Abstract:The protective effect of astragaloside IV against pancreatic injury induced by cadmium combined with high fat and high sugar diet in diabetic mice was studied. Diabetic model was established through high fat and high sugar combined with cadmium damage. Mice were randomly divided into a normal group, model group and protective group. After 8 weeks of modeling, the protective group were given different concentrations of astragaloside IV (As-IV) for 4 weeks. The blood glucose content, malondialdehyde (MDA) content，superoxide dismutase (SOD) content and glutathione (GSH) content were determined. Ultrathin sections of the pancreatic tissue were made and examined under transmission electron microscopy to investigate changes in subcellular structure. The results showed that the MDA content of the model group increased significantly, which was 1.90 times that of normal group (p<0.01). The contents of SOD and GSH decreased, which were 48.10% (p<0.01) and 44.40% of those of the normal group (p<0.05); Compared with the model group, the low, medium, and high dose protective groups had lower blood glucose level, with their MDA contents being 82.10% (p<0.05), 68.40% (p<0.01) and 58.90% (p<0.01) of those of the model group. The SOD contents of the medium and high dose groups increased 1.52 times (p<0.05) and 1.72 times (p<0.01), respectively. The GSH content of the high-dose protective group increased most significantly, which was twice that of the model group (p<0.01). The results of transmission electron microscopy showed that the density of secreted granules and mitochondria in the subcellular structure of the pancreas increased significantly, indicating that the high glucose environment can aggravate the oxidative stress in the pancreas causing damage; the intake of AS-IV decreased significantly the contents of various indicators and weakened the damage. Astragaloside IV may reduce the oxidative damage of the pancreas and preserve its normal function by scavenging free radicals.

Abstract:In this study, the effects and possible mechanism of inulin (INU) on atherosclerosis (AS) were investigated. Eight-week male ApoE-/- mice were randomly divided into control group (CON), atherosclerosis model group (AS) and INU treatment group (AS+INU), in which CON group fed with a standard chow diet, AS group fed with a high-fat diet, AS+INU group fed with dietary INU based on AS model. After 12 weeks of treatments, oil red O, Masson’s trichrome and HE stainings were used to evaluate the effects of INU on AS, 16S rRNA sequencing analysis was used to determine the community of gut microbiota. Limulus amebocyte lysate method was adopted to measure lipopolysaccharide (LPS) levels in plasma. Flow cytometry multiple proteins cytometric bead array (CBA) was used to measure the inflammatory cytokines. Fecal short-chain fatty acids (SCFAs) were determined using gas chromatography-mass spectrometer (GC-MS) method. The results showed that the lipid acceleration, fibrosis and vascular lesion of aorta plague were attenuated with dietary INU intervention. Total cholesterol (TC) Triglyceride (TG) and low density lipoprotein (LDL) in plasma with INU treatment were separately reduced to 14.04 mmol/L, 0.35 mmol/L, 2.31 mmol/mL, respectively (p<0.05). The gut microbiota was modulated in long-term INU administration by significantly reducing Alistipes (1.09×10-3), Intestinimonas (3.46×10-4), Bilophila (1.86×10-4), Oscillibacter (1.56×10-4), Negativibacillus (3.72×10-4) (p<0.05), as well as intriguingly increasing the relative abundance of Faecalibaculum (0.28) (p<0.05). Moreover, gut mcirobiota-derived SCFAs and plasma translocated LPS were improved with INU treatment. The pro-inflammatory tumor necrosis factor (TNF)-ɑ, interleukin (IL)-1β, IL-6, IL-17A in plasma and aorta root tissuewere notably decreased to 27.32 and 6.59 pg/mL, 19.15 and 4.60 pg/mL, 49.81 and 8.57 pg/mL, 16.70 and 3.57 pg/mL, respectively, in AS with long-term dietary INU intervention(p<0.05). Collectively, this study highlights that INU ameliorates AS via modulating gut microbiota and anti-inflammation.

Abstract:This research thoroughly investigated the mechanism of action for the aqueous extract of Chinese medicine Radix Codonopsis-Poria cocos-Glycyrrhizae Radix to ameliorate the learning and memory impairment in mice. The mice were randomly divided into a normal group, a model group, and Radix Codonopsis-Poria cocos-Glycyrrhizae Radix treatment groups (10, 20, 40 g/kg) and a positive drug group (donepezil, 1.5 mg/kg), with 10 mice for each group and 30 days of administration without interruption (10 mL/(kg•d)). The learning and memory impairment model was established by the intraperitoneal injection of scopolamine hydrobromide (2 mg/kg for 5 days). The behavioral changes of the mice were examined by the Morris water maze test, and the ACh and AChE levels in the hippocampal tissues of mice were evaluated by ELISA. The protein expression or phosphorylation related to the cholinergic signaling pathway were determined by Western blotting. The results showed that compared with the model group, the high-dose (40 g/kg) mice crossed the platform 5.48 times more, with their time in the third quadrant increased by 17.41% and the distance in the third quadrant increased by 14.39% in the Morris water maze test. The levels of ACh and AChE in the mouse hippocampal tissues of the middle dose group increased by 29% and decreased by 13.7%, respectively. The levels of Ach and AchE in the hippocampus of high-dose mice increased by 26%and decreased by 11.9% (p<0.05), respectively; The expression of α7-nAChR, CaMK Ⅱ, p-ERK1/2, p-CREB proteins in the hippocampus of medium- and high- dose mice increased significantly. These results suggest that the aqueous extract of Radix Codonopsis-Poria cocos-Glycyrrhizae Radix can ameliorate learning and memory impairments in mice, and its mechanism of action may be related to the activation of the cholinergic synaptic signaling pathway in the hippocampus and up-regulating the expression of related proteins. This research provides a research foundation for ameliorating learning and memory impairments using traditional Chinese medicine resources such as Radix Codonopsis, Poria cocos and Glycyrrhizae Radix, and a research direction for the development of the authentic medicinal material, Lu Codonopsis, in Shanxi province.

Abstract:This study aims to investigate the immunomodulatory effects of arabinoxylan (AX) from wheat bran on mouse peritoneal macrophages and the relevant mechanisms. The effects of AX at different concentrations on the release of nitric oxide (NO), as well as cell viability of mouse peritoneal macrophages, were studied. Mouse peritoneal macrophages were treated with AX for 0, 1, 3, and 6 h to observe the effects of AX on the expressions of immune-associated genes and proteins related to MAPK and Akt signaling pathways. The results show that AX at concentrations of 6.25 and 12.5 μg/mL have no significant toxicity to mouse peritoneal macrophages, and the cell survival rates are 90.42% and 89.99%, respectively (p>0.05). However, when the concentration exceeds 12.5 μg/mL, the cell survival rate is significantly reduced (p<0.05). Comparisons between the control and treatment group demonstrate that AX at 6.25~200 μg/mL can significantly increase NO release (p<0.05). Moreover, the expressions of immune-associated gene mRNAs (1L-1β, IL-6, TNF-α, iNOS, COX-2, and Nfkbia) are enhanced. The phosphorylation levels of MAPK and Akt pathway proteins (ERK1/2, JNK, p38 MAPK, and Akt) are also increased by AX. These results suggest that AX can regulate immunity by activating mouse peritoneal macrophages, increasing the production of NO, enhancing the mRNA expressions of immune-associated genes, and activating MAPK and Akt signaling pathways.

Abstract:The effect and mechanism of Acer truncatum Bunge seed oil on lipopolysaccharide (LPS, 3.5 mg/kg) intraperitoneal injection induced intestinal inflammation in male ICR mice were investigated. After 7 days, Acer truncatum Bunge seed oil was administrated by gavage, and corn oil was used as the control. The body weight and colon tissue of mice were observed. The levels of cytokines, including IL-1β, IL-6, IL-18 and TNF-α in serum and colon were measured by ELISA assay, respectively. The mRNA levels of Nlrp3, Asc, Caspase1 and Il1β in colon were detected by qRT-PCR assay. Acer truncatum Bunge seed oil can significantly inhibit the weight loss and reduce the ratio of colon weight to length in LPS-treated mice (p<0.05). At the same time, the levels of IL-1β (155.66 ng/L and 188.85 ng/L), IL-6 (75.42 ng/L and 57.88 ng/L), IL-18 (90.31 ng/L and 52.29 ng/L) and TNF-α (47.97 ng/L and 85.69 ng/L) in serum and colon of the model mice were significantly reduced by the intervention of Acer truncatum Bunge seed oil. The levels of MPO and MDA in colon of model mice were significantly reduced to 81.53 ng/L (vs injury group: 113.59 ng/L, p<0.05) and to 1.04 µmol/g protein (vs injury group: 1.60 µmol/g protein, p<0.05). Compared with the injured group, Acer truncatum Bunge seed oil inhibited the mRNA expression of Nlrp3 (41.80%), Asc (49.85%), Caspase1 (31.28%) and Il1β (39.83%). These results suggest that Acer truncatum Bunge seed oil improve the intestinal inflammation in LPS-treated mice. The mechanism may be associated with the reducing the activation of NLRP3 by Acer truncatum Bunge seed oil in LPS-treated mice.

Abstract:This study aimed to investigate the inhibitory effect of the isothiocyanate derivatives from Moringa oleifera seeds (MITC-21) on the growth and migration of colon cancer HCT-116 cells. Changes in cell proliferation, apoptosis, migration and protein expression levels of HCT-116 cells treated with different concentrations of MITC-21 were determined by the MTT assay, colony formation assay, flow cytometry, wound-healing assay and western blotting. The results showed that MITC-21 treatment decreased significantly the viability of HCT-116 cells in a dose- and time-dependent manner, with the IC50 values for MITC-21 against HCT-116 cells for 24, 48 and 72 h being 6.79 µmol/L, 3.71 µmol/L, and 1.13 µmol/L, respectively. The results of the colony formation assay indicated that MITC-21 (0, 2 and 4 µmol/L) significantly decreased the colony-forming ability of HCT-116 cells and after a 48 h treatment, the colony formation rate decreased from 100% to 68.36% (p<0.05) and 49.51% (p<0.01). When MITC-21 was at 4 µmol/L, the cell morphology of HCT-116 cells changed significantly. Flow cytometry analysis showed that the apoptosis rate of HCT-116 cells increased with an increase of the dose and time of MITC-21 treatment. After a 48 h treatment, compared with that of the control cells (14.97%), the apoptosis rate of MITC-21-treated groups increased to 21.60% (p<0.001) and 22.78% (p<0.001), respectively. The wound-healing assay revealed that MITC-21 significantly inhibited the migration of HCT-116 cells, with the cell migration rate decreasing from 61.53% to 32.89% (p<0.01) and 24.30% (p<0.001), respectively. MITC-21 at 4 µmol/L significantly increased the Bax/Bcl-2 ratio and decreased the expression levels of the cell migration-related proteins MMP2. Thus, MITC-21 can inhibit the proliferation, induce apoptosis and suppress migration of HCT-116 cells.

Abstract:In order to explore the sedative and hypnotic effects of Gastrodia elata Bl ferment, the physical and chemical indexes of Gastrodia elata Bl ferment and its regulation of neurotransmitters and oxidative stress in the brain tissue of mice with insomnia were examined in this study. KM male mice were randomly divided into blank group, model group, Zaoren Anshen liquid group (positive control group 1), Gastrodia powder group (positive control group 2), and low (0.10 g/kg), medium (0.30 g/kg) and high (0.49 g/kg) dose Gastrodia elata Bl ferment groups. The insomnia model was established with p-chlorophenylalanine. After the 7-day administration by gavage, the changes of autonomic activities, and levels of neurotransmitters and oxidative stress in the brain tissues of mice were measured to examine the sedative and hypnotic effects of Gastrodia elata Bl ferment on mice with insomnia. The results showed that the content of γ-aminobutyric acid in Gastrodia elata Bl ferment was 0.48 mg/kg, which was 16 times that required by the QB/T 5232-2018 standard. Compared with the model group, the activity duration and standing times of the mice in the high and medium dose Gastrodia elata Bl ferment groups were reduced significantly (p<0.05) (13.00 s and 14.63 s, and 10.62 times and 9.12 times, respectively). The contents of 5-HT, GABA and IL-1 β in the brain tissue of these two groups of mice increased significantly (p<0.01), with their SOD activity increasing significantly (p<0.05) and MDA content decreasing significantly (p<0.05) (increase by 50.62 and 49.51 pg/mL for 5-HT, and increase by 5.47 and 5.15 ng/mL for GABA). These results indicate that Gastrodia elata Bl. ferment can induce sedative and hypnotic effects by regulating the levels of neurotransmitters and oxidative stress in the brain tissues of mice.

Abstract:The antioxidant activity of anaqueous extract of Moringa oleifera leaves was investigated at the cellular level. Taking human hepatoma cells (HepG2 cells) injured by hydrogen peroxide (H2O2)-induced oxidative stress as the model, and the administration with different concentrations of the aqueous extract of Moringa oleifera leaves was for protective intervention. MTT method was used to measure the cell survival rate, and the antioxidant activity indexes such as levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA) were determined, to evaluate the protective effect of the aqueous extract of Moringa oleifera leaves against H2O2-induced oxidative damage in cells. The results showed that the survival rate of the HepG2 cells injured by H2O2 increased significantly (p<0.05) by the aqueous extract of Moringa oleifera leaves, with the cell survival rate recovered almost 100% athigh concentrations of the aqueous Moringa oleifera leaf extract (500 and 600 μg/mL). In addition, compared with the model group, the administration of the aqueous extract of Moringa oleifera leaves increased significantly (p<0.05) the activities of GSH-Px and SOD and decreased significantly (p<0.05) the MDA contents in a dose-dependent manner: increase by 20.77%~151.74% for GSH-Px, increase by 22.24%~139.07% for SOD, and decrease by 12.51%~34.04% for MDA. In summary, the aqueous extract of Moringa oleifera leaves has certain antioxidant activity at the cellular level, which can provide a reference for the development of antioxidant products of Moringa oleifera leaves.

Abstract:The monoglyceride lipase GMGL derived from Bacillus licheniformis was used as the research object. The fermentation conditions of recombinant Escherichia coli bacteria were optimized in a 5 L bioreactor, and the best inductive culture conditions were determined: inductive temperature 25 ℃, the pH of the fermentation mediumwas 7.0, the bacterial OD600 reached 20, and the final concentration of IPTG was 1 mmol/L. The glucose feeding method was variable speed feeding. After 24 hours of induction culture, the wet weight of the bacterial cell reached 125.40 g/L, and the fermentation activity was 1985 U/mL, which increasedby 67.5% compared to the pre-optimization period (1185 U/mL). Further immobilization studies were carried out on GMGL, and the optimal immobilization conditions were determined as follows: enzyme load was 100 mg/g, phosphate buffer salt concentration was 0.50 mol/L, and pH was 9. After optimization, the activity of immobilized GMGL was 4770 U/g, which increasedby 189.09% compared to that before optimization (1650 U/g). Using scanning electron microscopy (SEM) and Fourier infrared spectroscopy (FT-IR) for characterization, it was confirmed that GMGL was successfully loaded on ECR8285. These results will provide a research basis for the efficient preparation of monoglyceride lipase with high activity.

Abstract:The sensory and biological characteristics and pH properties of three batches of commercial composite LG media (referred to as the composite LG) and LG media prepared by three beverage companies using raw materials purchased by themselves (referred to as the self-made LG) were compared to evaluate the stability of the composite and self-made LG media and their performances in ensuring the sterility of cold aseptic filling production lines. Results reveal that the three batches of composite LG have similar sensory characteristics, whereas the three self-made LG have markedly different sensory characteristics. As precipitation or impurities are noted, the three media do not meet the appearance standards. Meanwhile, the pH values of the three batches of composite LG are all within the standard range (6.5±0.2), indicating that these media can be used directly without modifying their pH before use; in this regard, they outmatch the self-made LG media. Moreover, the composite LG media give similar culture rates, higher than those of the self-made LG. More specifically, the maximum growth of the eight examined bacteria was noted on the 7th day of culture for the three batches of composite LG, while Aspergillus Niger and Pseudomonas onioniae did not grow in two of the self-made LG media, namely media G and H. Therefore, the following conclusions are drawn: The overall performances of the composite LG are satisfactory, and adequate stability is noted for different batches. Hence, they are suitable for use in cold aseptic filling production lines because they can ensure the sterility of the latter. In contrast, the self-made LG media of different branches show poor stability. Moreover, as low detection sensitivity is observed for all self-made media, the risk of low counts of microorganisms remaining undetected exists when these media are used.

Abstract:In this study, a compound antibacterial liquid was prepared through combining essential oil and tea polyphenols. Then the synergistic antibacterial effects of the compound liquid containing different proportions of essential oil and tea polyphenols were studied. The antibacterial activity, antibacterial persistence and antioxidant activity of the compound antibacterial liquid with the greatest synergistic effect on the characteristic spoilage bacteria of fish were also investigated. It’s found that clove essential oil and tea polyphenols exhibited a strong synergistic antibacterial effect, with the strongest synergy occurring at the EO-to-TP mass ratio of 2:1. The minimum inhibitory concentration of 2E/T was 0.2%, and the inhibitory rate of 2E/T against Escherichia coli was 98.74%, with the synergistic coefficient as 4.46, and the bacteriostatic rate against Staphylococcus aureus being 73.37%, and the synergistic coefficient being 1.04. At the ratio to achieve the optimal synergistic effect, a total mass concentration of the compound antibacterial liquid at 0.6% led to the greatest cost-effectiveness in inhibiting Escherichia coli, Staphylococcus aureus, Vibrio parahaemolyticus and Pseudomonas aeruginosa, with the antibacterial persistence against these spoilage strains being 48 h、60 h、60 h and 72 h, respectively. At this mass concentration, the DPPH free radical scavenging rate and ABTS free radical scavenging rate could reach 86.68% and 81.26%, respectively. These results indicated that the antibacterial compound liquid of clove essential oil and tea polyphenols exhibited good antibacterial synergistic effect, antibacterial persistence and antioxidant activity, which can provide a theoretical basis for the application of natural antibacterial agents in the field of antibacterial presevation of fish products. Key words:

Abstract:Millet, glutinous rice and other cereals were used as main raw materials. Two probiotics, L. paracasei L1 and L. casei YQ336, isolated from naturally fermented sweet potato sour liquid and tofu sour liquid were used as fermentation bacteria. Non targeted metabonomics technology was used to analyze the differences of small molecular substances in cereal drinks before and after fermentation. Through principal component analysis (PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA), it was found that there were 25 categories and 145 differential metabolites with significant changes (VIP > 1 and p < 0.05) in beverages before and after fermentation, mainly including 34 organic acids and their derivatives, 21 flavonoids, 20 sugars and their derivatives, 16 alkaloids, 10 nucleotides and their derivatives 10 amino acids and their derivatives. The bioactive substances with significantly increased content after fermentation include 36668 times of 1-hydroxy-2-naphthoic acid, 1000 times of dihydroresveratrol, 800 times of 2-hydroxyvaleric acid, 517 times of daidzein, 488 times of vitexin, 238 times of apigenin, 148 times of isoerucic acid, 130 times of genistein, etc. The analysis of KEGG metabolic pathway showed that there were 19 metabolic pathways with significant differences. It is speculated that grain substrate may have certain effects on the synthesis and accumulation of secondary metabolism of L. paracasei L1 and L. casei YQ336. This study will lay a theoretical foundation for the fermentation of plant matrix food by lactic acid bacteria and the metabolic mechanism of plant matrix.

Abstract:The effects of gallic acid on the solubility, swelling, gelatinization, and rheological properties of rice starch, and the characteristics of the molecular and crystal structures of gallic acid-starch complexes were investigated. The results demonstrate that gallic acid significantly increased the solubility and reduced the swelling, gelatinization temperature, and gelatinization enthalpy of rice starch (p<0.05). This suggests that gallic acid could inhibit the gelatinization of starch and reduce its thermal stability. Gallic acid decreased the gelatinized viscosity and setback values of the treated rice starch, indicating that gallic acid reduced the cross-linking between the starch chains and inhibited the retrogradation of the rice starch. These gallic acid and rice starch mixtures represent a typical pseudoplastic fluid, and demonstrated the associated shear-thinning characteristics. The addition of gallic acid significantly reduced the storage modulus and loss modulus of starch gels, and the viscoelasticity of gallic acid-starch gel systems. This indicates that gallic acid has a destructive effect on starch gel structure. Infrared spectroscopy showed that the peak intensity ratio of the gallic acid-starch complex, at 1045/1022 cm-1, decreased, suggesting that the addition of gallic acid reduces the order structure of rice starch. In addition, the data suggests that these two products primarily interact via the production of hydrogen bonds. X-ray diffraction demonstrated that these complexes formed a new diffraction peak at 12.7 °, indicating that gallic acid interacts with rice starch to form a unique crystal structure. This study provides theoretical guidance for the application of gallic acid in the improvement of starch-based functional foods.

Abstract:Phytosterol (PS) has many excellent physiological activities, but the application of phytosterol in food industry is widely restricted due to low solubility and bioaccessibility. To provide a water-soluble phytosterol, okara protein (OP) was used as raw material to prepare phytosterol nanoparticles by anti-solvent method combined with dynamic high-pressure microfluidization, and physicochemical property were characterized. Dynamic high-pressure microfluidization can significantly reduce the size of OP-PS particles, and significantly improve the encapsulation efficiency of PS. After dynamic high-pressure microfluidization for 3 times at 120 MPa, the particle size of OP-PS particles can reach 139.28 nm with good re-dispersibility, and the encapsulation efficiency of PS is up to 98.63%, which can effectively improve the water-solubility and bioavailability of PS. The stability of OP-PS particles was evaluated. After 50 days of storage at room temperature, the encapsulation efficiency of PS was still about 66.90%, and the thermal stability was obviously better than that of soybean protein isolate-phytosterol particles prepared under the same conditions. The results of particle disulfide bond determination showed that high-pressure microfluidization could induce the formation and cross-linking of intramolecular or intermolecular disulfide bonds of protein. The free sulfhydryl and disulfide bonds of OP were significantly higher than those of SPI, and more disulfide bonds could be formed and cross-linked under high pressure homogenization. Therefore, OP-PS nanoparticles prepared by high pressure microjet technology have higher stability and sterol loading capacity, which can provide reference for industrial production of water-soluble sterols.

Abstract:The optimal preparation process of polyethylene glycol-modified luteolin liposome was investigated to enhance the bioavailability of luteolin. Polyethylene glycol-modified luteolin liposomes were prepared by the thin-film dispersion method. Phospholipids, cholesterol and phosphatidylethanolamine-polyethylene glycol 2000 (DSPE-PEG2000) were employed as carriers, and the encapsulation efficiency was used as the evaluation index. The Box-Behnken design experiment was used to optimize the process parameters by response surface optimization method. Then the size, zeta potential and morphology of the prepared liposomes were determined. Results showed that the optimal conditions were: ratio of membrane to material was 10:1, ratio of lipid to drug was 16:1, and mass fraction of DSPE-PEG2000 was 3%, ultrasonic treatment time was 15 min, and hydration temperature was 40 ℃. The average encapsulation efficiency of the modified luteolin liposomes was approximately 86.3%, with the mean particle size and potential being 134.1 nm and -14.07 mV, respectively. The cumulative release rates of luteolin from the liposomes in the simulated gastric juice, small intestinal juice and colon fluid were 39.08%, 43.67% and 71.71%, respectively. The prepared liposomes had a high encapsulation efficiency, uniform particle size and obvious sustained-release effect. The preparation method is simple and feasible.

Abstract:Pepper stems essential oil was extracted from pepper stems by enzymatic assisted steam distillation using cellulase as extractant. The four factors affecting the yield of essential oil (enzyme concentration, enzyme treatment time, enzyme treatment temperature and liquid-solid ratio) were optimized by single factor test and response surface methodology. The experimental results showed that: the best yield of pepper stems essential oil was 1.21%±0.02% when the enzyme concentration was 103.25 g/L, the enzyme treatment temperature was 41.28 ℃, the enzyme treatment time was 3.01 h, and the liquid-to-material ratio was 5.23:1, which was 51.25% higher than that of steam distillationunder the same conditions. The components of pepper stems essential oil were analyzed and identified by GC-MS. The results showed that: there were 47 chemical substances in pepper stems essential oil, mainly containing monoterpenes, sesquiterpenes, aromatic hydrocarbons, alcohol compounds, ester compounds, etc. Its composition was mainly enterpenoids, and the components with the highest content were limonene (19.4%), 1-caryophyllene (11.2%), β-pinene (10.9%), iso-eucalynol (10.7%), 3-carene (6.31%), etc. There are many common components of pepper stems, black pepper essential oil and pepper leaf essential oil, indicating that pepper stalk essential oil has a higher utilization value.

Abstract:In order to study the effect of electron beam irradiation on the quality of fresh pork, the irradiation doses of 1 kGy, 3 kGy, 5 kGy, 7 kGy and 9 kGy were used in this experiment to treat fresh pork, and then fresh pork was stored at 4 ℃.The physical and chemical indexes were measured during storage. The results showed that the irradiation dose less than 3 kGy could promote the color of fresh pork to some extent. High dose (more than 7 kGy) irradiation treatment will affect the color of fresh meat sensory. On the 12 th day, the TBARS value of blank group was the lowest, only 0.446 mg/kg, and the value of 9 kGy group was the highest, reaching 0.650 mg/kg. The shelf life of the blank group was only 7~8 days, while the colony value of the 7 kGy and 9 kGy groups was still within the qualified meat standard on the 12 th day, which extended the shelf life for 5 days. In terms of volatile flavor compounds, 13 compounds were detected in 0 kGy and 1 kGy groups, 10 compounds were detected in 3 kGy group, 16 compounds were detected in 5 kGy group, 15 compounds were detected in 7 kGy group and 14 compounds in 9 kGy group. High dose (more than 7 kGy) irradiation could increase the variety and content of flavor compounds of fresh pork, while low dose irradiation had little effect on the flavor of fresh pork. According to the comprehensive consideration of various physical and chemical indexes, 3 kGy irradiation treatment of fresh pork has the best effect.

Abstract:The total phenolic content, total anthocyanin content, and superoxide dismutase activity of four different cultivars of raspberry from Central China at different stages of ripening were detected by spectrophotometry. Phenolic compounds were identified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and their absolute contents were determined by high-performance liquid chromatography (HPLC). The total phenolic contents of all four types of raspberry were found to decrease during ripening, whereas their total anthocyanin contents increased. Mei 22raspberrieswere found to have the highest total phenolic and anthocyanin contents (31.94 mg/g FW and 1.31 mg/g FW, respectively) among the investigated fruit samples. In addition, a total of nine phenolic compounds were identified in the four raspberry samples, including five anthocyanin phenolic compounds and four non-anthocyanin phenolic compounds. Cyanidin 3-O-sophoroside and cyanidin 3-O-glucoside were found to be the dominant anthocyanin phenolic compounds, with lambertianin C and sanguiin H-6 being present as the major non-anthocyanin phenolic compounds. Additionally, the superoxide dismutase activities of the raspberries were observed to reduce during ripening, with the Tianmen No.3 sample exhibiting the largest decrease (37%) among the investigated samples. This study provides basic data for the development and utilization of raspberries from central China.

Abstract:In order to explore the synergistic effect of atomization fumigation and modified atmosphere packaging technology in preserving the quality of winter jujube during postharvest storage and transportation, Xinjiang winter jujube was used as the research material, and 2% CaCl2+100 mmol/L SA (salicylic acid) atomization fumigation combined with 8% O2+92% N2 modified atmosphere packaging treatment were applied. Using 8% O2+92% N2 modified atmosphere packaging only (without the atomization fumigation treatment) as the control group, the changes in related physiological indicators were measured. The results showed that 2% CaCl2+100 mmol/L SA atomization fumigation combined with modified atmosphere packaging technology inhibited significantly the decreases in the hardness, titratable acid, protopectin and cellulose content of the winter jujube, and delayed the rise of the decay rate, weight loss rate, cell membrane penetration, soluble solids, soluble pectin, cellulase (Cellulase Cx), pectin methyl esterase (PME) and polygalacturonase (PG). Atomized fumigation combined with modified atmosphere packaging seemed better than the control group. On the 6th day, the hardness was 9.16 N, weight loss rate was 1.54%, decay rate was 2.00%, cell membrane permeability was 43.65%, TSS was 17.20% and TA was 0.81%. The contents of cellulose, protopectin, and soluble pectin were 0.45%, 0.59%, and 0.88%, respectively. The enzyme activities of Cx, PME, and PG were lower by 23.52%, 18.60% and 10.00%, respectively, compared with those of the control group subjected only to 8% O2+92% N2 modified atmosphere packaging, and lower by 40.90%, 22.22% and 30.28% compared to the untreated control group. These results indicate that atomization fumigation combined with modified atmosphere packaging technology can significantly delay the decay of postharvest winter jujube, and can extend the shelf life. Therefore, atomization fumigation combined with modified atmosphere packaging technology as a new treatment method can improve the quality of winter jujube during storage and transportation.

Abstract:The quality of wheat flour and its derived products undergoes changes due to the influence by heating during processing. In this study, the changes in dough rheological properties and steamed bread quality after the heat treatment of wheat flour was heated were examined. Wheat flour was dry heated at 60 ~ 90℃ for 10 ~ 50 s, before the analyses of the gelatinization, silty and tensile properties of the dough as well as the color and texture of the steamed bread. The results showed that the heated wheat flour had a decreased peak viscosity (by 7.01%), reduced minimum viscosity (by 9.44%), and decreased final viscosity (by 5.58%), increased attenuation value (by 10.25%), increased regeneration value (by 8.38%), and decreased tensile curve area (by 19.74%), and decrease ductility (by 12.77%), compared with the original wheat flour. With the extension of time, the tensile resistance increased firstly and then decreased. The formation time of wheat flour was insignificantly affected by the treatment temperature and time. The stabilization time decreased by 10.74% and the degree of weakening increased by 9.90%, with the increase of treatment temperature. After the heating of wheat flour, the ratio of width to height and specific volume of the steamed bread increased by 17.81% and 22.22%,respectively, with its color becoming worse, along with decreases in hardness (by 62.25%), viscosity (by 75.64) and chew ability (by 63.46%). In summary, moderate heating of wheat flour can improve the quality of derived steamed bread.

Abstract:In order to enhance the mechanical properties of gelatin gel and expand its application value, gelatin-citric acid-stearic acid composite gel was prepared by using gelatin as raw material, citric acid as cross-linking agent and stearic acid as additive. The preparation conditions of composite gel were optimized with compressive strength as the response value. The morphology of the composite was observed with a scanning electron microscope (SEM), the chemical structure was characterized by infrared spectroscopy (FT-IR), and the cytotoxicity and curcumin release were studied. The results showed that the optimized process conditions were as follows: the quality of stearic acid was 0.013 g/mL, the quality of citric acid was 0.015 g/mL, and the temperature was 69 ℃. The mechanical strength of the gelatin-stearic acid composite gel prepared under the optimal conditions was 117% higher than that of the single component gelatin gel (45.55 kPa). The FT-IR spectrum analysis showed that the secondary structure of gelatin was changed due to the cross-linking effect of citric acid, resulting in the formation of GA-CA-SA composite gel. The hydrophilic gelatin was arranged outside and the hydrophobic stearic acid was wrapped in it. Inside, a regular pore structure was formed. It has no cytotoxicity and has a good slow release effect on curcumin.

Abstract:Butter-based whipping cream was prepared using salt-free butter and skim milk. The effects of first-stage homogenization pressure in two-stage homogenization (in which the second-stage homogenization pressure was kept unchanged) on the particle size, partial coalescence rate of fat, and rheological and whipping properties of the butter-based whipping cream were studied. Additionally, the correlations among the evaluation indices were analyzed. The results indicated that when the first-stage homogenization pressure was in the range of 10.0~15.0 MPa, as the pressure increased, the particle size D4,3 decreased from 1.85 to 1.57 µm. In particular, when the particle size reached its minimum of 1.57 µm at a first-stage homogenization pressure of 15.0 MPa, the partial coalescence rate of fat in the butter-based whipping cream increased gradually from 13.74% to 17.53% with an increase in the first-stage homogenization pressure, and the whipping time gradually decreased from 314 to 265 s. More specifically, when the first-stage homogenization pressure was 15.0 MPa, the whipping time was the shortest at 265 s. The foam stability increased from 78.09% to 87.26% as the first-stage homogenization pressure increased, and the foam stability reached its maximum of 87.26% when the pressure was 15.0 MPa. Therefore, the first-stage homogenization pressure of butter-based whipping cream should be controlled in the range of 10.0~15.0 MPa.

Abstract:Tofu production process by filtering raw soybean milk (FRSM) was optimized according to protein coagulation of fermented soybean whey (FSW). The effects of the soybean-to-water ratio, cooking temperature and duration, and amount of FSW added on the characteristics (yield, protein and water contents, and water-holding capacity) of the produced tofu were evaluated using the Box-Behnken design. Based on single-factor experiments, response surfaces of tofu yields and protein contents were obtained. Analysis of variance and interaction analysis were performed to determine the optimal process parameters of FRSM tofu production. Significant differences were observed concerning the tofu characteristics depending on the different soybean-to-water ratios, cooking temperatures and time, and FSW contents applied in the production process (p<0.05). The optimal tofu production conditions were the following: soybean-to-water ratio of 1:4 (kg:kg); cooking duration of 6.0 min, at a temperature of 105 ℃; and a FSW content equal to 26.5%. Under these conditions, the yield and protein content of the tofu were 224.09/100 (g/g) and 8.68%, respectively, which were 33.15/100 (g/g) and 3.29% higher as compared with the values obtained before the protocol optimization. Altogether, these results indicate that FRSM is feasible for high-yield and high-protein content tofu production.

Abstract:Beef protein was hydrolyzed by using six proteases (protamex, flavorenzyme, papain, bromelain, neutrase and alcalase) to produce beef protein hydrolysates. The change of ACE inhibitory activity of different proteases hydrolysates before and after simulated digestion was compared. The molecular mass distribution and sensory evaluation of different hydrolysates were analyzed. The results showed that alcalase was the most suitable for beef enzymolysis to produce anti-hypertension peptide. The ACE inhibitory activity of alcalase enzymolysis solution was 51.19%, and the activity decreased slightly after digestion, which was 39.65%. Meanwhile the hydrolysis degree of alcalase enzymolysis solution was 44.76%, and the beef protein was fully decomposed. The second was protamex and neutrase, their hydrolysates showed high ACE inhibitory activity before and after digestion. The inhibition rates before digestion are 67.97% and 62.00% respectively, the inhibition rates after digestion are 37.26% and 43.12% respectively, and the degree of hydrolysis is 37.47% and 36.35% respectively. However, the decomposition degree of protein was lower than that of alcalase hydrolysate. The results of sensory evaluation showed that the appearance, smell and taste of different enzymatic hydrolysates were not different from those of commercial products, and there was no obvious bad flavor, which could be used in the production of food auxiliary materials.

Abstract:In order to compare the antioxidant and antibacterial effects of the aqueous extract and acidic extract of Artemisia argyi. Deionized water and citric acid solution were used to obtain two extracts from Artemisia argyi, and the contents of total flavonoids, total polyphenols and polysaccharides in these extracts were measured. The antioxidant capacity of each extract was evaluated by the DPPH, hydroxyl and ABTS radical scavenging assays. The Oxford cup method was used to determine the antibacterial activity of the extract and examine the underlying antibacterial mechanism. The results showed that the contents of total flavonoids, total polyphenols and polysaccharides were 208.03, 51.77 and 398.72 mg/g, respectively, in the aqueous extract of Artemisia argyi, and 80.39, 25.44 and 453.45 mg/g, respectively, in its acidic extract. Within a certain concentration range, both the aqueous extract and acidic extract of Artemisia argyi had strong antioxidant capacities, with their median inhibition concentration (IC50) values 33.10 and 54.52 μg/mL, respectively, for DPPH radical, 2.92 and 1.63 mg/mL, respectively for hydroxyl radical, 0.17 and 0.32 mg/mL, respectively, for ABTS radical. The aqueous extract of Artemisia argyi exhibited insigficant antibacterial effect; whilst the acidic extract exerted significant antibacterial activity against Staphylococcus aureus, Shigella and Salmonella, with the minimum inhibitory concentration being 0.10, 0.10 and 0.20 g/mL, respectively. The examinations of antibacterial kinetics and cell membrane permeability confirmed that the acidic extract could effectively inhibit the growth of pathogenic bacteria and change the cell membrane permeability. Scanning electron microscopy and polyacrylamide gel electrophoresis experiments revealed that the acidic extract can destroy the morphology of bacterial cell walls and inhibit bacterial protein synthesis. The extraction using the citric acid solution is more suitable for the extraction of the active ingredients from Artemisia argyi than the aqueous extraction, and the acidic extract has a greater potential as food preservatives and antioxidants.

Abstract:Quercetin, as a kind of flavonol compound, has been applied in the fields of food and medicine, because of its attracting physiological functions and pharmacological activities such as anti-oxidation, anti-tumor, lipid-lowering and anti-bacteria. Porous silica is a new type of carrier material and it has many advantages including large specific surface area, good compatibility, ordered and controllable pore channels. More importantly, it is easy to be modified. In this paper, porous silica microspheres were prepared by modified Stöber method, and they were functionalized by introducing amino groups. Based on this, porous silica/quercetin composite materials were synthesized successfully. The prepared porous silica spheres exhibited high specific area (153.63 m2/g) and uniform distribution of pore size (2.40 nm). The control experiments displayed that 0.09 mg quercetin could be loaded per milligram amino-functionalized silica spheres, which was 2.25 times that of the pre-functionalized silica sphere. The possible reason is that amino groups are hydrophilic, so the water dispersion of silica spheres becomes better after introducingamino groups. On the other hand, hydrogen bonds can form easily between amino and hydroxyl groups, so that amino groups functionalized silica spheres can be composite withquercetin easily. The free radical removing activities of the hybrid materials were characterized by DPPH method. The results showed the free radical removing activities of porous silica/quercetin composite materials and pure quercetin were 48.44% and 32.81% under the same condition, respectively. This indicates that the antioxidant activities of composite materials were higher than that of pure quercetin, which may be related to the protective effect of porous silica microspheres on quercetin.

Abstract:The influence of key processing unit operations on the changes in the flavor compounds of NFC (not from concentration, NFC) Bisekxing melon juice by gas chromatography-ion mobility spectroscopy (GC-IMS), so as to provide certain theoretical guidance for its processing. Using the commercially available fresh thick-skinned muskmelon as the experimental material, NFC Bisekxing melon juice was processed through five operation units, fresh squeezing, enzyme inactivation, homogenization, ultrasound treatment and sterilization. GC-IMS was used to analyze qualitatively the flavor substances in the melon juice samples obtained after the processing step of each operation unit, and three-dimensional and two-dimensional topographic maps and fingerprints of the melon juice samples were constructed along with PCA analyses. The results showed that a total of 61 volatile substances belonging to 35 kinds of volatile substances were detected in the NFC Bisekxing melon juice, including 7 kinds of aldehydes, 9 kinds of alcohols, 10 kinds of hydrocarbons, 5 kinds of ketones, and 4 kinds of esters. Enzyme inactivation exerted the greatest impact on the flavor substances of melon juice, causing the melon juice to produce odor substances such as benzaldehyde, while promoting the formation of main aroma substances such as ethyl propionate. The flavor of melon juice after enzyme inactivation was significantly different from that of melon juice treated by other processing units. The main aroma substances of melon juice were aldehydes and esters. Other key processing unit operations hada certain influence on the flavor substances in melon juice. These results provide a theoretical basis for controlling the processing parameters in the preparation of NFC Bisekxing melon juice and improving the quality of melon juice.

Abstract:In this study, the newly brewed Maotai-flavor liquor was treated by irradiation technology, and the change of aroma components in samples before and after irradiation was analyzed by GC-MS-MS, and the effect of irradiation on Maotai-flavor liquor was discussed. After irradiation, the contents of alcohols in Maotai-flavor liquor samples were decreased obviously. Under 3.203 kGy irradiation treatment, the contents of isoamylol, isobutanol, butanol, hexanol and amyl alcohol were decreased by 20.11%, 57.65%, 23.14%, 90.13% and 71.42%, respectively, compared with the control group. Irradiation treatment can significantly reduce the content of furfural in Maotai-flavor liquor. Under 2.93 and 3.203 kGy irradiation treatment, the contents of furfural were decreased by 34.48% and 68.07%, compared with the control group. When the irradiation absorption dose was between 1.347 kGy and 3.203 kGy, the contents of ester substances in liquor did not change significantly, except acetic acid propenyl ester. However, the contents of volatile esters in Maotai-flavor liquor were decreased obviously after high dose irradiation treatment, and caused the flavor and aftertaste becoming worse. When the absorbed dose was 5.59 kGy, the contents of ethyl lactate, ethyl caproate, amyl lactate, ethyl octanoate and ethyl levulinate decreased by 8.73%, 13.52%, 23.58%, 44.01% and 67.54%, respectively, compared with the control group. Oganic acids, phenols, ethers and pyrazines were barely affected by irradiation treatment. When the irradiation dose was between 2 kGy and 3 kGy, the irradiation treatment can not only quickly reduce the contents of fusel alcohol and furfural in the liquor, but also will not cause the significant degradation of esters in the liquor, which was helpful to improve the smoothness and flavor coordination of Maotai-flavor liquor. Therefore, the dose for irradiation processing of Maotai-flavor liquor should be between 2 kGy and 3 kGy.

Abstract:To further improve the quality of raw black tea from Southern Henan, the processes of sun-drying and shaking were introduced to the primary production of raw black tea from Southern Henan, and the main biochemical components in the tea in different processing stages were determined. The catechins in tea at different processing stages were analyzed by high-performance liquid chromatography. Concurrently, headspace solid-phase microextraction gas chromatography-mass spectrometry was used to analyze the aroma compounds in the tea, with results: The contents of tea polyphenols, ester catechins, and amino acids in the raw black tea prepared by the traditional technique are 12.22%, 33.72 μg/mL, and 19.77 mg/g, respectively, whereas those in the raw black tea prepared by the new technique are 9.87%, 20.58 μg/mL, and 20.73 mg/g, respectively. Results show that, after sun-drying and shaking, the contents of bitter tea polyphenols and ester catechins noticeably decrease while the contents of refreshing amino acids increase. The contents of floral and fruity compounds in the raw black tea processed using the new technique increase significantly, while compounds with unpleasant smells decrease considerably. A comprehensive analysis suggests that introducing the shaking technique can effectively reduce the bitterness of raw black tea, making the taste more refreshing and enhancing the aroma significantly.

Abstract:To evaluate the flavor difference between commercial soybean paste and γ-aminobutyric acid (GABA) bean paste, headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used to measure and analyze the volatile components and the common indexes in nine commercial soybean paste samples (S1-S9) and the GABA soybean paste sample (S10). The key volatile components were determined by principal component analysis (PCA) and odor activity value (OAV). The results showed that 144 compounds in eight categories were detected in 10 soybean paste samples and the content of γ-aminobutyric acid in S10 reached 1.87 mg/g, the pH value was 4.69, and the color was bright without impurities. Among them, esters, alcohols and acids accounted for more than 60% of the total volatile components. Additionally, the results of PCA of 41 common volatile substances were identified in 10 soybean paste samples, demonstrating that 2-methyl-butyraldehyde, 3-methyl-butyraldehyde, dimethyl-trisulfide and guaiacol significantly contributed to the flavor formation of bean paste. Besides, the GABA soybean paste has a rich variety of flavors, in which the contents of 2-pentylfuran, 2-ethyl-6-methylpyrazine, guaiacol and dimethyl trisulfide (which exhibited aromas of mung bean, nut and clove) were significantly higher than other samples. This could be the reason for some differences in flavor substances between GABA soybean paste and other samples. The results of this study could provide theoretical reference for the development of functional soybean paste and the flavor improvement in soybean paste products.

Abstract:The components of Guizhou Dong nationality traditional Kam sweet rice wine were explored, including the basic physical and chemical indexes, nutrient and volatile flavor. The antioxidant activity of the Kam sweet rice wine was compared with ordinary Baijiu. The volatile components of Kam sweet rice wine were detected by gas chromatography-mass spectrometry (GC-MS) and 45volatile components were detected in Kam sweet rice wine. Inductively coupled plasma mass-spectrometry (ICP-MS) was used to detect the 9 elements in the two wine samples. Results have shown that Kam sweet rice wine had higher contents of Mn, Fe, Zn, Se and other essential microelement in hunman body than ordinary Baijiu. The automatic amino acid analyzer detected the amino acids in the Kam sweet rice wine sample, which has shown 14 kinds of amino acids and 6 kinds of essential amino acids for the human body. By measuring the DPPH free radical, ABTS free radical and •OH free radical scavenging ability of Kam sweet rice wine and ordinary Baijiu, the results showed that the antioxidant rate of Kam sweet rice wine reached 95.68%, 83.20%, and 83.20%, respectively, with the addition of 1.8 mL volume. Which was a increase of 71.31%, 33.93%, and 75.69%, respectively, compared with ordinary Baijiu significantly. It shows that Kam sweet rice wine retains the basic characteristics of distilled wine, has both the nutrition and taste of fermented wine, and has a certain value for excavation and development.

Abstract:In this study, anear infrared (NIR) quantitative prediction model for the lysine in the freeze-dried chicken breast muscle powder was developed using the partial least squares method. The model was optimized through four aspects, spectrum preprocessing, model characteristic spectrum screening, outlier samples elimination, and sample selection for modeling and verification, in order to improve the prediction accuracy and robustness of the model. Taking a total of 263 freeze-dried chicken breast muscle powders as the research object, the effects of seven different spectral preprocessing methods, four characteristic spectrum screening methods, MCCV outlier samples elimination methods, and two samples selection methods for modeling and verification, SPXY and chicken breeds, on the NIR quantitative prediction model for the lysine of in freeze-dried chicken breast muscle powder. The results showed that (1) the best model was established on the basis of 156 calibration samples and 39 external verification samples after the elimination of 68 outlier samples from the original spectra in the 1000~2502 nm; (2) The spectral region in the 1000~2502 nm used for modeling should be pretreated by SNV+gapsegment (1#,15,7) method when there was no outlier spectrum or model characteristic spectral region for selection; (3) Least impact on the accuracy of the model established using the original spectra, was exerted by outlier sample elimination and samples selection for modeling in 1386~1379 nm, 1329~1323 nm, 1289~1283 nm, 1276~1258 nm, 1240~1235 nm, 1194~1184 nm, 1173~1168 nm、1142~1137 nm, 1103~1099 nm, 1080~1076 nm, 1058~1054 nm, 1012~1009 nm, 1004~1001 nm. Research showed that the establishment of a near-infrared quantitative prediction model for the lysine of in freeze-dried chicken breast muscle powder is greatly affected by outlier samples, samples for modeling and external sample selection for verification. The applicability of the model is greatly affected by characteristic spectra regions for modeling. The preprocessing of the whole spectrum without other pretreatments has a greater impact on the accuracy of model.

Abstract:A high-performance liquid chromatography-tandem quadrupole electrostatic-ion-trap high-resolution mass spectrometry (Q Exactive HF, HRMS) method with mixed-mode-adsorbent-based purification was established for the simultaneous determination of sulfaquinoxaline and diaveridine in eggs. The egg samples were first extracted by ultrasonic solvent extraction, followed by centrifugation of the extracts at 8000 r/min, and purification and collection via the addition of adsorbents with different operating mechanisms. The extracts were subsequently dried under nitrogen at 40 ℃, followed by the addition of 0.1% formic acid-acetonitrile solution (9:1, V/V) to prepare constant-volume samples suitable for mass spectrometry. An Acquity ultra-performance liquid chromatography (UPLC) Beh C18 (2.1 mm×100 mm, 1.7 μm) column was employed for separation, with 0.1% formic acid-water and 0.1% formic acid-methanol being used as the mobile phases for gradient elution. Mass spectrometry was conducted in the parallel reaction monitoring mode for the quantitative analysis of the target compounds. The two investigated compounds could be adequately separated under the established chromatographic conditions. Acceptable linear relationships in the linear range, and correlation coefficients greater than 0.999 were obtained. Standard addition validation at addition levels of 10, 50, and 200 ng/g resulted in average recoveries of 96.4%~106.8% of the two compounds being obtained, with relative standard deviations (RSDs) of less than 7.1%. The limit of detection (LOD, S/N=3) and limit of quantification (LOQ, S/N=10) of the developed method were found to be 0.1~0.2 μg/kg and 0.3~0.6 μg/kg, respectively. This method requires straightforward sample processing and enables a short duration of analysis, while ensuring accuracy, reliability, and high sensitivity, thereby establishing its suitability for the simultaneous determination of sulfaquinoxaline and sulfonamide potentiators in eggs.

Abstract:A method was established for determining the di(2-ethylhexyl) terephthalate in foods containing fats and oil, through acetonitrile extraction, PSA/silica composite solid phase extraction column purification, and gas chromatography-mass spectrometry analysis. The samples were subjected to ultrasound-assisted extraction with acetonitrile multiple times and purified by PSA/silica composite solid phase extraction column, concentrated by a rotary evaporator, and separated by HP-5MS UI quartz capillary chromatographic column, before the analysis of di(2-ethylhexyl) terephthalate in the samples by the external standard method under the selected ion monitoring (SIM) mode. The experimental results show that a good linear relationship was found in the di(2-ethylhexyl) terephthalate concentration range of 0.125~2.50 μg/mL, with correlation coefficients higher than 0.99, limit of detection as 0.20 mg/kg, and the limit of quantitation as 0.50 mg/kg. When the spiked levels were 0.50, 1.00 and 5.00 mg/kg, the mean recoveries of di(2-ethylhexyl) terephthalate in foods containing fats and oil ranged between 78.11% and 104.53% with the relative standard deviations (RSD, n=6) not higher than 7.21%. This method is simple, rapid and sensitive, which is suitable for determining the di(2-ethylhexyl) terephthalate in foods containing fats and oil. Among the 40 fat/oil-containing food samples analyzed by the established method, 10 samples involving sesame paste, chili oil, vegetable oil and meat products were found to contain di(2-ethylhexyl) terephthalate (concentration: 0.64 mg/kg~1586.34 mg/kg), in particular, some positive samples had a high content, thereby deserving high attention

Abstract:Molecularly imprinted polymers (MIPs) of benzimidazole fungicides were synthesized by the precipitation polymerization method. The common maternal nucleus, 2-aminobenzimidazole (AMB), was selected as template molecule, Gaussian 09W molecular modelling software and H-NMR were involved to determine types and proportions of functional monomers and types of solvents in preassembled system. The optimum preparation conditions of MIPs were optimized through orthogonal experiment design. Under optimal conditions, structural characterization and adsorption properties of MIPs were studied by scanning electron microscopy (SEM), brunauer-emmett-teller (BET), fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analyser (TGA) and adsorption experiment. According to computer molecular simulation and nuclear magnetic spectral analysis, itaconic acid (IA) and acetonitrile were selected as function monomer and solvent, respectively. The molar ratio of AMB and IA was determined as 1:2. Based on the above results, the optimum imprinting conditions were established through orthogonal experiments. MIPs were prepared under the above mentioned preparation conditions, indicating a good thermal stability. The results of dynamic adsorption experiments showed that the adsorption process of MIPs to carbendazim (CBZ) conformed to the pseudo-second-order kinetic model, and the adsorption equilibrium time was 120 min. The equilibrium adsorption capacity (Q) of CBZ was 8.87 mg/g, and the imprinting factor (IF) was 2.89. The Scatchard analysis showed that MIPs had two classes of adsorption sites. MIPs showed good adsorbability not only to CBZ, but also to other benzimidazole fungicides such as thiamidazim, albendazole and benzimidazim. The MIPs synthesized by this method were used as solid-phase extraction fillers to remove the benzimidazole fungicides in Dendrobium polysaccharide extract. The removal rates of four benzimidazole fungicides were higher than 92% and the loss rate of total sugar was 14.94%.

Abstract:Four major mung bean growing areas, Tailai County, Dumeng County, Longjiang County, and Daqing County, in Heilongjiang Province were studied to investigate the soil heavy metal pollution in the major mung bean producing areas in the province. Soil samples were obtained at 0~20 cm below the ground surface to determine the pH values, organic matter contents, and heavy metal contents. Risk assessments for seven heavy metals, namely, copper, zinc, cadmium, lead, chromium, arsenic, and nickel, in soil were carried out using the Nemero comprehensive pollution index and the potential ecological risk index. In the calculations of these indices, the background values were adopted from the national soil environmental quality/agricultural land soil pollution risk control standard (trial) (GB 15618-2018). The results indicated slight soil heavy metal pollution levels in the major mung bean producing areas in Heilongjiang. For the soil at 0~20 cm, the average pH value is 8.04, indicating that the soil is slightly alkaline. The average organic matter content is 2.21%, and the contents of copper, zinc, cadmium, lead, chromium, arsenic, and nickel are 4.40~25.88, 27.16~66.97, 0.06~0.19, 11.36~19.19, 11.63~69.95, 10.46~58.92, and 7.03~33.63 mg/kg. In particular, the arsenic content exceeds the screening value stipulated by the national standard. The comprehensive pollution index values range from 0.98 to 1.24, suggesting a slight pollution level. The comprehensive potential ecological risk index values range from 20.03 to 23.95. They are much lower than 80, indicating that the potential ecological harm is slight.

Abstract:In this study, UHPLC quadrupole-orbitrap mass spectrometry was used to collect the chromatographic information, mass charge ratio of molecular ions and mass charge ratio of secondary fragmentation fragments of 12 kinds of chloronicotinoids and their metabolites, the fragmentation pathway was analyzed, the standard database of chloronicotinoids and their metabolites were established, and characteristic fragments were screened; The independent data scanning mode was used to obtain the traceable mass spectrum information of samples, and a non targeted screening method for chloronicotinoids and their metabolites in dairy products was established. The determination limit and the detection capacity of this method were in range of 0.01 μg/kg~0.33 μg/kg and 0.03 μg/kg~0.59 μg/kg, respectively. The recoveries were 84%~104%, and the relative standard deviations were 4.4%~7.1%. The established method was applied to the screening of chloronicotinoids and their metabolites in 81 batches of pasteurized milk. It was found that the samples contained acetamiprid-metabolite-IM-1-4, which was not detected, and the content was 0.32 μg/kg. The results showed that the method was rapid and simple, and could realize the accurate qualitative and quantitative analysis of chloronicotinoids and their metabolites in dairy products.

Abstract:The danofloxacin polyclonal antibody and barcoded DNA strand were simultaneously modified on the surface of gold nanoparticles to prepare gold nanocomposite probe (NP). The magnetic probes (MMPs) were prepared through combining the monoclonal antibody and magnetic particles. After the above two probes are successfully prepared, the hybridization reaction was carried out with the standard, danofloxacin. At the same time, the magnetic field was used to immobilize MMP and remove the unbound NP probe. Finally, the DNA strands labeled on the gold nanocomposite probe were released, and the collected and released DNA strands were detected by microplate silver-stainedbio-barcode technology to obtain indirectly the residual amount of danofloxacin. The detection method does not require expensive equipment, and ordinary laboratories can complete all the experimental operations by using the microplate reader. The operation is simple, the detection is fast, and the detection efficiency is higher than that of traditional ELISA. The results showed that the limit of detection IC15 was 3.62 ng/mL for danofloxacin in the range of 0.05~50 ng/mL, with the detection sensitivity being 100 times that of conventional immunoassay. This method realizes ultra-highly sensitive detection of danofloxacin residue, and can be applied to the rapid detection of other antibiotics. Therefore, the established method is reasonably practicable.

Abstract:To provide scientific bases for the safe application of Astragalus stem and leaf, acute oral toxicity, genetic toxicity, and 90-day subchronic toxicity tests were performed, following standard procedures for toxicological safety evaluation of food, in mice and rats. The acute oral LD50 of male and female mice and rats was more than 250.00 g/kg BW, indicating that the stem and leaf of Astragalus are non-toxic. Results obtained from all the three genotoxicity tests indicate that the stem and leaf of Astragalus are non-toxic; in addition, mutagenicity was not detected. In the 90-day oral toxicity test, all the rats in each treatment group grew well, and no symptoms of poisoning were observed. There was no significant difference in eye performance, body weight, weight gain, food intake, food utilization efficiency, hematology, blood biochemistry, urine chemistry, organ weight, and organ/body weight ratio and no obvious histopathological changes were found. A dose of 15.00 g/kg BW was found to have no harmful effects on the experimental animals. Results showed the doses of Astragalus stem and leaf used in this study to safe and non-toxic. The findings of this research will provide toxicological data, which can indicate the safe consumption of this product.

Abstract:Soymilk is a plant protein beverage with high nutritional value and beneficial health functions such as prevention from heart disease, cancer and osteoporosis. However, productoverall flavor, consumer preference and promotion of soymilk-based products are affected severely by its beany flavor. On the basis of a systematic literature review, the volatile compounds related to the beany flavor such as aldehydes, alcohols, furans and ketones, as well as their enzymatic and non-enzymatic formation pathways, were reviewed in this artilce. The factors affecting the formation of beany flavor, including soybean variety, growth environment, pulping technology and storage conditions, were presented. In the meantime, a series of currently existing methods to help eliminate the beany flavorsuch as the development of lipoxygenase-free soybean varieties, addition of pretreatment process for soybean, and improvement of the pulping process, are also summarized. The present limitations and future research directions are also provided, which lays a theoretical foundation for the development of non-beany flavor soymilk preferred by consumers.

Abstract:Oil peony is a new woody oil crop in China. It has important ornamental and oil values. Peony seed oil is a new resource food with high nutrition and health value, which contains rich unsaturated fatty acids. It has the effect of antioxidant, regulatingthe glucose and lipid metabolism, preventing cardiovascular and cerebrovascular diseases. In addition to the oil value, the roots, flowers, leaves, and seeds of oil peony contain many active substances including monoterpene glucosides, phenolics and phenolic glycosides, oligostilbenes, flavonoids, triterpenoids, fatty acids and other constituents. Currently, the development and utilization of oil peony mainly focus on peony seed oil. The deep processing and comprehensive utilization of flowers and leaves of oil peonyare still lagged behind, which needs further research and development.In this paper, chemical constituents and utilization of different parts (seed, root, flower and leaf) of oil peony were reviewed, and the influence factors restricting the deep processing of oil peony were discussed, in order to provide the basis for the comprehensive development and utilization of oil peony industry.