2015, 33(1):1-5. DOI: 10.3969/j.issn.2095-6002.2015.01.001
Abstract:Flavonoids are plant secondary metabolites, which are valuable natural products widely used in human health and nutrition due to its biochemical properties such as antiviral, antiobesity, and anticancer. The efficient production of pure flavonoid compounds through plant extraction or chemical production continues to be a major challenge for drug development. Hence, the microbial production of flavonoids has emerged as an interesting and commercially attractive approach. The emergence of systems metabolic engineering offers new perspectives on strain and process optimization. In this review, the strategies of systems metabolic engineering used to overcome these challenges are summarized, which will offer insights into overcoming the limitations and challenges of large-scale microbial production of these important pharmaceutical compounds.
2015, 33(1):6-12. DOI: 10.3969/j.issn.2095-6002.2015.01.002
Abstract:Oil frying is a good method for fried food flavor, process, and popularity. However, it also results in many issues of quality and safety. The main challenges of frying oils are prompt and efficient evaluation for frying process, determination of frying oil authenticity, and reduction and removal of the harmful compounds by frying. The current demands for the safety and quality of Chinese fried foods are to reduce oil content in fried products, control aluminum level in traditional fried foods, and prevent deterioration of fried foods during frying and preservation. Based on the main safety problems and their reasons, this paper reviewed a number of solutions, including new detection technology, big data technology, science popularization for teenagers, risk assessment, administration and sharing platform.
2015, 33(1):13-17, 24. DOI: 10.3969/j.issn.2095-6002.2015.01.003
Abstract:Sesame oil is edible oil with rich nutrients. The varieties of production processes lead to discrepancies in product qualities and the lose of nutrients. Moreover, there were contradictory problems between dietary habits and product qualities of sesame oil. The management of the market was passive due to the timeliness and deviation of the detection technology. Building up the standards of the production process and product qualities was the effective method to solve the problems.
2015, 33(1):18-24. DOI: 10.3969/j.issn.2095-6002.2015.01.004
Abstract:The radioprotective effects and molecular mechanisms of black tomato powder (BTP) in mice were investigated in this study. ICR mice irradiated by 5Gy 60Coγ were treated with BTP (1.5,3.0, and 4.5g/kg body weight). After 14 days' treatment, thymus and spleen indices, white blood cells' number (WBC), bone marrow cells' number, spleen lymphocytes, cytokine levels, NF-κB, and I-κB were investigated. The results revealed that the thymus index was significantly(P<0.05)higher in mice treated by 4.5g/kg BTP while mice in the 3.0 g/kg BTP treatment group had the significantly(P<0.05)higher bone marrow cells' number compared with the irradiation (IR) control group. Compared with the IR control group, the spleen lymphocytes in the 1.5g/kg BTP treatment group were significantly(P<0.01)different. The 4.5g/kg BTP treatment also inhibited the increasing of IL-1α和IL-10. Moreover, the 3.0g/kg and 4.5g/kg BTP treatment decreased the hepatic MDA contents and increased the hepatic GSH-Px and SOD contents. Meanwhile, the 4.5g/kg BTP treatment could also increase the serum SOD content. The radioprotective effects of BTP might be due to the modulation of the expression of NF-κB and I-κB, which could further modulate the proinflammatory cytokines release and immune responses.
2015, 33(1):25-31. DOI: 10.3969/j.issn.2095-6002.2015.01.005
Abstract:The study aimed to investigate effects of procyanidine on rats treated by iron overload under the condition of simulated weightlessness. Simulated weightlessness was simulated by hind limb unloading rats, which maintained about -30° head down tilt position and freely took food and water. Iron overload was administrated by giving 5 doses (one dose every two days) intraperitoneal injection of iron-dextran at a dose of 100mg/(kg·bodyweight) while correspondingly the other rats received the isovolumic injection of saline. Treatment of procyanidine was conducted by gavage of procyanidine dissolved in water at a dose of 40 mg/(d·(kg·bodyweight)-1). After 11-day treatment, the changes of body weight, concentration of hemoglobin, and serum ferritin were sued to estimate the models. Body weight, concentration of hemoglobin, red blood cell, serum ferritin, liver sections, and femur were used to estimate the effects of procyanidine on rats. Results showed that iron overload and simulated weightlessness had synergetic effects on the health of rats. Procyanidine did not inhibit the decrease of body weight, the increase of hemoglobin and serum ferritin, the iron deposition in liver, and the loss of bone volume fraction induced by iron overload under the condition of simulated weightlessness.
2015, 33(1):32-37. DOI: 10.3969/j.issn.2095-6002.2015.01.006
Abstract:The diversity of culturable endophytes in wild Noni leaves from Paracel Islands was discussed in this study. Strains were isolated by using conventional tablet separation methods. The isolates were identified by the fungal internal transcribed spacer 1 and 2 (ITS gene) amplification and the bacterial 16S rDNA amplification, combined with phylogenetic analysis. Total 32 endophytes were isolated and identified as 19 types. Two types of mold were Chaetomium sp. and Nemania sp. Seventeen types of bacteria (30 strains) belonged to 7 genera Bacillus sp., which were Lysinibacillus sp., Micrococcus sp., Terribacillus sp., Enterobacter sp., Xanthomonas sp., Flavobacterium sp., and Bacillus sp.. Bacillus sp. was the dominant genus among the endophytic bacte, which had 20 strains divided into 11 types.
2015, 33(1):38-42, 48. DOI: 10.3969/j.issn.2095-6002.2015.01.007
Abstract:The influence of deacification on the sensory quality of Italian Riesling dry white wine in Yangling, Shanxi was studied. After alcohol fermentation, wine was deacidified by different amounts of calcium carbonate. and wine color was evaluated by detecting CIELab parameters. Wine aroma characteristics were analyzed and quantified by trained panelists. The total sensory analysis of sample wines was also made. Data were processed by principal component analysis (PCA) to show the influence of different amounts of calcium carbonate on wine color and aroma. Wine treated by 0.5g/L calcium carbonate retained the most aroma, and its total sensory score was the highest. After treated by 1.0g/L and 1.5g/L calcium carbonate, wine had much sweet flavor, less fresh fruity, and lower total sensory score. Meanwhile, wine treated by 2.0g/L calcium carbonate lost most fresh fruity and had the lowest total sensory score. Therefore, the optimum concentration of calcium carbonate for the deacidification of Italian Riesling dry white wine in Yangling was 0.5g/L.
2015, 33(1):43-48. DOI: 10.3969/j.issn.2095-6002.2015.01.008
Abstract:A strain named P3-2 with the ability to produce protease was isolated from castor bean meal and laboratory preservation by the casein plate culture method and enzyme activity detection. The optimal fermentation conditions were investigated. The optimum carbon and nitrate sources were maltose and castor bean meal. Meanwhile, the yield of protease was increased by adding Na+ and one peak of the protease yield was obtained when the initial pH value of medium was 7.5. Moreover, the optimum amount of inoculum was 4% and there were two peaks of the protease yield when culture time was 36 h and 84 h. Through the orthogonal experiment, the optimum compositions of medium were as follows:2.0% maltose, 1.0% castor bean meal, and 1.0% NaCl.
2015, 33(1):49-54. DOI: 10.3969/j.issn.2095-6002.2015.01.009
Abstract:Chemical fingerprint is a comprehensive and quantifiable quality control method. In recent yeas, the chemical fingerprint technique was applied more and more in the identification of quality, authenticity, variety, and origin of tea. The main techniques and data analysis methods to establish the tea chemical fingerprint technique were reviewed in this paper. Meanwhile, the problems and development prospect of the application of chemical fingerprint in tea were pointed.
2015, 33(1):55-58. DOI: 10.3969/j.issn.2095-6002.2015.01.010
Abstract:Fresh-cut yam was easily oxidized in the air and produced brown pigment, which affected its quality. The effects of EDTA-2Na, NaCl, citric acid (CA), and Vc on the color of fresh-cut Chinese yam were studied by the single-factor experiment and the optimum concentrations of color fixative were obtained. The uniform design was used to optimize color-protecting formula of fresh-cut Chinese yam. The optimize color-protecting formula was as follows:EDTA-2Na 0.8%, citric acid 2.0%, and Vc 0.2%. Meanwhile, effects of different pretreatment methods, such as disinfection using different concentrations (0.005% and 0.010%) NaClO and 65℃ blanching, on fresh-cut Chinese yam were also studied .The result showed that the NaClO disinfection and 65℃ blanching treatment all could protect the color of fresh-cut Chinese yam and 0.005% NaClO had better effect than 0.010% NaClO.
2015, 33(1):59-64. DOI: 10.3969/j.issn.2095-6002.2015.01.011
Abstract:In order to investigate effects of different drying methods on the nutritional quality of walnuts, the fresh walnuts were dried by the changeable-temperature hot air drying and far-infrared radiation drying methods and the conventional hot air drying method was used as the control. The nutrition functional component and quality stability of walnuts stored at room temperature were compared. The results showed that the far-infrared drying method could half decrease the dry time compared with the control method when the water content of walnuts was 4%. After 6-month storage, the contents of oleic acid, linoleic acid, and linolenic acid of walnuts dried by the changeable-temperature hot air method were reduced 9.59%, 10.58%, and 12.71%, respectively. As for walnuts dried with the far-infrared radiation method, they were reduced 7.49%, 7.34%, and 6.77%, respectively and the contents of oleic acid, linoleic acid, and linolenic acid of walnuts in the control group were reduced 14.44%, 11.79%, and 15.50%, respectively. The peroxide values of walnuts treated by the changeable-temperature hot air method, far-infrared radiation method, and the conventional hot air drying method were 0.88,2.94, and 0.60meq/kg, respectively while the carbonyl values of walnuts treated by the three methods were 2.08,0.98, and 3.52meq/kg, respectively. Compared with the conventional hot air drying method, the far infrared-assisted hot air drying method not only reduced the drying time but also retarded the development of oxidative rancidity, and improved the quality of walnuts.
2015, 33(1):65-68. DOI: 10.3969/j.issn.2095-6002.2015.01.012
Abstract:The main nutrition components and physico-chemical properties of oatmeal treated by different dosages irradiation (0 to 9kGy) were evaluated in this study. The results showed that the lowest fat content and the highest moisture content was 7.7% and 9.72% when the irradiation dosage was 2kGy. The viscosity, protein content, and starch content decreased with the increasing irradiation dosages. Additionally, the starch content was slightly decreased when the irradiation dosage was lower than 6kGy. The color was not affected by the irradiation treatment. The irradiation treatment degraded the long-chain compounds, but the physico-chemical properties of the short-chain compounds were not changed.
2015, 33(1):69-74. DOI: 10.3969/j.issn.2095-6002.2015.01.013
Abstract:Purge and trap (P&T) was used to extract volatile compounds in Ghana cocoa butter and cocoa mass and gas chromatography-mass spectrometry (GC-MS) was used to identify volatile compounds. Fifty compounds were identified, which were aldehydes, acids, alcohols, esters, pyrazines, ketones, thioethers, olefinic aldehydes, furans,pyrroles, and so on. Cocoa butter had 44 compounds while cocoa mass had 40 compounds. The volatile compounds contents in cocoa butter and cocoa mass were analyzed using the semi-quantitative method by adding the internal standard. The results showed that most compounds had higher levels in the cocoa butter, while the contents of acids(acetic acid,3-methylbutanoic acid), aldehydes (2-methylpropanal,3-methylbutanal ), and aldehydespyrazines (trimethylpyrazine, tetramethylpyrazine, 2,5/6-dimethylpyrazine) were particularly prominent.
2015, 33(1):75-78. DOI: 10.3969/j.issn.2095-6002.2015.01.014
Abstract:In view of the current actual situation of pesticide residues of fruits and vegetables, the necessity of fruits and vegetables cleaning was expounded. The status and application of the fruits and vegetables cleaning technology were analyzed. The inadequacy of the typical domestic products was found out according to their technical characteristics. The research of fruits and vegetables deep cleaning technology was pointedly carried out. Meanwhile, the complete set of engineering design was proposed and verified by testing. A new way was provided for ensuring food safety.