Theabrownins(TBs)are the characteristic functional and quality components of dark teas such as Pu’er tea and Chin-brick tea.TBs are a class of water-soluble brown polymers with multi-molecular weight distribution pro...Theabrownins(TBs)are the characteristic functional and quality components of dark teas such as Pu’er tea and Chin-brick tea.TBs are a class of water-soluble brown polymers with multi-molecular weight distribution produced by the oxidative polymerisation of tea polyphenols during the fermentation process of dark tea,both enzymatically and non-enzymatically.TBs have been extracted and purified from dark tea all the time,but the obtained TBs contain heterogeneous components such as polysaccharides and caffeine in the bound state,which are difficult to remove.The isolation and purification process was tedious and required the use of organic solvents,which made it difficult to industrialise TBs.In this study,epigallocatechin(EGC),epigallocatechin gallate(EGCG),epigallocatechin gallate(ECG),EGC/EGCG(mass ratio 1:1),EGCG/ECG(mass ratio 1:1),EGC/ECG(mass ratio 1:1)and EGC/EGCG/ECG(mass ratio 1:1:1)as substrates and catalyzed by polyphenol oxidase(PPO)and peroxidase(POD)in turn to produce TBs,named TBs-dE-1,TBs-dE-2,TBs-dE-3,TBs-dE-4,TBs-dE-5,TBs-dE-6 and TBs-dE-7.The physicochemical properties and the antibacterial activity and mechanism of TBs-dE-1–7 were investigated.Sensory and colour difference measurements showed that all seven tea browning samples showed varying degrees of brownish hue.Zeta potential in aqueous solutions at pH 3.0–9.0 indicated that TBs-dE-1–7 was negatively charged and the potential increased with increasing pH.The characteristic absorption peaks of TBs-dE-1–7 were observed at 208 and 274 nm by UV-visible(UV-vis)scanning spectroscopy.Fourier transform infrared(FT-IR)spectra indicated that they were phenolic compounds.TBs-dE-1–7 showed significant inhibition of Escherichia coli DH5α(E.coli DH5α).TBs-dE-3 showed the strongest inhibitory effect with minimum inhibitory concentration(MIC)of 1.25 mg mL–1 and MBC of 10 mg mL–1,followed by TBs-dE-5 and TBs-dE-6.These three TBs-dEs were selected to further investigate their inhibition mechanism.The TBs-dE was found to damage the extracellular membrane of E.coli DH5α,causing leakage of contents,and increase intracellular reactive oxygen content,resulting in abnormal cell metabolism due to oxidative stress.The results of the study provide a theoretical basis for the industrial preparation and product development of TBs.展开更多
Iron deficiency anemia(IDA)is a major global health problem.Tegillarca granosa has been considered as an excellent source of iron given its high content of iron-binding protein,ferritin.The aim of the present study wa...Iron deficiency anemia(IDA)is a major global health problem.Tegillarca granosa has been considered as an excellent source of iron given its high content of iron-binding protein,ferritin.The aim of the present study was to determine the physicochemical properties,protein structures,and iron uptake of ferritin extracted from T.granosa,and to evaluate the potential impacts of chitosan glycosylation on these characteristics.Based on Box-Behnken design and response surface methodology,the optimal conditions for glycosylation included a ferritin/chitosan mass ratio of 4:1,a pH of 5.5,a reaction time of 10 min,and a reaction temperature of 50℃.Glycosylation caused decreased surface hydrophobicity and elevated water-holding capacity of ferritin due to the introduction of hydrophilic groups.Additionally,glycosylation improved antioxidant capacity of ferritin by 20.69%–189.66%,likely owing to the protons donated by saccharide moiety to terminate free radical chain reaction.The in vitro digestibility of ferritin was elevated by 22.56%–104.85%after glycosylation,which could be associated with lessβ-sheet content in secondary structure that made the glycosylated protein less resistant to enzymatic digestion.The results of the iron bioavailability in Caco-2 cells revealed that ferritin(78.85–231.77 ngmg^(−1))exhibited better iron bioavailability than FeSO4(51.48–114.37 ngmg^(−1))and the values were further elevated by glycosylation with chitosan(296.23–358.20 ngmg^(−1)),which may be related to the physicochemical properties of ferritin via glycosylation modification.These results provide a basis for the development of T.granosa derived ferritin and its glycosylated products,and can promote the utilization of aquatic resources.展开更多
Crop rotation periodicity has always been one of the research focuses currently. In this study, the physicochemical properties, nutrient contents and enzyme activities were investigated in soils from rice-cherry tomat...Crop rotation periodicity has always been one of the research focuses currently. In this study, the physicochemical properties, nutrient contents and enzyme activities were investigated in soils from rice-cherry tomato rotation for one year (1a), three years (3a), five years (5a), seven years (7a) and ten years (10a), respectively. The major objective was to analyze the optimal rotation years of rice-cherry tomato from soil perspective, so as to provide theoretical basis for effectively avoiding continuous cropping obstacles of cherry tomato via studying the response characteristics of soil physicochemical properties, nutrient contents and enzyme activities to planting years of rice-cherry tomato rotation system. The results were as follows: 1) Soil pH value was increased year by year during 1a to 5a, reached the highest value 5.32 at 5a. However, soil acidity was sharply enhanced during 7a to 10a (P P •kg<sup>-1</sup> at 5a. 3) The content of soil available phosphorus was increased year by year with increasing of crop rotation years, and increased by 110% to 173% during 3a to 10a (P P P < 0.05). In conclusion, long-term single rotation pattern of rice-cherry tomato would aggravate soil acidification, prompt soil nutrient imbalance and reduce soil enzyme activity. 5a to 7a would be the appropriate rotation period for rice-cherry tomato, or else it would reduce soil quality, resulting in a new continuous cropping obstacle of cherry tomato.展开更多
The development of advanced air transportation has raised new demands for high-performance liquid hydrocarbon fuels.However,the measurement of fuel properties is time-consuming,cost-intensive,and limited to the operat...The development of advanced air transportation has raised new demands for high-performance liquid hydrocarbon fuels.However,the measurement of fuel properties is time-consuming,cost-intensive,and limited to the operating conditions.The physicochemical properties of aerospace fuels are directly infl uenced by chemical composition.Thus,a thorough investigation should be conducted on the inherent relationship between fuel properties and composition for the design and synthesis of high-grade fuels and the prediction of fuel properties in the future.This work summarized the eff ects of fuel composition and hydrocarbon molecular structure on the fuel physicochemical properties,including density,net heat of combustion(NHOC),low-temperature fl uidity(viscosity and freezing point),fl ash point,and thermal-oxidative stability.Several correlations and predictions of fuel properties from chemical composition were reviewed.Additionally,we correlated the fuel properties with hydrogen/carbon molar ratios(n H/C)and molecular weight(M).The results from the least-square method implicate that the coupling of H/C molar ratio and M is suitable for the estimation of density,NHOC,viscosity and eff ectiveness for the design,manufacture,and evaluation of aviation hydrocarbon fuels.展开更多
Soil microorganisms and physicochemical properties are considered the two most influencing factors for maintaining plant diversity.However,the operational mechanisms and which factor is the most influential manipulato...Soil microorganisms and physicochemical properties are considered the two most influencing factors for maintaining plant diversity.However,the operational mechanisms and which factor is the most influential manipulator remain poorly understood.In this study,we examine the collaborative influences of soil physicochemical properties(i.e.,soil water,soil organic matter(SOM),salinity,total phosphorus and nitrogen,pH,soil bulk density and fine root biomass)and soil microorganisms(fungi and bacteria)on plant diversity across two types of tree patches dominated by big and small trees(big trees:height≥7 m and DBH≥60 cm;small trees:height≤4.5 m and DBH≤20 cm)in an arid desert region.Tree patch is consists of a single tree or group of trees and their accompanying shrubs and herbs.It was hypothesized that soil physicochemical properties and microorganisms affect plant diversity but their influence differ.The results show that plant and soil microbial diversity increased with increasing distances from big trees.SOM,salinity,fine root biomass,soil water,total phosphorus and total nitrogen contents decreased with increasing distance from big trees,while pH and soil bulk density did not change.Plant and soil microbial diversity were higher in areas close to big trees compared with small trees,whereas soil physicochemical properties were opposite.The average contribution of soil physicochemical properties(12.2%-13.5%)to plant diversity was higher than microbial diversity(4.8%-6.7%).Salinity had the largest negative affect on plant diversity(24.7%-27.4%).This study suggests that soil fungi constrain plant diversity while bacteria improve it in tree patches.Soil physicochemical properties are the most important factor modulating plant diversity in arid desert tree patches.展开更多
A major challenge in modern rice production is to achieve the dual goals of high yield and good quality with low environmental costs.This study was designed to determine whether optimized nitrogen(N)fertilization coul...A major challenge in modern rice production is to achieve the dual goals of high yield and good quality with low environmental costs.This study was designed to determine whether optimized nitrogen(N)fertilization could fulfill these multiple goals.In two-year experiments,two high yielding‘super’rice cultivars were grown with different N fertilization management regimes,including zero N input,local farmers’practice(LFP)with heavy N inputs,and optimized N fertilization(ONF).In ONF,by reducing N input,increasing planting density,and optimizing the ratio of urea application at different stages,N use efficiency and the physicochemical and textural properties of milled rice were improved at higher yield levels.Compared with LFP,yield and partial factor productivity of applied N(PFP)under ONF were increased(on average)by 1.70 and 13.06%,respectively.ONF increased starch and amylose content,and significantly decreased protein content.The contents of the short chains of A chain(degree of polymerization(DP)6-12)and B1 chain(DP 13-25)of amylopectin were significantly increased under ONF,which resulted in a decrease in the stability of rice starch crystals.ONF increased viscosity values and improved the thermodynamic properties of starch,which resulted in better eating and cooking quality of the rice.Thus,ONF could substantially compensate the negative effects caused by N fertilizer and achieve the multiple goals of higher grain quality and nitrogen use efficiency(NUE)at high yield levels.These results will be useful for applications of high quality rice production at high yield levels.展开更多
The physicochemical properties of the system, such as density, surface tension, specific conductance and melting point were measured. The results were discussed.
Moringa oleifera is a plant that successfully grows recently in Egypt and has rich of nutrients seeds with valuable content of edible oil. The present study aimed at determining the physicochemical properties of morin...Moringa oleifera is a plant that successfully grows recently in Egypt and has rich of nutrients seeds with valuable content of edible oil. The present study aimed at determining the physicochemical properties of moringa seeds and their extracted oil of which cultivated at different regions in Egypt. Obtained results revealed that protein, lipid, ash, fiber and total carbohydrate contents were in range of 34.51% - 36.5%, 28.62% - 30.06%, 4.22% - 5.06%, 10.92% - 12.16% and 19.00% - 20.29%, respectively. Consequently, caloric value was around 450.36 - 451.32 kcal 100 g<sup>-1</sup> for dried moringa seeds. As confirmed, dried moringa seeds are considered as a rich source of dietary minerals. TPCs content of M. oleifera seed were ranged from 16.9 - 18.5 mg GAE g<sup>-1</sup> dw. The anti-oxidants activity was in a range of 0.17 - 0.28 μmol TE g<sup>-1</sup> dw (DPPH scavenging activity) and was in a range of 4.19 - 6.29 μmol TE g<sup>-1</sup> dw (DPPH scavenging activity). The chlorophyll a, chlorophyll b, carotenoids, flavonoids and flavonols contents were ranged from 0.93 to 1.78, 4.89 to 8.41, 13.53 to 19.56 mg g<sup>-1</sup> dw, 3.30 to 5.40 and 2.30 to 4.10 mg QE g<sup>-1</sup> dw, respectively. Obviously, the individual essential amino acids (EAAs) and nonessential amino acids (NEAAs) recorded higher contents when compared to referenced protein. Total AA showed in triple amount in moringa protein when compared FAO standard. The acid value, iodine value, unsaponificable matter, peroxide value, refractive index, saponification value of cold pressed moringa seeds oil found to be 0.29 - 0.37 mg·g<sup>-1</sup>, 65.7 - 67.5, 0.60 to 0.74 g 100 g<sup>-1</sup>, 1.67 - 2.47 mEq/Kg, 1.4607 - 1.4613, 171.7 to 178.3 mg KOH g<sup>-1</sup>, respectively. Clearly, the unsaturated fatty acids (USFA) contents of M. oleifera edible oils were 77.14% - 84.98%, especially oleic (73.30% - 79.58%). On the contrary, the saturated fatty acids (SFA) recorded 15.00% - 22.83% where palmitic and stearic acids were the predominant SFA. The results of oil physicochemical parameters were compared with those of commercial oils. It could be illustrated that moringa seeds and its oil considered as a good source for dietary nutraceuticals and valuable characteristics for potential nutritional and technological applications.展开更多
The pulsed corona discharge(CD)generated in contact with water and directly in water,and high-power air plasma jet(APJ)were studied for production of plasma activated water(PAW).The changes of physical(pH,redox potent...The pulsed corona discharge(CD)generated in contact with water and directly in water,and high-power air plasma jet(APJ)were studied for production of plasma activated water(PAW).The changes of physical(pH,redox potential,conductivity,temperature)and chemical(peroxides,nitrites,nitrates concentrations)properties of treated water were investigated.The comparison of CD generated in gas/water interface and underwater configuration in the same system showed that the interaction of reactive oxygen and nitrogen species formed in ambient air in gas/water system induces different chemical processes,leading to lower pH,higher oxidation-reduction potential(ORP)and higher conductivity of PAW than in underwater discharge.High yield of peroxide was observed in both configurations.The PAW prepared by APJ exhibits high concentration of nitrites and nitrates according to supplied energy,and related significant decrease of pH and increase of ORP and conductivity after treatment.The antimicrobial effect of PAW prepared by CD and plasma jet on lentils sprouts was studied in different treatment and washing times.The APJ appears to have great efficacy on water activation resulted in strong decontamination effect.The PAW treated by APJ for 10 min led to bacterial reduction from initial 8.3 to 5.9 and 4.0 log10 CFU g^(-1)after 10 and 30 min of washing,respectively.展开更多
Objective:To study physicochemical properties,antioxidant and anti-inflammatory activities of coumarin-carbonodithioate hybrids.Methods:The substituted 4-bromomethyl coumarins were synthesized in first step by the cyc...Objective:To study physicochemical properties,antioxidant and anti-inflammatory activities of coumarin-carbonodithioate hybrids.Methods:The substituted 4-bromomethyl coumarins were synthesized in first step by the cyclization.Then the reaction of substituted coumarins(a-e)with potassium O-ethyl/methyl carbonodithioate(1)by using absolute ethanol as solvent,afforded coumarin-carbonodithioate(1a-1j)derivatives under microwave irradiation and the conventional method.The spectroscopic analysis was used for the characterization of coumarin derivatives.The title(1a-1j)compounds were confirmed by spectroscopic methods.Antioxidant property was evaluated by using DPPH free radical-scavenging ability assay method and anti-inflammatory activity was evaluated by protein denaturation procedure using diclofenac sodium as a standard.Drug-likeness.In-silico toxicity was predicted with LD_(50)value and bioactivity score was also calculated for all the compounds.Results:All coumarin(1a-1j)compounds exhibited promisingin-vitro antioxidant and anti-inflammatory properties in comparison to standard drugs.All tested compounds were used for evaluating their physicochemical properties as set by Lipinski rule.It was observed that the synthesized compounds followed rule of five,indicating more'drug-like'nature.Conclusions:All the screened coumarin-carbonodithioates display promising in vitro antioxidant and antiinflammatory activities.From the physicochemical properties of coumarin derivatives,it is found that none of the compounds violate the Lipinski rule and they fall well in the range of rule of five.It is concluded that the coumarin-carbonodithioate hybrids act with more'drug-like'nature.展开更多
The objective of this work was to investigate and compare the structural and physicochemical properties of Dioscorea opposita Thunb. flour(DF), starch(DS) and purified starch(PDS). DS and PDS showed higher total starc...The objective of this work was to investigate and compare the structural and physicochemical properties of Dioscorea opposita Thunb. flour(DF), starch(DS) and purified starch(PDS). DS and PDS showed higher total starch and amylose content as compared to DF. Starch granules of DF were oval shape with rough surface while DS and PDS were relatively smooth by SEM. According to XRD measurements, FT-IR spectroscopy and 13 C CP/MAS NMR spectroscopy, all samples displayed C-type crystalline pattern, and PDS displayed the highest relative crystallinity and short-range order structure. However, DF contained the greatest content of the amorphous-phase. DF displayed the absorption peaks at 1730 and 1560 cm^(-1) related to the characteristic groups of lipid and protein using FT-IR spectroscopy. Furthermore, DF exhibited significantly higher pasting temperature while DS displayed the great peak and breakdown viscosity, as well as PDS had the highest setback and final viscosity, presumably due to the chemical composition and structural differences. DF exhibited the highest gelatinization temperature whereas PDS displayed the greatest gelatinization enthalpy. The pasting and gelatinization properties of flour and starch might be related to the relative crystallinity, short-range order structure or the interactions between starch and its associated compounds. The results allow the improvement in the manufacture of Dioscorea opposita Thunb. flour and starch with desirable pasting and gelatinization properties.展开更多
[Objectives]This study was conducted to explore the differences in physicochemical properties and surface properties of biochar from different sources.[Methods]Four kinds of materials including rice husk and corn stra...[Objectives]This study was conducted to explore the differences in physicochemical properties and surface properties of biochar from different sources.[Methods]Four kinds of materials including rice husk and corn straw were prepared at 450℃by the limited-oxygen program temperature control method into biochar,and the differences in physicochemical properties and surface properties of the biochar from different sources were studied.[Results]All four kinds of biochar were alkaline(pH=8.7-10.0).Corn straw biochar had the highest organic carbon content(653.6 g/kg),while rice husk biochar had the lowest organic carbon content(486.1 g/kg).Corn straw biochar had the highest nitrogen content(2.7%),while rice husk biochar had the lowest nitrogen content(0.75%).Corn straw biochar had the highest total phosphorus content(5.64 g/kg),while rice husk biochar had the lowest total phosphorus content(1.1 g/kg).Rice straw biochar had the highest total potassium content(53.1 g/kg),while rice husk biochar had the lowest total potassium content(10.6 g/kg).The four types of biochar were all porous,but their pore structure sizes and shapes were different to certain degrees.The order of the specific surface areas of the four types of biochar was rice stalk biochar>corn stalk biochar>wheat stalk biochar>rice husk biochar;the order of the pore volumes was rice stalk biochar>corn stalk biochar>wheat stalk biochar Charcoal>rice husk biochar;and the pore sizes ranked as wheat stalk biochar>corn stalk biochar>rice husk biochar>rice stalk biochar.The biochar from different sources ranked according to the comprehensive evaluation of all indicators as corn straw biochar>wheat straw biochar>rice straw biochar>rice husk biochar.[Conclusions]This study provides reference data for the preparation process of biochar from industrial and agricultural wastes and its application and promotion.展开更多
[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three differe...[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three different types of returning farmland to forest(Hippophae rhamnoides Linn.forest,Caragana korshinskii forest and Ulmus pumila L.forest)were analyzed by taking the enclosed grassland as comparison in Bashang area of northern Hebei Province.[Result]The results showed that there were significant differences among different types.Order of the bulk density of soil:H.rhamnoides Linn.forest(1.17 g/cm^3)<U.pumila L.forest(1.24 g/cm^3)<C.korshinskii forest(1.26 g/cm^3)<enclosed grassland(1.61 g/cm^3);order of the total porosity of soil:H.rhamnoides Linn.forest(55.29%)>U.pumila L.forest(52.55%)>C.korshinskii forest(51.93%)<enclosed grassland(38.85%);order of the organic matter content of soil:H.rhamnoides Linn.forest(3.191%)>C.korshinskii forest(3.128%)>U.pumila L.forest(2.804%)>enclosed grassland(2.536%).[Conclusion]After returning farmland to forest,vegetation played a positive role in physicochemical properties of soil.There were significant differences in physicochemical properties of soil among different modes of returning farmland to forest,and the improvement effect of H.rhamnoides Linn.forest on physicochemical properties of soil was the best.展开更多
The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this ca...The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.展开更多
One of the important stages in the preparation of fuel for the smooth progress of combustion is to remove humidity from it. Natural resin, a natural product from Pinus nigra was used in order to remove water residues ...One of the important stages in the preparation of fuel for the smooth progress of combustion is to remove humidity from it. Natural resin, a natural product from Pinus nigra was used in order to remove water residues from petroleum fuels. The mass of resin was mixed with diesel fuel, JP-8, and mix diesel-biodiesel and main physicochemical properties measured and compared with those of the raw fuels were measured. The humidity eliminated 38% of diesel, 21% of jet fuel, and 30% of mix diesel-biodiesel (80% - 20%) and improved the physicochemical properties. The resin can be replaced and re-generated as often needed.展开更多
In this research, locust bean gums were removed from seeds with different extraction methods and some physicochemical properties were analyzed for gums and also locust beans. Three different extractions were treated a...In this research, locust bean gums were removed from seeds with different extraction methods and some physicochemical properties were analyzed for gums and also locust beans. Three different extractions were treated at different temperatures and durations of sulfuric acid (H2SO4, 60%) solution, hydrochloric acid (HCl, 30%) solution and boiling water. Following dehulling and drying processes, seeds were milled and locust bean gums (LBG) were obtained eventually. The color values, moisture, protein, ash, sugar, pH, total acidity, soluble solids content, foreign particulates, acid insoluble ash contents and viscosity curves were compared for all samples. The results exhibited that the highest ash (1.94%) and protein (6.65%) contents were determined by water extraction gum, the highest acid-insoluble ash (3.58%) and foreign particulates (44.17%) contents were determined by HCl extraction gum. The lowest protein (5.01%), acid insoluble ash (1.29%), the foreign particulates (34.99%) and the highest viscosity value (533.9 mPas) were found from H2SO4 extraction gum. The results of investigation also showed that the H2SO4 extraction method was found to be more appropriate than HCl and water extraction methods to obtain a good quality gum.展开更多
Correlation among physicochemical properties, which include amylose content, alkali spreading values, gel consistency, water absorption, expansion rate, solid content of rice-water, protein content and fat content, an...Correlation among physicochemical properties, which include amylose content, alkali spreading values, gel consistency, water absorption, expansion rate, solid content of rice-water, protein content and fat content, and eating qualities of six kinds of rice samples planted in Heilongjiang Province were studied. Correlation analysis showed that amylose content, water absorption and expansion rate were negatively correlated with eating qualities, yet gel consistency, alkali spreading values, solid content of rice-water and fat content were positively correlated with eating qualities. Among them, eating quality had an obvious correlation with amylose content and gel consistency, but no significant correlation with protein content. The regression equation, which described the relationship of the eating quality scores and physicochemical indexes, was Y=94.439–12.711X1–23.721X2–0.701X3+0.570X4+186.938X5(X1, X2, X3, X4 and X5 represented amylose content, water absorption, expansion rate gel, consistency and fat content). The single factor analysis of variance showed that six kinds of rice existed significant differences in quality category.展开更多
The study of the heterogeneity of soil enzyme activities at different sampling locations in canopy gaps will help understand the influence mechanism of canopy gaps on soil ecological processes.In this paper,we analyze...The study of the heterogeneity of soil enzyme activities at different sampling locations in canopy gaps will help understand the influence mechanism of canopy gaps on soil ecological processes.In this paper,we analyzed the spatiotemporal variation of soil enzyme activities and soil physicochemical properties at different sampling locations(closed canopy,expanded edge,canopy edge,gap center)in different sampling time(December,February,April,June,August,and October)on the northern slope of the Tianshan Mountains,Northwest China.The results showed that soil catalase,cellulase,sucrase,and acid phosphatase activities were relatively high from June to October and low from December to April,and most of soil enzyme activities were higher at closed canopy than at gap center.Soil urease activity was high during December-February.The soil temperature reached the highest value during June-August and was relatively high at gap center in October,December,and February.Soil water content was significantly higher in December and April than in other months.Soil bulk density was higher at gap center than at closed canopy in December.Soil pH and soil electrical conductivity in most months were higher at closed canopy than at gap center.Soil organic carbon,soil total nitrogen,and soil total phosphorus were generally higher at gap center than at closed canopy.Furthermore,sampling time played a leading role in the dynamic change of soil enzyme activity.The key factors affecting soil enzyme activity were soil temperature and soil water content,which were governed by canopy gaps.These results provide important support for further understanding the influence mechanism of forest ecosystem management and conservation on the Tianshan Mountains.展开更多
Ginseng polysaccharides were extracted by water decoction from Panax ginseng C.A.Meyer(Cultivated Ginseng),named CGPS.Four polysaccharide fractions,CGPS-20,CGPS-40,CGPS-60 and CGPS-80,were precipitated at final ethano...Ginseng polysaccharides were extracted by water decoction from Panax ginseng C.A.Meyer(Cultivated Ginseng),named CGPS.Four polysaccharide fractions,CGPS-20,CGPS-40,CGPS-60 and CGPS-80,were precipitated at final ethanol concentrations of 20%,40%,60%and 80%,respectively.Physicochemical properties,molecular weight,monosaccharide composition and antioxidant capacity of polysaccharide fractions were all investigated.The results indicated that changing the concentration of ethanol could precipitate polysaccharides into fractions with different molecular weights,functional group composition and physicochemical properties,eventually leading to differences in antioxidant activity,which would help to find a simple,efficient,and reliable method for rapid extraction and purification of antioxidant polysaccharides from Panax ginseng C.A.Meyer.Among the four polysaccharide fractions,CGPS-80 had lower molecular weight,higher contents of uronic acid and total phenolic,and stronger scavenging ability on DPPH∙and ABTS∙+radicals.展开更多
基金financially supported by the National Natural Science Foundation of China(31871813).
文摘Theabrownins(TBs)are the characteristic functional and quality components of dark teas such as Pu’er tea and Chin-brick tea.TBs are a class of water-soluble brown polymers with multi-molecular weight distribution produced by the oxidative polymerisation of tea polyphenols during the fermentation process of dark tea,both enzymatically and non-enzymatically.TBs have been extracted and purified from dark tea all the time,but the obtained TBs contain heterogeneous components such as polysaccharides and caffeine in the bound state,which are difficult to remove.The isolation and purification process was tedious and required the use of organic solvents,which made it difficult to industrialise TBs.In this study,epigallocatechin(EGC),epigallocatechin gallate(EGCG),epigallocatechin gallate(ECG),EGC/EGCG(mass ratio 1:1),EGCG/ECG(mass ratio 1:1),EGC/ECG(mass ratio 1:1)and EGC/EGCG/ECG(mass ratio 1:1:1)as substrates and catalyzed by polyphenol oxidase(PPO)and peroxidase(POD)in turn to produce TBs,named TBs-dE-1,TBs-dE-2,TBs-dE-3,TBs-dE-4,TBs-dE-5,TBs-dE-6 and TBs-dE-7.The physicochemical properties and the antibacterial activity and mechanism of TBs-dE-1–7 were investigated.Sensory and colour difference measurements showed that all seven tea browning samples showed varying degrees of brownish hue.Zeta potential in aqueous solutions at pH 3.0–9.0 indicated that TBs-dE-1–7 was negatively charged and the potential increased with increasing pH.The characteristic absorption peaks of TBs-dE-1–7 were observed at 208 and 274 nm by UV-visible(UV-vis)scanning spectroscopy.Fourier transform infrared(FT-IR)spectra indicated that they were phenolic compounds.TBs-dE-1–7 showed significant inhibition of Escherichia coli DH5α(E.coli DH5α).TBs-dE-3 showed the strongest inhibitory effect with minimum inhibitory concentration(MIC)of 1.25 mg mL–1 and MBC of 10 mg mL–1,followed by TBs-dE-5 and TBs-dE-6.These three TBs-dEs were selected to further investigate their inhibition mechanism.The TBs-dE was found to damage the extracellular membrane of E.coli DH5α,causing leakage of contents,and increase intracellular reactive oxygen content,resulting in abnormal cell metabolism due to oxidative stress.The results of the study provide a theoretical basis for the industrial preparation and product development of TBs.
基金supported by the National Key R&D Program of China(No.2018YFD0901105).
文摘Iron deficiency anemia(IDA)is a major global health problem.Tegillarca granosa has been considered as an excellent source of iron given its high content of iron-binding protein,ferritin.The aim of the present study was to determine the physicochemical properties,protein structures,and iron uptake of ferritin extracted from T.granosa,and to evaluate the potential impacts of chitosan glycosylation on these characteristics.Based on Box-Behnken design and response surface methodology,the optimal conditions for glycosylation included a ferritin/chitosan mass ratio of 4:1,a pH of 5.5,a reaction time of 10 min,and a reaction temperature of 50℃.Glycosylation caused decreased surface hydrophobicity and elevated water-holding capacity of ferritin due to the introduction of hydrophilic groups.Additionally,glycosylation improved antioxidant capacity of ferritin by 20.69%–189.66%,likely owing to the protons donated by saccharide moiety to terminate free radical chain reaction.The in vitro digestibility of ferritin was elevated by 22.56%–104.85%after glycosylation,which could be associated with lessβ-sheet content in secondary structure that made the glycosylated protein less resistant to enzymatic digestion.The results of the iron bioavailability in Caco-2 cells revealed that ferritin(78.85–231.77 ngmg^(−1))exhibited better iron bioavailability than FeSO4(51.48–114.37 ngmg^(−1))and the values were further elevated by glycosylation with chitosan(296.23–358.20 ngmg^(−1)),which may be related to the physicochemical properties of ferritin via glycosylation modification.These results provide a basis for the development of T.granosa derived ferritin and its glycosylated products,and can promote the utilization of aquatic resources.
文摘Crop rotation periodicity has always been one of the research focuses currently. In this study, the physicochemical properties, nutrient contents and enzyme activities were investigated in soils from rice-cherry tomato rotation for one year (1a), three years (3a), five years (5a), seven years (7a) and ten years (10a), respectively. The major objective was to analyze the optimal rotation years of rice-cherry tomato from soil perspective, so as to provide theoretical basis for effectively avoiding continuous cropping obstacles of cherry tomato via studying the response characteristics of soil physicochemical properties, nutrient contents and enzyme activities to planting years of rice-cherry tomato rotation system. The results were as follows: 1) Soil pH value was increased year by year during 1a to 5a, reached the highest value 5.32 at 5a. However, soil acidity was sharply enhanced during 7a to 10a (P P •kg<sup>-1</sup> at 5a. 3) The content of soil available phosphorus was increased year by year with increasing of crop rotation years, and increased by 110% to 173% during 3a to 10a (P P P < 0.05). In conclusion, long-term single rotation pattern of rice-cherry tomato would aggravate soil acidification, prompt soil nutrient imbalance and reduce soil enzyme activity. 5a to 7a would be the appropriate rotation period for rice-cherry tomato, or else it would reduce soil quality, resulting in a new continuous cropping obstacle of cherry tomato.
基金This work was supported by the Scientific Research Projects of the Ministry of Education of China(6141A02033522)the National Natural Science Foundation of China(No.21978200).
文摘The development of advanced air transportation has raised new demands for high-performance liquid hydrocarbon fuels.However,the measurement of fuel properties is time-consuming,cost-intensive,and limited to the operating conditions.The physicochemical properties of aerospace fuels are directly infl uenced by chemical composition.Thus,a thorough investigation should be conducted on the inherent relationship between fuel properties and composition for the design and synthesis of high-grade fuels and the prediction of fuel properties in the future.This work summarized the eff ects of fuel composition and hydrocarbon molecular structure on the fuel physicochemical properties,including density,net heat of combustion(NHOC),low-temperature fl uidity(viscosity and freezing point),fl ash point,and thermal-oxidative stability.Several correlations and predictions of fuel properties from chemical composition were reviewed.Additionally,we correlated the fuel properties with hydrogen/carbon molar ratios(n H/C)and molecular weight(M).The results from the least-square method implicate that the coupling of H/C molar ratio and M is suitable for the estimation of density,NHOC,viscosity and eff ectiveness for the design,manufacture,and evaluation of aviation hydrocarbon fuels.
基金This work was supported fi nancially by National Natural Science Foundation of China(Grant Nos.and 41,871,031 and 31,860,111)Natural Science Foundation of Xinjiang(Grant No.2017D01C080).
文摘Soil microorganisms and physicochemical properties are considered the two most influencing factors for maintaining plant diversity.However,the operational mechanisms and which factor is the most influential manipulator remain poorly understood.In this study,we examine the collaborative influences of soil physicochemical properties(i.e.,soil water,soil organic matter(SOM),salinity,total phosphorus and nitrogen,pH,soil bulk density and fine root biomass)and soil microorganisms(fungi and bacteria)on plant diversity across two types of tree patches dominated by big and small trees(big trees:height≥7 m and DBH≥60 cm;small trees:height≤4.5 m and DBH≤20 cm)in an arid desert region.Tree patch is consists of a single tree or group of trees and their accompanying shrubs and herbs.It was hypothesized that soil physicochemical properties and microorganisms affect plant diversity but their influence differ.The results show that plant and soil microbial diversity increased with increasing distances from big trees.SOM,salinity,fine root biomass,soil water,total phosphorus and total nitrogen contents decreased with increasing distance from big trees,while pH and soil bulk density did not change.Plant and soil microbial diversity were higher in areas close to big trees compared with small trees,whereas soil physicochemical properties were opposite.The average contribution of soil physicochemical properties(12.2%-13.5%)to plant diversity was higher than microbial diversity(4.8%-6.7%).Salinity had the largest negative affect on plant diversity(24.7%-27.4%).This study suggests that soil fungi constrain plant diversity while bacteria improve it in tree patches.Soil physicochemical properties are the most important factor modulating plant diversity in arid desert tree patches.
基金financially supported by the National Natural Science Foundation of China (32071943 and 31872853)the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (PAPD)
文摘A major challenge in modern rice production is to achieve the dual goals of high yield and good quality with low environmental costs.This study was designed to determine whether optimized nitrogen(N)fertilization could fulfill these multiple goals.In two-year experiments,two high yielding‘super’rice cultivars were grown with different N fertilization management regimes,including zero N input,local farmers’practice(LFP)with heavy N inputs,and optimized N fertilization(ONF).In ONF,by reducing N input,increasing planting density,and optimizing the ratio of urea application at different stages,N use efficiency and the physicochemical and textural properties of milled rice were improved at higher yield levels.Compared with LFP,yield and partial factor productivity of applied N(PFP)under ONF were increased(on average)by 1.70 and 13.06%,respectively.ONF increased starch and amylose content,and significantly decreased protein content.The contents of the short chains of A chain(degree of polymerization(DP)6-12)and B1 chain(DP 13-25)of amylopectin were significantly increased under ONF,which resulted in a decrease in the stability of rice starch crystals.ONF increased viscosity values and improved the thermodynamic properties of starch,which resulted in better eating and cooking quality of the rice.Thus,ONF could substantially compensate the negative effects caused by N fertilizer and achieve the multiple goals of higher grain quality and nitrogen use efficiency(NUE)at high yield levels.These results will be useful for applications of high quality rice production at high yield levels.
文摘The physicochemical properties of the system, such as density, surface tension, specific conductance and melting point were measured. The results were discussed.
文摘Moringa oleifera is a plant that successfully grows recently in Egypt and has rich of nutrients seeds with valuable content of edible oil. The present study aimed at determining the physicochemical properties of moringa seeds and their extracted oil of which cultivated at different regions in Egypt. Obtained results revealed that protein, lipid, ash, fiber and total carbohydrate contents were in range of 34.51% - 36.5%, 28.62% - 30.06%, 4.22% - 5.06%, 10.92% - 12.16% and 19.00% - 20.29%, respectively. Consequently, caloric value was around 450.36 - 451.32 kcal 100 g<sup>-1</sup> for dried moringa seeds. As confirmed, dried moringa seeds are considered as a rich source of dietary minerals. TPCs content of M. oleifera seed were ranged from 16.9 - 18.5 mg GAE g<sup>-1</sup> dw. The anti-oxidants activity was in a range of 0.17 - 0.28 μmol TE g<sup>-1</sup> dw (DPPH scavenging activity) and was in a range of 4.19 - 6.29 μmol TE g<sup>-1</sup> dw (DPPH scavenging activity). The chlorophyll a, chlorophyll b, carotenoids, flavonoids and flavonols contents were ranged from 0.93 to 1.78, 4.89 to 8.41, 13.53 to 19.56 mg g<sup>-1</sup> dw, 3.30 to 5.40 and 2.30 to 4.10 mg QE g<sup>-1</sup> dw, respectively. Obviously, the individual essential amino acids (EAAs) and nonessential amino acids (NEAAs) recorded higher contents when compared to referenced protein. Total AA showed in triple amount in moringa protein when compared FAO standard. The acid value, iodine value, unsaponificable matter, peroxide value, refractive index, saponification value of cold pressed moringa seeds oil found to be 0.29 - 0.37 mg·g<sup>-1</sup>, 65.7 - 67.5, 0.60 to 0.74 g 100 g<sup>-1</sup>, 1.67 - 2.47 mEq/Kg, 1.4607 - 1.4613, 171.7 to 178.3 mg KOH g<sup>-1</sup>, respectively. Clearly, the unsaturated fatty acids (USFA) contents of M. oleifera edible oils were 77.14% - 84.98%, especially oleic (73.30% - 79.58%). On the contrary, the saturated fatty acids (SFA) recorded 15.00% - 22.83% where palmitic and stearic acids were the predominant SFA. The results of oil physicochemical parameters were compared with those of commercial oils. It could be illustrated that moringa seeds and its oil considered as a good source for dietary nutraceuticals and valuable characteristics for potential nutritional and technological applications.
基金supported by the Slovak Research and Development Agency under the contract Nos.APVV-16-0216,APVV-19-0386 and Slovak Grant Agency No.1/0782/19。
文摘The pulsed corona discharge(CD)generated in contact with water and directly in water,and high-power air plasma jet(APJ)were studied for production of plasma activated water(PAW).The changes of physical(pH,redox potential,conductivity,temperature)and chemical(peroxides,nitrites,nitrates concentrations)properties of treated water were investigated.The comparison of CD generated in gas/water interface and underwater configuration in the same system showed that the interaction of reactive oxygen and nitrogen species formed in ambient air in gas/water system induces different chemical processes,leading to lower pH,higher oxidation-reduction potential(ORP)and higher conductivity of PAW than in underwater discharge.High yield of peroxide was observed in both configurations.The PAW prepared by APJ exhibits high concentration of nitrites and nitrates according to supplied energy,and related significant decrease of pH and increase of ORP and conductivity after treatment.The antimicrobial effect of PAW prepared by CD and plasma jet on lentils sprouts was studied in different treatment and washing times.The APJ appears to have great efficacy on water activation resulted in strong decontamination effect.The PAW treated by APJ for 10 min led to bacterial reduction from initial 8.3 to 5.9 and 4.0 log10 CFU g^(-1)after 10 and 30 min of washing,respectively.
文摘Objective:To study physicochemical properties,antioxidant and anti-inflammatory activities of coumarin-carbonodithioate hybrids.Methods:The substituted 4-bromomethyl coumarins were synthesized in first step by the cyclization.Then the reaction of substituted coumarins(a-e)with potassium O-ethyl/methyl carbonodithioate(1)by using absolute ethanol as solvent,afforded coumarin-carbonodithioate(1a-1j)derivatives under microwave irradiation and the conventional method.The spectroscopic analysis was used for the characterization of coumarin derivatives.The title(1a-1j)compounds were confirmed by spectroscopic methods.Antioxidant property was evaluated by using DPPH free radical-scavenging ability assay method and anti-inflammatory activity was evaluated by protein denaturation procedure using diclofenac sodium as a standard.Drug-likeness.In-silico toxicity was predicted with LD_(50)value and bioactivity score was also calculated for all the compounds.Results:All coumarin(1a-1j)compounds exhibited promisingin-vitro antioxidant and anti-inflammatory properties in comparison to standard drugs.All tested compounds were used for evaluating their physicochemical properties as set by Lipinski rule.It was observed that the synthesized compounds followed rule of five,indicating more'drug-like'nature.Conclusions:All the screened coumarin-carbonodithioates display promising in vitro antioxidant and antiinflammatory activities.From the physicochemical properties of coumarin derivatives,it is found that none of the compounds violate the Lipinski rule and they fall well in the range of rule of five.It is concluded that the coumarin-carbonodithioate hybrids act with more'drug-like'nature.
基金Supported by the National Natural Science Foundation of China(No.31701552)Leading Talents Support Program of Science and Technology Innovation in Fujian Province(KRC16002A)Excellent Talents Support Program of Colleges and Universities in Fujian Province(JA14094)
文摘The objective of this work was to investigate and compare the structural and physicochemical properties of Dioscorea opposita Thunb. flour(DF), starch(DS) and purified starch(PDS). DS and PDS showed higher total starch and amylose content as compared to DF. Starch granules of DF were oval shape with rough surface while DS and PDS were relatively smooth by SEM. According to XRD measurements, FT-IR spectroscopy and 13 C CP/MAS NMR spectroscopy, all samples displayed C-type crystalline pattern, and PDS displayed the highest relative crystallinity and short-range order structure. However, DF contained the greatest content of the amorphous-phase. DF displayed the absorption peaks at 1730 and 1560 cm^(-1) related to the characteristic groups of lipid and protein using FT-IR spectroscopy. Furthermore, DF exhibited significantly higher pasting temperature while DS displayed the great peak and breakdown viscosity, as well as PDS had the highest setback and final viscosity, presumably due to the chemical composition and structural differences. DF exhibited the highest gelatinization temperature whereas PDS displayed the greatest gelatinization enthalpy. The pasting and gelatinization properties of flour and starch might be related to the relative crystallinity, short-range order structure or the interactions between starch and its associated compounds. The results allow the improvement in the manufacture of Dioscorea opposita Thunb. flour and starch with desirable pasting and gelatinization properties.
基金General Project of Chongqing Technology Innovation and Application Demonstration(Social People s Livelihood)(cstc2018jscx-msybX0215)Science and Technology Planning Project of Kaizhou District,Chongqing City(KZKJ-2020-J-10).
文摘[Objectives]This study was conducted to explore the differences in physicochemical properties and surface properties of biochar from different sources.[Methods]Four kinds of materials including rice husk and corn straw were prepared at 450℃by the limited-oxygen program temperature control method into biochar,and the differences in physicochemical properties and surface properties of the biochar from different sources were studied.[Results]All four kinds of biochar were alkaline(pH=8.7-10.0).Corn straw biochar had the highest organic carbon content(653.6 g/kg),while rice husk biochar had the lowest organic carbon content(486.1 g/kg).Corn straw biochar had the highest nitrogen content(2.7%),while rice husk biochar had the lowest nitrogen content(0.75%).Corn straw biochar had the highest total phosphorus content(5.64 g/kg),while rice husk biochar had the lowest total phosphorus content(1.1 g/kg).Rice straw biochar had the highest total potassium content(53.1 g/kg),while rice husk biochar had the lowest total potassium content(10.6 g/kg).The four types of biochar were all porous,but their pore structure sizes and shapes were different to certain degrees.The order of the specific surface areas of the four types of biochar was rice stalk biochar>corn stalk biochar>wheat stalk biochar>rice husk biochar;the order of the pore volumes was rice stalk biochar>corn stalk biochar>wheat stalk biochar Charcoal>rice husk biochar;and the pore sizes ranked as wheat stalk biochar>corn stalk biochar>rice husk biochar>rice stalk biochar.The biochar from different sources ranked according to the comprehensive evaluation of all indicators as corn straw biochar>wheat straw biochar>rice straw biochar>rice husk biochar.[Conclusions]This study provides reference data for the preparation process of biochar from industrial and agricultural wastes and its application and promotion.
基金Supported by Science and Technology Research Project of Colleges and Universities in Hebei Province(QN2015320)Natural Science Foundation of Hebei Province(C2015101020,E2019101012)Project of Chengde Finance Bureau(CZ2013011).
文摘[Objective]The research aimed to understand the change rules of physicochemical properties of soil in the different modes of returning farmland to forest.[Method]The physicochemical properties of soil in three different types of returning farmland to forest(Hippophae rhamnoides Linn.forest,Caragana korshinskii forest and Ulmus pumila L.forest)were analyzed by taking the enclosed grassland as comparison in Bashang area of northern Hebei Province.[Result]The results showed that there were significant differences among different types.Order of the bulk density of soil:H.rhamnoides Linn.forest(1.17 g/cm^3)<U.pumila L.forest(1.24 g/cm^3)<C.korshinskii forest(1.26 g/cm^3)<enclosed grassland(1.61 g/cm^3);order of the total porosity of soil:H.rhamnoides Linn.forest(55.29%)>U.pumila L.forest(52.55%)>C.korshinskii forest(51.93%)<enclosed grassland(38.85%);order of the organic matter content of soil:H.rhamnoides Linn.forest(3.191%)>C.korshinskii forest(3.128%)>U.pumila L.forest(2.804%)>enclosed grassland(2.536%).[Conclusion]After returning farmland to forest,vegetation played a positive role in physicochemical properties of soil.There were significant differences in physicochemical properties of soil among different modes of returning farmland to forest,and the improvement effect of H.rhamnoides Linn.forest on physicochemical properties of soil was the best.
文摘The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.
文摘One of the important stages in the preparation of fuel for the smooth progress of combustion is to remove humidity from it. Natural resin, a natural product from Pinus nigra was used in order to remove water residues from petroleum fuels. The mass of resin was mixed with diesel fuel, JP-8, and mix diesel-biodiesel and main physicochemical properties measured and compared with those of the raw fuels were measured. The humidity eliminated 38% of diesel, 21% of jet fuel, and 30% of mix diesel-biodiesel (80% - 20%) and improved the physicochemical properties. The resin can be replaced and re-generated as often needed.
基金“Suleyman Demirel University Unit of Scientific Research Project Commission”for funding of the research and“Directorate of Konya Provincial Control Laboratory”for their support to methodology.
文摘In this research, locust bean gums were removed from seeds with different extraction methods and some physicochemical properties were analyzed for gums and also locust beans. Three different extractions were treated at different temperatures and durations of sulfuric acid (H2SO4, 60%) solution, hydrochloric acid (HCl, 30%) solution and boiling water. Following dehulling and drying processes, seeds were milled and locust bean gums (LBG) were obtained eventually. The color values, moisture, protein, ash, sugar, pH, total acidity, soluble solids content, foreign particulates, acid insoluble ash contents and viscosity curves were compared for all samples. The results exhibited that the highest ash (1.94%) and protein (6.65%) contents were determined by water extraction gum, the highest acid-insoluble ash (3.58%) and foreign particulates (44.17%) contents were determined by HCl extraction gum. The lowest protein (5.01%), acid insoluble ash (1.29%), the foreign particulates (34.99%) and the highest viscosity value (533.9 mPas) were found from H2SO4 extraction gum. The results of investigation also showed that the H2SO4 extraction method was found to be more appropriate than HCl and water extraction methods to obtain a good quality gum.
基金Supported by Program for Technological Innovation Research Team in University of Heilongjiang Province(2010td04)
文摘Correlation among physicochemical properties, which include amylose content, alkali spreading values, gel consistency, water absorption, expansion rate, solid content of rice-water, protein content and fat content, and eating qualities of six kinds of rice samples planted in Heilongjiang Province were studied. Correlation analysis showed that amylose content, water absorption and expansion rate were negatively correlated with eating qualities, yet gel consistency, alkali spreading values, solid content of rice-water and fat content were positively correlated with eating qualities. Among them, eating quality had an obvious correlation with amylose content and gel consistency, but no significant correlation with protein content. The regression equation, which described the relationship of the eating quality scores and physicochemical indexes, was Y=94.439–12.711X1–23.721X2–0.701X3+0.570X4+186.938X5(X1, X2, X3, X4 and X5 represented amylose content, water absorption, expansion rate gel, consistency and fat content). The single factor analysis of variance showed that six kinds of rice existed significant differences in quality category.
基金supported by the National Natural Science Foundation of China (31760142)
文摘The study of the heterogeneity of soil enzyme activities at different sampling locations in canopy gaps will help understand the influence mechanism of canopy gaps on soil ecological processes.In this paper,we analyzed the spatiotemporal variation of soil enzyme activities and soil physicochemical properties at different sampling locations(closed canopy,expanded edge,canopy edge,gap center)in different sampling time(December,February,April,June,August,and October)on the northern slope of the Tianshan Mountains,Northwest China.The results showed that soil catalase,cellulase,sucrase,and acid phosphatase activities were relatively high from June to October and low from December to April,and most of soil enzyme activities were higher at closed canopy than at gap center.Soil urease activity was high during December-February.The soil temperature reached the highest value during June-August and was relatively high at gap center in October,December,and February.Soil water content was significantly higher in December and April than in other months.Soil bulk density was higher at gap center than at closed canopy in December.Soil pH and soil electrical conductivity in most months were higher at closed canopy than at gap center.Soil organic carbon,soil total nitrogen,and soil total phosphorus were generally higher at gap center than at closed canopy.Furthermore,sampling time played a leading role in the dynamic change of soil enzyme activity.The key factors affecting soil enzyme activity were soil temperature and soil water content,which were governed by canopy gaps.These results provide important support for further understanding the influence mechanism of forest ecosystem management and conservation on the Tianshan Mountains.
基金This work was granted by the National Key R&D Program of China(2017YFC1702302)LiaoNing Revitalization Talents Program(XLYC1902119).
文摘Ginseng polysaccharides were extracted by water decoction from Panax ginseng C.A.Meyer(Cultivated Ginseng),named CGPS.Four polysaccharide fractions,CGPS-20,CGPS-40,CGPS-60 and CGPS-80,were precipitated at final ethanol concentrations of 20%,40%,60%and 80%,respectively.Physicochemical properties,molecular weight,monosaccharide composition and antioxidant capacity of polysaccharide fractions were all investigated.The results indicated that changing the concentration of ethanol could precipitate polysaccharides into fractions with different molecular weights,functional group composition and physicochemical properties,eventually leading to differences in antioxidant activity,which would help to find a simple,efficient,and reliable method for rapid extraction and purification of antioxidant polysaccharides from Panax ginseng C.A.Meyer.Among the four polysaccharide fractions,CGPS-80 had lower molecular weight,higher contents of uronic acid and total phenolic,and stronger scavenging ability on DPPH∙and ABTS∙+radicals.
