Abstract:The categories and research status of Chinese traditional fermented food were analyzed, combined with the technical characteristics of fermented food production procedure, including fermentation processes, complex environment, mixed bacteria system, sensory evaluation, etc. And the advanced technologies of Chinese traditional fermented food were further explored, such as the application of artificial sensing technology, the application of new technologies for fermented food microorganisms and fermented food perception, etc. The application of advanced biotechnologies for Chinese traditional fermented food were discussed, such as genetic engineering, synthetic biology, molecular biology and neurobiology, etc. It might be smarter and more controllable of the fermentation process through the screening and modification of microorganisms. Based on human senses and big data, new perception technologies (such as fermentation regulation based on neurobiology, flavor network technology based on big data, etc.) should be established to promote the Chinese traditional fermented food to be more delicious, healthier and safer in terms of flavor, nutrition, safety and stability. In the future, we should take improving Chinese traditional fermented food as the starting point further accelerates the development of key common technologies, modern engineering technologies, cutting-edge leading technologies, and disruptive technologies for fermented foods, to promote the innovation of our national overall food fermentation industry, and lead the world iteration of the food fermentation industry.

Abstract:During the 13th Five-Year Plan period, China's economic development mode has changed. Facing the severe external environment and the pressure of economic downturn, the bio-fermentation industry has made great achievements in industrial upgrading and capacity increase. The achievements of China's bio-fermentation industry in the fields of industrial scale, export situation, technological innovation, industrial cluster, standard system and green construction during the 13th Five-Year Plan period were summarized. The existing problems of the industry at this stage in three aspects:standards and regulations, core technology, and market environment were analyzed. Through analyzing the development opportunities of China's bio-fermentation industry during the 14th Five-Year Plan period, the key tasks and safeguard measures for industrial development have been proposed from five aspects :making up for the shortcomings of the industrial chain, improving the level of bacterial strains, promoting intelligent manufacturing, promoting green manufacturing, energy conservation and environmental protection, and escorting industry development by improving standards. During the 14th Five-Year Plan period, the bio-fermentation industry will continue to maintain a healthy and steady development, lead product production with consumer demand, and improve market power, and gradually establish the concept of bio-boosting technology and fermentation leading the future. Finally, the goal of enabling healthy China through biological fermentation will be achieved.

Abstract:Aroma is one of the most important quality standards of fruits and their products. Maintaining natural flavor, improving aroma and product quality are always the pursued goals of the industry, which determinated the critical importance of accurate and comprehensive analysis of aroma substances in fruits. Due to the complexity of fruit matrix and the low content of aroma compounds, especially trace amounts and instability of some key aroma compounds, the accurate analysis of fruit aroma components is a complicated and difficult work. The extraction methods of fruit aroma substance and the current research direction of fruit aroma, and the key aroma material identification method were summarized, and the impact on the overall aroma of fruit was introduced from the aspect of perceptual interaction. Finally, the improvement and the research trend of the analytic methods of fruit aroma compounds were prospected, which might provide a theoretical foundation of aroma research for developing high quality fruit and its processed products.

Abstract:Baijiu is a traditional fermented beverage with thousands of years of history, and plays a very important role in Chinese catering culture. The analytical methods of volatile flavor compounds and non-volatile flavor compounds in Baijiu and the research status of the interaction of flavor compounds in Baijiu were systematically discussed. There are additive, synergistic, masking or irrelevant effects among volatile flavor compounds in Baijiu. There are many methods to analyze these interactions including S curve method, OAV method, σ-τ diagram method, partition coefficient method, vector model method and PDE model method. Studies using S curve method had shown the synergistic effect of alkyl sulfide on fruit flavor in Maotai-flavor Baijiu. The study of Maotai Baijiu by OAV method also indicated the synergistic effect of ethyl caproate mixtured with ethyl lactate or ethyl acetate, and additive effect was observed in the mixture of ethyl acetate and ethyl lactate. The method of σ-τ diagram method was used to analyze the interaction of aldoketones compounds and alcohols in Fen-flavor Baijiu. The masking effect was usually occurred in the presence of alcohols, while hexanol and benzyl alcohol did not interact with each other. And the synergistic effect was found among aldoketones. The partition coefficient method indicated that the release of 3-methyl butyric acid could be inhibited by high concentration of 2-phenethyl alcohol and 1-propanol in Baijiu. The influence of 1-propanol on release of 3-methyl butyric acid was greater than that of 2-phenethyl alcohol. The vector model method showed that the aroma intensity of the mixture had a good linear relationship with the aroma intensity sum of the single component. PDE model method had a good prediction performance for the aroma intensity of the mixture in Baijiu. Each method possessed its own advantages and disadvantages, and mutual verification will make the research results more accurate.

Abstract:The Hericium erinaceus alkali-extracted polysaccharide (HEAEP, a kind of β-glucan) was prepared by alkali extraction and alcohol precipitation. The effect of ascorbic acid on the apparent viscosity of HEAEP under different conditions (ascorbic acid concentration, metal ion, temperature, pH value, etc.) was systematically studied, and the effect on the structural characteristics of HEAEP was analyzed. The results showed that the apparent viscosity of HEAEP was dependent on the concentration of ascorbic acid. When the mass fraction of ascorbic acid exceeded 0.10000%, the degradation effect was significant less with the increasing concentration of ascorbic acid. Besides, metal ions (Cu²⁺ and Fe²⁺) addition would further promote the reduction of apparent viscosity of HEAEP induced by ascorbic acid. Moreover, the relative less effect of temperature was observed. The influence of temperature is relatively small. In addition, the pH value and reaction time also had certain influence. When the pH value was 4 and the reaction time was 12 hours, ascorbic acid had the best degradation effect on HEAEP. Furthermore, ascorbic acid could reduce the molecular weight of HEAEP, but had little effect on the structure and characteristics of HEAEP such as glycosidic bond type and ratio, monosaccharide composition and characteristic functional groups. The reducing effect of ascorbic acid on the apparent viscosity of HEAEP was affected by multiple factors, among that the concentration of ascorbic acid and metal ions (Cu²⁺ and Fe²⁺) had a greater impact. However, the main structural characteristics of the polysaccharide did not change significantly before and after ascorbic acid treatment. The research results aimed to provide a theoretical basis for the production of coexisting foods of ascorbic acid and β-glucan.

Abstract:In order to study the inhibitory effect of propolis extract on human norovirus in vitro, murine norovirus and phage MS2 virus were used as alternative viruses to study the inhibitory effect and mechanism of propolis aqueous extract and ethanol extract at different concentrations and time. Concentration-dependent experiments showed that the titers of murine norovirus and MS2 viruses decreased significantly with the increasing concentration of propolis ethanol extract. When the mass concentration of propolis ethanol extract reached 500μg/mL, the titers of murine norovirus and MS2 viruses decreased by 6.93 lgPFU/mL and 3.75 lgPFU/mL, respectively. The time-correlation experiment showed that during murine norovirus and MS2 for 60 min culturing with 250μg/mL propolis ethanol extract, the virus titers of murine norovirus and MS2 decreased by 4.18 lgPFU/mL and 3.30 lgPFU/mL in the first 40min, and then slowed down. After culture for 60min, the total titers of murine norovirus and MS2 decreased by 4.48 lgPFU/mL and 3.67 lgPFU/mL, respectively. Mechanism studies had shown that propolis ethanol extract may bind to host cells (receptors) or directly bind to virus particles to denature viral capsid proteins and prevent viruses from entering host cells. Images taken by transmission electron microscope further confirmed that propoils ethanol extract directly acted on the virus and triggered expansion and rupture. Finally, after propolis ethanol extract treatment, the titer of virus in the vegetable and fruit juices contaminated with man-made virus was significantly reduced. The results of this study might provide more options for selecting suitable additives in fresh pressing process of fruits and vegetables.

Abstract:The extraction conditions of maca polysaccharides were optimized and its antioxidant activity and hypolipidemic effect in vitro were explored. Response surface methodology of ultrasonic-assisted hot water leaching method was used to optimize the extraction conditions of maca polysaccharides. Free radical scavenging rate and cholate binding capacity were used to evaluate the antioxidant activity and the hypolipidemic effect of maca polysaccharides, respectively. Under the conditions of extraction temperature at 50℃, extraction time of 42min, ultrasonic power at 220W and material-liquid ratio at (g/mL) 1∶32, the extraction rate of polysaccharide reached a maximum of 11.0%.Furthermore, maca crude polysaccharides (MCP)were separated by an ion exchange column to obtain three components, named maca polysaccharides 1(MPS1),maca polysaccharides 2(MPS2) and maca polysaccharides 3(MPS3). Among them, MCP, MPS1 and MPS2 had strong antioxidant activity. The best scavenging rate of DPPH radicals by MCP,MPS1 and MPS2 reached 83.9%,81.8% and 63.7%, and the best scavenging rate of hydroxyl radicals reached 73.3%,56.8% and 76.7%, respectively. In addition, the binding rate of MPS3 to sodium taurocholate and sodium glycocholate in vitro was 49.1% and 32.2%, respectively. The results suggested that MCP, MPS1 and MPS2 had good antioxidant activity, and MPS3 owned certain hypolipidemic effect.

Abstract:In order to investigate the effect and mechanism of Agaricus blazei Murill polysaccharide on reducing blood lipid in hyperlipidemic rats, the crude polysaccharide was extracted by water extraction and alcohol precipitation method, and the polysaccharide was graded by DEAE cellulose ion exchange column chromatography. The monosaccharide composition was analyzed by high performance liquid chromatography, and the content of polysaccharide was determined. The rats were randomly divided into four groups:blank control group, model group, simvastatin positive control group, Agaricus blazei Murill polysaccharide group, and oral administration for 42 days. The contents of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) in serum were detected by ELISA. HE staining method was used to observe the pathological changes of liver tissue, and the mRNA levels of LDL-R, SREBP-1C, CYP7a-1, PPAR - α and SCARB-1F were detected by RT-PCR. The results showed that the content of sugar in Agaricus blazei polysaccharide was 75.1%, and ABP-A contained 88.6 GLc, 2.4% Gal, 1.9% Man, 1.0% Rha, 0.5% GalA, 1.9% Xyl, 2.1% Ara, and 1.6% Fuc. ABP-A significantly decreased liver index (P<0.05), and serum TC, TG, LDL-C (P<0.01), but significantly increased HDL-C (P<0.01), lipid droplets deposition in liver was decreased by ABP-A. LDL-R, SCARB-1F mRNA expression (P<0.05) and CYP7a-1, PPAR - α mRNA levels (P<0.01) significantly increased, and SREBP-1C mRNA expression dramatically decreased (P<0.01) .These results indicated that ABP-A exerted significant effects on lowering blood lipid, and the mechanism may be related to regulate the expression of LDL-R, SREBP-1c, CYP7a-1, PPAR-α and SCARB-1F.

Abstract:Aromadendrin is an important component of citrus flavonoids, and flavanone-3-hydroxylase (F3H) plays a key role in the formation pathway of aromadendrin. In this study, we summarized and analyzed the characteristics of F3H, and expressed them in Escherichia coli BL21. First, 5 kinds of f3h from Citrus reticulata Banco, Gossypium hirsutum, Zea mays, Saussurea medusa and Petroselinum crispumin NCBI database were chosen. Then, physicochemical properties, secondary and tertiary structure of protein, sequence alignment and other bioinformatics analysis were carried out. At last, recombinant expression system were constructed and expressed with E.coli BL21. The open reading frame of f3h gene was 1032-1119bp, encoding 343-372 amino acids. The molecular weight of F3H was 38.89-41.45kDa, and the theoretical isoelectric point was 5.43-5.96. The physical and chemical properties, domains and protein structures of F3H from different species were also similar.By constructing the expression system of E.coli BL21,we found that all F3H could be prokaryotic expression. Except the F3H from Saussurea medusi, the other 4 kinds of F3H could convert naringin to aromadendrin with different production amounts, and the highest production amount of ZmF3H was 20.12mg/L.

Abstract:The nutritional value of Portunus trituberculatus in two different sea areas was comprehensively evaluated by analyzing and comparing the muscle nutritional components. The water content, ash, crude protein, crude fat, fatty acid, amino acid, mineral element, nucleotide, betaine and cholesterol in muscle were determined by the national standard method. Nutritive quality evaluation was conducted according to the Food and Agricultural Organization (FAO) standards, and the correlation between nutrient composition, flavor content and production place was compared and analyzed. The results showed that there were significant differences in protein, amino acid, nucleotide, and betaine in two different sea areas. The contents of muscle protein, essential amino acids and total amino acids of wild male swimming crabs in Taizhou, Zhejiang were significantly higher than those in Rizhao, Shandong (P<0.05). The muscle contents of inosine acid and betaine of wild swimming crabs in Taizhou, Zhejiang were significantly higher than those in Rizhao, Shandong (P<0.05). There were some differences in muscle nutritional components and affected flavor and nutritional value of crabs from two different sea areas, which might be related to environmental factors, genetic factors and food intake.

Abstract:Monascus purpureus M1 with stable yield of Monacolin K preserved in the Beijing Engineering and Technology Research Center of Food Additive, was used as the starting strain, the effects of nicotinamide addition on the secondary metabolites of Monascus were investigated by ultraviolet visible spectrophotometry, ultra-high performance liquid chromatography and real-time fluorescent quantitative PCR. The results showed that the yield of red, orange and yellow pigments in the experimental group was lower than those in the control group, and the yield of Monacolin K increased 31.34% to 124.23mg/L. Electron microscope observation showed that the degree of folding of spore head and mycelium in the experimental group was significantly higher than that in the control group. Real-time fluoresent quantitative PCR showed that the expression levels of mokA, mokB, mokC, mokD, mokE, mokF, mokG and mokH genes related to the yield of Monacolin K were up-regulated, while the expression level of mokI genes was down regulated. Nicotinamide was used as additive in the experiment, and the results were expected to provide reference for the optimization of Monascus culture medium and the screening of high-yield Monacolin K products.

Abstract:The free amino acids (FAAs) are involved in the synthesis of flavor compounds in peppers. The types and contents of FAAs are closely related to pepper varieties. FAAs contents of six cultivar peppers including Dahong, Qingjian, Luosi, Xiaomi, Xiaohong and Daqing in Hunan province were analyzed by high performance liquid chromatography-tandem mass spectrometry. The results showed that the FAAs composition of different peppers was different, which provided a theoretical basis for the rational development and utilization of pepper resources. Twenty-four FAAs were identified in six peppers. Cystine was not detected in Qingjian, Luosi and Daqing, and hydroxyproline was not detected in Dahong, Xiaomi and Xiaohong. The contents of asparagine, glutamine, aspartic acid, serine, γ-aminobutyric acid, and lysine were higher than other FAAs. The content of total free amino acids in six peppers ranged from 7.28mg/g to 19.36mg/g (dry weight). The content of total free amino acids in Dahong was the highest, while the lowest was Luosi. Through the analysis of taste active value, it was found that umami amino acid was the main delicious amino acids of peppers. Glutamic acid, aspartic acid, and lysine contributed a lot to the umami taste, and other flavor amino acids played a role in coordinating the flavor. Dahong and Xiaomi were more delicious than other peppers based on taste active value. Cluster analysis showed the quality of some peppers was close, including Dahong and Xiaomi, Daqing and Qingjian, Xiaohong and Luosi. Some amino acids such as threonine and asparagine, arginine and glutamine, leucine and isoleucine, phenylalanine and proline showed a strong correlation. Combined with principal component analysis and comprehensive evaluation, the quality of FAAs in Dahong, Xiaomi and Daqing was better than that in Qingjian, Xiaohong and Luosi.

Abstract:To study the improvement of phosphorylation on calcium-binding ability of polypeptide, silkworm pupa polypeptide was phosphorylated by different kinds of phosphorylation reagents with diverse additive volume, then reacted with CaCl₂ to prepare calcium-peptide complex. The content of calcium and phosphorus, phosphorylation site, FTIR and SEM of samples were analyzed. The results showed that phosphorylation occurred between polypeptide and Na₃PO₄, NaH₂PO₄, and (NaPO₃)₆, which led to the calcium content of the calcium-peptide complex enhanced from 145.12mg/g to 202.32mg/g. The calcium-binding ability was irrelated to the kinds of phosphorylation reagents, but related to the level of phosphorylation. The calcium content first increased then decreased with the increment of phosphorylation reagents. When the mass fraction of NaH₂PO₄ was 0.50%, the binding calcium content reached maximum. Twenty-two increased phosphorylation sites were identified in 17 peptides after phosphorylation treatment by NaH₂PO₄. FTIR and phosphorylation site detection confirmed that phosphate groups were successfully grafted onto the peptide backbone through hydroxyl groups on serine and threonine. Phosphorylation could improve the calcium-binding ability of polypeptide, and provide new ideas and methods for development of effective calcium supplements.

Abstract:In order to improve the quality of highland barley flour and the taste of highland barley biscuit which is rough and difficult to swallow, the semi-solid fermentation of highland barley flour with transglutaminase was performed, and the quality of highland barley flour and the taste of highland barley biscuit were investigated. The optimum conditions were selected via evaluating swelling index of glutenin, water retention and total sugar content before and after fermentation. Sensory scores of highland barley biscuits before and after fermentation were compared. The results showed that with the conditions of fermentation temperature 25℃, enzymatic time 5h, and enzyme mass fraction 0.3%, the swelling index of glutein, water retention rate, and total sugar content were 3.36,60.70%, and 7.19mg/mL, respectively. In comparison with biscuit of highland barley, the biscuit of fermented highland barley was easy to form gluten during the making process and had better taste and pleasant aroma.

Abstract:The physicochemical properties of different heat-treated skim milk powder were compared, and it was applied to the production of brown Lactobacillus beverage. Compared with freshly prepared skim milk, the effects of different prepared skim milk and production processes on the stability of beverage were discussed. The results showed that there was no significant difference in the content of protein, fat, water and acidity in the different heat-treated skim milk powder (P>0.05), but there was significant difference in emulsibility, foamability and whey protein nitrogen index (P<0.05). The emulsibility, foamability and stability of skim milk powder decreased with the increased intensity of heat treatment. In the process of beverage production, the medium-temperature heated skim milk powder was more conducive to maintain the stability of the beverage, while the high-temperature, low-temperature heated milk powder and freshly prepared skim milk were less effective. High temperature browning process increased the particle size and centrifugal precipitation rate and decreased zeta potential and product stability. However, the homogenization treatment and volume ingredient combination improved the stability. This study provides technical reference for effectively improving the stability of the product of brown Lactobacillus beverage.

Abstract:In order to provide theoretical support and technical guidance for improving the quality of dried food, the effects of osmosis and freezing pretreatment on the drying characteristics of blueberry were investigated. In this study, blueberries were treated with different combination modes of osmosis (trehalose, calcium chloride, sucrose) and freeze-thaw (liquid nitrogen -80℃, room temperature) before the same drying treatment (hot air, 30 h, 60 ℃), and the dehydration rate, water content, color, texture, total sugar content and antioxidant active substances were determined and compared. The results showed that different combination of osmosis and freeze-thaw pretreatment had a significant effect on the physical and chemical quality of blueberry. The freezing-thawing-osmotic-drying group was the best, and compared with the single osmotic group, the single freezing-thawing group, and the untreated group, the dehydration rate was increased by 5.55%, 6.39% and 36.91%, the hardness was enhanced by 8.59%, 39.80%, 909.00%, the retention rate of total sugar content was elevated by 1.10,1.44,2.70 times, and the antioxidant activity (total phenol, anthocyanin, oxygen radical absorbance capacity) was increased by more than 16%, respectively. In conclusion, freezing-thawing treatment could improve the osmotic influence on drying characteristics of blueberry, the combination of them had significant synergy on the enhancement of drying rate and drying quality.

Abstract:To explore the effect of polysaccharide extraction by two-aqueous phase from Chinese leek seed meal, two aqueous phase of polyethylene glycol-ammonium sulfate extraction system was used to extract polysaccharide and its antioxidative activity was detected. The optimal conditions were obtained using single factor experiments and response surface methodology by Design Expert 8.06. The results indicated that the optimum extraction conditions were as follows:relative molecular mass of PEG 6000, mass fraction of PEG 14.50%, mass fraction of ammonium sulfate 20.46%. Under the optimal conditions, the extraction rate of polysaccharides from Chinese leek seed meal was 85.39%. The scavenging capacity of the polysaccharides to DPPH· and ·OH and its total reducing power was measured. The results showed that the polysaccharides from Chinese leek seed meal possessed antioxidant properties in vitro. And the antioxidant activity was enhanced gradually with the increasing concentration of polysaccharides.

Abstract:A fast and low-cost determination method of 16 EU (European Union) priority polycyclic aromatic hydrocarbons (PAHs) in smoked and roasted meat products by dispersive solid-phase extraction with ultra-low temperature liquid-liquid microextraction combined with gas chromatography-mass spectrometry (GC-MS) analysis was developed. The samples were extracted by acetonitrile, and the supernatants were purified using mixed adsorbent by dispersive solid-phase extraction and then extracted by methylbenzene using liquid-liquid microextraction at -80℃. The analytes were separated on a DB-EUPAH high resolution gas chromatography column (20m×0.18mm×0.14μm), and the data were collected by single ion monitoring mass spectrometry, followed by qualitative screening and quantitative analysis. The result showed that the linear relationship of 16 EU priority PAHs at the concentration range of 5-500μg/L were good, and the correlation coefficients were greater than 0.999. Smoked and roasted meat products were spiked at three levels, the average recoveries of 16 EU priority PAHs ranged from 75.2%-114.2% with RSDs of 1.84%-7.57% (n=6). The limits of detection (S/N=3) were 0.1-0.5μg/kg. This method was applied to detect PAHs in 40 batches of smoked and roasted meat on market, and it was found that the content of PAHs in some smoked and roasted meat exceeded the requirements of relevant standards and regulations. The detection method had the advantages including low cost, sensitive, and reliable, which also met the requirements of national standard and EU regulation for the limited detection of PAHs in smoked and roasted meat.

Abstract:The extraction of food public opinion entity relationship is the key technology for constructing the map of food sensation knowledge, and it is also an important research topic in the field of information extraction. Aiming at the entity-to-many relationship problem often appearing in food grievances, the location-aware domain-based semantic attention mechanism is introduced to the convolutional neural network (CNN) and location-aware semantic roles attention mechanism is introduced to the bidirectional long short-term memory network (BLSTM). Then, model was constructed based on CNN-BLSTM for food sentiment entity relationship extraction. In this paper, a comparative experiment was carried out on the food moisture dataset. The experimental results showed that the accuracy of the entity relationship extraction model of food public opinion based on CNN-BLSTM was higher than that of the commonly used deep neural network models. From 8.7% to 13.94%, the rationality and effectiveness of the proposed model were verified.