Microflora structure and functional capacity in Tibetan kefir grains and selenium-enriched Tibetan kefir grains: A metagenomic analysis.

Tibetan kefir grains (TKGs) are a complex protein-lipid-polysaccharide matrix composed of various microorganisms. Microorganisms have the benefit of being effective, secure, and controllable when used for selenium enrichment. In this study, selenium-enriched Tibetan kefir grains (Se-TKGs) were made, and the microbiology composition was analyzed through a metagenomic analysis, to explore the influence of selenium enrichment. The microbial composition of TKGs and Se-TKGs, as well as the probiotic species, quorum sensing system (QS) and functional genes were compared and evaluated. Lactobacillus kefiranofaciens was the most abundant microbial species in both communities. Compared with TKGs, Se-TKGs had a much higher relative abundance of acetic acid bacteria. Lactobacillus helveticus was the most common probiotic species both in TKGs and Se-TKGs. Probiotics with antibacterial and anti-inflammatory properties were more abundant in Se-TKGs. QS analysis revealed that Se-TKGs contained more QS system-associated genes than TKGs. Moreover, Kyoto Encyclopedia of Genes and Genomes analysis revealed that the pathway for human disease ko01501 had the greatest relative abundance in both TKGs and Se-TKGs. Compared with TKGs, Se-TKGs demonstrated a greater relative abundance of different drug resistance-related metabolic pathways. Additionally, linear discriminant analysis effect size was used to examine the biomarkers responsible for the difference between the two groups. In this study, we focused on the microbiological structure of TKGs and Se-TKGs, with the aim of establishing a foundation for a more thorough investigation of Se-TKGs and providing a basis for exploring potential future use.

Removal of ochratoxin A in wine by Cryptococcus albidus and safety assessment of degradation products.

BACKGROUND: Ochratoxin A (OTA) is a mycotoxin that contaminates grape-based products and is extremely harmful to the health of the host. It is effectively removed by yeast during the fermentation of wine, whereas the removal mechanism of OTA remains unclear. Therefore, the present study aimed to investigate the removal mechanism of ochratoxin A by yeast and to evaluate the safety of its degradation products. RESULTS: Cryptococcus albidus (20-G) with better effect on ochratoxin A (OTA) was screened out in the main fermentation stage of wine. The results showed that 20-G removed OTA through biosorption and biodegradation. Intracellular enzymes played the main role (18.44%) and yeast cell walls adsorbed a small amount of OTA (8.44%). Furthermore, the identification of proteins in 20-G revealed that the decrease in OTA content was mainly a result of the action of peroxidase, and validation tests were carried out. By analyzing the degradation products of OTA, OTα and phenylalanine with lower toxicity were obtained. Animal experiments showed that the intervention of yeast 20-G reduced the damage and adverse effects caused by OTA toxicity to the mice. CONCLUSION: The present study demonstrates the mechanism of OTA removal by 20-G and the toxicity of OTA was reduced by peroxidase in 20-G. © 2023 Society of Chemical Industry.

Innovative beverage creation through symbiotic microbial communities inspired by traditional fermented beverages: current status, challenges and future directions.

Fermented beverages (FBs) are facing challenges in functional performance and flavor complexity, necessitating the development of new multi-functional options. Traditional fermented beverages (TFBs), both alcoholic and nonalcoholic, have gained increased attention for their health-promoting effects during the COVID-19 pandemic. This review summarized the primary commercially available probiotics of FBs, along with the limitations of single and mixed probiotic FBs. It also examined the recent research progress on TFBs, emphasizing the typical microbial communities (MC) of TFBs, and TFBs made from crops (grains, vegetables, fruits, etc.) worldwide and their associated functions and health benefits. Furthermore, the construction, technical bottlenecks of the synthetic MC involved in developing innovative FBs were presented, and the promising perspective of FBs was described. Drawing inspiration from the MC of TFBs, developing of stable and multifunctional FBs using synthetic MC holds great promise for beverage industry. However, synthetic MC suffers from structural instability and poorly acknowledged interaction mechanisms, resulting in disappointing results in FBs. Future researches should prioritize creating synthetic MC fermentation that closely resemble natural fermentation, tailored to meet the needs of different consumers. Creating personalized FBs with high-tech intelligence is vital in attracting potential consumers and developing novel beverages for the future.

The optimization of sequential fermentation in the dealcoholized apple juice for reducing lipids.

Yeast and lactic acid bacteria are widely used in fermented foods and the nutrients and metabolites produced by fermentation have cholesterol degrading effects. This study utilized Xinjiang Aksu apples as the material to optimize the sequential fermentation process of different strains and construct a fermentation kinetic model to develop a functional fermentation product with low-sugar, probiotics-rich and lipid-lowering properties. The sequential fermentation of dealcoholized apple juice with Saccharomyces cerevisiae and Lactobacillus plantarum was optimized by response surface design, based on which a sequential fermentation kinetic model was constructed. The changes of short-chain fatty acids, cholesterol elimination rate and hydrophobic properties during the fermentation process were studied. The results showed that the kinetic model established under the optimal conditions could effectively predict the dynamic changes of the basic indexes during the fermentation process. After fermentation, the viable number of L. plantarum was 4.96 × 108 CFU/mL, short-chain fatty acids increased, the cholesterol elimination rate reached 45.06%, and the hydrophobicity was 51.37%, which had favorable lipid-lowering properties and hydrophobic effect. This research will provide a theoretical basis and technical support for the monitoring of microbial dynamics and functionalization development of sequentially fermented apple juice with different strains. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05741-z.

Application of nanostructures as antimicrobials in the control of foodborne pathogen.

Foodborne pathogens are the main cause of human foodborne diseases and pose a serious threat to food safety. The control of them has always been a significant issue in food industry. With good biocompatibility and stability, nanomaterials display excellent bactericidal properties against many kinds of bacteria. In this review, the generation and application of nanostructures as antibacterial in the control of foodborne pathogens was summarized. The antibacterial effects of photocatalytic and contact bacteriostatic nanomaterials agents were mainly introduced. The influence factors and mechanisms of nanomaterials on the inactivation of foodborne pathogens were displayed. The photocatalytic nanostructured bacteriostatic agents can produce reactive oxygen species (ROS) and lead to charge transfer, which result in damaging of cell wall and leakage of small molecules under light irradiation. In addition, metals and metal oxide nanoparticles can kill bacterial cells by releasing metal ions, forming ROS and electrostatic interaction with cell membrane. Besides, the synergistic action of nanoparticles with natural antibacterial agents can improve the stability of these agents and their bactericidal performance. These current researches provided a broader idea for the control of microorganisms in food.

Effects of fermentation with Lactobacillus fermentum 21828 on the nutritional characteristics and antioxidant activity of Lentinus edodes liquid.

BACKGROUND: Few studies to date have evaluated the use of Lactobacillus and Bifidobacterium in edible fungus fermentation. To obtain a fermented Lentinus edodes liquid product with good taste and effects, a strain with good fermentation performance from nine strains tested was selected, and the physicochemical properties and antioxidant capacity of the resulting product were evaluated. RESULTS: Lactobacillus fermentum 21828 exhibited adhesion, tolerance to low pH and bile salts, and good fermentation performance. The number of viable bacteria was 1.05 × 108 CFU mL-1 , and the extraction rate of crude polysaccharide from L. edodes was 2.79% after fermentation. The effects of fermentation on the contents and composition of nutrients in L. edodes liquid were marked, with changes in total soluble protein, total soluble sugar, total acid, and total phenol levels. The 2,2-diphenyl-1-picrylhydrazyl radical-scavenging rate in the fermentation liquid was 93.01%, which was significantly higher than that in non-fermented liquid (80.33%). Furthermore, analysis of volatile and 5'-nucleotide contents showed that fermentation altered the flavor of the product, whereas sensory evaluation showed that the fermented product was preferred. CONCLUSION: Our study demonstrated that the fermented L. edodes liquid exhibited better nutritional and functional properties, as well as sensory characteristics, compared with unfermented liquid. © 2021 Society of Chemical Industry.

Antimicrobial and anti-biofilm activity of thymoquinone against Shigella flexneri.

Shigella flexneri (Sh. flexneri), a common foodborne pathogen, has become one of the main threats to food safety and human health due to its high pathogenicity and persistent infection. The objective of this study was to explore the antimicrobial and anti-biofilm activities and the possible mechanism of thymoquinone (TQ) against Sh. flexneri. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of TQ against Sh. flexneri were 0.4 and 0.5 mg/mL, respectively. TQ showed bactericidal activity against Sh. flexneri in culture medium and milk system. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) observations demonstrated that TQ could induce abnormal cell morphology and destroy cell membrane. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis suggested that TQ could inhibit protein synthesis in Sh. flexneri. Also, at sub-inhibitory concentrations (SICs), TQ exhibited an inhibitory effect on Sh. flexneri biofilm formation, which was confirmed by crystal violet quantitative analysis and SEM observation. Real-time quantitative PCR (RT-qPCR) analyses revealed that TQ downregulated the expression of genes involved in Sh. flexneri biofilm formation. Thus, TQ has potential as a natural antimicrobial and anti-biofilm agent to address the contamination and infection caused by Sh. flexneri. KEY POINTS: • Antimicrobial and anti-biofilm activity of TQ on Shigella flexneri were investigated. • TQ inhibited biofilm formation by Shigella flexneri. • TQ provided a new strategy for Shigella flexneri control.

Microbial community diversity associated with Tibetan kefir grains and its detoxification of Ochratoxin A during fermentation.

Tibetan kefir grains (TKG) are multi-functional starter cultures used in foods and have been applied in various fermentation systems. This study aimed to investigate the microbial community composition of TKG, the detoxification abilities of TKG and their isolates towards common mycotoxins, and the potential for applying TKG and their associated microbial populations to avoid mycotoxin contamination in dairy products. Cultivation-independent high-throughput sequencing of bacterial and fungal rDNA genes indicated that Lactobacillus kefiranofaciens and Kazachstania turicensis were the most abundant bacterial and fungal taxa, respectively. In addition, 27 total isolates were obtained using cultivation methods. TKG removed more than 90% of the Ochratoxin A (OTA) after 24 h, while the isolate Kazachstania unisporus AC-2 exhibited the highest removal capacity (~46.1%). Further, the isolate exhibited good resistance to acid and bile salts environment. Analysis of the OTA detoxification mechanism revealed that both adsorption and degradation activities were exhibited by TKG, with adsorption playing a major detoxification role. Furthermore, the addition of OTA did not affect the microbial community structure of TKG. These results indicate that TKG-fermented products can naturally remove mycotoxin contamination of milk and could potentially be practically applied as probiotics in fermentation products.

Immunomagnetic separation: An effective pretreatment technology for isolation and enrichment in food microorganisms detection.

The high efficiency and accurate detection of foodborne pathogens and spoilage microorganisms in food are a task of great social, economic, and public health importance. However, the contamination levels of target bacteria in food samples are very low. Owing to the background interference of food ingredients and negative impact of nontarget flora, the establishment of efficient pretreatment techniques is very crucial for the detection of food microorganisms. With the significant advantages of high specificity and great separation efficiency, immunomagnetic separation (IMS) assay based on immunomagnetic particles (IMPs) has been considered as a powerful system for the separation and enrichment of target bacteria. This paper mainly focuses on the development of IMS as well as their application in food microorganisms detection. First, the basic principle of IMS in the concentration of food bacteria is presented. Second, the effect of different factors, including the sizes of magnetic particles (MPs), immobilization of antibody and operation parameters (the molar ratio of antibody to MPs, the amount of IMPs, incubation time, and bacteria concentration) on the immunocapture efficiency of IMPs are discussed. The performance of IMPs in different food samples is also evaluated. Finally, the combination of IMS and various kinds of detection methods (immunology-based methods, nucleic acid-based methods, fluorescence methods, and biosensors) to detect pathogenic and spoilage organisms is summarized. The challenges and future trends of IMS are also proposed. As an effective pretreatment technique, IMS can improve the detection sensitivity and shorten their testing time, thus exhibiting broad prospect in the field of food bacteria detection.

Extraction, partial purification and characterisation of vanillic acid decarboxylase from Alicyclobacillus acidoterrestris DSM 3923.

BACKGROUND: Vanillic acid decarboxylase (VAD) is the key enzyme responsible for guaiacol production in Alicyclobacillus acidoterrestris; however, information related to this enzyme is currently unavailable. The aim of this study is to characterise the VAD from A. acidoterrestris. RESULTS: Specific activity of VAD in vanillic acid-induced A. acidoterrestris DSM 3923 cells was highest in the early stage of the log phase, and almost undetectable in the stationary and death phases. Of the four techniques used to extract VAD, sonication was found to be the most effective and recovered 3.23 U mg(-1) of VAD. Through optimisation of the crucial parameters for sonication, the recovery of VAD had more than doubled (6.81 U mg(-1) ). The crude enzyme extract was purified by ammonium sulfate precipitation and a 9.87-fold purification was obtained. The partially purified VAD exhibited optimum activity at pH 6.0-6.5, 45°C and was stable at pH 5.0-7.5, 20-45°C. The Km and Vmax values of the VAD were 0.53 mmol L(-1) and 96 U mg(-1) protein, respectively. VAD activity was stimulated by Co(2+) and Mn(2+) , but was inhibited by Ni(2+) , Cu(2+) , Ba(2+) and Fe(3+) . Cinnamic acid, ferulic acid, resveratrol, quercetin and rutin at the concentration of 1 mmol L(-1) could completely inhibit the activity of VAD. CONCLUSION: The present study provides the first report on the characteristics of the VAD from A. acidoterrestris, which will contribute to the development of more effective control methods to minimise A. acidoterrestris-related spoilage in fruit juices. © 2015 Society of Chemical Industry.

Comprehensive distribution and species of selenium in Se-enriched Pichia kudriavzevii 1845.

This study is the first to demonstrate the yeast Pichia kudriavzevii can effectively deliver Se and investigate the distribution and species of Se in Se-enriched P. kudriavzevii. Results showed that P. kudriavzevii can accumulate Se and convert 84.883% of absorbed Se into organic forms, of which 78.338% was incorporated into protein, 1.978% combined with polysaccharides, and 0.456% bound to nucleic acid. Besides, water-soluble, salt-soluble, and alkali-soluble proteins account for 49.398%, 1.867%, and 20.628% of selenoprotein, respectively. The dominant Se species were SeCys2 and MeSeCys. Additionally, Se-enrichment enhanced nutritional value of P. kudriavzevii by increasing the levels of amino acids, iron, and zinc. The activity of key rate-limiting enzyme sephosphate synthetase involved in Se biotransformation was improved after Se enrichment. The extracellular pH results suggest that Se enrichment ability can be further enhanced by elevating pH. These results suggest P. kudriavzevii holds great promise as an effective vehicle for delivering Se.

Inactivation activity and mechanism of pulsed light against Alicyclobacillus acidoterrestris vegetative cells and spores in concentrated apple juice.

Alicyclobacillus acidoterrestris has received much attention due to its unique thermo-acidophilic property and implication in the spoilage of pasteurized juices. The objective of this study was to evaluate the sterilization characteristics and mechanisms of pulsed light (PL) against A. acidoterrestris vegetative cells and spores in apple juice. The results indicated that bacteria cells in apple juice (8-20°Brix) can be completely inactivated within the fluence range of 20.25-47.25 J/cm2, which mainly depended on the soluble solids content (SSC) of juice, and the spores in apple juice (12°Brix) can be completely inactivated by PL with the fluence of 54.00 J/cm2. The PL treatment can significantly increase the leakage of reactive oxygen species (ROS) and proteins from cells and spores. Fluorescence studies of bacterial adenosine triphosphate (ATP) indicated that the loss of ATP was evident. Scanning electron microscopy and confocal laser scanning microscope presented that PL-treated cells or spores had serious morphological damage, which reduced the integrity of cell membrane and led to intracellular electrolyte leakage. In addition, there were no significant negative effects on total sugars, total acids, total phenols, pH value, SSC and soluble sugars, and organic acid content decreased slightly during the PL treatment. The contents of esters and acids in aroma components had a certain loss, while that of alcohols, aldehydes and ketones were increased. These results demonstrated that PL treatment can effectively inactivate the bacteria cells and spores in apple juice with little effect on its quality. This study provides an efficient method for the inactivation of A. acidoterrestris in fruit juice.

Sea Buckthorn Flavonoid Extracted by High Hydrostatic Pressure Inhibited IgE-Stimulated Mast Cell Activation through the Mitogen-Activated Protein Kinase Signaling Pathway.

Sea buckthorn (Hippophaë rhamnoides L.), as one of the Elaeagnaceae family, has the significant function of anti-tumor, anti-inflammation, anti-oxidation, and other physiological activities. High hydrostatic pressure (HHP) extraction has the advantages of being easy and efficient, while maintaining biological activity. In this study, sea buckthorn flavonoid (SBF) was extracted with HHP and purified sea buckthorn flavonoid (PSBF) was isolated by AB-8 macroporous resin column. HPLC analysis was used to quantified them. In addition, the effect of anti-allergy in RBL-2H3 cells by SBF, PSBF, and their flavonoid compounds was evaluated. The results demonstrate the conditions for obtaining the maximum flavonoid amount of SBF: 415 MPa for 10 min, 72% ethanol concentration, and a liquid to solid ratio of 40 mL/g, which increased the purity from 1.46% to 13.26%. Both SBF and PSBF included rutin, quercitrin, quercetin, isorhamnetin, and kaempferol. In addition, quercitrin, kaempferol, and SBF could regulate Th1/Th2 cytokine balance. Moreover, extracellular Ca2+ influx was reduced by quercitrin and PSBF. Furthermore, rutin, quercetin, iso-rhamnetin, and SBF could also inhibit P-p38 and P-JNK expression, thereby suppressing the phosphorylation of the MAPK signaling pathways. Overall, SBF is effective for relieving food allergy and might be a promising anti-allergic therapeutic agent.

Detoxification of Mycotoxin Patulin by the Yeast Kluyveromyces marxianus YG-4 in Apple Juice.

Patulin (PAT) is a mycotoxin produced by Penicillium species, which often contaminates fruit and fruit-derived products, posing a threat to human health and food safety. This work aims to investigate the detoxification of PAT by Kluyveromyces marxianus YG-4 (K. marxianus YG-4) and its application in apple juice. The results revealed that the detoxification effect of K. marxianus YG-4 on PAT includes adsorption and degradation. The adsorption binding sites were polysaccharides, proteins, and some lipids on the cell wall of K. marxianus YG-4, and the adsorption groups were hydroxyl groups, amino acid side chains, carboxyl groups, and ester groups, which were combined through strong forces (ion interactions, electrostatic interactions, and hydrogen bonding) and not easily eluted. The degradation active substance was an intracellular enzyme, and the degradation product was desoxypatulinic acid (DPA) without cytotoxicity. K. marxianus YG-4 can also effectively adsorb and degrade PAT in apple juice. The contents of organic acids and polyphenols significantly increased after detoxification, significantly improving the quality of apple juice. The detoxification ability of K. marxianus YG-4 toward PAT would be a novel approach for the elimination of PAT contamination.

Immobilization of pancreatin based on ultrasound-assisted polydopamine functionalized magnetic porous chitosan for the detoxification of ochratoxin A in wine.

Ochratoxin A (OTA) is a mycotoxin that globally contaminates fruits and their products. Since OTA have a huge negative impact on health hazards and economic losses, it is imperative to establish an effective and safe strategy for detoxification. Here, pancreatin was immobilized on the surface of polydopamine functionalized magnetic porous chitosan (MPCTS@ PDA) for the degradation of OTA. Compared with free pancreatin, MPCTS@ PDA@ pancreatin displayed excellent thermal stability, acid resistance, storage stability and OTA detoxification in wine (>58%). Moreover, the MPCTS@ PDA@ pancreatin retained 43% initial activity after 8 reuse cycles. There was no significant change in the quality of wine after MPCTS@ PDA@ pancreatin treatment. Moreover, it did not exhibit cytotoxicity which facilitated its application in wine. These results demonstrated that MPCTS@ PDA@ pancreatin can be used as a highly effective biocatalysate for OTA detoxification in wine.

Enzymatically green-produced bacterial cellulose nanoparticle-stabilized Pickering emulsion for enhancing anthocyanin colorimetric performance of versatile films.

To enhance the colorimetric performance of anthocyanin (Ant), a konjac glucomannan (KGM)-based multifunctional pH-responsive indicator film was fabricated by introducing enzymatically prepared bacterial nanocellulose (EBNC) stabilized camellia oil/camellia essential oil Pickering emulsion (BCCE). Specifically, optimized enzymatic hydrolysis time (36 h) was determined based on the particle size and microstructure. Then BCCE (containing 0.4% EBNC) was incorporated into Ant-containing KGM, and the novel active indicator film (KGM-Ant-BCCE) was constructed. Films with varying BCCE concentrations (3%-11%) exhibited enhanced UV shielding, thermal stability, mechanical strength, water vapor and oxygen permeability, hydrophobicity, and antioxidant performance. The pronounced color change of KGM-Ant-BCCE indicated its potential for visually detecting shrimp freshness. Moreover, the biodegradability (25 days) confirmed the environmentally benign property of the film. In summary, incorporating green-produced EBNC nanoparticle-stabilized BCCE offers an innovative pathway to improve the color indication capability of polysaccharide-based smart packaging.

A versatile bilayer smart packaging based on konjac glucomannan/alginate for maintaining and monitoring seafood freshness.

This study introduces a novel multi-functional double-layer intelligent packaging. It focuses on developing a dual-function system capable of real-time monitoring and freshness preservation. Specifically, cellulose nanocrystalline (CNC) was obtained through acid hydrolysis, and then CNC/soybean protein isolate (CNC/SPI) complex colloid particles were prepared via antisolvent method. These particles served as stabilizers to prepare oil-in-water (O/W) cinnamon essential oil Pickering emulsion (CSCEO). The CSCEO was then integrated into the emulsified hydrophobic layer of a konjac glucomannan (Kgm) matrix through intermolecular hydrogen bonding. Finally, alginate (Alg) matrix containing alizarin (Al) as an indicator was added to construct the bilayer structure using a layer-by-layer casting strategy. The inner layer Alg/Al was the pH/NH3-responsive indicator layer, while the outer layer Kgm/CSCEO acted as the high-barrier bacteriostatic layer. The obtained dual-function, double-layer film (Alg/Al-Kgm/CSCEO), which possesses a sensitive, reversible and rapid response towards pH/NH3, shows exceptional antibacterial and antioxidant properties, as well as excellent mechanical property, light-blocking capability and hydrophobicity. For monitoring and maintaining the actual freshness of shrimp, such a bilayer packaging displays smallest change of ∆E and TVB-N (18.65 mg/100 g) even after 72 h, which further highlighting its potential in enhancing food safety and extending shelf life.

Regulation of Gut Microbiota and Microbial Metabolome of Kefir Supernatant against Fusobacterium nucleatum and DSS-Coinduced Colitis.

The aim of this study was to investigate the intervention effect of kefir supernatant (KS) on the initiation and progression of an ulcerative colitis (UC) murine model. We established an UC murine model by orally administrating with 109 CFUs of Fusobacterium nucleatum for 3 weeks and 3% dextran sulfate sodium (DSS) treatment in the third week. KS was used to intervene in this colitis model. Our results showed that KS supplementation ameliorated the symptoms, restrained the secretion of pro-inflammatory cytokines (TNF-α, IL-6, and IL-17F), promoted the release of anti-inflammatory cytokines (IL-4 and IL-10), and ameliorated oxidative stress. Furthermore, the increased number of goblet cells and upregulated expression of MUC2, occludin and claudin-1 indicated that the colon barrier was protected by KS. Additionally, KS supplementation mitigated gut microbiota dysbiosis in the UC murine model, leading to an increase in the abundance of Blautia and Akkermansia and a decrease in the level of Bacteroides. The altered gut microbiota also affected colon metabolism, with differential metabolites mainly associated with the biosynthesis of the l-arginine pathway. This study revealed that KS supplementation restored the community structure of gut microbiota, altered the biosynthesis of l-arginine, and thereby modulated the process of colonic inflammation.

[Study on mechanism of inactivated cider yeast adsorbing patulin by Fourier transform infrared spectroscopy].

The mechanism of patulin adsorption by inactivated cider yeast was studied by chemical modification and FTIR The results of patulin removal by various modified yeast biomass showed that the ability of patulin biosorption by acetone-treated yeast and NaOH-treated yeast increased siginificantly, while the methylation of amino group and esterification of carboxylate functionalities of yeast cell surface caused a decrease in patulin binding, which indicated that amino group and carboxyl group presented in the cell walls of yeast might be involved in the binding of patulin to the yeast. The FTIR analysis indicated that the main functional groups were amino group, carboxyl group and hydroxy group which are associated with protein and polysaccharides.

Contribution of the leaf and silique photosynthesis to the seeds yield and quality of oilseed rape (Brassica napus L.) in reproductive stage.

Influences of photosynthesis of leaf and silique on seeds yield and quality of oilseed rape (Brassica napus L.) were explored in this study. A field comparing experiment with several rapeseed varieties was conducted and the results showed, that the leaf area index (LAI), silique surface area index (SAI), siliques number per plant, and biological yield were statistically classified as the first principal factors which greatly influenced seeds yield, the leaf net photosynthetic rate (Pn) and silique Pn were the second principal factors; the stomatal conductance (Gs) and chlorophyll a (Chl a) content were the first principal factors which influenced leaf Pn and silique Pn. A shading experiment was conducted and the results showed that, under treatments of the ZH1, ZH2, and ZH3 (shading rapeseed plants during flowering stage, during time from initial flowering until seeds ripening, and during time from flowering ending until seeds ripening, respectively), respectively the seeds yield per plant was reduced by 34.6%, 84.3%, and 86.1%, the seed protein content was significantly increased. The treatment ZH1 Not, but the ZH2 and ZH3 caused significant decrease in both seed oil content and oleic acid (C18:1) content in seed oil, and the contents of linoleic acid (C18:2), linolenic acid (C18:3) in oil were significantly increased, gene expression of the ACCase (Acetyl-CoA carboxylase), FAD2 (fatty acid desaturase), and FAD3 (ω-3 fatty acid dehydrogenase) in green seeds was restrained/changed. Thus the LAI, SAI, siliques number per plant, biological yield per plant, leaf Pn, silique Pn, and the Gs, Chl a content of leaf and silique formed an indexes system to be used in screening rapeseed variety with higher light efficiency and seeds yield; the silique photosynthesis inhibition and the photosynthates deficiency in rapeseed plant after flowering stage predominately influenced seeds yield and quality.