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    2023,41(11):1-10
    Abstract:
    Zearalenone (ZEN) and deoxynivalenol (DON) are common mycotoxins found in grain, and long-term dietary exposure can cause serious harm to organisms. Currently, simultaneous immunoassays for ZEN and DON mostly rely on their respective monoclonal antibodies. However, the preparation of traditional monoclonal antibodies requires long production cycles and high costs. In this study, bispecific antibodies(Bis-scFv) that could simultaneously recognize both ZEN and DON were obtained in a short time using recombinant antibody expression technology. An indirect competitive enzyme-linked immunosorbent assay(IC-ELISA) based on Bis-scFv was established. The half-maximal inhibitory concentrations(IC50) for ZEN and DON standard curves was determined to be 20.64 ng/mL and 132.29 ng/mL, respectively. Bis-scFv exhibited excellent specificity with no significant cross-reactivity with other mycotoxins. Moreover, IC-ELISA was used to conduct spike recovery experiments for ZEN and DON in corn, yielding recovery rates ranging from 86.02% to 108.14%. The study demonstrates that the developed Bis-scFv has the potential for future application in the development of synchronous and rapid detection of ZEN and DON in grain samples.
    2023,41(11):11-18
    Abstract:
    To explore the effect of konjac glucomannan (KGM) on genomic stability in colonic epithelial cells, the normal colon cell line NCM460 and the colonic cancer cell lines SW620 and HCT116 were used as the research materials. The tested cells were treated with KGM at concentrations of 0, 0.625, 0.625, 2.5,5, 10, 20, and 40 mg/mL for 24, 48, and 72 h. Cell viability was detected by methylthiazolyldiphenyl-tetrazolium bromide(MTT) assay. The CBMN-Cyt assay was performed to detect the genome instability (GIN), nuclear division index (NDI), and apoptosis levels in the tested cells after treatment with different concentrations of KGM (5, 20, and 30 mg/mL) for 72 h. The results showed that after 72 h of treatment with different concentrations of KGM, the viability of NCM460 cells increased significantly(P<0.05) within 5~40 mg/mL, while their GIN significantly decreased(P<0.001) at 5 mg/mL KGM and significantly increased at 30 mg/mL(P<0.01). The viability of HCT116 cells was significantly inhibited by KGM at concentrations of 5~40 mg/mL (P<0.05), while KGM at a concentration of 40 mg/mL exhibited an extremely pronounced inhibitory effect on the viability of SW620 cells(P<0.01). Moreover, GIN and apoptosis rate of SW620 and HCT11 cells significantly increased at KGM concentrations of 5~30 mg/mL(P<0.001), while NDI reduced significantly(P<0.05). The results suggest that low concentration(5 mg/mL) of KGM is beneficial to maintain the genomic stability in normal epithelial cell NCM460, and various concentrations(5~30 mg/mL) of KGM increases GIN and apoptosis rate in the colon cancer cells SW620 and HCT116, which may provide a molecular basis for maintaining intestinal health.
    2023,41(11):19-26
    Abstract:
    This study aimed to evaluate the potential application of bacteriocins produced by iLactobacillus buchneri i (L. buchneri i) in the food industry. The substance with antibacterial activity against iStaphylococcus aureus (S. aureus ) was obtained through the cultivation of L.buchneri . After purification, its molecular weight and antibacterial characteristics were identified, and the inhibition of S.aureus biofilm formation was explored. The results showed that L.buchneri reached a stable period after cultivation in MRS medium at 37 ℃ for 20 h, and the diameter of inhibition zone against S. aureus reached the peak value of(26.36±0.86) mm at 26 h. After purification by АKTA pure system in tandem with Superdex 30 Increase, the molecular weight of the antibacterial active substance(BSX01) was identified as 773.56, which was sensitive to a variety of proteases and presumed to be a class I bacteriocin. BSX01 retained good inhibitory activity even after treatment at pH 10(2 h) and 121 ℃(30 min), with a minimum inhibitory concentration(MIC) of only 12.50 μg/mL. In addition, BSX01 effectively reduced the formation of S.aureus biofilm at 1/2MIC, and completely inhibited the formation of S.aureus biofilm at 2MIC. Based on these results, the bacteriocin BSX01 produced by L. buchneri is demonstrated to be a potential bio-preservative and an effective candidate for inhibiting the formation of biofilm by foodborne pathogenic bacteria in the food industry.
    2023,41(11):27-33
    Abstract:
    This study aimed to explore the therapeutic effect of iron-containing bovine blood peptide on iron-deficiency anemia (IDA) in rats, and to provide a theoretical basis for the development of functional products from bovine blood peptides. Early weaned female SD rats were fed with low-iron rat diet for 3 weeks to establish an iron-deficiency anemia model. Iron-containing rat diet was used as the normal control, and Shengxuening was used as the positive control. Rats were orally administered with the iron-containing bovine blood peptide until the level of haemoglobin exceeded 100 g/L. Changes in rat body weight and blood routine were monitored during the experiment. Iron-containing bovine blood peptide significantly improved the body weight and increased the hematological parameters such as leukocytes, red blood cells, hemoglobin, and hematocrit caused by iron-deficiency anemia in rats. At the meanwhile, it improved iron metabolism indicators, including serum iron and serum ferritin. The effects of low-dose bovine blood peptide were comparable to Shengxuening, while the medium-does and high-dose bovine blood peptide showed better effect than Shengxuening. Oral administration of iron-containing bovine blood peptide could effectively improve iron-deficiency anemia in rats.
    2023,41(11):34-41
    Abstract:
    Celery(Apium graveolens L.), a leaf vegetable, is a biennial herb in Apiaceae. Soluble sugar is an important nutritional component of leafy vegetable crops. In this study, two celery cultivars of ‘Sijixiaoxiangqin’ and ‘Liuhehuangxinqin’ were selected as samples. The soluble sugar content was determined and analyzed after storage at room temperature (25 ℃), low temperature (4 ℃) and room temperature in the dark (25 ℃) for 0, 6, 24, 30, 48 and 54 h. The expression characteristics of soluble sugar metabolism-related genes (AgIVR1, AgSPP, AgSPS, AgSS1 and AgUDPG ) were detected by real-time quantitative PCR technology. The results showed that there were varietal and tissue differences in the soluble sugar content of celery under the three storage conditions. The soluble sugar content in ‘Sijixiaoxiangqin’ was higher than that in ‘Liuhehuangxinqin’, and the soluble sugar content in the petioles was higher than that in the leaves. The soluble sugar content had no obvious change under different storage conditions. After storage at low temperature for 54 h, the expression levels of AgSS1 in both celery cultivars increased significantly, and the overall expression level of AgSPS in celery exhibited a downward trend under different storage conditions. Diverse genes might co-regulate the change in soluble sugar content through interaction during celery storage. The accumulation of soluble sugar was correlated with the changes in related genes.
    2023,41(11):42-54
    Abstract:
    Escherichia coli possesses a complex and diverse array of extracellular biofilm components. These biomolecules not only consume a large amount of energy and substrates during their synthesis and assembly, but certain components also present huge risks for pathogenicity. In order to mitigate the adverse effects, Crisp-Cas9 gene-editing method was employed to remove non-essentia biofilm components from Escherichia coli MG1655 at the genetic level. A series of mutant strains with deleted non-essential biofilm components were constructed, and the cellular characteristics of these mutant strains were investigated to identify those with superior performances. The results showed that knockout of genes encoding flagellum(fliE-R, fliY-T , and flhE-D ), type 4 capsule, sialic acid and poly- β-1,6-glucosamine could promote the growth of mutants in M9 medium. Deletion of flagellar gene clusters flgN-L and exopolysaccharide components enhanced PHB synthesis, while knocking out four gene clusters related to extracellular polysaccharide components or flagella could enhance the membrane permeability. The removal of core polysaccharides from Escherichia coli could remodel metabolic regulation and promote the production of colanic acid.
    2023,41(11):55-62
    Abstract:
    In order to explore the application of silver-loaded hydroxyapatite/titanium dioxide (Ag-HA/TiO 2 ) antibacterial agent in aquatic products, this study conducted the structural characterization of Ag-HA/TiO 2 and selected Escherichia coli and Staphylococcus aureus as the test strains for a comparison between silver-loaded hydroxyapatite(AgHAp) and titanium dioxide(Ag-HA/TiO 2 ) in antibacterial performance. A preliminary evaluation on the antibacterial rate of Ag-HA/TiO 2 against specific spoilage bacteria(SSOs) in aquatic products was also assessed. Based on these evaluations, the study conducted practical applications to investigate the effects of the antibacterial solution concentration and the soaking time on the microorganisms in large yellow croaker and the standard for Grade I fresh meat. The results showed that Ag-HA/TiO2 maintained its crystalline structure after loading titanium dioxide and reducing silver content by half. The antibacterial rate of Ag-HA/TiO 2 against Escherichia coli and Staphylococcus aureus was 100%, which was superior to AgHAp containing 3.00% of silver, and the minimum inhibitory concentration for both strains was 312.5 μg/mL. The antibacterial rates of 10 mg/mL Ag-HA/TiO 2 against SSOs-pseudomonas fluorescens and shewanella putrefaciens at 0.5 h were (97.58±3.43) % and 100% respectively, reaching 100% at 1 h and 1.5 h. As the Ag-HA/TiO 2 was applied to large yellow croaker, higher concentration of soaking solution or longer soaking time resulted in more pronounced inhibition effect on the growth of bacteria in large yellow croaker, extending the standard shelf life for Grade I fresh meat of large yellow croaker. The study demonstrates the high antibacterial effectiveness of Ag-HA/TiO 2 and suggests its potential as an ideal antibacterial agent for aquatic products.
    2023,41(11):63-73
    Abstract:
    In order to screen probiotic lactic acid bacteria for food with cholesterol-lowering ability from fermented vegetable. In present study, taking Weissella confusa (RW) as a reference, 5 probiotic lactic acid bacteria isolated with cholesterol-lowering ability were obtained from different fermented vegetable samples via directional separation method combined with 16SrDNA identification method. The results showed that the five strains had excellent probiotic characteristics, with exhibiting the tolerance to acid(pH 2.0), bile salt(3 g/L) and simulated gastrointestinal fluids, and superior cholesterol-lowering ability(54.79%~62.54%),and inhibiting pathogen and adhere to Caco-2 cells. The strains showed excellent probiotic characteristics. Further, five isolates were safety with no hemolysis phenomenon, no biogenic amines producing, and showed sensitivity to a variety of antibiotics. Five isolates were identified as Lactiplantibacillus plantarum (JCSMC-1), Lactobacillus plantarum (SYB and JCSMC6-2), Lacticaseibacillus paracasei (SYD and XSMC-1) by 16S rDNA. The isolates of 1 Lactiplantibacillus plantarum, 2 Lactobacillus plantarum, and 2 Lacticaseibacillus paracasei all have the basic characteristics of probiotic lactic acid bacteria for food, providing new resources for the development of probiotic lactic acid bacteria for food.
    2023,41(11):74-80
    Abstract:
    To address the issue of short shelf life due to microbial proliferation in the industrialized production of a traditional food Shao-Mai, the pre-made and unsteamed Shao-Mai was treated with electron beam irradiation at different doses. The growth patterns of microorganisms and changes in peroxide values in irradiated Shao-Mai under different storage temperatures were studied. The results showed that electron beam irradiation effectively reduced the microbial count in Shao-Mai and prolonged the shelf life. However, higher doses of irradiation promoted lipid oxidation. Irradiation doses of 6~8 kGy irradiation showed no promoting effect on lipid oxidation, and the irradiated Shao-Mai exhibited no significant difference in peroxide value compared to non-irradiated products (P>0.05) after 3 days of storage at 30 ℃. When refrigerated at 4 ℃, Shao-Mai irradiated at dose of 6~8 kGy had a shelf life of up to 30 days, which was 20 days longer compared to non-irradiated products. According to the changes of total bacterial count and moulds and yeasts under different storage temperatures, the corresponding Gompertz microbial growth models were established respectively. The correlation coefficients of the models were all greater than 0.95, effectively describing the dynamic changes in microbial growth of irradiated Shao-Mai during storage and predicting the microbial level over different storage times.
    2023,41(11):81-87
    Abstract:
    This experiment aimed to investigate the effectiveness and evaluation of the reverse transcription-loop-mediated isothermal amplification(RT-LAMP) in detecting Listeria monocytogenes infection in meat products. The assay was designed to target the iap gene of Listeria monocytogenes for detection of meat samples based on the principle of RT-LAMP. The specificity, sensitivity and differentiation between living and dead bacteria of this identification were compared to Chinese national standards. This experiment optimized the RT-LAMP conditions and obtained the optimum amplification at 63 ℃ for 60 min, the optimal concentrations of the primers were 0.4 μmol/L outer primer and 0.8 μmol/L inner primer, 2.0 mmol/L MgSO4, 1.0 mol/L betaine, 2.0 mmol/L dNTPs, 10 U/μL AMV reverse transcriptase, 320 U/mL Bst DNA polymerase. The assay has a sensitivity of 7.3×101 CFU/per reaction, which was twice as sensitive as LAMP. The specificity test demonstrated that only the target genes of Listeria monocytogenes were detected without false positives. The ability of RT-LAMP to detect Listeria monocytogenes in commercially available meat samples(n=100) was comparable to the Chinese National Standard GB 4789.30-2016, and RT-LAMP only amplified live microorganisms. Differentiation experiments between living and dead bacteria revealed that this method could eliminate the interference from dead bacteria in meat samples. In comparison with the method of national standards, RT-LAMP proves to be an effective detection method.
    2023,41(11):88-97
    Abstract:
    A combination of 16S rRNA high-throughput sequencing technology and traditional culture methods was used to analyze and compare the microbial communities in raw materials for canned bird's nest and different production processes. Meanwhile, α and β microbial diversity analyses were used to investigate key control points for microbial contamination sources and processes in the canned production lines. The results revealed that the primary source of contamination in canned bird's nest production was the raw material of rock sugar, and the Geobacillus and Bacillus were the main contaminant genus responsible for the spoilage of canned bird's nest. Furthermore, the production processes associated with rock sugar raw materials in the production line were identified as the production critical control points. This study provides a theoretical basis for the production quality control and hygiene supervision in canned bird's nest production.
    2023,41(11):98-105
    Abstract:
    In order to produce bacteriocin in large quantity through prokaryotic expression and investigate its physicochemical properties, this study amplified and recycled the Pediococcus acidilactici R-4 bacteriocin pedA gene. The gene was subsequently ligated into the pMD19-T vector and transferred into E. coli DH5α receptor cells for cloning. The cloned pedA gene was extracted and connected to the expression vector pET-32a(+) to form a recombinant plasmid pET-32a-pedA, which was then transferred into E. coli BL21(DE3) receptor cells. Following induction with isopropyl-β-D- thiogalactoside(IPTG), Pediococcus acidilactici R-4 bacteriocin PA-1 was expressed within E. coli BL21 (DE3) cells. The expressed protein was purified by a Ni-NTA column and its physicochemical properties were determined using Staphylococcus aureus as an indicator. The results demonstrated successful expression and purification of the 26 000 of Pediococcus acidilactici R-4 bacteriocin PA-1 in E. coli BL21 (DE3) cells. The purified Pediococcus acidilactici R-4 bacteriocin PA-1 exhibited antibacterial activity within the ranges of 14.7~15.6 mm, 14.0~16.5 mm, 15.1~15.8 mm, and 14.9 mm, respectively, under the treatment of 40~121 ℃ for 20 min, pH 2 to 12, 0~10 h ultraviolet irradiation, and 2 h catalase. However, the antibacterial activity was lost after treatment with pepsin and trypsin for 2 hours. This indicates that Pediococcus acidilactici R-4 bacteriocin PA-1 has good stability to high temperature, strong acid and alkali, UV radiation, and catalase. However, it could be deactivated by pepsin and trypsin.
    2023,41(11):106-112
    Abstract:
    Intraflagellar transport protein 20 (IFT20) of Chlamydomonas reinhardtii is a component of the intraflagellar transport complex B(IFT-B). IFT20 is known to be involved in regulating intracellular transport processes of macromolecules, but its detailed function as a flagellar protein in flagella remains to be investigated. This study aimed to develop highly specific polyclonal antibodies against Chlamydomonas reinhardtii IFT20 from rabbit serum to lay the foundation for further investigation into its flagellar function. To achieve this goal, the N-terminal 6×His-tagged IFT20 fusion protein(6×His::IFT20) was first expressed in Escherichia coli, and 6×His::IFT20 was purified by Ni-column. The purified 6×His::IFT20 was then applied to immunize the New Zealand white rabbits. The antiserum was collected after three rounds of immunization, and the titer was determined to be 1∶102 400 by an indirect ELISA method. Subsequently, the obtained anti-serum was purified using protein A purification beads to enrich the IgG subtype antibodies. Next, N-terminal MBP-tagged IFT20(MBP::IFT20) expressed and purified from Escherichia coli was used for antigen-antibody affinity purification of IgG antiserum. The western blotting assay of whole cell protein extracts from CC-125 identified the high specificity of the obtained IFT20 polyclonal antibodies, making them suitable for future investigations on the flagellar function of IFT20 in Chlamydomonas reinhardtii.
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    2023,42(1):66-74, DOI: 10.3969/j.issn.1673-1689.2023.01.005
    Abstract:
    Isomaltooligosaccharides (IMO) are oligosaccharides mainly composed of α-1,6 glycosidic bonds linked glucoses, which have physiological characteristics of hypoglycemic index and promoting probiotics proliferation. The current commercial IMO production has low yield and high isomaltose content in the product, while the probiotic function of IMO is mainly attributed to the high polymerization fractions like disaccharides and above. In this study, α-glucosidase from Aspergillus niger and cyclodextrin glucosyltransferase (CGTase) from Bacillus stearothermophilus NO2 were combined for synthesis of IMO with improved yield and polymerization (named IMOH). In this study, the effects of reaction pH, temperature, time, substrate type and enzyme addition on the yield were investigated by single-factor experiments, and the effects of compound enzyme amount and reaction time were subsequently explored. The results showed that the yield of IMOH reached 64.27%, and the high polymerization content of trisaccharides and above was 71.57% under pH 5.5 at 50 ℃, using 300 g/L maltodextrin with DE values ranges from 15 to 20 as the substrate, and with α-glucosidase of 5 U/g substrate (calculated by substrate mass) and CGTase of 20 U/g substrate (calculated by substrate mass). The structural analysis of IMOH products showed that the ratio of α-1,6 bond ratio was 70.67%, and the average molecular weight of products was 706, which was higher than that of commercial IMO50. The in vitro fermentation experiments of intestinal microorganisms suggested that compared with commercial IMO50, the IMOH had a better proliferative effect on Bifidobacterium adolescentis, and could further inhibit the growth of opportunistic bacteria Escherichia coli in intestinal tract, showing a certain in vitro probiotic effect. This study proposed a new process of the IMO synthesis by the dual-enzyme compounds, providing a new idea for the industrial synthesis of IMO with high yield and high degree of polymerization.
    2023,42(1):18-39, DOI: 10.3969/j.issn.1673-1689.2023.01.002
    Abstract:
    As a linear polysaccharide, alginate has different physiological and biochemical characteristics according to its structure and composition. It holds great application value and potential in food, medicine and cosmetics. These characteristics of alginate are mainly controlled by the action of alginate-modifying enzymes such as alginate lyase, mannuronan C5-epimerase, alginate acetylase and alginate deacetylase. This review mainly introduced the synthesis of alginate-modifying enzymes and the mechanism of alginate modification, and summarized the source, classification, structure, mode of action and research progress of several alginate modifying enzymes. The emphasis was laid on the research progress of alginate lyase and mannuronan C5-epimerase. And we also prospected the future development of related research, providing reference for the further development and application of alginate and its related modifying enzymes.
    2023,42(1):1-17, DOI: 10.3969/j.issn.1673-1689.2023.01.001
    Abstract:
    Mycotoxins are a group of secondary metabolites produced by fungi during their growth. Mycotoxins not only seriously affect the yield of food crops, but also pose big threat to human health. There are various physical treatments for mycotoxins including cleaning, peeling, exposure, irradiation, ion pulse and so on, however, these physical methods are difficult to ensure complete removal of toxins. Also, the loss of nutrients in crops would be possibly caused during the physical treatment. Chemical methods can also eliminate mycotoxins to some extent, but the introduction of chemical reagents and the potential indirect contamination can limit the further application in practical field. With a continuous development of biotechnology, microbial enzymes have shown great advantages in the degradation of mycotoxins due to the mild reaction conditions, high degradation efficiency and low toxicity of degradation products. The discovery, identification and application of mycotoxin-degrading enzymes which have been reported so far were thoroughly reviewed in this manuscript. It is believed that with the deepening of research, the mycotoxin-degrading enzymes are expected to be further developed and employed in the feed and food industries.
    2022,41(10):67-76, DOI: 10.3969/j.issn.1673-1689.2022.10.006
    Abstract:
    Cold-adapted maltopentaose-forming amylases have relatively high catalytic activities at low temperatures and enable an efficient and specific conversion of starch to functional maltopentaose at room temperature, resulting in a broad applications in food, medical and pharmaceutical fields. In this study, SdG5A and SdG5A-CD from Saccharophagus degradans were expressed in Bacillus subtilis. Further, the cold adaptation of the recombinant enzymes was characterized and compared. The results showed that recombinant SdG5A retained 27.8% of its maximal activity at 0 ℃ and could produce 48.6% of maltopentaose at room temperature, indicating a strong cold adaptation of SdG5A. In contrast, SdG5A-CD, lacking the linker and starch-binding domain (SBD), did not show any cold adaptation. To investigate the mechanisms that might underlie the cold adaptation of SdG5A, the structure was predicted by RoseTTAFold and the structural flexibility was analyzed through molecular dynamics simulation. An extremely high flexibility in the C-terminal linker-SBD region was observed and its root-mean-square fluctuation at 0 ℃ was consistent with that at 45 ℃, indicating that the highly flexible linker-SBD region acted as a critical component for the cold adaptation of SdG5A.
    2022,41(10):58-66, DOI: 10.3969/j.issn.1673-1689.2022.10.005
    Abstract:
    γ-Gminobutyric acid is an important biologically active factor, which is synthesized though the decarboxylation of L-glutamic acid by glutamate decarboxylase (GAD). The author firstly cloned and expressed the glutamate decarboxylase-encoding gene from Saccharomyces cerevisiae in E. coli. The specific activity of the recombinant ScGAD purified by affinity chromatography reached a maximum value of 66.55 U/mg. Further enzymatic property analysis results indicated that ScGAD exhibited an optimum reaction temperature of 60 ℃, an optimum reaction pH of 4.0, excellent stability in the range of 30~50 ℃ and pH 4.0~9.0, and the value of 14.28 mmol/L for kinetic constant Km indicating ScGAD of a good affinity to L-glutamic acid. Finally, through the investigation of the optimal conditions for GABA preparation by whole-cell catalysis using ScGAD, the highest generation efficiency of GABA was achieved at the conditions of 60 ℃ and pH 4.0. On this basis, 100 mmol/L of the substrate (sodium L-glutamate) could be converted to 35.9 g/(g·h) of GABA through whole-cell catalysis. This study provides a basis for efficient production of GABA.
    2022,41(10):37-48, DOI: 10.3969/j.issn.1673-1689.2022.10.003
    Abstract:
    The development and application of functional starch are one of the hot research areas in food and medicine industries. Functional starch draws more and more attention from customs. It is an efficient method for the synthesis of functional starch by enzymatic catalysis. Due to its green environmental protection, safety and health characteristics, it has received extensive attention from scholars in many fields. In this paper, the structural regulation principle of artificial synthesis of amylose and highly branched starch using sucrose is summarized, and the research progress of amylosucrase and glycogen branching enzyme in the synthesis of functional starch is reviewed. The research trends and application prospects of starch in the field of functional food and medicine is illustrated, providing a reference for further development of functional starch.
    2022,41(7):111-119, DOI: 10.3969/j.issn.1673-1689.2022.07.010
    Abstract:
    Quercetin is a kind of important citrus flavonoid with antibacterial, anti-inflammatory and antioxidant activities, but with poor water solubility and lipid solubility. It has been proved that the metabolic stability and bioavailability of quercetin can be improved by methylation, and microbial transformation method is a good method to obtain methylated quercetin. In this study, 11 flavonoid O-methyltransferase(FOMT) from different sources were screened and classified according to methylation sites, and then the corresponding Escherichia coli engineering bacteria were constructed. Four mono O-methylated quercetin(tamarixetin, rhamnetin, isorhamnetin and 3-O-methylquercetin)were synthesized by fermentation with quercetin as substrate. The highest yields were 31.17, 11.17, 8.90, 52.95 mg/L, respectively. Then, the co-culture system of E.coli was constructed, and the whole cell catalyst containing MpOMT4 and OsNOMT was added step by step. By adjusting the proportion and biomass of the two bacteria in the system, it was finally determined that when the dry weight of cell was 24 g/L and the ratio of cell 1 and cell 2 was 1∶2, and the highest yields of 4′, 7-dimethoxyquercetin was 21.56 mg/L.
    2022,41(7):1-11, DOI: 10.3969/j.issn.1673-1689.2022.07.001
    [Abstract] (524) [HTML] (0) [PDF 5.09 M] (1385)
    Abstract:
    Plant-based foods generally refer to food made from plant materials. There is much room for the growth of plant-based foods in the era of great health. Lactic acid bacteria (LAB) fermentation technology has great potentials in the development of diversified plant-based foods, which can achieve the diversification of flavor and health of plant-based foods. Thus, LAB-fermented plant-based foods industry is very promising in the future. This review summarizes the types of LAB-fermented plant-based foods, the relevant basic theories, key technologies as well as the industrialization status at home and abroad, and briefly discusses the main development trend of LAB-fermented plant-based food industry from the aspects of basic theory, key technology, and product a development. The aim of this review is to provide reference for the research and development of new LAB fermented plant-based food products.
    2022,41(6):41-50, DOI: 10.3969/j.issn.1673-1689.2022.06.005
    Abstract:
    Triacylglycerols in human milk are important for infant lipid digestion and absorption. Previous research by our group has shown that human milk is naturally rich in medium- and long- chain triacylglycerols (MLCT). MLCTs are the most abundant triacylglycerols in human milk, accounting for about 30% of the total triacylglycerols, and the main structure of MLCT is a single medium chain (MLL) type triglyceride with one medium-chain fatty acid and two long-chain fatty acids. There are few medium-chain triacylglycerols (MCT) in human milk. The content, composition and influencing factors of MLCT in human milk, and the differences between human milk and infant formulas are reviewed in this paper. The digestive and metabolic characteristics of MLCT are summarized, as well as the research progress of MLCT type human milk substitute fat. The research would provide theoretical basis for the development of infant formula.
    2022,41(6):1-12, DOI: 10.3969/j.issn.1673-1689.2022.06.001
    [Abstract] (834) [HTML] (0) [PDF 1.82 M] (1332)
    Abstract:
    The modern edible oil manufacturing technology has been developed for more than half a century in China. With the advent of a new round of scientific and technological revolution and industrial revolution, the research of new technologies of edible vegetable oil preparation and refining has attracted extensive attention. The important way to realize the industrial transformation, structural readjustment and development facilitation was through the flexible processing and accurate and appropriate processing technology of oils and greases based on the low-carbon and green manufacturing, high efficiency and low energy consumption, individualization of products, and new demands of nutrition and health. The authors briefly summarized the current research progress of novel technologies from three aspects, i.e. the oil-bearing materials pretreatment technology, the oil manufacturing technology, and the oil refining technology. The current application problems have been analyzed, and the future development trends have been prospected, providing the references of future oil technology development in China.
    2022,41(5):1-10, DOI: 10.3969/j.issn.1673-1689.2022.05.001
    [Abstract] (666) [HTML] (0) [PDF 1.51 M] (1124)
    Abstract:
    Mycotoxins are important pollutants that have long been a serious problem of food security, especially for cereal crops. Therefore, the detection and degradation of mycotoxins has always been a focus of food safety research. According to the existing research, the main degradation methods are physicochemical and biological methods. In addition, a variety of synergistic degradation methods have emerged with a diversified trend. Therefore, the recent research efforts in different strategies used to control the contamination of various mycotoxins in food and other products were reviewed in this article, aiming to further promote the application of more convenient and efficient mycotoxin degradation methods to the relevant food fields, to reduce the impact of degradants on food quality, and to inspire new mycotoxin degradation methods. The corresponding toxin production mechanisms were analyzed, and the advantages and disadvantages of various methods to prevent and control mycotoxins at present were discussed. At the same time, the future development trend of mycotoxin degradation methods in food industry was prospected, and new research points were put forward.
    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.
    Abstract:
    Biogenic amines widely existed in some foods, especially in fermented foods, which have certain hidden danger of food safety. In order to obtain biogenic amines degrading strains used in fish sauce and other fermentation products, non-biogenic amines producing strains were primarily screened from the natural fermentation fish sauce by double-layer chromogenic medium method, which was re-screened by high-performance liquid chromatography (HPLC) method to obtain a strain MZ5 with high efficiency of histamine degradation. The strain was identified as Pichia kudriavzevii, and the strain showed high histamine degradation activity in the range of 10~200 mg/L histamine concentration, 0~5% volume fraction of ethanol, pH 5~7 and 0~8 g/dL NaCl. The histamine degradation rate was 98.61% at the initial histamine mass concentration of 50 mg/kg and pH 7. Pichia kudriavzevii had good tolerance to ethanol, pH and salt concentration, and could be used as the fermentation preparation. This study could provide a research basis for the development of biological amine degradants in fermented food.
    2022,41(2):8-21, DOI: 10.3969/j.issn.1673-1689.2022.02.002
    [Abstract] (897) [HTML] (0) [PDF 1.80 M] (1024)
    Abstract:
    Vine tea is classified as an Ampelopsis grossedentata of the Ampelopsis michx. in the the family of Vitacea. Vine tea is rich in flavonoids, among which dihydromyricetin (DMY) is the most important component. Scientific research has found that vine tea and its main bioactive components have various biological effects such as anti-cancer, anti-oxidation, lipid-lowering, anti-inflammation, anti-bacteria and anti-fatigue. Current studies have found that vine tea and its main bioactive components participate in different biological functions via targeting some important genes and regulating signal transduction pathways. However, the molecular mechanism of its effects is still unclear. In this paper, the biological activities, signal transduction pathways and key target genes of vine tea and its main bioactive components were systematically reviewed according to the updated domestic and international progress, expecting to provide theoretical reference for the in-depth study of vine tea and its bioactive components, and to be conducive to the further development and utilization of vine tea and its main bioactive components in the future.
    2022,41(1):36-43, DOI: 10.3969/j.issn.1673-1689.2022.01.005
    Abstract:
    Based on Au@PDA core-shell nanoparticles (NPs) and the fluorescence quenching toward quantum dots, a dual-signal readout mode lateral flow immunoassay strip (LFIA) was fabricated for qualitative or quantitative determination of tebuconazole in fruits and vegetables. The effects of the preparation of Au@PDA and Au@PDA-antibody complex, the load of sensing elements and buffers of the strip were investigated on the strip sensitivity. Under the optimal conditions, the qualitative detection limit of tebuconazole by the naked eyes was 1 μg/mL in colorimetric mode and 100 ng/mL in fluorescent detection mode. The developed strip was applied in the tebuconazole detection in cucumber samples. And the results showed the interference of sample matrix could be eliminated by an appropriate dilution of cucumber sample extract. The limit of detection for tebuconazole in cucumber was 0.8 mg/kg, meeting the limit requirement of national safety standard.
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    November 22, 2023, DOI: 10.12441/spyswjs.20230412003
    Abstract:
    Yeast β-glucan is a type of polysaccharide that is difficult to dissolve in commonly used solvents such as water, acids, and alkalis. Traditional preparation methods are complex, cumbersome, and often result in low product yield or impurities, causing difficulties in industrialization. In this study, an alkaline method combined with dimethyl sulfoxide(DMSO) was used to explore and optimize the production process of yeast β-glucan. The results showed that under the conditions of 0.7 g/dL NaOH at 80 ℃ for 2.6 hour alkaline treatment, the highest impurity removal rate was 71.84%. Separation and purification of β-glucan were accomplished under the conditions of the solid-to-liquid ratio of 30 mg∶1 mL and 80% volume fraction of DMSO at 80 ℃ for 30 minutes, resulting in a β-glucan product with a purity of 95.84%. The product was identified by thin-layer chromatography and Fourier-transform infrared spectroscopy, and the product was indicated as β-glucan composed of glucose monomers. Moreover, Anti-inflammatory experiments showed that this product had a certain biological activity. The study aimed to simplify production processes, scale up production, improve product quality, and provide a theoretical reference for industrialized production.
    November 21, 2023, DOI: 10.12441/spyswjs.20221107001
    Abstract:
    This study aimed to detect the polymorphisms of κ-casein and αs1-casein gene in yak milk from seven different pastures in certain areas of Qinghai province, and to analyze the effect of gene polymorphisms on cheese coagulation characteristics. Yak milk somatic cells were extracted, and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis technique was used to extract DNA for PCR amplification and enzymatic digestion, followed by gene typing based on electrophoresis bands. Yak milk proteins were also extracted and high-performance liquid chromatography(HPLC) was used to analyze the chromatographic profiles of various samples compared to the standard samples, with a focus on peak time and peak shape for gene typing. The rheological characteristics during coagulation for different genotypes of yak milk were determined by rheometer. Cheese coagulation time was recorded, and cheese yield was calculated. The results showed that there were three genotypes for the κ-casein gene in yak milk, i.e., type AA, AB and BB. The analysis of the three genotypes and coagulation characteristics showed that the A allele was favorable in terms of coagulation time. Similarly, for the αs1-casein gene in yak milk, three genotypes (AA, AB, and BB) were also identified. The analysis of the coagulation time, cheese yield, maximum dynamic viscosity, and maximum shear rate revealed that the B allele was favorable. The above results suggest that both κ-casein and αs1-casein of yak milk in seven Qinghai farms have gene polymorphisms. The A allele in κ-casein and B allele in αs1-casein are the main effective genes affecting the coagulation characteristics of yak milk.
    November 21, 2023, DOI: 10.12441/spyswjs.20230320004
    Abstract:
    Dextran sulfate sodium(DSS) was used to induce colitis in mice, and the effects of feruloylated oligosaccharides(FOs) on alleviating colitis and regulating intestinal flora imbalance were investigated by tissue sectioning combined with 16S rRNA gene sequencing. The results showed that compared to the DSS group, FOs ameliorated the histological damage, up-regulated the expression of intestinal tight junction proteins, and decreased the expression of pro-inflammatory factors, exerting protective effects on the intestinal barrier. In addition, FOs improved the colitis-induced imbalance in the intestinal microbiota of mice, decreased the abundance ratio of the Firmicutes to Bacteroidetes, increased the abundance of probiotic bacteria such as Lactobacillus and Muribaculaceae, and inhibited the colonization of pathogenic bacteria such as Staphylococcus. Compared to the normal group, FOs significantly increased the content of colonic short-chain fatty acids, positively affecting the intestinal micro-ecology. The results indicated that FOs could regulate DSS-induced intestinal flora disorders, optimize intestinal flora structure, improve intestinal flora diversity, and effectively ameliorate colonic inflammation.

Journal Information

    Competent Authority:Ministry of Education of the People's Republic of China
    Sponsor:Jiangnan University
    Publishing Institute:Editorial Department of Journal of Food Science and Biotechnology
    Editor-in-chief:Chen Wei
    Co-Editor-in-Chief:Jiang Bo
    Address:No. 1800, Lihu Avenue, Wuxi 214122, Jiangsu Province,China
    PostCode:214122
    Tel:0510-85913526
    E-mail:xbbjb@jiangnan.edu.cn
    ISSN:1673-1689
    CN:32-1751/TS

Copy Right:Editorial Board of Journal of Food Science and Biotechnology

Address:No. 1800, Lihu Avenue, Wuxi 214122, Jiangsu Province,China  PostCode:214122

Phone:0510-85913526  E-mail:xbbjb@jiangnan.edu.cn

Supported by:Beijing E-Tiller Technology Development Co., Ltd.

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