Antibacterial activity of red and white wine against oral streptococci

Wine contains a number of biologically active compounds with beneficial effects on human health. The antibacterial action of commercial red and white wines against oral streptococci responsible for caries development and against S. pyogenes responsible for pharyngitis was studied. Its postcontact effect against S. mutans was also studied. Both wines displayed activity. The compounds responsible for such activities were succinic, malic, lactic, tartaric, citric, and acetic acid. The synthetic mixtures of the organic acids tested at the concentrations found in wine had greater antibacterial activity than the beverages, indicating that in wine they are inhibited by other components. Wine polyphenols displayed no activity against oral streptococci or S. pyogenes. Findings show that wine is active against oral streptococci and S. pyogenes and suggest that it enhances oral health.     

Identification of beer bitter acids regulating mechanisms of gastric acid secretion

Beer, one of the most consumed beverages worldwide, has been shown to stimulate gastric acid secretion. Although organic acids, formed by fermentation of glucose, are known to be stimulants of gastric acid secretion, very little is known about the effects of different types of beer or the active constituents thereof. In the present study, we compared the effects of different beers on mechanisms of gastric acid secretion. To investigate compound-specific effects on mechanisms of gastric acid secretion, organic acids and bitter compounds were quantified by HPLC-DAD and UPLC-MS/MS and tested in human gastric cancer cells (HGT-1) by means of a pH-sensitive fluorescent dye which determines the intracellular pH as an indicator of proton secretion. The expression of relevant genes, coding the H(+)/K(+)-ATPase, ATP4A, the histamine receptor, HRH2, the acetylcholine receptor, CHRM3, and the somatostatin receptor, SSTR2, was determined by qPCR. Ethanol and the organic acids succinic acid, malic acid, and citric acid were demonstrated to contribute to some extent to the effect of beer. The bitter acids comprising α-, β-, and iso-α-acids were identified as potential key components promoting gastric acid secretion and up-regulation of CHRM3 gene expression by a maximum factor of 2.01 compared to that of untreated control cells with a correlation to their respective bitterness.     

红曲中非酿酒酵母的分离鉴定及其对黄酒风味成分的影响

为探究红曲中非酿酒酵母对黄酒风味成分的影响,首先对红曲中的酵母菌株进行分离纯化,并采用分子生物学方法进行鉴定,然后将分离的非酿酒酵母菌株分别与红曲霉相结合,以纯种发酵的方式酿造红曲黄酒,分析各酒样中有机酸、氨基酸、挥发性物质等风味成分的组成及含量。结果表明,分离获得的4株非酿酒酵母CKS-2为威克汉姆酵母(Wickerhamomyces sp.)、CKS-3为季也蒙毕赤酵母(Meyerozyma guilliermondii)、CKS-4为胶红酵母(Rhodotorula mucilaginosa)、CKS-7为德尔布有孢酵母(Torulaspora delbrueckii),其中,CKS-7具有较好的产乙醇和苹果酸能力,发酵酒样中丝氨酸、组氨酸、色氨酸和亮氨酸的含量也较高,并且具有良好的合成2-苯乙醇、异戊醇、棕榈酸乙酯等挥发性风味成分的能力。本研究对红曲黄酒品质提升,以及筛选潜在可应用于红曲黄酒酿造的优良非酿酒酵母菌株具有一定作用。     

Determination of organic acids by high-performance liquid chromatography with electrochemical detection during wine brewing

Voltammetric determination of acids by means of the electrochemical reduction of quinone was applied to high-performance liquid chromatography (HPLC) with electrochemical detection (ED) for determining organic acids in fruit wines. A two-channel HPLC-ED system was fabricated by use of an ion-exclusion column and an electrochemical detector with a glassy carbon working electrode. Aqueous solution of 0.1 mM HClO(4) and ethanol containing 2-methyl-1,4-naphthoquinone served as a mobile phase and reagent solution, respectively. Determination of acetic, citric, lactic, malic, succinic, and tartaric acids was made by measuring the peak areas of the flow signals due to the reduction current of quinone caused by the eluted acids. The peak area was found to be linearly related to the acid amount ranging from 0.1 to 40 nmol per 20 microL injection. The present method was characterized by reproducibility with the simple and rapid procedure without derivatization of analytes. The method was shown as an effective means for following acid contents in fruit juices during fermentation with wine yeast.     

蜡样芽孢杆菌及其生物被膜对有机酸及乙醇的抗性比较

为比较蜡样芽孢杆菌及其生物被膜对环境压力的抗性,该文主要研究了4种有机酸（乙酸、柠檬酸、乳酸和苹果酸）和乙醇对蜡样芽孢杆菌及其生物被膜存活率的影响。结果表明：生物被膜态蜡样芽孢杆菌对乙酸的抗性高于浮游态菌。扫描电镜结果显示,经乙酸处理后,浮游态蜡样芽孢杆菌的细胞表面严重受损,而生物被膜态菌的表面形态未发生明显变化。在柠檬酸、乳酸、苹果酸和乙醇存在的条件下,生物被膜态蜡样芽孢杆菌比浮游态菌表现出更强的压力抗性,特别是在高浓度（有机酸16%～20%,乙醇50%～60%）的情况下,该现象尤为显著。因此,在食品工业中控制被膜态蜡样芽孢杆菌对预防和阻止食品腐败非常重要。该研究结果为实际生产中有效控制蜡样芽孢杆菌及其生物被膜的形成提供参考。     

Effect of organic acids and nitrogen source on alcoholic fermentation: study of their buffering capacity

The effect of tartaric acid and other organic acids on alcoholic fermentation was studied. Organic acids in media with high sugar concentrations and ammonium as the sole nitrogen source had an enormous impact on Saccharomyces cerevisiae metabolism during alcoholic fermentation. The main effect on yeast metabolism was the quick acidification of the media in the absence of organic acids. All of the organic acids used in this study (tartaric, malic, citric, and succinic acids) showed a buffering capacity, but not all of the acids had the same one. However, the results suggested that buffering should not be considered the only effect of organic acids on yeast metabolism. Nitrogen source also had a great influence on media pH. Ammonium consumption by yeasts produced a greater acidification of the media than when amino acids were used.     

Effects of Low-Molecular-Weight Organic Acids on Soil Micropores and Implication for Organic Contaminant Availability

Experiments were conducted to study the effects of low-molecular-weight organic acids (LMWOAs) on micropore properties of black soil, red soil, lignin, and humin. Black soil and red soil were treated with four LMWOAs including malic, citric, succinic, and tartaric acids, whereas lignin and humin were treated with malic and citric acids. The results indicated that soil micropore distribution was changed by LMWOAs. Citric and malic acids reduced soil micropore surface area and volume significantly, but lignin micropores were not changed significantly by these two acids. Therefore, clogging may not be a main reason for the surface area and micropore volume reduction of soil organic matter. The release of metal ions from humin and soils was enhanced by LMWOAs, indicating the dissolution of soil mineral particles. Therefore, soil micropore reduction may result from the destruction of soil aggregates due to dissolution of mineral particles and extraction of metals from bridging sites.     

绿肥腐解液中有机酸组成对铝磷和铁磷活化能力的影响

  【目的】  研究绿肥还田腐解过程中产生的有机酸阴离子对土壤中难溶性磷素的活化效果,以深化理解绿肥作物提高土壤养分供应能力的机理。  【方法】  供试6种绿肥作物为紫云英 (Astragalus sinicus L.)、肥田萝卜 (Raphanus sativus var. Longipinnatus)、二月兰 (Orychophragmus violaceus)、双低甘蓝型油菜 (Brassica napus L.)、双高甘蓝型油菜 (Brassica napus L.) 和芥菜型油菜 (Brassica juncea)。将绿肥植株切碎后,置于离心管中,加入土壤浸提液于室外背光处密闭腐解45天,采用离心法提取植株腐解液。测定腐解液中10种有机酸组分 (丙二酸、苹果酸、柠檬酸、草酸、乳酸、酒石酸、乙酸、琥珀酸、马来酸和富马酸阴离子) 含量。采用室内模拟方法,分别用6种绿肥腐解液溶解难溶性铝磷 (Al-P,AlPO₄) 和铁磷 (Fe-P,FePO₄·2H₂O),测定溶液中的无机磷含量。  【结果】  二月兰腐解液中10种有机酸组分总含量最高,其次为肥田萝卜、双低甘蓝型油菜和芥菜型油菜,双高甘蓝型油菜和紫云英腐解后腐解液中较低。所有绿肥作物腐解液中10种有机酸组分含量大小依次为酒石酸、丙二酸、柠檬酸、琥珀酸、乳酸、苹果酸、乙酸、草酸、马来酸和富马酸阴离子。其中酒石酸和丙二酸阴离子占上述10种主要有机酸总量的15%以上,马来酸和富马酸阴离子占比最低,不到总量的1%。不同绿肥腐解液对Al-P和Fe-P的活化能力有显著差异,肥田萝卜对两种难溶性磷素的活化能力最高,理论上1000 kg肥田萝卜绿肥可活化0.6～1.2 kg的Al-P和Fe-P,其次为紫云英和芥菜型油菜,对Al-P和Fe-P的活化量均约为0.6～1.0 kg,而二月兰的活化量最低,约为0.2～0.6 kg。对不同有机酸含量与难溶性磷活化量进行相关性分析发现,Al-P活化量与柠檬酸、苹果酸和草酸阴离子的含量呈现正相关关系,Fe-P的活化量与酒石酸的含量呈现正相关关系。  【结论】  与Al-P和Fe-P的活化密切相关的是有机酸中含有较高的柠檬酸、草酸、苹果酸和酒石酸。供试6种绿肥作物腐解液中的10种有机酸的总含量及各有机酸组分的占比差异很大。二月兰虽然有机酸总量高,但是柠檬酸、草酸和酒石酸比例均较低;而肥田萝卜腐解液中的酒石酸含量及其占比高于其他绿肥,且柠檬酸和琥珀酸占比较高,对Fe-P的活化能力强;芥菜型油菜和紫云英腐解液中草酸、柠檬酸和琥珀酸占比高于其他绿肥,对Al-P的活化能力强。供试6种绿肥中以肥田萝卜腐解液的活化能力最强,芥菜型油菜和紫云英腐解液的活化能力次之。     

低分子量有机酸对可变电荷土壤铝活化动力学的影响

从动力学角度研究了几种低分子量有机酸对2种酸性土壤中铝的活化和活化铝在土壤固/液相之间分配的影响。结果表明:对于络合能力弱的醋酸和乳酸,主要通过质子作用活化铝,且活化作用明显小于盐酸。而络合能力较强的苹果酸、草酸和柠檬酸,主要通过络合作用促进铝的释放,且这种作用随有机酸根阴离子络合能力的增强而增加。在氧化铁含量较高的砖红壤中,苹果酸、草酸和柠檬酸通过专性吸附增加土壤表面负电荷,从而增加土壤交换态铝;但在氧化铁含量较低的红壤中,草酸和柠檬酸主要通过形成可溶性铝络合物降低交换态铝。活化铝在土壤固/液相间的分配主要决定于溶液中有机阴离子与土壤固相表面对铝离子的竞争。醋酸和乳酸活化的铝主要以交换态铝存在;而草酸和柠檬酸活化的铝主要以有机酸-铝络合物存在于溶液中,特别是在氧化铁低的红壤中,这将促进铝在土壤-水体中的迁移。     

低分子量有机酸对红壤磷酸单酯酶活性的影响

采用室内模拟试验研究了低分子量有机酸(柠檬酸、草酸、苹果酸、酒石酸)对红壤磷酸单酯酶活性的影响。结果表明,低浓度有机酸(<1μmol g-1)对磷酸单酯酶活性有促进作用,且促进作用大小依次为柠檬酸≈草酸>苹果酸>酒石酸;而高浓度有机酸(>5μmol g-1)则为抑制作用,且抑制作用大小依次为柠檬酸>草酸>苹果酸>酒石酸。当体系pH趋向酶促反应最佳pH时,磷酸单酯酶活性增强;反之,当体系pH远离酶促反应最佳pH时,磷酸单酯酶活性减弱。有机酸根一方面通过羧基的辅助作用提高磷酸单酯酶活性;另一方面通过释放土壤A l3+、Fe3+等金属离子,对土壤磷酸单酯酶活性有一定的抑制作用。     

Quantitation of nine organic acids in wild mushrooms

The organic acids composition of six wild edible mushroom species (Amanita caesarea, Boletus edulis, Gyroporus castaneus, Lactarius deliciosus, Suillus collinitus, and Xerocomus chrysenteron) was determined by an HPLC-UV detector method. The results showed that all of the samples presented a profile composed of at least five organic acids: citric, ketoglutaric, malic, succinic, and fumaric acids. Several samples also contained oxalic, ascorbic, quinic, and shikimic acids. In a general way, the quantitation of the identified compounds indicated that malic acid, followed by the pair citric plus ketoglutaric acids, were the main compounds in the analyzed species, with the exception of A. caesarea, in which malic and ascorbic acids were the most abundant compounds. The relative amounts and the presence/absence of each identified compound may be useful for the differentiation of the species.     

红壤施用包膜有机酸对解除小麦铝毒的作用研究

通过盆栽试验研究红壤施用柠檬酸、草酸和苹果酸三种不同包膜有机酸对不同小麦品种解铝毒的作用。结果表明,红壤上施用包膜有机酸对小麦具有较好的解铝毒效果,增加了小麦产量。三种包膜有机酸中柠檬酸的效果最佳。有机酸解铝毒的效果因小麦品种而异,其中敏感小麦优于抗性小麦。     

Quantitative reconstruction of the nonvolatile sensometabolome of a red wine

The first comprehensive quantitative determination of 82 putative taste-active metabolites and mineral salts, the ranking of these compounds in their sensory impact based on dose-over-threshold (DoT) factors, followed by the confirmation of their sensory relevance by taste reconstruction and omission experiments enabled the decoding of the nonvolatile sensometabolome of a red wine. For the first time, the bitterness of the red wine could be demonstrated to be induced by subthreshold concentrations of phenolic acid ethyl esters and flavan-3-ols. Whereas the velvety astringent onset was imparted by three flavon-3-ol glucosides and dihydroflavon-3-ol rhamnosides, the puckering astringent offset was caused by a polymeric fraction exhibiting molecular masses above >5 kDa and was found to be amplified by the organic acids. The perceived sourness was imparted by l-tartaric acid, d-galacturonic acid, acetic acid, succinic acid, l-malic acid, and l-lactic acid and was slightly suppressed by the chlorides of potassium, magnesium, and ammonium, respectively. In addition, d-fructose and glycerol as well as subthreshold concentrations of glucose, 1,2-propandiol, and myo-inositol were found to be responsible for the sweetness, whereas the mouthfulness and body of the red wine were induced only by glycerol, 1,2-propandiol, and myo-inositol.     

Development of a new high-performance liquid chromatography-electrospray ionization time-of-flight mass spectrometry method for the determination of low molecular mass organic acids in plant tissue extracts

A liquid chromatography-electrospray ionization time-of-flight mass spectrometry method has been developed for the direct and simultaneous determination of 10 low molecular mass organic acids in different plant tissue extracts. The method does not include a derivatization step. Quantification was accomplished using (13)C-labeled malic and succinic acids as internal standards. Good limits of detection (0.05-1.27 pmol) were obtained for malic, 2-oxoglutaric, succinic, quinic, shikimic, cis-aconitic, and citric acids, whereas for oxalic, ascorbic, and fumaric acids limits of detection were 255, 25, and 11 pmol, respectively. Repeatability values for the retention time and peak area were <5%, with the exception of ascorbic acid. Analyte recovery was between 92% and 110% in most cases, with the exception of oxalic (39-108%), 2-oxoglutaric (44-69%), and ascorbic (22-86%) acids, which may require specific extraction procedures and use of the corresponding (13)C-labeled organic acid as internal standards to improve accuracy. The method was applied to three types of plant materials: sugar beet leaf extracts, tomato xylem sap, and commercial orange juice.     

Assessing the Photocatalytic Reduction of Cr(VI) by CuO in Combination with Different Organic Acids

Cupric oxide (CuO) photocatalytic reduction of chromium(VI) [Cr(VI)] by organic acids including tartaric acid, citric acid, malic acid, lactic acid, and succinic acid was investigated at pH 3 and 25 °C through batch experiments. The results demonstrate that the removal of Cr(VI) by organic acids assisted with CuO could markedly be improved under the irradiation of simulated solar light. The removal rates of Cr(VI) were in the order: tartaric acid (with two α-OH groups and two -COOH groups) > citric acid (with one α-OH group and three -COOH groups) > malic acid (with one α-OH group and two -COOH groups) > lactic acid (with one α-OH group and one -COOH group) > succinic acid (with no α-OH group and two -COOH groups), suggesting that the reductive efficiency of Cr(VI) strongly depends on the number of α-OH groups in organic acids. A possible mechanism of CuO photocatalytic reduction of Cr(VI) by organic acids is proposed. CuO is firstly dissolved to release Cu(II), and then form Cu(II)-organic acid complexes. Furthermore, Cu(I) and active intermediates are produced through a ligand-to-metal charge-transfer pathway under irradiation, responsible for the rapid reduction of Cr(VI). In addition, the impact factors for CuO photocatalytic reduction of Cr(VI) by tartaric acid were further examined. High CuO loading and tartaric acid concentration, and low pH in the reaction system were conducive to the reduction of Cr(VI), and the removal of Cr(VI) obeyed to a pseudo zero-order kinetic model.     

添加有机酸对土壤镉形态转化及苋菜镉积累的影响

植物根系分泌的低分子量有机酸能够与土壤中的镉形成镉–有机酸复合体,从而影响根际镉的移动性。本文通过添加有机酸对土壤镉形态转化的研究,阐明有机酸与镉生物积累的关系。采用盆栽试验及土壤培养等方法,研究了添加苹果酸、柠檬酸对赤红壤和黄棕壤中镉的形态转化以及超积累型苋菜天星米镉生物积累的影响。结果表明,与Cd 25 mg/kg处理比较,Cd 25 mg/kg＋苹果酸、Cd 25mg/kg＋柠檬酸处理对苋菜生物量未产生影响,但显著增加苋菜根系及地上部镉含量;添加苹果酸、柠檬酸处理显著降低土壤专性吸附态Cd含量,却显著增加了交换态Cd、碳酸盐结合态Cd和有机结合态Cd含量。说明添加苹果酸、柠檬酸还能够通过影响土壤镉形态转化而促进苋菜对镉的积累。     

籽粒苋不同富钾基因型根系分泌物中有机酸和氨基酸的变化特点

采用溶液培养试验研究了籽粒苋(Amaranthus.spp.)不同富钾基因型在不同供钾水平条件下3个不同生长时期内根系分泌物中氨基酸和有机酸的种类及含量变化情况。结果表明,1)籽粒苋根系分泌物中氨基酸和有机酸含量随着供钾水平的升高而降低,且富钾基因型始终大于一般基因型。在低钾胁迫时,根系分泌物中有10种氨基酸和5种有机酸出现,而在供钾正常时则缺少谷氨酸、甘氨酸、苯丙氨酸、草酸和柠檬酸等;酪氨酸、-氨基丁酸和丝氨酸的含量约占氨基酸分泌总量的一半以上;苹果酸含量约占有机酸分泌总量的60%以上。2)籽粒苋生长50d时,一般基因型氨基酸和有机酸的分泌总量较生长40d时迅速降低,而富钾基因型降低速度则相对较为平稳。在3个生长期内,酪氨酸、-氨基丁酸和丝氨酸均为两类基因型根系分泌物中的主要氨基酸种类,苹果酸则是主要的有机酸类型,其在氨基酸和有机酸分泌总量中所占相对比例均随生长期的延长而升高。3)籽粒苋根系分泌物处理后的土壤速效钾含量均高于清水对照处理,富钾基因型在低钾胁迫时的根系分泌物对土壤钾的活化作用明显大于一般基因型。     

饼肥中的有机营养物质及其在发酵过程中的变化

分析测定了在恒温、恒湿条件下 4种植物油饼发酵过程中有机物质的变化。结果表明 ,由于不同植物油饼化学组成不同在发酵过程中所产生有机营养物质的成分和数量存在较大差异。发酵过程所产生的高级脂肪酸以C18、C16酸为主 ,并且不饱和脂肪酸的含量明显高于饱和脂肪酸 ;有机酸则以乳酸、苹果酸、柠檬酸、琥珀酸、酒石酸、乙酸含量较高 ,草酸含量较低 ;氨基酸则以谷氨酸含量最高 ,天门冬氨酸、亮氨酸和精氨酸含量次之。有机酸和高级脂肪酸含量随发酵时间的增加而增加 ,腐熟到一定程度时达到最高 ;而饼肥发酵 70d时各种氨基酸含量明显降低。 4种饼肥相比 ,豆饼和花生饼在发酵过程中氨基酸产生量大于芝麻饼和菜籽饼。从速度来看 ,芝麻饼腐熟最快 ,其次是豆饼 ,再次是花生饼 ,菜籽饼腐熟最慢。     

Decrease of heat shock protein levels and cell populations by wine phenolic extracts

The effect of red and white wine total extracts and phenolic fractions on heat shock protein (Hsp) levels in tumor cells and on tumor and endothelial cell populations in vitro has been investigated. Total extracts of red wines decreased Hsp70 and Hsp27 levels and the numbers of tumor and endothelial cells. Several red and white wine fractions significantly decreased Hsp27 levels, and some of them had also an effect on Hsp70 levels. A red wine fraction rich in polymeric flavanols and a white wine one rich in phenolic acids, flavonols, and tyrosol strongly lowered Hsp27 levels. Some red and white wine fractions strongly reduced tumor cell numbers, whereas most of them decreased endothelial cell numbers to variable extents. The present results indicate that wine phenolics decrease Hsp levels in tumor cells and tumor and endothelial cell populations. These properties may be important in the potent anticarcinogenic action of wine phenolics.