Acetic acid,butyric acid,octoic acid and capric acid which are the main organic acids in brandy accounting for 80% of the total wine acid,can react with alcohols affording esters,such as ethyl acetate,ethyl hexanoate,ethyl lactate,ethyl caprylic acid,capric acid ethyl ester and lauric acid ethyl ester which are the main aroma esters compounds in brandy. The present study was to investigate the effect of applying an electric field treatment on acids and esters of brandy stored in French medium toasting oak barrels. The results showed that the content of esters and acids in both barrels increased gradually with aging time,meanwhile,the EF treatment caused the reduction of acids,but enhanced the increment of esters. The results showed that the concentration of acids in brandy treated by EF was 20.1% lower than those of the control brandy after 12 months of maturation in5 L oak barrels,but esters in brandy treated by EF was 9.4% higher than those of the control brandy in 5 L oak barrels. It was demonstrated that the application of electric field treatment directly on oak barrel could increase the ester contents and decrease the acids excess generation. The mechanism was that,under the effect of electric field,the motion velocity and interaction between molecules were accelerated inducing the increase of the activity and ionization of the molecules. The activation energy required for the chemical reactions were reduced,so as to accelerate the esterification reaction,association reaction and oxidation reduction reaction,etc. And the energy of the electric field could accelerate the Brown thermal motion of the molecules in the wine,thereby promoting the diffusion of volatile matter in the bucket.
The content of Yellowhorn seed is 35% ~40%,while kernel is 59% ~73%. The Yellowhorn oil,which is known as the oil treasures,is a mixture consisted by 90 kinds of materials and the content of unsaturated fatty acid is high. Comprehensive evaluation on Shiny-leaf Yellowhorn quality provides the basis for the industrial production. The present study was to investigate the principal component and K means cluster of Shiny-leaf Yellowhorn by SPSS software. The results of the correlation analysis of crude fat content and fatty acid composition of Yellowhorn showed that the crude fat had a significantly positive correlation with oleic acid,while had a significantly negative correlation with linoleic acid. The three main components were extracted which standard for 79% information of the Yellowhorn quanlity and according to the suitability of crops,Shiny-leaf Yellowhorn was divided into 4 categories. Clustering analysis from 15 regions showed that the Shiny-leaf Yellowhorn from Zhidan and Jianpin were most appropriate for extraction the Shiny-leaf Yellowhorn oil,followed by Fangshan. The discrimination analysis of the Yellowhorn and the function model could be used to determine the suitability of the unknown Yellowhorn on the industrial production.
We conducted stored grain insects and mites trapping tests on the surface of grain bulk in a granary by corrugated board method to study the species of stored grain insects and mites trapped by the corrugated board method,and compared the species of stored grain insects and mites trapped on the surface of different kinds of grain bulk(wheat,maize,indica rice and japonica rice). The results showed that 29 species of stored grain insects and mites was trapped by the corrugated board method,including 26 species of stored grain insects(e.g.Liposcelis entomophila Enderlein, Cryptolestes ferrugineus Stephens,Tribolium castaneum Herbst,Sitophilus oryzae Linnaeus, Rhizopertha dominica Fabricius, Sitotroga cereatella Olivier and Lariophagus distinguendus Forster) and 3 species of mites(e.g. Cheyletus fortis Oudemans). The corrugated board method could trap different species of stored grain insects and mites on the grain surface of different kinds of grain,wherein 24 species of stored grain insects and mites were trapped on the surface of indica rice bulk,which were larger than those of wheat(15),japonica rice(9) and maize(5). The corrugated board method can be used for trapping the main stored grain insects and mites on the surface of grain bulk,and can be used for monitor and control of stored grain insects and mites on the surface of grain bulk in China because of its low cost,high use convenience,and wide spectrum of trapped insects.
The granary environment quality classification granary is one of the important methods for evaluating modern granary quality management. This paper analyzed the factors affecting grain storage safety,and focused on the important parameters influencing granary environment quality grading,such as temperature,humidity,harmful gas,and insect damage. We also constructed an artificial neural network model of the four factors by computer neural network technology to evaluate and classify granary environment scientifically and objectively.
As a financial intermediary target,M2 /GDP has always been highly concerned by scholars.In re-cent years,China’s M2 /GDP has been increased year by year,and domestic scholars analyze the causes of the higher M2 /GDP as well as the consequences it is likely to bring about from different angles.In order to ex-plore whether the M2 /GDP is really high in China,the paper first analyzes the world average level of M2 /GDP and compares the M2 /GDP situation in different countries.Based on this analysis,the paper compares the M2 /GDP of China with that of the developed economies,the BRIC countries,and Asian countries,analyzes the status of M2 /GDP in China and the reasons for its growth,and then provides the basis for the government to formulate a reasonable monetary policy.
Flaxseed gum is a kind of natural polymer,which contains polysaccharide,protein and mineral elements. It has many functions,such as viscosity,water holding,emulsification and emulsification stability,foaming and foam stability. The properties of flaxseed gum are greatly affected by temperature. The present study was to investigate the effect of the extraction temperature on the composition,color and viscosity of flaxseed gum.Through the study of the rheological properties of at different temperatures,the gel properties of the flax seed were determined. The results showed that in a relatively short extraction time,the content of polysaccharide and protein in the gel increased with the temperature increasing;the content of polysaccharide was decreased in the long time extraction. The consistency coefficient and flow index of the flaxseed gum were different at the different extraction temperatures. The viscosity of flaxseed gum solution greatly depended upon temperature,and the viscosity of the gum was obviously asymmetry during cooling and heating. Furthermore,the gelling properties of flaxseed gum were also measured. The flaxseed gun solution could form a kind of heat reversible gel,and the change of sol-gel of flaxseed gum showed a hysteresis phenomenon on the temperature.
Pancreatin is a kind of mixed enzyme containing trypsin, lipase and amylase and other bioactive substances, which is extracted from animal pancreas. The present study was to investigate the optimal extraction conditions using chicken pancreas as raw material and the effect of the extraction temperature, p H value,extraction time and the concentration of extraction solvent on the pancreatin activity. The activities of pancreatic amylase, pancreatic lipase and pancreatic trypsin were determined according to the method of pancreatin of the Chinese pharmacopoeia. The single factor experiment analysis, four factors and three levels orthogonal experimental design were carried on in this study. The results showed that the optimum conditions for chicken pancreatin extraction were as follows: extracting or activating p H value of 7, extraction time of 5 h, temperature of 10 ℃, isopropyl alcohol concentration of 7.5%, activators of 0.2% calcium chloride, protective solvent of0.5% maltose and 0.5% potato starch, the precipitating solvent isopropyl alcohol concentration of 60%. Under these conditions, the extraction yield of pancreatin was 9.2%, the residual amount of fat was 18.99 mg·g-1, and the dry weight loss was 3.86%, while the activity of pancreatic lipase, pancreatic amylase and pancreatic trypsin were 13 800 U /g, 11 600 U/g, 1 596 U/g, respectively. The enzyme activity met the Chinese pharmacopoeia standard. It was concluded that it was reasonable and effective to extract chicken pancreatin with organic solvent isopropanol as the extraction and precipitant agent.
A PVC Cr( III) ion selective electrode based on N-( benzo[ d][ 1,3] dioxol-5-ylmethylene)-1H-bezon[ d] imidazole-2-carbohydrazide( L) has been prepared. The results show that the electrode is high sensitive and selective to Cr3+. The response slope is 22.9 m V/decade in the range of 10-1~10-6mol/L with the detection limit of4.6 ×10-7mol/L. The electrode is reproducible and stable, and could work in a certain concentration aqueous ethanol solution( volume percentage 20%) and certain range of p H( 1.13~6.15). The proposed electrode has been used for the determination of Cr3+ions in water samples and as an indicator electrode in potentiometric titration of Cr3+ions with EDTA.
The total flavonoids were extracted from Pholidota Chinensis Lindl(PCL) by hot leaching method using ethanol as the solvent. Based on the results of single factor experiments,we designed four-factor three-level experiments according to Box-Behnken central composite design,and conducted response surface analysis by Design-Expert 8.05 b to establish an extraction rate regression equation of total flavonoids of Pholidota Chinensis Lindl. The regression equation was reasonable and reliable by experimental verification,and could well predict the extraction rate of total flavonoids of Pholidota Chinensis Lindl. The extraction process optimization results showed that the extraction temperature had the largest impact on the extraction rate of total flavonoids and secondly was the ethanol volume fraction; the extraction time and the material-to-liquid ratio had less impact; and the highest extraction rate of total flavonoids obtained under the conditions of extraction temperature 66 ℃,ethanol volume fraction 65%,material-to-liquid ratio 30 m L·g-1,and extraction time 151 minutes was 1.23%,which was similar to the theoretical value(1.24%),and the relative error was 0.81%. Tests verify the effectiveness of the model.
泡沫分离技术作为一种新型的分离浓缩方法,目前已经广泛应用于食品工业中.主要综述泡沫分离技术在蛋白质与酶、糖及皂苷类有效成分的分离提取中的应用现状,指出了泡沫分离技术目前存在的问题及发展趋势.
β-sitosterol widely exists in various kinds of vegetable oils, nuts and other plant seeds, has comprehensive pharmacological activities,such as reducing serum cholesterol,anti-inflammatory, antipyretic,antioxidant,antitumor and anti-cancer,and has also extensive use in food,health products and cosmetics industry.In recent years,a great amount of work on the structure modification and biological activities of β-sitosterol has been done intensively. A series of β-sitosterol derivatives were synthesized. Herein, the research reviewed the progress on structure modification of β-sitosterol.
We constructed a dynamic pipe system through small laboratory membrane filtration equipment to simulate the flowing condition of dairy processing pipes,observed morphology of biofilms on the pipe wall by scanning electron microscopy,stripped the biofilms on the pipe wall by ultrasonic concussion,and studied the morphology and microbial populations of the biofilms. The results showed that a composite multilayer biofilm composed of a large amount of coccus,bacillus and extracellular products was formed on the pipe wall after12-hours operation of the equipment;and the biofilm on the pipe wall of the membrane filtration equipment was mainly composed of Lactobacillus lactis, Lactobacillus plantarum, Streptococcus lactis,Leuconostoc lactis,Staphylococcus aureus,Bacillus cereus and Bacillus stearothermophilus.
The wall of a reinforced concrete underground granary is under the action of various loads,including pressure of stored materials, soil, and water, deadweight and so on, so that the wall has complex bearing characteristics. Selecting an empty underground granary under water and soil pressures as the most adverse condition,we calculated the wall bearing capacity by cylindrical shell model with a fixed lower and a simply supported upper and finite element analysis method. We studied the wall bearing characteristics of the reinforced concrete underground granary,and analyzed vertical bending moment and circumferential force distribution rule of the wall based on the calculation results of the above two methods. The results showed that the force conditions at the junctions between the wall and the top and between the wall and the bottom of the reinforced concrete underground granary were complex because of the edge constraint effect;and we recommend finite element analysis method as the proper method.
We discussed the anti-aging effect of polysaccharides in mushroom from different places on subacute aging model mice. We prepared aging mice models by injecting D-galactose,and randomly grouped the models to a normal group,a model group, Inner Mongolia mushroom polysaccharide groups(low-,medium- and high-dose),Zhangjiakou mushroom polysaccharide groups(low-,medium- and high-dose),and a positive control group. We determined the learning ability of the mice by Morris water maze test after consecutive intragastric administration for 30 days,and studied the effects of mushroom polysaccharides on SOD(superoxide dismutase)activity,CAT(catalase) activity and MDA(malondialdehyde) content in serum,liver and brain tissue of mice.The results showed that the learning ability of mice of the Inner Mongolia mushroom polysaccharide groups and the Zhangjiakou mushroom polysaccharide groups was improved(P0.05);and mushroom polysaccharides could enhance the activities of SOD and CAT in serum,liver and brain tissue,and remarkably reduce the MDA content. The indexes of mice of the Inner Mongolia mushroom polysaccharide groups and the Zhangjiakou mushroom polysaccharide groups of the same dose had no obvious remarkable difference.
The paper analyzes the problems in the security of food rations through an awareness of the new strategy for national food security. It proposes the countermeasures to protect the safety of food rations and dis-cusses the roles and responsibilities Henan Province bears as the major grain producing area in China.
Taking raw flaxseed meal as starting material,we studied the flaxseed protein separation process by foam separation method. We applied response surface methodology to study the optimum foam separation condition;and the optimum foam separation parameters were as follows: mass concentration of flaxseed meal solution 1.8 mg·m L-1,p H 3.0,solution loading amount 190 m L,and Na Cl mass fraction 0.75%. Under the optimum conditions, the enrichment ratio and the yield of flaxseed protein reached 9.80 and 95.8%,respectively. The result indicates the foam separation technology can realize separation and purification of flaxseed protein from raw flaxseed meal,and is effective in preliminary separation of flaxseed protein.
A novel method of preparing interpenetrating networks(IPN) hydrogels was reported. First,hydroxypropylmethylcellulose(HPMC) was modified by 3-[(furan-2-ylmethyl)carbamoyl] propanoic acid(SFA)and 2-maleimidopropionic acid(AMI) respectively to synthesize hydroxypropyl methyl cellulose(HPMC)containing diene group and dienophile group, i.e. HPMC-SFA and HPMC-AMI. Second,HPMC-AMI,HPMC-SFA,the monomer of N-isopropylacrylamide,the crosslinker of poly(ethyleneglycol) dimethacrylate and the photoinitiator were dissolved in water,and then temperature was increased to 50 ℃ and kept for 4.5 h to form a first network through Diels-Alder reaction. Third,the monometer and the crosslinker were exposed to the UV light and polymerized to form a second network. The hydrogels were characterized by FTIR, SEM and rheometer. The results of swelling dynamic performance study showed that the hydrogel microspheres had good swelling property,and the swelling degree was reduced as the temperature rose. Based on the advantages of Diels-Alder reaction and photopolymerization,the IPN hydrogels preparation method reported by the paper has wide application prospect in preparing biomaterials.
The paper studied the effects of oregano oil,carvacrol,cinnamaldehyde,and citral on the moisture sorption property of edible carrot puree film. Results showed that the carrot puree film had a reverse S-shaped moisture sorption isotherm;the moisture content of the carrot puree film increased slowly as the humidity rose when water activity(aw) was equal to or smaller than 0.69; the moisture content of the carrot puree film increased rapidly as the humidity rose when the water activity(aw) was larger than 0.69;and the moisture content of the carrot puree film decreased slightly with the increase of the content of oregano oil,carvacrol,cinnamaldehyde,and citral. The carrot puree film can be used for food processing as edible package materials or coating materials.
As edible packaging materials,soy protein isolate(SPI) films have its own unique superiority,but the problem to be solved is the film stability. This research mainly studied the changes on moisture content and mechanical properties of the SIP films during storage. Results showed that relative humidity( RH),storage mode(room temperature,chilled,frozen),and glycerol addition amount affected the moisture content and mechanical properties of SPI films. During storage,the moisture changed in the SPI films during storage is mainly the intermediate water. In addition,change on moisture content is the major factor affecting the mechanical properties.
Piperic acid ethyl ester is prepared from piperic acid under the refluxed conditions.Take its yield as an indicator,the single factor and orthogonal tests are used to optimize the synthesis conditions of piperic acid ethyl ester.The optimal reaction conditions are as follows:p-toluene sulfonic acid is chosen as catalyst,the mass of catalyst is 0.15 g,the reaction time is 6.0 h,the reaction temperature is 95 ℃,and the yield is above 80%.The preparation process of piperic acid ethyl ester is simple,feasible and of good stability.
