Abstract:Deoxynivalenol has a high detectable rate in corn, wheat, barley and livestock feed. It is one of the most contaminated mycotoxin and harmful to food safety. Therefore, how to remove deoxynivalenol efficiently and safely has become a research hotspot. Compared with the traditional physical and chemical treatment methods, biodegradation has attracted much attention due to its high efficiency, environmental friendliness and high specificity. This paper summarizes the methods of biodegradation of deoxynivalenol, the species, enzymes and genes of biodegradation strains. The limitations and prospects in practical application are also discussed.

Abstract:Microcapsule technology has received widespread attention since its invention. In recent years, it has been widely used in various industries. With the continuous development of social technology, stimulus-responsive microcapsules have emerged as the times require, and become a research hotspot because of their unique characteristics. In this paper, different types of stimulus- responsive microcapsules are reviewed, including single stimulus-responsive microcapsules and multi-stimulus responsive microcapsules, and their future development trends are prospected.

Abstract:The flower of Nymphaea hybrida Peck, one of the large lotuses in Nymphaeaceae with high ornamental, food and pharmacological activities, contains abundant plant functional secondary metabolites, mainly including flavonoids, polyphenols, polysaccharides and essential oils. The current studies have shown that Nymphaea hybrida Peck has extensively physiological activities and multiple biological functions, especially antioxidant, anti-aging, memory improvement and hypolipidemic effect. In this review, the chemical constituents and pharmacological activities of Nymphaea hybrida Peck in domestic and foreign research were summarized, in order to provide theoretic basis and research prospect for the bioactive functionality studies and industrialization of Nymphaea hybrida Peck.

Abstract:Lycopene is an important natural red pigment with strong anti-inflammatory, anti-cancer, and anti-oxidation activities. It has been widely used in food, health products, medical and other industries. In the process of lycopene fermentation, a cyclase inhibitor can block the cyclization of lycopene to β-carotene, thereby greatly increasing the lycopene production. In recent years, the widespread application of cyclase inhibitors in bacteria, yeast, mold, algae and higher plants has been achieved. This article reviews the types of cyclase inhibitors and their effects on lycopene production in different organisms. The application prospect and research direction of cyclase inhibitors are also prospected.

Abstract:The effects of the addition of relatively inexpensive coenzyme precursors on glutamate decarboxylase(GAD) enzyme activity and catalytic efficiency during the fermentation were studied. The recombinant strain B.subtilis/pHY300PLK-gadB which contained the gadB gene deriving from Escherichia coli was constructed. The effects of coenzyme pyridoxal phosphate(PLP), coenzyme precursors pyridoxal(PL) and pyridoxine(PN) on the production of GAD were studied. The rotating speed of shaking flask was 200 r/min. The fermentation temperature was 33 ℃. The initial pH of fermentation medium was 7.0, while PLP, PL and PN were added to the final concentration of 0.5 mmol/L. The enzyme activity reached 25.40, 28.14 and 15.55 U/mL after 48 h induction, respectively. Compared with the control group, the enzyme activity was increased by 1.55, 1.72 and 0.95 times. Based on the above results, the effects of PL concentration on the growth of recombinant bacteria and the expression of GAD protein were further studied. The results showed that the production of GAD in the fermentation broth increased with the increase of PL concentration. When PL concentration was 0.1 mmol/L, the maximum activity of GAD was 28.28 U/mL. The preparation of γ-aminobutyric acid(GABA) by whole cells of recombinant bacteria showed that the optimum pH was 5.0, the optimum temperature was 40 ℃, and the optimum amounts of the recombinant bacteria with PL (GAD-PL) and the recombinant bacteria without coenzyme precursor (GAD-0) were 40 U/g (in glutamic acid) and 50 U/g(in glutamic acid), respectively. With the concentration of 400 g/L glutamic acid, the GABA yield reached 275.60 g/L and 273.61 g/L, respectively.

Abstract:In order to effectively prevent the illegal addition of meloxicam in Chinese patent medicines and healthcare products, a sensitive, convenient and accurate method for detecting meloxicam was developed. Silver nanodendrite-modified silicon nanoarrays（AgNDs/SiNWs） were prepared by metal-assisted chemical etching and used as the enhanced substrate for surface-enhanced Raman spectroscopy. Meloxicam was utilized as the Raman probe molecule. The Raman enhanced effect, reproducibility, reusability and storage stability were evaluated by optimizing the preparation and detection conditions. The HF-H₂O₂-H₂O system was chosen as the etching solution. A two-step method was adopted with etching time of 25 min and silver plating time of 120 s, and 5 μL of meloxicam was subsequently added to AgNDs/SiNWs materials for Raman detection. The lowest detected concentration of meloxicam was determined to be 0.1 μg/mL, and the linear range of meloxicam concentration was between 0.1 to 25 μg/mL (y=8.688 7x+89.945 9, R²=0.992 3) at the Raman peak intensity of 1 160 cm^-1. Meloxicam in a compound capsule of anti-rheumatic Chinese patent medicine was further tested using the above mentioned method. Results showed that no meloxicam was detected in all of the samples. It was indicated that the concentration of meloxicam was less than 16.7 μg/g, far below the legal additional level of meloxicam (7.5 mg/g). The recovery rate of meloxicam was between 80.0% to 112.4%, which again proved the feasibility of the developed method in practical sample detection of meloxicam.

Abstract:This study aimed to investigate the difference of immunomodulatory activity between polysaccharides from fresh (LPX3) and dried longan pulp (LPG2). The effects of LPX3 and LPG2 on the proliferation of mouse mesenteric lymph node cells and macrophages, phagocytosis and NO, IL-6 and TNF-α secretion of macrophages were analyzed. The results showed that LPX3 and LPG2 significantly promoted the proliferation of mouse mesenteric lymph node cells and macrophages, and promoted the macrophage phagocytosis and NO secretion(P< 0.05). When treated with 400 μg/mL LPX3 or LPG2, the secretion levels of IL-6 were increased to 27.31 times and 31.54 times of the control, respectively, while TNF-α contents were increased to 17.67 times and 18.42 times of the control, respectively. At the same concentration, LPG2 exhibited a stronger effect on promoting the proliferation of mesenteric lymph node cells and macrophages and activating macrophages.

Abstract:The effects of two sterilization processes, pre-sterilization and post-sterilization, on the quality of blueberry juice were studied. The results showed that with sterilization intensity F= 3 min, the two sterilization processes both achieved commercial sterility. The quality of juice with pre-sterilization was better than that with post-sterilization. For the juice with pre-sterilization under 108 ℃ for 5 s, its color was close to that of the non-sterilized juice with suspension stability significantly improved, and the total anthocyanin retention rate was 97.22%. For the process of post-sterilization, the quality of juice sterilized at 85 ℃ for 60.5 min was poor and the production efficiency was too low, while the quality of juice sterilized at 95 ℃ for 17.5 min was relatively good and the total anthocyanin retention rate was 87.46%.

Abstract:In order to prepare immobilized enzyme, the crude urethanase was immobilized using the carrier cross-linked by 5% glutaraldehyde solution with chitosan for 8 h and the enzymatic properties of immobilized urethanase were analyzed. The results showed that the optimal temperature and pH of immobilized urethanase were 42 ℃and pH 3.6, respectively.The enzyme activity could be kept above 50% within the range of 7%~25% ethanol or reused within 8 times, which indicated that the immobilized enzyme had wide ethanol tolerance range and high catalytic activity. The enzyme activity loss rate was less than 30% or 40% when stored at 4 ℃or 20 ℃ for 6 weeks. Based on the above characteristics, the effect of free and immobilized enzyme on ethyl carbamate(EC) and volatile flavor substances in ‘Merlot’ wine were analyzed by aqueous two-phase extraction combined with gas chromatography-mass spectrometry method and headspace solid-phase microextraction combined with gas chromatography-mass spectrometry(HS-SPME-GC/MS) method in order to investigate the practical application effect. The results showed that the EC removal rate of immobilized urethanase reached 30.90%, which was 81.53% of free enzyme. The treatment of urethanase had insignificant effect on volatile substances content in wine, and only caused the reduction of aroma species and changes of aroma components. However, the adverse effects of immobilized enzymes on volatile flavor substances were much less than those of free enzyme.

Abstract:Effects of noodle processing technology(extrusion, cutting) and water content (mass fraction) on adhesion of cooked noodle were investigated by disulfide bond content determination, sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE), Fourier transform infrared spectroscopy(FTIR), scanning electron microscope(SEM) and etc., and the mechanism was also discussed. Results showed that the brightness and surface viscosity of noodles prepared by cutting were significantly lower(P<0.05) than those prepared by extrusion. No significant difference was observed in hardness and cooking quality.The sheeting procedure induced the decrease of α-helix structure and the increase of disulfide bonds content in noodles, favoring the formation of a dense and continuous gluten network which inhibited the gelatinization and escape of starch granules. Additionally, the brightness of noodles, the surface tackiness and hardness of cooked noodles obtained by both processing technology decreased significantly(P<0.05) with the increase of water content in the range of 35%~37%, while the gluten network and surface structure were improved. The results could provide a reference for the improvement of noodle extrusion technology, and also provide a basisfor the optimization of noodle processing technology.

Abstract:This study was aimed to investigate the effect of vacuum cooling on the shelf life of chicken, and to predict the growth of microbialin chicken breast. The chicken breast was cooled by cold air and vacuum cooling, respectively. The total number of colonies during storage was measured. Vacuum cooling was beneficial for extending the shelf life of chicken. The method of Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis(PCR-DGGE) was used to measure the bacterial floras' changes on the surface of vacuum-cooled chicken stored at 5 ℃, ensuring Pseudomonas was the predominant bacteria. The maximum of dominant spoilage bacteria was 5.373 （lg(CFU/g)） during cold storage with the total number of colony and predominant spoilage bacteria as the microbial index and TVB-N and pH as the physical and chemical index. A primary model and a secondary model of microbial growth were established by placing chilled chicken breast at different temperatures from 0 ℃ to 25 ℃, and the model was validated and evaluated. The results showed that the established mathematical model could better predict the growth trend of predominant spoilage bacteria.

Abstract:To further analyze the antitumor activities and mechanism of chitosan oligosaccharides,enzymatic hydrolysis method was applied to obtain chitosan oligosaccharides with clear composition. The optimized enzymatic hydrolysis conditions were 4 h of reaction time and 120 U/g for the ratio of enzyme and substrate dosage. Chitosan oligosaccharides with degree of polymerization 2 to 4 were obtained by ethanol precipitation, ultrafiltration and nanofiltration. Comparative evaluation of inhibitory effect on three tumor cell lines was conducted with chitosan oligosaccharides and its combination with doxorubicin. The most significant effect was observed on the cell viability of human breast cancer MDA-MB-231 with 20% reduction. Cell migration assay and confocal laser scanning microscopy (CLSM) were used for mechanism analysis, which showed that chitosan oligosaccharides could inhibit cell migration and facilitate doxorubicin to enter the nucleusin MDA-MB-231 cells. The results implied chitosan oligosaccharides could enhance the sensitivity of MDA-MB-231 cells to doxorubicin.

Abstract:An agarase-producing strain with high initial enzyme was isolated from Taisui. The strain was identified as Paenibacillus after morphological and molecular biological analysis and named Paenibacillus sp. P1(abbreviated as P1). The strain P1 which had a rod-shaped cell was a Gram-negative bacterium. And it could not hydrolyze gelatin or cellulose. The optimum fermentation time of strain P1 was 40 h based on the study of the growth and enzyme production of strain P1. Single factor experiment was used to optimize the fermentation medium.The optimal medium for agarase production from P1 strain were Agar 3 g/L, peptone 2 g/L,K₂HPO₄·3H₂O 1.0 g/L, NaCl 0.3 g/L, MgSO₄·7H₂O 0.05 g/L, FeSO₄·3H₂O 0.02 g/L, and CaCl₂ 0.04 g/L. The strain P1 was fermented in the optimized medium for 40 h and the agarose activity was 3.47×10⁴ U/L after optimization, which was 3.4 times higher than that before optimization. The results lay a foundation for the screening of agarose-producing strains from non-marine sources and the scale-up fermentation of agarose.

Abstract:Apple-ferment has good antioxidant activity. In order to increase the antioxidant activity of fermented goat milk, apple-ferment and compound starter cultures were used to ferment goat milk, and the physicochemical properties and antioxidant activity of fermented goat milk were studied. The addition amount of apple-ferment, and the type and addition amount of starter cultures were determined based on the physicochemical properties and sensory evaluation. The result showed when the addition of apple-ferment and B starter culture were 4% and 1%, the protein content, fat content and non-fat milk solid content of fermented goat milk were 3.85 g/hg, 3.72 g/hg, and 9.28 g/hg, respectively, and the DPPH scavenging ability was 95.17%. The fermented goat milk had a good curd, characteristic flavor of fermented goat milk and smell of apple, pleasant taste with moderate sweet and sour. This experiment could provide a theoretical basis for the research and development of fermented goat milk products.