary metabolites were analyzed by 1H nuclear magnetic resonance (NMR) spectroscopy. The antioxidant activity was evaluated through 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radical cation (ABTS+), and hydroxyl radical scavenging assays, and the α-glucosidase and pancreatic lipase inhibitory activities were determined. Results: The contents of total phenols and total flavonoids in the fermented supernatants of P. haitanensis were significantly increased by both L. delbrueckii subsp. bulgaricus and L. plantarum subsp. plantarum, and the release of metabolites including lactic acid, arginine and proline was also promoted by Lactobacillus fermentation. Interestingly, a significant increase in the antioxidant activity and inhibitory activities against α-glucosidase and pancreatic lipase were observed in the fermented supernatants, and the most pronounced scavenging effect was recorded on hydroxyl radicals, similar to that of 700 μg/mL vitamin C (VC). Compared with unfermented P. haitanensis, the α-glucosidase inhibitory activity was increased by 2.1–2.2 times in fermented P. haitanensis and the lipase inhibitory activity was increased up to (95.3 ± 1.3)% by 95.7%. The increase in antioxidant activity and α-glucosidase and pancreatic lipase inhibitory activities may be mainly attributed to the increase in the contents of total phenols and total flavonoids in the fermentation supernatants. Conclusion: Lactobacillus fermentation can effectively improve the antioxidant activity and the inhibitory activities against α-glucosidase and pancreatic lipase of Porphyra haitanensis. Our findings suggest that the fermented supernatant of P. haitanensis with Lactobacillus has the potential to be developed into functional foods and special dietary foods for the alleviation and adjuvant treatment of chronic diseases, such as diabetes and obesity.

The variation of fungal community structure and dominant fungi during the fermentation of high-salt liquid-state soy sauce were studied by high-throughput sequencing on the Illumina MiSeq platform, and the changes of reducing sugars, amino acid nitrogen, total acids and volatile flavor compounds were analyzed. The results showed that a total of 44 fungal genera were obtained in soy sauce samples. The dominant genus was Aspergillus (62.62% to 93.85%) during the first two months of fermentation, which promoted the production of reducing sugars and amino acid nitrogen. The content of amino acid nitrogen exceeded 10.45 g/L after three months of fermentation. The dominant genus was Kodamaea (85.64% to 99.50%) from the 3rd to the 5th month, and Zygosaccharomyces (78.12%) in the 6th month. The contents of reducing sugars, amino acid nitrogen and total acid were 17.73, 10.72 and 21.68 g/L after 6 months of fermentation, respectively. A total of 61 volatile flavor compounds were detected in all samples by gas chromatography-mass spectrometry (GC-MS), and the total content of volatile flavor compounds was 12 404.15 μg/L at the end of fermentation. The contents of alcohols and acids as major volatile compounds were 8 826.2 and 2 349.97 μg/L, respectively. Correlation analysis between the dominant fungi and volatile flavor compounds indicated that Aspergillus was significantly positively correlated with 1-octen-3-ol (P < 0.05). Kodamaea was not significantly correlated with any changes in flavor compounds. Zygosaccharomyces was significantly positively correlated with phenethyl alcohol, 3-methyl-1-butanol, 2-methyl-1-butanol, benzaldehyde, and ethyl acetate (P < 0.05). This study has proved that the variation of fungal community structure and the dominant fungi are important factors affecting the formation of flavor compounds, and constructing beneficial fungal flora is beneficial to improve the quality of soy sauce.

In this study, an oil-producing filamentous fungus, Mortierella elongata MD-3, was obtained from oil-producing plants and their rhizospheres with the aim to develop a new microbial oil resource. The oil content and yield of the strain were 30.15% and 4.67 g/L, respectively. A stable mutant designated MD-3-7 was obtained after treatment of strain MD-3 by atmospheric and room temperature plasma (ARTP), and its oil content and yield were 41.69% and 6.62 g/L, respectively, which increased by 38.27% and 41.76% compared with the original strain. It was found that most of the mycelial pellets of the mutant were villous, and compared to the parental strain, the mycelia became shorter and the density increased, conducive to the accumulation of oil; real-time polymerase chain reaction (real-time PCR) showed that the expression of the acetyl CoA carboxylase (ACC) and the fatty acid synthase (FAS) genes in the mutant strain were up-regulated by 9.25 and 4.37-fold, respectively. This study provides a valuable source for the development and utilization of oil-producing microorganisms.

Raw and cooked berries and juice of Lonicera edulis were used as raw materials to prepare fruit wines in order to explore the effects of each of the three fermentation processes on the ethanol content, active ingredients, in vitro antioxidant activity and aroma components of L. edulis wine as a function of fermentation time. The results showed that the ethanol content of the three wines increased first and then became stable. At the end of fermentation, the contents ethanol, anthocyanins and total phenols in the wine made from cooked berries were the highest, (12.29 ± 0.08)%, (830.17 ± 8.65) mg/L, and (2.41 ± 0.03) g/L, and it showed the strongest capacity to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH), (14.25 ± 0.14) mmol/L, and superoxide anion (O2-·), (8.93 ± 1.37) mmol/L. The highest flavonoid content of (470.50 ± 6.15) mg/L and strongest hydroxyl radical-scavenging capacity of (40.43 ± 3.33) mmol/L were observed for the wine made from fresh berries. Different fermentation processes showed great impacts on the aroma components of L. edulis wine. The main aroma components of the wines made from fresh and cooked berries were esters, with relative contents of esters of 60.23% and 85.31%, respectively. The relative contents of terpenes and esters as the major aroma components in the wine made from juice were 11.50% and 61.96%, respectively. After fermentation, the contents of alcohols and acids in cooked berries decreased, while the content of esters increased significantly, which changed the aroma structure of L. edulis wine, accelerated its ripening, and produced unique aromatic substances such as isoamyl laurate, ethyl myristic acid, and isoamyl caproate. Fermentation using cooked L. edulis berries as raw material is not only beneficial to improve the contents of functional components and antioxidant capacity in vitro, but also can enhance the comprehensive quality of the wine by endowing it with more intense aroma.

In order to obtain special lactic acid bacteria with potent uric acid-lowering activity, this study screened lactic acid bacterial strains for their ability to degrade inosine and guanosine by high performance liquid chromatography (HPLC). The strain LB1lac20 was found to give the highest degradation rate of inosine (91.19%) and guanosine (89.67%). By sequence?alignment of 16S rRNA gene using the Basic Local Alignment Search Tool (BLAST), LB1lac20 was identified as Lactobacillus brevis. To evaluate its uric acid-lowering potential, an in vitro model was established by the uric acid production method and used to analyze the inhibitory effect of LB1lac20 on xanthine oxidase. The results showed that the activity of xanthine oxidase was 21.27% and 19.60% inhibited by the live suspension and intracellular extract of LB1lac20, respectively (P < 0.05). To sum up, L. brevis LB1lac20 may set the stage for the development of drugs for the prevention and treatment of hyperuricemia.

In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify the structures of peptides in Colla Corii Asini (Ejiao) subjected to simulated gastrointestinal digestion. The peptides were screened for their anti-hypertensive, anti-Alzheimer, and anti-tumor potential by molecular docking. The results showed that 519 active peptides with molecular mass ranging from 661.4 to 2 851.4 Da were obtained from the digested products of Ejiao. These peptides were mainly derived from the enzymatic hydrolysis of collagen and hemoglobin. Peptides KGETGLR, SGLDGAKG, and ADGVAGPK were found to have the highest anti-hypertensive, anti-Alzheimer and anti-tumor potential. Hydrogen bond and electrostatic interactions played a vital role in the anti-hypertensive, anti-Alzheimer, and anti-tumor activities of the Ejiao peptides.

In this study, the ergothioneine synthase gene Egt 1 of Pleurotus was excavated and the structure and function of its encoded protein were predicted by using bioinformatics methods. Then, an expression vector of Saccharomyces cerevisiae was constructed, and functional verification in S. cerevisiae EC 1118 was performed. The ergothioneine synthase genes PoEgt 1, PeEgt 1 and PtEgt 1 from P. ostreatus, P. eryngii and P. tuoliensis were cloned. Among these genes, the homology of nucleotide sequences was 97.03% and the homology of amino acid sequences was 97.93%. As determined by cell disruption and in vitro enzymatic reaction, the yield of ergothioneine was (2.5 ± 0.08) mg/L, which proved that the Egt 1 gene had the activity to synthesize ergothioneine.

In order to gain an in-depth understanding of the mechanism for the changes in the major ingredients and volatile compounds of cream during heating treatment, nuclear magnetic resonance (NMR) spectroscopy was used to analyze quantitatively the polar and apolar components of cream, and gas chromatography-mass spectrometry (GC-MS) was used to identify the volatile compounds of cream before and after heating treatment. NMR analysis revealed lactose as a major polar component, as well as lesser amounts of free amino acids, free fatty acids and organic acids; and triglycerides as major apolar components, as well as lesser amounts of diglycerides and monoglycerides. After heating treatment, the content of polar components, mainly including lactose and free amino acids, was reduced greatly, while the content of apolar components was reduced less. GC-MS analysis showed that the contents of short-chain fatty acids and aldehydes were increased less, whereas the contents of methyl ketones, lactones and Maillard reaction products were increased significantly, among which methional, maltol and furaneol were only detected in heated cream. The results showed that the formation of the Maillard reaction products and the growth of lipid-derived compounds during thermal treatment resulted in a reduction of polar components and fatty acids in cream, respectively, which provides a new idea for further research on cream flavor and products.

To explore the effect of reducing the sodium content on the lipid oxidation and flavor quality of naturally fermented yak meat sausages, low-sodium and control sausages were prepared by adding 2% and 4% sodium salt and natural ripening or constant temperature ripening, respectively. Physicochemical indicators were measured during the ripening process. The results showed that regardless of the ripening method used, the water content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity and hydroxyl radical scavenging capacity of the low-sodium group were significantly lower than those of the control group (P < 0.05), and the pH was significantly higher than that of the control group (P < 0.05). The degrees of lipid hydrolysis and oxidation in the four treatment groups increased with ripening time, being significantly higher in the low-sodium group than in the control group for each ripening method (P < 0.05). There was no significant difference in lipoxygenase activity between the two groups of natural maturation (P > 0.05), while at the late stage of constant-temperature ripening, the lipoxygenase activity in the low-sodium group was significantly higher than that in the control group (P < 0.05). In addition, a total of 69 volatile flavor compounds were detected from the sausages, and the cumulative contribution rate of the first three principal components was as high as 96.206%. Principal component analysis (PCA) showed that on the 9th and 17th (end) day of maturation, the relative contents of alcohols, aldehydes and other substances generated by lipid oxidation in the low-sodium group were higher than those in the control group. Different sodium contents had a significant effect on the hydrolysis and oxidation of lipids in sausage. Directly reducing the sodium content to 2% may promote the oxidation of lipids.

An ultra-fast gas chromatography-based electronic nose was used to qualitatively and quantitatively analyze the volatile flavor components in 36 samples of whole milk, low-fat milk, and skimmed milk subjected to ultra-high temperature (UHT) treatment. Using a combination of principal component analysis (PCA) and multi-layer perceptron neural network (MLP-NN), UHT-treated milk samples were classified and predicted according to their aroma characteristics. The results showed that 29 volatile flavor components were detected in all milk samples, mainly including acetone, n-butanol, and δ-decalactone, acetone and decanal being the most and least abundant, respectively. Isobutanol, acetoin, 1-pentanol, E-3-hexenal and decanal only existed in UHT-treated whole milk. 3-Methylheptane, 2,6-dimethylpyrazine, and E-2-nonen-1-ol were exclusively detected in UHT-treated low-fat milk. α-Pinene, 5-methylfurfural and decanoic acid were only detected in UHT-treated skimmed milk. The major aroma characteristics of UHT-treated milk were vegetable-like, creamy, grassy, fruity, and malty aroma notes. Among them, vegetable-like, creamy and malty aromas were the most widely distributed in UHT-treated whole fat milk. Fruity aroma was the most widely distributed in UHT-treated low-fat milk. Grassy aroma was the most widely distributed in UHT-treated skimmed milk. PCA showed that there was a significant difference between different brands of UHT-treated milk. The prediction accuracy of MLP-NN for UHT-treated milk was as high as 98.6%.

This study aimed to compare the differences in the sensory (appearance and cross-sectional morphology) and physicochemical characteristics (juice yield, total soluble solids (TSS), total sugars, pH, titratable acids, vitamin C, total phenolics, anthocyanins, flavonoids and tannins) of four different varieties of kiwifruit (Hongyang, Jinyan, Wanzhou Hongxin and Donghong). The fruit quality data were analyzed by?principal?component?analysis?(PCA) and cluster analysis (CA), and the volatile aroma compounds of juice samples were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS). The results showed that there was no significant?difference?in juice yield or total acid content among varieties, and the contents of total sugars, vitamin C, total phenolics, flavonoids, anthocyanins in Wanzhou Hongxin were higher than those in the other varieties, while tannin content was higher in Jinyan than in the other varieties. The results of PCA and CA consistently showed that Jinyan was classified into one group, whereas Hongyang, Wanzhou Hongxin and Donghong were classified into another group. A?total?of 55?volatile?components?were?detected?across four?juice samples, and there were significant differences in volatile compounds among these samples. The results of classification by PCA and CA based on volatile components were consistent with those based on quality index.

In order to explore the difference in aroma quality of dried jujube and its different extracts, headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with electronic nose was used to investigate the volatile components of dried jujube and its extracts and absolute oils obtained by heat reflux extraction and microwave-assisted heat reflux extraction. The results showed that a total of 96 volatile components were detected in dried jujube and its extracts, the major aroma components being acids, esters, aldehydes and ketones. The relative content of acidic volatile components was the highest in the extract and absolute oil obtained using heat reflux extraction, 44.433% and 39.304%, respectively, and their contents of volatile ketones were significantly higher than those of the other samples (P < 0.05). The highest relative content of volatile esters of 52.196% and 45.863% was observed in the extract and absolute oil obtained using microwave-assisted heat reflux extraction, respectively. According to the results of GC-MS and electronic nose, the two absolute oils, extracted from the extracts, respectively, had similar aroma characteristics. The results of loading analysis showed that the aroma components of dried jujube and its different extracts could be recognized by sensors W1S, W1W, W2S and W2W. In general, HS-SPME-GC-MS combined with electronic nose can be used toevaluate the difference in aroma quality of dried jujube and its extracts.

In this study, we performed a comparative analysis of the total fatty acid, sn-2 fatty acid and triglyceride composition of infant formula (IF) with four different fat sources and human milk. The results showed that a total of 27 fatty acids and 87 triglycerides were detected across all samples. Compared with human milk, the four IFs contained more saturated fatty acids and less polyunsaturated fatty acids. More than 70% of the saturated fatty acids in human milk were esterified at the sn-2 position of triglycerides, whereas the sn-2 position of triglycerides in the four IFs was mostly occupied by unsaturated fatty acids, especially vegetable oil-based IF1 and IF2, with 80% sn-2 unsaturated fatty acids. In terms of triglyceride composition, the contents of 1-oleic acid-2-palmitate-3-linoleic acid triglyceride (OPL), 1,3-dioleic acid-2-palmitic acid triglyceride (OPO) and some medium and long-chain triglycerides in human milk were significantly higher than those in the IFs (P < 0.05), while the IFs contained more triolein (OOO), 1-oleic acid-2,3- linoleic acid triglycerides (OLL) and some medium-chain triglycerides (P < 0.05). Different fat sources could significantly affect the lipid composition of IF. IF1 and IF2 had similar triglyceride and fatty acid composition and distribution. They were clearly distinguished from IF3 and IF4 with added milk fat, and milk/vegetable oil mixed-based IF was closer to human milk in terms of overall lipid composition. Finally, based on multivariate analysis, a total of 16 triglycerides were found to useful to discriminate between human milk and infant formula. The results reported herein are useful in designing new milk formula that can better mimic human milk.

The changes of volatile flavor compounds in three varieties of sweet corn, “Zhongtian 9”, “Zhuyutian 8” and “Zhuyutian 1”, were investigated during the ripening process. The volatile flavor compounds were identified by headspace solid phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) through NIST14 mass spectral database searching and retention index analysis as well as by gas chromatography-olfactory (GC-O), and were quantified by the internal standard method, in order to construct a volatile flavor profile and evaluate the aroma characteristics of sweet corn. The results showed that 61 volatile flavor compounds were detected across the three varieties during the ripening process. Maturity had significant effects on the type and content of volatile flavor compounds in sweet corn. The contents of ethyl nonylate, 1-heptanol and 1-hexanol significantly decreased with increasing maturity, while the contents of styrene, toluene, ethylbenzene and m-xylene significantly increased. Arenes were mainly accumulated in sweet corn during the maturation process. In terms of odor characteristics, the intensity of fatty aroma increased obviously with maturity, while the intensity of grassy aroma decreased obviously. There were significant differences among varieties in the composition and content of volatile flavor compounds. The number and amount of volatile flavor compounds in “Zhongtian 9” were significantly greater than those in the other two varieties at maturity, and the overall flavor intensity was the highest.

In this study, headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the composition and relative content of volatile compounds in Cyperus esculentus oils obtained by different methods (supercritical CO2 extraction, pressing, leaching, and aqueous enzymatic extraction), and these oils were classified by using principal component analysis (PCA) and electronic nose. The key flavor compounds were determined by their relative odor activity values (ROAV). The results showed that the composition and relative content of volatile compounds were significantly different among the C. esculentus oils. A total of 101 volatile compounds were identified across all samples, 22 of which were common to them, the predominant ones being aldehydes, ketones, esters and alkanes. The relative content of aldehydes was higher in the samples obtained by supercritical CO2 extraction (36.71%) and pressing (25.64%) than the other methods, and the relative contents of alkanes and esters were the highest in the samples obtained by leaching (31.07%) and aqueous enzymatic extraction (45.66%), respectively. Electronic nose combined with PCA effectively distinguished the four oil methods. Nonanal, cedrol and D-limonene were identified as key flavor compounds and were found in each sample.

In the present study, three orange cultivars (Citrus sinensis L. Osbeck), including Trovita, Early-golden, and Hamlin, were selected to produce not from concentrate (NFC) orange juice and from concentrate (FC) orange juice by the commercial manufacturing processes. Eight pairs of primers to obtain targeted fragments of different lengths were designed based on the chloroplast maturase K (matK) and nicotinamide adenine dinucleotide dehydrogenase (ndhF) genes. Polymerase chain reaction (PCR) coupled with capillary electrophoresis (CE) was used to analyze the effects of key processing steps such as extraction, homogenization, pasteurization, concentration, and secondary pasteurization on DNA degradation in the chloroplast matK and ndhF genes in Trovita orange juice. By comparing the differences in DNA degradation between NFC and FC orange juice, we selected the characteristic differential fragment sets and established a PCR-CE method to discriminate between NFC and FC orange juice. The developed method was applicable to analyze NFC and FC orange juice within shelf life. It was equally applicable to discriminate between NFC and FC orange juice manufactured from Early Golden and Hamlin sweet oranges. Finally, this method was used to test commercial NFC orange juice. The results were not consistent with the label information. The PCR-CE method will provide technical support for the effective regulation of the juice industry.

Objective: This study aimed to evaluate the risk of Staphylococcus aureus food poisoning associated with ready-to-eat lettuce for the purpose of providing theoretical references for adopting effective risk management measures. Methods: The incidence and level of S. aureus contamination in environmental samples from lettuce planting in greenhouses or open fields were investigated. With regard to hazard recognition, the description of hazard and risk characteristics and exposure estimation, a risk assessment of S. aureus food positioning caused by eating raw lettuce in China was carried out based on residents’ consumption habit survey data from the statistical yearbook of China and the change in S. aureus count in lettuce from farm to table described using a predictive model describing the growth of S. aureus in lettuce. Results: The detection rate of S. aureus in greenhouse soil was 0.04%, at levels of ?8.72 to 3.01 (lg(CFU/g)). The average concentration of S. aureus in lettuce to be consumed, which underwent irrigation, harvest, transportation, sale, purchase, storage and washing was ?1.95 (lg(CFU/g)) with a 90% confidence interval of ?8.98 to 4.40 (lg(CFU/g)). In China, the probability of S. aureus poisoning caused by the consumption of raw lettuce was estimated to be 2.72 × 10-4 with a mean probability of 7.7 illness per 10 million servings per year. The sensitivity analysis showed that the initial concentration of S. aureus in the soil had the biggest effect on the contamination level of S. aureus in lettuce, followed by household storage temperature and washing before consumption. It is concluded that controlling lettuce-planting environment, rational use of refrigerators, and washing lettuce in a scientific way can reduce the risk of S. aureus food poisoning caused by the consumption of raw lettuce.

This sthdy investigated the changes in the sensory score, electronic tongue Euclidean distance (ED) and electronic nose odor distance of fresh whole milk during storage at 4, 15, 23 and 30 ℃. Using combination of a zero-order reaction kinetics model and the Arrhenius equation, shelf life prediction models for fresh milk were established based on the thresholds calculated for electronic tongue ED and electronic nose odor distance from the critical point of sensory quality changes, separately. The predicted shelf life using electronic nose and tongue was 16.2 and 15.7 days, respectively, showing 8.0% and 4.7% errors compared with the actual value, respectively. The results showed that electronic nose and electronic tongue technology can effectively monitor the quality changes of milk during accelerated shelf life, which provides a new idea for the determination of milk shelf life.

A quantitative prediction model for the moisture content of work-in-process Yongchuan Xiuya tea was established using partial least squares regression (PLSR) based on its color changes as evaluated using different color models. The results showed that during the initial production process, the red-green and mean blue channel value increased, while the moisture content and 15 other color model components such as lightness, yellow-blue, mean red channel value, mean green channel value and mean hue value decreased, suggesting that the color became darker and yellower. Through heatmap and cluster analysis, the samples were divided into two categories and four sub-categories, and the carding process had the most significant impact on the moisture and color of the products. Based on the 17 color model components, the predictive model was established, and its performance was evaluated by considering correlation coefficient of calibration set (Rc), root-mean-square error of cross-validation (RMSECV), correlation coefficient of predication set (Rp), root-mean-square error of prediction (RMSEP) and relative percent deviation (RPD). The values of Rc, Rp, RMSECV and RMSEP were 0.979, 0.980, 0.044 7, and 0.044 3, respectively. The difference between RMSECV and RMSEP was merely 0.000 4, and the RPD value was 5.04, indicating that the model had excellent prediction capacity and generalization capacity and could provide a new method for the online monitoring of the moisture content in work-in-process Yongchuan Xiuya tea.

Quality control samples were independently developed by adding different concentrations of florfenicol to blank eggs. According to CNAS-GL003:2018 Guidelines on Evaluating the Homogeneity and Stability of Samples used for proficiency Testing, their homogeneity and stability were evaluated by using liquid chromatography-mass spectrometry (LC-MS) specified in GB/T 22338-2008 as a reference method. At the same time, the factors affecting the stability of the quality control samples were studied, and reference values for the quality control samples were determined jointly by six laboratories. The results showed that both the non-freeze-dried (liquid) and freeze-dried (solid) quality control samples had good homogeneity and stability. Sample state and storage temperature had an impact on the stability of the quality control samples. The freeze-dried quality control samples were stable at ?18 ℃ for 12 months. The certified values for the freeze-dried quality control samples at three concentration levels were 0.23, 0.39 and 1.92 μg/kg, and these quality control samples could be applied for process quality control in the fields of rapid testing and conventional laboratory detection.

In this study, the contents of 25 mineral elements in Tan sheep bone samples from Etuokeqian banner of Inner Mongolia autonomous region, Yanchi county of Ningxia autonomous region, Huan county of Gansu province and Dingbian county of Shaanxi province were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the distribution characteristics of bone mineral elements in Tan sheep from different regions were different, and the contents of some mineral elements were significantly different among different geographical origins. In addition, through principal component analysis (PCA), cluster analysis (CA), Ca, Cd, Cd, Mg, Mn, Na, P, Rb, Te, and Zn were selected to develop a fingerprint for tracing the geographical origin of Tan sheep. The overall accuracy rates of back substitution test and cross-validation were 87.50% and 86.87%, respectively. The results showed that the 10 mineral elements were effective for identification of the regional origin of Tan sheep bones, and the discriminant model established by using the 10 elements was also effective.

A method using bovine β-lactoglobulin as the adulteration marker was developed for the qualitative and quantitative detection of cow milk in adulterated camel milk by ultra-high performance liquid chromatography (UPLC). The effects of different heat treatments on the adulteration marker were discussed to meet the need for the detection of different commercial camel dairy products. The results showed that this method could effectively detect milk in adulterated raw camel milk, pasteurized camel milk and camel milk powder. The regression equations of the three adulterated milk samples showed good linearity, with correlation coefficients (R2) of 0.997 9, 0.996 9 and 0.997 8, respectively. The limits of detection for the adulterated samples were 2%, 3% and 5%, respectively, which could meet the detection requirements. Using this method, out of 10 different brands of commercial pure camel milk powder, four were found to be adulterated.

A rapid screening method for 56 illegally added drugs in herbal tea was developed by ultra-high performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). The samples were extracted with methanol and separated on an Accucore RP-MS column (100 mm × 2.1 mm, 2.6 μm) by gradient elution. A full mass scan/data dependent MS2 (Full MS/dd MS2) mode was used to collect data for rapid screening and confirmation. The correlation coefficients (R2) of the calibration curves of the analytes were all greater than 0.99 in the concentration range of 2–100 μg/L. The average recoveries ranged from 90.4% to 105.0% at three different spiked levels with relative standard deviations (RSDs) not more than 6.0%, the limits of detection were between 0.5 and 2.5 μg/L, and the limits of quantification were between 1.5 μg/L to 8.0 μg/L. This method was rapid, accurate and sensitive, and it was suitable for simultaneous screening and quantitation. It can be used for rapid screening and confirmation of illegal additives in herbal tea.