Dietary organic acids ameliorate high stocking density stress-induced intestinal inflammation through the restoration of intestinal microbiota in broilers

Background:High stocking density(HSD)stress has detrimental effects on growth performance,intestinal barrier function,and intestinal microbiota in intensive animal production.Organic acids(OA)are widely used as feed addi-tives for their ability to improve growth performance and intestinal health in poultry.However,whether dietary OA can ameliorate HSD stress-induced impaired intestinal barrier in broilers remains elusive.In this study,a total of 528 one-day-old male Arbor Acres broilers were randomly allocated into 3 treatments with 12 replicates per treatment including 10 birds for normal stocking density and 17 birds for HSD.The dietary treatments were as follows:1)Normal stocking density+basal diet;2)HSD+basal diets;3)HSD+OA.Results:HSD stress can induce increased levels of serum corticosterone,lipopolysaccharides,interleukin-1β,tumor necrosis factor-α,and down-regulated mRNA expression of ZO-1,resulting in compromised growth performance of broilers(P<0.05).Dietary OA could significantly reduce levels of serum corticosterone,lipopolysaccharides,interleukin-1β,and tumor necrosis factor-α,which were accompanied by up-regulated interleukin-10,mRNA expres-sion of ZO-1,and growth performance(P<0.05).Moreover,OA could down-regulate the mRNA expression of TLR4 and MyD88 to inhibit the NF-κB signaling pathway(P<0.05).Additionally,HSD stress significantly decreased the abundance of Bacteroidetes and disturbed the balance of microbial ecosystems,whereas OA significantly increased the abundance of Bacteroidetes and restored the disordered gut microbiota by reducing competitive and exploita-tive interactions in microbial communities(P<0.05).Meanwhile,OA significantly increased the content of acetic and butyric acids,which showed significant correlations with intestinal inflammation indicators(P<0.05).Conclusions:Dietary OA ameliorated intestinal inflammation and growth performance of broilers through restor-ing the disordered gut microbial compositions and interactions induced by HSD and elevating short-chain fatty acid production to inhibit the TLR4/NF-κB signaling pathway.These findings demonstrated the critical role of intestinal microbiota in mediating the HSD-induced inflammatory responses,contributing to exploring nutritional strategies to alleviate HSD-induced stress in animals.

Dietary supplemental coated essential oils and organic acids mixture improves growth performance and gut health along with reduces Salmonella load of broiler chickens infected with Salmonella Enteritidis

Background Reducing Salmonella infection in broiler chickens by using effective and safe alternatives to antibiotics is vital to provide safer poultry meat and minimize the emergence of drug-resistant Salmonella and the spread of salmonellosis to humans.This study was to first evaluate the protective efficacy of feeding coated essential oils and organic acids mixture(EOA)on broiler chickens infected with Salmonella Enteritidis(S.Enteritidis,SE),and then its action mechanism was further explored.Methods A total of 4801-day-old Arbor Acres male chickens were randomly assigned into five treatments with six replicates,including non-challenged control fed with basal diet(A),SE-challenged control(B),and SE-infected birds fed a basal diet with 300 mg/kg of EOA(BL),500 mg/kg of EOA(BM)and 800 mg/kg of EOA(BH),respectively.All birds on challenged groups were infected with Salmonella Enteritidis on d 13.Results Feeding EOA showed a reversed ability on negative effects caused by SE infection,as evidenced by decreasing the feed conversion rate(FCR)and the ratio of villus height to crypt depth(VH/CD)(P<0.05),obviously decreasing intestinal and internal organs Salmonella load along with increasing cecal butyric acid-producing bacteria abundance(P<0.05).Moreover,supplemental different levels of EOA notably up-regulated claudin-1(CLDN-1),occludin(OCLN),zonula occludens-1(ZO-1),mucin-2(MUC-2),fatty acid binding protein-2(FABP-2),nuclear factor kappa-light-chainenhancer of activated B cells(NF-κB),myeloid differential protein-88(MyD88)and interleukin-6(IL-6)mRNA levels in the ileum of the infected chickens after challenge,whereas down-regulated toll-like receptor-4(TLR-4)mRNA levels(P<0.05).Linear discriminant analysis combined effect size measurements analysis(LEfSe)showed that the relative abundance of g_Butyricicoccus,g_Anaerotruncus and g_unclassified_f_Bacillaceae significantly was enriched in infected birds given EOA.Also,phylogenetic investigation of communities by reconstruction of unobserved states(PICRUSt)analysis showed that alpha-linolenic acid metabolism,fatty acid metabolism and biosynthesis of unsaturated fatty acids were significantly enriched in the EOA group.Conclusion Our data suggest that the essential oils and organic acids mixture can be used as an effective strategy to ameliorate and alleviate Salmonella Enteritidis infection in broilers.

Formation mechanisms of ethyl acetate and organic acids in Kluyveromyces marxianus L1-1 in Chinese acid rice soup

This study aims to explore the formation mechanism of ethyl acetate and organic acids in acid rice soup(rice-acid soup)inoculated with Kluyveromyces marxianus L1-1 through the complementary analysis of transcriptome and proteome.The quantity of K.marxianus L1-1 varied significantly in the fermentation process of rice-acid soup and the first and third days were the two key turning points in the growth phase of K.marxianus L1-1.Importantly,the concentrations of ethyl acetate,ethanol,acetic acid,and L-lactic acid increased from day 1 to day 3.At least 4231 genes and 2937 proteins were identified and 610 differentially expressed proteins were annotated to 30 Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways based on the analysis results of transcriptome and proteome.The key genes and proteins including up-regulated alcohol dehydrogenase family,alcohol O-acetyltransferase,acetyl-CoA C-acetyltransferase,acyl-coenzyme A thioester hydrolase,and down-regulated aldehyde dehydrogenase family were involved in glycolysis/gluconeogenesis pathways,starch and sucrose metabolism pathways,amino sugar and nucleotide sugar metabolism pathways,tricarboxylic acid(TCA)cycle,and pyruvate metabolism pathways,thus promoting the formation of ethyl acetate,organic acids,alcohols,and other esters.Our results revealed the formation mechanisms of ethyl acetate and organic acids in rice-acid soup inoculated with K.marxianus L1-1.

Ability of Agrogyron elongatum to accumulate the single metal of cadmium, copper, nickel and lead and root exudation of organic acids

Agrogyron elongatum were grown in nutrient solution containing moderate to high amounts of separate heavy metal of Cd, Cu, Ni and Ph in a greenhouse for a 9 - day. Cd, Cu, Ni and Ph generally led to decrease in the elongation of roots although the length of seedlings exposed to Cd and Ph at 0.05 and 0.5 mg/L showed to be slightly greater than that of controls. Of the four metals in the experiment, Ph was absorbed and accumulated to the highest level, with the concentrations of 92754 mg/kg dry weight (DW) in roots and 11683 mg/kg DW in shoots. Cd was moderately accumulated in Agrogyron elongatum, but the maximum bioaccumulation coefficients (BCs) for roots and shoots were observed. The patterns for Cu and Ni uptake and distribution in plants differed from those of Ph and Cd, as it was showed that the shoot accumulation of Cu and Ni was significantly higher than in roots. A. elongation had the highest Ni concentration in shoots (30261 mg/kg DW) at the external concentration of 250 mg/L. Cu ranked second, with a shoot concentration of 12230 mg/kg DW when 50 mg/L Cu in solution was applied. For the four trace elements tested, the highest concentrations in shoots decreased by the order of Ni > Cu > Ph > Cd (mg/kg DW), and those in roots were Ph > Cd > Ni > Cu (mg/kg DW). Malic, oxalic and citric acids exuded by roots exposed to 1 and 50 mg/L of the metals were detected. Release of organic acids from plants significantly differed among the metal treatments. Cu was most effectively in inducing root exudation of the three types of organic acids. Cd, and Ni were also the inducers of secretion of malic and oxalic acids. With reference of Pb, a small amounts of malic and oxalic acids were detected in the root exudates, but few quantities, of citric acid were. found. However, no correlation between alternations in root exudation of organic acids and metal accumulation could be established.

A review of the effects of dietary organic acids fed to swine

Animal production depends on nutrient utilization and if done there is an accelerated momentum towards growth with a low cost to feed ratio Public concern over the consumption of pork with antibiotic residues of the animals fed with antibiotic growth promoters （AGP） has paved the way to use other additives like herbs and their products, probiotics, prebiotics etc. Numerous feed additives are in vogue for achieving this target and one such classical example is the usage of organic acids and their salts. Usage of organic acids was in progress for over four decades. Early weaned piglets are （3-4 weeks age） exposed to stress with a reduced feed intake, little or no weight gain. This post weaning lag period is due to a limited digestive and absorptive capacity due to insufficient production of hydrochloric acid, pancreatic enzymes and sudden changes in feed consistency and intake. Lowering dietary pH by weak organic acids was found to overcome these problems. The main activity of organic acids is associated with a reduction in gastric pH converting the inactive pepsinogen to active pepsin for effective protein hydrolysis. Organic acids are both bacteriostatic and bactericidal. Lactic acid has been reported to reduce gastric pH and delay the multiplication of an enterotoxigenic E. coil These acids are the intermediary products in Kreb＇s cycle and thus act as an energy source preventing the tissue breakdown resulting from gluconeogenesis and lipolysis. Excretion of supplemental minerals and nitrogen are minimized with organic acids as these form complexes with minerals and aids for their bio-availability. Short chain fatty cids like acetic, propionic and n-butyric acid produced by microbial fermentation of dietary fibre in the large intestines may increase the proliferation of epithelial cells and have stimulatory effects on both endocrine and exocrine pancreatic secretions in pigs. Organic acids also enhances apparent total tract digestibility and improves growth performance. It is concluded that organic acids and their salts increase the protein utilization especially in weaner pigs and improves production indices.

Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids

Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the p K _a values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was not correlated with p K _a. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

Cd uptake in rice cultivars treated with organic acids and EDTA

A pot experiment was conducted to examine the activity of antioxidant enzymes, the content of malondialdehyde （MDA）, proline and protein, and Cd uptake in different rice cultivars exposed to Cd （0, 1 and 5 mg/kg） in the presence of organic acids and ethylenediamine tetraacetic acid （EDTA）. The results showed the increase in activity of dismutase （SOD）, contents of proline and protein but a decline in activities of peroxidase （POD） and catalase （CAT）, and MDA content for cultivars Xiushui63 and IIyou527. The resistance to Cd was higher in Xiushui63 than that in IIyou527 under the same Cd treatment. Cadmium contents in grain, straw and roots of both cultivars were markedly reduced in the presence of organic acids and EDTA. Grain Cd contents was the highest for plants treated with organic acids, followed by organic acids ＋ 1/2EDTA, and the lowest with EDTA; Cd contents in straw and root were the lowest for plants treated with organic acids, followed by organic acids ＋ 1/2EDTA, and the highest with EDTA treatment when exposed to Cd.

Evaluation of sugar and organic acid composition and their levels in highbush blueberries from two regions of China

Sweet and sour are the most important taste of blueberries,and they are produced by sugar and acid,respectively.Their contributions to the taste depend not only on the levels of sugar and acid,but also on the types and relative proportions of sugar and acid.Therefore,it is very important to evaluate the composition and levels of sugar and acid in blueberries.Regional differences and variety diversity also affect the sugar and acid characteristics of fruits.Therefore,this study selected two main producing regions in northern China(Weihai and Yingkou)to examine the sugar and acid characteristics of 11 common blueberry cultivars.The indexes measured included soluble sugars,organic acids,soluble solid content and titratable acidity.The results showed that glucose and fructose were the major sugars,and citric acid and quinic acid were the major organic acids.Correlation analysis showed that glucose,fructose,and sucrose were positively correlated with total sugar content;the citric acid content was positively correlated with the titratable acidity and total organic acids.Titratable acidity,glucose,fructose,sucrose,total sugar content,citric acid,shikimic acid and total acid content of the blueberries varied significantly between regions(P<0.05).In general,compared with Weihai blueberries,Yingkou blueberries had higher sugar content and lower acid content.The results of this study may provide useful references for the evaluation of sweet and sour flavors and cultivar selection of blueberries.

Microencapsulated essential oils combined with organic acids improves immune antioxidant capacity and intestinal barrier function as well as modulates the hindgut microbial community in piglets

Background:The objective of this experiment was to evaluate the effect of a combination of microencapsulated essential oils and organic acids(MOA)on growth performance,immuno-antioxidant status,intestinal barrier function and microbial structure of the hindgut in piglets.A total of 120 piglets(Duroc×[Landrace×Yorkshire];weighted 7.66±1.79 kg,weaned at d 28)were randomly selected and allocated to 3 treatments with 4 replicates per group and 10 piglets per replicate according to the initial body weight and gender.The dietary treatments were as follows:1)basal diet(Ctrl);2)Ctrl+chlortetracycline(75 mg/kg)(AGP);3)Ctrl+MOA(1500 mg/kg).The experiment period was lasted for 21 d.Results:Compared to the Ctrl group,dietary supplemented MOA alleviated(P<0.05)the diarrhea rate from d 12 to 21,enhanced(P<0.05)the concentration of serum interlukin-10 and glutathione peroxidase in piglets on d 11 after weaning and serum superoxide dismutase in 21-day piglets.The MOA group also improved(P<0.05)the apparent digestibility of dry matter(DM),organic matter(OM)and gross energy(GE),up-regulated(P<0.05)the mRNA expression level of occludin,claudin-1 and mucin-2 in ileum and increased(P<0.05)the contents of propionic and butyric acids in the cecum of piglets.The MOA group modulated the cecal and colonic microbial community structure and increased(P<0.05)the abundance of Faecalibacterium and Muribaculaceae in cecum and Streptococcus and Weissella in colon.Additionally,AGP group decreased(P<0.05)apparent digestibility of DM,OM and GE as well as down-regulated(P<0.05)relative gene expression level of claudin-1 in duodenum and jejunum,ZO-1 and mucin-1 in jejunum of piglets.Conclusion:In summary,dietary supplemented MOA alleviated diarrhea and improved nutrient apparent digestibility in piglets via enhancing immuno-antioxidant properties,increasing digestive enzyme activity,upregulating the expression of intestinal barrier-related genes,and modifying the microbial community structure of the cecum and colon.Therefore,dietary supplementation with MOA as an alternative to antibiotics was feasible to improve intestinal health of piglets in practical production.

Characteristics and distribution of low molecular weight organic acids in the sediment porewaters in Bosten Lake, China

The composition and vertical profiles of low molecular-weight organic acids （LMWOAs） and the contribution of them to dissolved organic matter （DOM） in sediment porewaters in Bosten Lake, Xinjiang, China were investigated. The results showed that total concentration of LMWOAs was up to 94.5 μmol/L and their proportion in DOM was 5.6%, suggesting that LMWOAs were important chemical components in DOM in lake sediment porewaters. Among the seven LMWOAs, pyruvic and acetic acid had the highest concentrations with 26.30 and 8.31 μmol/L, accounting for 51.4% and 14.92% of LMWOAs, respectively. Trifluoroacetic and sorbic acid had the lowest concentrations, indicating that the compositions of LMWOAs in relative reducing environments were largely different from those reported in glacier, atmosphere and soils. The concentrations of lactic, acetic, formic, sorbic and oxalic acid decreased with increasing depth, probably relating to stronger microbial activities in the initial stage of early diagenesis. Trifluoroacetic acid was mainly anthropogenic with its concentration, showing a diusive trend from the surface to bottom sediments. The concentrations of lactic acid and nitrate generally showed a consistent profile. The increasing concentration of pyruvic acid in the vertical profile was just opposite to that of sulfate, revealing a significant negative relationship between them. Oxalic acid remained constant except for an obvious peak at 6 cm depth. The results indicated the diversities in sources and behaviors for various LMWOAs during early diagenesis in sediments.

Analysis of Organic Acids Accumulated in Kochia Scoparia Shoots and Roots by Reverse-phase High Performance Liquid Chromatography Under Salt and Alkali Stress

Several organic acids accumulated in Kochia Scoparia shoots and roots were studied by means of reverse-phase high performance liquid chromatography with a C18 column. Five types of binary organic acids were separated. The organic acid concentrations were determined in K. Scoparia seedlings stressed by saline （NaCI） and alkaline （NaHCO3） at the same Na^＋ concentration. Concentrations of organic acids are stimulated by alkaline because the cells will adjust their pH values through the accumulation of organic acids, when the environment is basic. The concentrations of oxalic acid and succinic acid are higher than those of other organic acids, including tartaric acid and malic acid, and the concentration of citric acid is the lowest. The concentrations of the organic acids in the roots are higher than those in the shoots under salt（NaCI） stress, but the results are opposite while the roots are under alkali （ NaHCO3 ） stress. This indicates that there are different adaptive strategies for K. Scopar/a seedlings in organic acid metabolism under salt and alkali stress.

Dietary encapsulated essential oils and organic acids mixture improves gut health in broiler chickens challenged with necrotic enteritis

Background:The poultry industry is in need of effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE)due to Clostridium perfringens.In the present study,we investigated the effects of dietary supplementation with a blend of encapsulated essential oils and organic acids(BLJ)on growth performance and gut health using a coinfection model of NE in broiler chickens.Methods:Two hundred and eighty-eight one-day-old male Arbor Acres broiler chicks were randomly assigned using a 2×2 factorial design into two groups fed either 0 or 500 mg/kg dietary BLJ and co-challenged(or not challenged for the control)with Eimeria spp./C.perfringens.Results:Infected birds fed the BLJ-supplemented diet exhibited an improved feed conversion ratio throughout the trial(P<0.01),a higher villus height and villus height/crypt depth ratio,and reduced intestinal C.perfringens counts,liver C.perfringens carriage,gut lesion scores and serum fluorescein isothiocyanate dextran(FITC-D)concentrations at 7 d postinfection compared with those of birds without BLJ supplementation(P<0.05).NE-infected birds fed BLJ exhibited significantly upregulated claudin-1 and IGF-2 mRNA levels(P<0.05),increased A20 mRNA expression and significantly downregulated TRAF-6,TNFSF15 and TOLLIP mRNA levels in the jejunum at 7 d post-infection compared with those in birds without BLJ supplementation(P<0.05).Compared with the uninfected and untreated birds,the uninfected birds fed BLJ displayed increased relative abundances of Lactobacillus and Coprococcus but reduced Rikenellaceae levels.Compared with the unsupplemented NE-challenged birds,infected birds fed BLJ showed an increased relative abundance of Unclassified_Lachnospiraceae and a significantly decreased relative abundance of Erysipelotrichaceae.Conclusion:BLJ supplementation improved growth performance and gut health in NE-infected broiler chickens by strengthening the intestinal barrier function,positively modulating the gut microbiota community and differentially regulating intestinal immune responses.Our results also suggested that adding BLJ effectively controlled NE infections after experimental Eimeria and Clostridium perfringens coinfection.

Combined fluorescence and electrochemical investigation on the binding interaction between organic acid and human serum albumin

Human serum albumin （HSA） is a plasma protein responsible for the binding and transport of fatty acids and a variety of exogenous chemicals such as drugs and environmental pollutants. Such binding plays a crucial role in determining the ADME （absorption, distribution, metabolism, and excretion） and bioavailability of the pollutants. The binding interaction between HSA and acetic acid （C2）, octanoic acid （C8） and dodecanoic acid （C12） has been investigated by the combination of site-specific fluorescent probe, tryptophan intrinsic fluorescence and tyrosine electrochemistry. For the study of the fatty acid interaction with the two drug-binding sites on HSA, two fluorescent probes, dansylamide and dansyl-L-proline were employed in the displacement measurements. Intrinsic fluorescence of tryptophan in HSA was monitored upon addition of the fatty acids into HSA. Electrocatalyzed response of the tyrosine residues in HSA by a redox mediator was used to investigate the binding interaction. Qualitatively, observations from these three approaches were very similar. HSA did not show any change in the fluorescence and electrochemical experiments after mixing with C2, suggesting there is no significant interaction with the short-chain fatty acid. For C8, the measured signal dropped in a single-exponential mode, indicating an independent and non-cooperative binding. The calculated association constant and binding ratio were 3.1 × 10^6 L/mol and 1 with drug binding Site Ⅰ, 1.1 × 107 L/mol and 1 with Site Ⅱ, and 7.0× 0^4 L/mol and 4 with the tryptophan site, respectively. The measurements with C12 displayed multiple phases of fluorescence change, suggesting cooperativity and allosteric effect of the C12 binding. These results correlate well with those obtained by the established methods, and validate the new approach as a viable tool to study the interactions of environmental pollutants with biological molecules.

Organic Acid Concentrations and the Relative Enzymatic Changes During the Development of the Citrus Fruits

Seasonal changes in enzyme activities and citrate concentration during the development of citrus fruits were investigated. The result showed that the organic acid concentrations reached a peak in the 100 -130 days after anthesis and gradually declined during later stages of fruit maturation in most varieties of citrus, but declined only slightly thereafter in lemon [Citrus limon(L.)Burm]; there is no relation between the activity of citrate synthetase(CS)and the different acid concentration in different citrus fruits; the increase of the activity of the cytosolic aconitase in the late period of the development of citrus fruits accelerated the degradation of citric acid in citrus fruits; the higher the activity of phosphoenolpyruvate carboxylase(PEPC)and the ratio of NAD-dependent isocitrate hydrogenase(PEPC /NAD-IDH),the more the concentrations of organic acids in citrus fruit.

Effect of Zn deficiency and excessive bicarbonate on the allocation and exudation of organic acids in two Moraceae plants

The effect of zinc(Zn) deficiency and excessive bicarbonate on the allocation and exudation of organic acids in plant organs(root, stem, and leaf) and root exudates of two Moraceae plants(Broussonetia papyrifera and Morus alba) were investigated. Two Moraceae plants were hydroponically grown and cultured in nutrient solution in four different treatments with 0.02 mM Zn or no Zn,combined with no or 10 mM bicarbonate. The variations of organic acids in different plant organs were similar to those of root exudates in the four treatments except B. papyrifera, which was in a treatment that was a combination of 0.02 mM Zn and no bicarbonate. The response characteristics in the production, translocation, and allocation of organic acids in the plant organs and root exudates varied with species and treatments. Organic acids in plant organs and root exudates increased under Zn-deficient conditions,excessive bicarbonate, or both. An increase of organic acids in the leaves resulted in an increase of root-exuded organic acids. B. papyrifera translocated more oxalate and citrate from the roots to the rhizosphere than M. alba under the dual influence of 10 mM bicarbonate and Zn deficiency. Organic acids of leaves may be derived from dark respiration and photorespiration. By comparison, organic acids in stems, roots, and root exudates may be derived from dark respiration and organic acid translocation from the leaves. These results provide evidence for the selective adaptation of plants to environments with low Zn levels or high bicarbonate levels such as a karst ecosystem.

Generation of Hydrogen from Photolysis of Organic Acids by Photosynthetic Bacteria

Photodecomposition of ten kinds of organic acids by Rhodopseudomonas palustris for producing hydrogen has been investigated. By using acetate as hydrogen donor, dynamics of hydrogen production and cell growth has been determined; the influences of acetate concentration, temperature, light intensity and the effects of the interaction among metal ions (Fe3+, Ni2+), acetate and glutamate in aqueous solution on hydrogen production have been examined for optimizing the conditions of H2 generation. The results show that H2 production is partially correlated with cell growth; Ni2+ inhibits hydrogen production, but enhances cell growth; Fe3+ promotes hydrogen production evidently. The highest rate of H2 production is 22.1 mL L-1 h-1 under the conditions of 35 ~ 37℃, 6000 ~ 8000 lx, 30 mmolL-1 of acetate, 9 mmolL-1 of glutamate, and 50 mmolL-1 of Fe3+.

Effect of Metaxenia on Sugars and Organic Acids and Taste Quality of Bagged Fuji Apple Fruits

In order to provide reference for the selection of appropriate pollination varieties facilitating the improvement of the flavor quality of bagged Fuji apple, the metaxenia effects of 5 pollination varieties on sugars, organic acids and flavor quality of bagged Fuji fruit were studied. The results showed that the 5 pollination varieties had significant metaxenia effects on sugars, organic acids and flavor quality of bagged Fuji fruit. For the sugar components, the fruits pollinated with Golden Delicious and Jinxiuhaitang showed higher glucose contents, and the fruit pollinated with Gala had the highest sucrose content; the fruits pollinated by Gala, Golden Delicious and Ruby exhibited higher malic acids, and the oxalic acid content and the succinic acid content were higher in the fruits pollinated with Jinxiuhaitang and Ruby ; and the fruit pollinated with Gala had the highest total sugar content, and the total acid content was higher in the fruits pollinated by Jinxiuhaitang and Ruby. The sugar-acid ratio was higher in the fruits pollinated with Gala and Golden Delicious, and the lowest in the fruit pollinated with Ruby. The senso- ry evaluation of fruits showed that the fruit pollinated with Ruby tasted sour-sweet, while the fruits pollinated with other 4 pollination varieties were sour and sweet moderately.

Compositional and Structural Difference of Fulvic Acid from Black Soil Applied with Different Organic Materials: Assessment After Three Years

Knowledge of different effects of various organic materials on soil humic substance is important for both environmental safety and sustainable agriculture.A pot experiment was conducted at Jilin Agricultural University,Jilin Province in northeast China to discover the influence of herb residue,animal excrement,woody residue,animal remnant on fulvic acid（FA） composition and structure using differential thermal analysis-thermogravimetric（DTA-TG）,fourier transform infrared spectroscopy（FTIR） and elemental analysis.DTA-TG showed the range of peak temperature in the first exothermic reaction increased following the trend： CK〉herb residue〉animal excrement〉woody residue=animal remnant,and the most weight loss was observed in animal excrement.Moreover,the second exothermic reaction of CK-and animal excrement-FA was presented as double peaks,the order of weight loss in that area was animal remnant〉CK〉woody residue〉animal excrement〉herb residue.According to FTIR,herb residue displayed higher adsorption intensity at 2 950,1 420,1 240 and 1 030 cm-1,animal excrement was in reverse.At the same time,herb residue-and animal excrement-FA had an absorption peak at 1 720 cm-1,while other organic materials didn＇t have this peak.As elemental analysis showed,FA isolated from various treatments was significantly distinct.It was clearly shown from our results that FA composition and structure in amended soils may be affected in different ways and at various extents on dependence of the nature and origin of amendment.

Ion Chromatographic Determination of Organic Acids and Cations via Exchange Columns Connected in Parallel

A column switching technique has been developed for the sequential determination of organic acids and cations in alcoholic drinks. An anion exchange column and a cation exchange column were connected in parallel for the measurement. Oxalic acid was employed as a common eluent for both the anion and cation exchange columns. Under the same chromatographic conditions, the organic acids and cations can be separated sequentially by a switching operation selecting the path way through the anion and cation exchange columns. This method is simple to operate and is very sensitive with detection limits of 0 1～ 1 0 mg/L for organic acids and 10～ 20 μg/L for cations.

Novel additives for the separation of organic acids by ion-pair chromatography

This paper proposes the use of novel surfactant additives for the separation of organic acids by ion-pair chromatography and studies the influences of surfactants on the chromatographic separation behaviors.Researches have been carried out on both silica gel matrix and polymer supporters in order to compare the two ordinary kinds of stationary phases,and the phenomenon is similar. Separation is based on differences in the stabilities of analyte-additive complexes in solution.Retention times of analytes can ...