Abstract:The effects of γ-oryzanol and cysteamine on the redox status and immunity of stressed mice were investigated. Ninety male ICR mice aged five weeks were randomly divided into 6 groups with 15 mice in each group. Stressed mouse model was developed by glucocorticoid injection, meanwhile, different doses of γ-oryzanol and cysteamine were added to the feed for 8-week administration. Compared with the model group, the activity of total superoxide dismutase (SOD) in tissues, the activity of glutathione peroxidase (GSH-Px) and the total antioxidant capacity (T-AOC) in plasma and tissues of the combination group 1 were significantly increased (P<0.05), while the malondialdehyde (MDA) content in plasma and tissues was significantly decreased (P<0.05). The activity of Mn-SOD, membrane potential, acetyl coenzyme A (A-CoA), and ATP in the mitochondria of combination group 1 were significantly increased (P<0.05), while the mitochondrial MDA content was significantly decreased (P<0.05). The spleen index, thymus index and the content of immunoglobulin in the plasma of combination group 1 were significantly increased (P<0.05). The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were significantly decreased (P< 0.05), while the level of interleukin-10 (IL-10) was significantly increased (P<0.05). The results showed that the redox status and immune function of stressed mice were improved in the four experimental groups, and the combination group 1 had the most significant effect, indicating that the combination of γ-oryzanol and cysteamine at a lower dose could play a synergistic role in anti-oxidation and regulating immune function, thus effectively resisting the harm caused by oxidative stress.

Abstract:In order to remove the excessive salt from zein glycopeptide solution, the nanofiltration membrane with a molecular weight cut-off of 200 was applied for the desalination of antioxidant zein glycopeptide solution. The membrane flux, Na⁺ mass fraction, desalination rate, electrical conductivity, recovery rate of short peptide of zein glycopeptide solution, and the free radical scavenging rate and Fe²⁺-chelating activity of products after nanofiltration were studied to determine the nanofiltration desalination process of zein glycopeptides. The results showed that zein glycopeptides was desalted by a 200 nanofiltration membrane was carried out continuously for 5 times nanofiltration under 2.0 MPa at 20 ℃ with each nanofiltration volumetric concentration factor of 2. After 5 times of nanofiltrations, the electrical conductivity of retentate was decreased by 60.87%. The desalting rate and the recovery rate of short zein glycopeptide were 81.60% and 96.97%, respectively. The hydroxyl radical scavenging rate of desalted zein glycopeptide was increased from 11.25% to 15.85%, and the 1,1-diphenyl-2-picrylhydrazyl radical scavenging rate and Fe²⁺-chelating activity were decreased by 11.83% and 46.07%, respectively. Moreover, the 200 nanofiltration membrane could remove 55.54% of unreacted D-glucosamine in the glycosylation reaction product, playing a triple role of desalination, desugarization and concentration.

Abstract:The therapeutic effect of Astragalus polysaccharides (APS) on chronic intestinal inflammation caused by high fat diet through regulating intestinal flora was investigated. Thirty C57BL/6J mice were randomly divided into three groups including the control group (C, fed with normal diet), the model group (M, fed with high fat diet) and APS group (D, fed with high-fat diet and 2 g/dL APS solution), with 10 mice in each group. The serum was collected at week 11, and the adipose tissue around the spleen and kidney was stripped and weighed. The mice faeces were collected for 16S rRNA high-throughput sequencing. The levels of TC, TG, IgA, IgG, IgM, LPS, IL-1β, IL-6 and TNF-α in serum were detected by ELISA. The results showed that APS promoted the abundance of Bacteroidota, decreased the abundance of Firmicutes, increased the ratio of Bacteroidota to Firmicutes, and increased the abundance of Bifidobacterium. It reduced the level of LPS and decreased the release of inflammatory cytokines including IL-1β, IL-6 and TNF-α. It improved spleen index and promoted the secretion of IgA, IgG and IgM. It is thus speculated that APS could regulate the structure of intestinal flora, enhance the immune function of mice, and inhibit LPS-induced intestinal inflammation.

Abstract:In this study, Lycium barbarum（L. barbarum） juice was added to yogurt as the functional component to explore the antioxidant activity in vitro and hepatoprotective function of L. barbarum yogurt. In the experiment of antioxidant activity in vitro , potassium ferricyanide method, 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and salicylic acid method were used. The results showed that within the range of this study, the total antioxidant reduction capacity, DPPH radical scavenging rate and hydroxyl radical scavenging rate increased with the increase of L. barbarum juice content. Here, the probiotic function of L. barbarum yogurt was evaluated by the animal model of acute alcoholic liver injury. The results showed that L. barbarum yogurt reduced the level of cereal third transaminase (ALT) in serum and the content of lipopolysaccharide (LPS) in liver tissues, while increased the content of glutathione (GSH) and total antioxidant capacity (T-AOC) in liver tissues. Therefore, L. barbarum yogurt might have auxiliary protective effect on acute alcoholic liver injury in mice. In conclusion, L. barbarum yogurt showed strong antioxidant and hepatoprotective activity, providing data support and theoretical basis for the future development of L. barbarum fermented dairy products with hepatoprotective function and alcohol hangover relieving effect.

Abstract:In order to improve the gelation of soybean protein isolate (SPI), the structure and properties of composite gels were studied by adding egg albumin (OVA) to SPI and measuring the molecular interaction of composite gels. The results showed that the content of free sulfhydryl group in OVA-SPI composite solution increased compared with SPI solution. The intermolecular disulfide bond, α-helix, β-fold of composite gel were increased, while its surface hydrophobicity decreased compared with SPI gel. Protein interaction and the change of secondary structure reduced the surface aperture of composite gel, and formed smooth and dense gel, which significantly improved the hardness, springiness and water retention of gel. The results showed that the combination of OVA and SPI could improve the gel texture.

Abstract:Juvenile fruit of golden pomelo was studied to efficiently extract its total dietary fiber through the single factor experiment and response surface analysis. The effects of ultrasonic time, solid-liquid ratio and oscillating temperature on the yield of juvenile fruit total dietary fiber were discussed. The extracted total dietary fiber was added into protein bars, and the content of total dietary fiber in protein bars was determined. Finally, the sensory evaluation and texture changes of protein bars stored at different temperatures were investigated. The results showed that the highest extraction rate of (56.3±1.0) % was achieved at 1 g∶10 mL of the solid to liquid ratio for 55 min ultrasonication under 35 ℃ oscillation temperature after 3 times of extraction. By sensory evaluation, the optimal mass fraction of total dietary fiber added was 4%. When the protein bars were stored at different temperatures, the hardness, viscosity and color increased, flavor deteriorated and sensory evaluation score decreased with the increase of temperature or duration.

Abstract:In order to study the quality of Aronia melanocarpa , various Aronia melanocarpa samples from 15 different origins in China were investigated, and the physical and chemical quality, nutritional quality, texture characteristics and sensory quality were comprehensively analyzed. The results showed that 9 of the 12 quality indicators had a coefficient of variation greater than 15%, including chewiness, anthocyanin, proanthocyanidin, flavonoid and polyphenol, etc., indicating significant quality differences between samples from different origins. The 12 quality indicators were reduced into 3 principal components by principal component analysis, and their cumulative variance contribution rate was up to 77.42 %, which well-expressed the quality of Aronia melanocarpa , and suggested the top three origins were HLJ-MDJ-8, LN-SY-1 and LN-TL-6. Aronia melanocarpa from different origins could be divided into three categories by cluster analysis, which was basically consistent with the comprehensive ranking results of principal component analysis. Based on the results, it was concluded that HLJ-MDJ-8, LN-SY-1 and LN-TL-6 were more suitable to be used as raw materials to develop health care products due to their high nutrient content, while GS-JC-14 was more suitable for fresh food because of its high sweetness and good taste.

Abstract:Artemia salina is a small crustacean. The hatched larvae are high-quality bait for aquatic animals, and the remaining eggshells are treated as waste. However, Artemia salina eggshells are rich in protein and chitin, which have great potential for application. To prepare chitin oligosaccharides from Artemia salina eggshells, chitinase ChiB565, which is derived from Aeromonas veronii, and has a wide distribution of hydrolysates and contains chitin binding domain, is selected and recombinantly expressed in Pichia pastoris. The enzymatic properties are studied and high-density fermentation is carried out. A green process for preparation of chitin oligosaccharides by synergistic treatment of Artemia salina eggshells with neutral protease and recombinant chitinase ChiB565 is established. The results show that the highest enzyme activity of recombinant bacteria fermentation is 13.2 U/mL, which is 3.88 times that of shake flask fermentation. When Artemia salina eggshells are treated with neutral protease (30 mg/g substrate and 4 h) first to remove protein, and then treatd with recombinant ChiB565(40 U/g substrate and 5 h) to hydrolyze chitin, products are mainly chitobiose to chitotetraose, with a small amount of chitopentaose and chitohexaose. And the scavenging ability of the hydrolysate to DPPH and ABTS are 59.94% and 53.15%, respectively. The studies above illustrat that the preparation of chitin oligosaccharides by biological enzymatic method using Artemia salina eggshells as substrate has a higher recovery rate and a shorter time than traditional chemical methods. This research has laid an important foundation for the industrial preparation of chitin oligosaccharides.

Abstract:To explore the microencapsulation process of using modified porous starch (MPS) and xanthan gum (XG) as wall materials to embed cinnamon essential oil and sodium metabisulfite. In order to delay the volatilization of cinnamon essential oil (CEO), microcapsules were prepared by freeze-drying, and the microcapsules were characterized and their antibacterial effects were studied. The optimal conditions for preparing cinnamon essential oil and sodium metabisulfite microcapsules are m（MPS）∶m（XG）=20∶1, V （CEO）∶m（MPS）=0.67 mL∶1 g, m（Na₂S₂O₅）∶m（MPS）=1∶100, CEO's the embedding rate is 68.73%, and that of Na₂S₂O₅ is 72.42%. Microcapsules have obvious antibacterial effects on Escherichia coli , Bacillus subtilis , yeast and mold, and the sensitivity index is: mold>yeast> Bacillus subtilis > E.coli . Modified porous starch and xanthan gum as composite wall materials are beneficial to the embedding of microcapsules. Cinnamon essential oil and sodium metabisulfite are prepared into microcapsules to achieve long-term antibacterial effects and broaden its application in the preservation of fruits and vegetables.

Abstract:To understand the biosynthesis pathway of flavonoids in the medicinal plant Polygonatum cyrtonema and provide molecular data for the study on anabolism pathway and regulatory mechanism of flavonoids in Polygonatum plant, next-generation sequencing technique was emloyed to perform transcriptome sequencing on the rhizome of P. cyrtonema at development stage of 3 and 9 months. The results showed that a total of 73 218 unigenes were obtained by de novo transcriptome assembly, of which 35 511 were annotated. Eighty-three unigenes were identified from the transcriptome database, which encoded 18 key enzymes associated with flavonoids biosynthesis. Among the transcription factors expressed in rhizome of P. cyrtonema seedlings, bHLH was the main type, followed by ERF, MYB-relaed, C2H2 and NAC. Analysis of expression of 18 key enzymes based on FPKM showed that 9 were obviously up-regulated, 3 obviously down-regulated and 6 stably expressed with increasing flavonoid content in rhizome of P. cyrtonema seedlings. RT-qPCR analysis further verified the reliability of gene expression from FPKM. This present study provide a reference for further explore on the molecular mechanism on biosynthesis and accumulation of flavonoids in Polygonatum plant.

Abstract:The identification of Perilla frutescens and its varieties, Perilla fructus and its adulterants was studied based on ITS2 primary sequence combined with its secondary structure, providing a more scientific classification method for the usage of Perilla frutescens as a medicinal plant. After the collection of Perillae fructus and its adulterants, Perilla frutescens and its varieties, their DNA was isolated for PCR amplification. The ITS2 sequences of all species were obtained through the combination with the sequences in GenBank. MEGA 7.0 software was used for analysis of sequence, calculation of intra-species and inter-species genetic distances, and construction of NJ cluster tree. The prediction of ITS2 secondary structure of each species was based on ITS2 database. 4Sale software was used to compare the primary structure with the second structure matrix, and ProfDistS software was used to construct the evolutionary tree of PNJ. ITS2 sequence had high success rate of amplification. Except P. frutescens var. frutescens, ITS2 sequences of Perilla frutescens and other varieties had significant barcoding gap. NJ tree showed that ITS2 could distinguish Perilla frutescens and P. frutescens var. frutescens from other varieties. Perilla frutescens and P. frutescens var. frutescens differed in the secondary structures of ITS2. The ITS2 sequences of Perilla fructus and its adulterants were quite different, and there was significant genetic distance between various species. NJ tree and PNJ tree showed that Perilla fructus and its adulterants were clustered into separate branches with higher bootstrap values. Based on ITS2 barcode, Perillae fructus and its adulterants could be accurately identified, providing a reliable method for standardizing the pharmacopeial herbs market and ensuring the clinical medication safety. However, the identification of Perilla frutescens and its variety P. frutescens var. frutescens should be combined with the secondary structure of ITS2. It is also suggested that Perilla frutescensa and P. frutescens var. frutescens could be combined into one species to provide reference for the classification of Perilla genus.

Abstract:The effect of lychee rose wine on the skin of aging mice was investigated. Sixty ICR mice were divided into: Normal group (fed with drinking water containing 12% ethanol), D-galactose group (fed with drinking water containing 12% ethanol), VC control group (fed with 450 mg/kg VC), low, medium and high dose lychee rose wine groups (fed with 10, 20 and 40 mL/kg lychee rose wine, respectively). The normal group was injected with normal saline, and the other five groups were subcutaneously injected with D-galactose, which were analyzed after 6 weeks. The content of skin moisture, hydroxyprolinic acid and collagen could be recovered in mice fed with high dose lychee rose wine. The results of skin section showed that high dose of lychee rose wine could improve the skin condition, thickening the dermis deposition and increasing the collagen fiber content. Meanwhile, lychee rose wine could effectively reduce the contents of ROS and MDA in skin and the levels of inflammatory factors in plasma of aging mice (P<0.05). RT-PCR results showed that the effect of lychee rose wine on skin aging might be related to the regulation of expression levels of collagen-synthesizing genes (TGF-β1, COl1a1, COl3a1, NF-κB, AP-1, MMP-1, MMP-8) and antioxidant related genes (Nrf2, GSK-3β, HO-1, NQO1) (P<0.05). The appropriate dosage of lychee rose wine has certain intervention effect on the skin aging of mice.

Abstract:Based on the system of corn peptides-xylose-cysteine, the relationship between temperature, time and flavor profile and composition of Maillard reaction products was investigated. Results showed that with the increase of temperature（100~140 ℃） and the expansion of time (60~180 min), the meaty flavor, roasted flavor, mouthful taste and flavor persistence of Maillard reaction products increased continuously. But the overall acceptability increased at first and then decreased, the score of 120~150 min was higher at 120~130 ℃. The increase of temperature promoted the reaction toward degradation, and the types and contents of flavor amino acids and key volatile flavor compounds increased with the increase of temperature and time. Based on partial least square regression analysis, the relevant contribution components of different sensory characteristics were clarified. Furan, sulfur and ketone compounds were significantly positively correlated with meaty flavor, furan compounds have a significant effect on the roasted smell, peptides with relative molecular weight less than 1 000 had an important contribution to mouthful taste and flavor persistence, and bad smell mainly came from sulfur-containing compounds. This study can provide guidance for the directional preparation of Maillard reaction products of corn peptides with different flavor characteristics.