Small Amounts Of Organic Acids Research Articles

Physicochemical properties, total phenolic content, and antioxidant activity of the honey samples from the Herzegovina region

Honey is a natural product that is an excellent source of energy containing mainly carbohydrates and water, as well as small amounts of organic acids, vitamins, minerals, flavonoids, and enzymes. Due to the presence of bioactive compounds, it has been shown that honey is beneficial for many diseases, e.g. gastrointestinal diseases, skin diseases, cancer, heart diseases, and neurological degeneration. The study of the physical and chemical properties of honey and the content of bioactive compounds has been increasingly applied in order to determine the quality of honey samples. The aim of this study is to investigate physicochemical properties as well as the total phenol content and antioxidant activity of seven multifloral honey samples from the Herzegovina region. Physicochemical parameters determined in the honey samples (moisture, acidity, electrical conductivity, reducing sugars, sucrose, and insoluble matter) were within the quality standard limits of the Regulation on methods for control of honey and other bee products. Total phenolic content was determined using the Folin-Ciocalteu method and it ranged from 46.98 ± 6.36 to 152.94 ± 4.95 mg GAE/100 g of honey. To determine the antioxidant activity of the honey samples, two methods, FRAP and ABTS, were used. The total phenolic content of honey correlated positively with its antioxidant activity.

Effect of nanofluid on CO2-wettability reversal of sandstone formation; implications for CO2 geo-storage

HypothesisNanofluid treatment is a promising technique which can be used for wettability reversal of CO2-brine-mineral systems towards a further favourable less CO2-wet state in the existence of organic acids. However, literature requires more information and study with respect to organic acids and nanoparticles’ effect at reservoir (high pressure and high temperature) conditions. ExperimentsTherefore, we have measured in this study that what influence small amounts of organic acids exposed to quartz for aging time of (7 days and 1 year) have on their wettability and how this impact can be reduced by using different concentrations of nanoparticles at reservoir conditions. Precisely, we have tested lignoceric acid (C24), stearic acid (C18), lauric acid (C12) and hexanoic acid (C6) at 10−2 Molarity, as well as, we have also used different concentrations (0.75 wt%, 0.25 wt%, 0.1 wt%, 0.05 wt%) of silica nanoparticles at realistic storage conditions. FindingsThe quartz surface turned significantly hydrophobic when exposed to organic acids for longer aging time of 1 year, and significantly hydrophilic after nanofluid treatment at optimum concentration of 0.1 wt%. It was observed that most nanoparticles were mechanistically irreversibly adsorbed on the surface of quartz sample. This wettability shift thus may increase CO2 storage capacities and containment security.

Physical and chemical screening of honey samples available in the Saudi market: An important aspect in the authentication process and quality assessment

Honey is becoming accepted as a reputable and effective therapeutic agent by practitioners of conventional medicine and by the general public. It has many biological activities and has been effectively used in the treatment of many diseases, e.g. gastrointestinal diseases, skin diseases, cancer, heart diseases, and neurological degeneration. Honey is an excellent source of energy containing mainly carbohydrates and water, as well as, small amounts of organic acids, vitamins, minerals, flavonoids, and enzymes. As a natural product with a relatively high price, honey has been for a long time a target for adulteration. The authenticity of honey is of great importance from commercial and health aspects. The study of the physical and chemical properties of honey has been increasingly applied as a certification process for the purpose of qualification of honey samples. The current work focusses on studying the authenticity of various types of honey sold in Riyadh market (24 samples). For this purpose, physical properties (pH, hydroxylmethylfurfural HMF, and pollen test) were measured. Besides, sugar composition was evaluated using Fehling test and an HPLC method. Elemental analysis was carried out using inductively coupled plasma (ICP). In addition, the presence of drug additives was assessed by means of GC–MS. The obtained results were compared with the Saudi Arabian standards, Codex Alimentarius Commission (2001), and harmonized methods of the international honey commission.

Separate production of hydrogen and methane from biodiesel wastewater with added glycerin by two-stage anaerobic sequencing batch reactors (ASBR)

The objective of this study was to investigate hydrogen and methane production from biodiesel wastewater with added glycerin by using two-stage anaerobic sequencing batch reactors (ASBR) under 37 °C with a recycle ratio of the effluent from the methane ASBR unit-to-the feed flow rate of 1:1. Hydrogen ASBR unit was operated at a constant pH of 5.5 whereas the pH of methane ASBR unit was not controlled. Glycerin was added into biodiesel wastewater having 2330 mg/l COD to obtain a constant feed chemical oxygen demand (COD) of 45,000 m/l. At optimum COD loading rate 11.3 kg/m3d (based on feed COD load and methane ASBR volume), the system provided the highest overall hydrogen and methane production performance (75.15 ml H2/g glycerin removed) which was consistent with the maximum overall COD removal of 76.7% and the highest overall glycerin uptake of 90%. Most of added glycerin was converted to gaseous products with small amounts of organic acids and 1,3 propanediol. The low volumetric ratio of hydrogen ASBR unit-to-methane ASBR unit of 1:6 resulted in low hydrogen yields with high methane yields. Process performance of the two-stage ASBR system was limited by the inhibition of total volatile organic acids produced in both bioreactors.

Contrasting responses of root morphology and root-exuded organic acids to low phosphorus availability in three important food crops with divergent root traits.

Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers. Most P fertilizers applied to land are sorbed onto soil particles, so research on improving plant uptake of less easily available P is important. In the current study, we investigated the responses in root morphology and root-exuded organic acids (OAs) to low available P (1 μM P) and sufficient P (50 μM P) in barley, canola and micropropagated seedlings of potato-three important food crops with divergent root traits, using a hydroponic plant growth system. We hypothesized that the dicots canola and tuber-producing potato and the monocot barley would respond differently under various P availabilities. WinRHIZO and liquid chromatography triple quadrupole mass spectrometry results suggested that under low P availability, canola developed longer roots and exhibited the fastest root exudation rate for citric acid. Barley showed a reduction in root length and root surface area and an increase in root-exuded malic acid under low-P conditions. Potato exuded relatively small amounts of OAs under low P, while there was a marked increase in root tips. Based on the results, we conclude that different crops show divergent morphological and physiological responses to low P availability, having evolved specific traits of root morphology and root exudation that enhance their P-uptake capacity under low-P conditions. These results could underpin future efforts to improve P uptake of the three crops that are of importance for future sustainable crop production.

Nitrososphaera viennensis gen. nov., sp. nov., an aerobic and mesophilic, ammonia-oxidizing archaeon from soil and a member of the archaeal phylum Thaumarchaeota.

A mesophilic, neutrophilic and aerobic, ammonia-oxidizing archaeon, strain EN76T, was isolated from garden soil in Vienna (Austria). Cells were irregular cocci with a diameter of 0.6–0.9 µm and possessed archaella and archaeal pili as cell appendages. Electron microscopy also indicated clearly discernible areas of high and low electron density, as well as tubule-like structures. Strain EN76T had an S-layer with p3 symmetry, so far only reported for members of the Sulfolobales. Crenarchaeol was the major core lipid. The organism gained energy by oxidizing ammonia to nitrite aerobically, thereby fixing CO2, but growth depended on the addition of small amounts of organic acids. The optimal growth temperature was 42 °C and the optimal pH was 7.5, with ammonium and pyruvate concentrations of 2.6 and 1 mM, respectively. The genome of strain EN76T had a DNA G+C content of 52.7 mol%. Phylogenetic analyses of 16S rRNA genes showed that strain EN76T is affiliated with the recently proposed phylum Thaumarchaeota, sharing 85 % 16S rRNA gene sequence identity with the closest cultivated relative ‘Candidatus Nitrosopumilus maritimus’ SCM1, a marine ammonia-oxidizing archaeon, and a maximum of 81 % 16S rRNA gene sequence identity with members of the phyla Crenarchaeota and Euryarchaeota and any of the other recently proposed phyla (e.g. ‘Korarchaeota’ and ‘Aigarchaeota’). We propose the name Nitrososphaera viennensis gen. nov., sp. nov. to accommodate strain EN76T. The type strain of Nitrososphaera viennensis is strain EN76T ( = DSM 26422T = JMC 19564T). Additionally, we propose the family Nitrososphaeraceae fam. nov., the order Nitrososphaerales ord. nov. and the class Nitrososphaeria classis nov.

Barley malt wort fermentation by exopolysaccharide-forming Weissella cibaria MG1 for the production of a novel beverage

The growing interest of governments and industry in developing healthy and natural alternative foods and beverages that will fulfil the consumer drive towards a healthy lifestyle and clean-label, natural diet has led to an increase in traditional lactic acid bacteria fermentation research. In particular, this research aims to address the organoleptic modulation of beverages using in situ-produced bacterial polysaccharides. Weissella cibaria MG1 is capable of producing exopolysaccharides (dextran) and oligosaccharides (glucooligosaccharides) during sucrose-supplemented barley-malt-derived wort fermentation. Up to 36·4g l(-1) of dextran was produced in an optimized system, which improved the rheological profile of the resulting fermentate. Additionally, small amounts of organic acids were formed, and ethanol remained below 0·5%(v/v), the threshold volume for a potential health claim designation. The results suggest that the cereal fermentate produced by W.cibaria MG1 could be potentially used for the production of a range of novel, nutritious and functional beverages. Using conventional raw materials and traditional processes, novel LAB-fermented beverages can be produced representing an innovative mechanism towards fulfilling the aim to decrease government and personal costs as well as potentially ameliorating consumer lifestyle regarding dietary-related disease.

Acid-Mediated Prevention of Aspartimide Formation in Solid Phase Peptide Synthesis

Aspartimide formation is one of the major obstacles that impedes the solid phase synthesis of large peptides and proteins. Until now, no cost-effective strategy to suppress this side reaction has been developed. Here it is demonstrated that addition of small amounts of organic acids to the standard Fmoc cleavage agent piperidine efficiently prevents formation of aspartimide side products. This effect is shown to be virtually independent of the acid strength.

Optimization of biogas production with bioconversion of organic solid wastes (manure) and food industry wastes

The increasing demand for bioethanolworldwide inducesmany efforts for increasing its production, and the metabolic engineering of yeast cells is one alternative for increasing fermentation yield. At industrial conditions, ethanol yield is in the range of 90% of the maximal due to side production of glycerol, biomass and small amounts of organic acids. Thus,metabolic engineering strategies have been focus on the decrease of glycerol, the major batch fermentation by-product, in order to increase ethanol production. Recombinant strains of S. cerevisiae cells for different metabolic engineering strategies were submitted to fermentation assays in different medium carbon/nitrogen ratio, using high biomass and oxygen limitation. Three strategies were tested. The first was based on the modification of ammonia assimilation by changing the NADPH-dependent GDH1 pathway by ATP-consuming NADHdependent GS-GOGAT pathway (Nissen et al 2000). The second strategy attempt to by-pass the yeast NAD-dependent glutaraldehyde 3-P dehydrogenase by a bacterial NADP-dependent enzyme expressing the gapN gene (Bro et al, 2006). And in the third strategy, yeast cells expressed the bacterial gene encoding NADdependent alanine dehydrogenase. Both laboratory and industrial strains were modified. The results corroborated the published metabolic effect under laboratory medium composition. However, when the substrate was changed to composition closer to those found in industrial sugar cane juice thegeneticmodificationshardly produced theexpectedeffect onethanol yield.Only cellswith lower growth rates (over-expressing gapN or deleted for gdh1) produced significantly more ethanol and less glycerol than their parental. However, as we already know, such low growing cell might not be stableunderhardenvironmental conditions (Silva-Filhoet al 2005). Another important question to be raised is the fact that industrial strains are alreadymuch close tomaximal theoretical yield, so that measuring small changesathighcell density andhigh sugar content can be a difficult task.

Removal of pathogenic bacteria and nitrogens by Lactobacillus spp. JK-8 and JK-11

The feasibility of using Lactobacillus strains for the simultaneous removal of pathogenic bacteria and nitrogens, with the ultimate aim of application for the improvement of water quality in shrimp farms, was explored. Initially, strains of Lactobacillus spp. JK-8 and JK-11 in shrimp ponds were screened for their ability to remove pathogenic bacteria and nitrogen compounds. At the end of the incubation period in cultures of JK-8 and JK-11, JK-8 had produced 192.8 mM lactic acid and 43.6 mM acetic acid, and the pH of the culture had decreased from 7.0 to 3.8. However, the JK-11 strain produced only small amounts of organic acids, and the pH of the culture decreased from 7.0 to pH 5.4. Pathogen survival following exposure to concentrated cell-free supernatants derived from JK-8 and JK-11 cultures was also investigated. Pathogens were completely removed within 4 min of exposure to either culture supernatant. Cell-free supernatants concentrated from pH-nonadjusted JK-8 cultures and either pH-adjusted or pH-nonadjusted JK-11 cultures demonstrated remarkable antimicrobial activities against target bacteria (e.g., Vibrio parahemolyticus, V. harveyi, Edwardsiella tarda). Scanning electron microscopy analyses revealed perforations in bacterial cells and irregular rod shapes with wrinkled surfaces following incubation with the concentrated supernatants. Both JK-8 and JK-11 cultures facilitated the removal of up to 400 µM NH 4 +, NO 2 −, and NO 3 −. The results of this work are applicable for the simultaneous removal of pathogens and nitrogens from contaminated shrimp farms.

Oxidation of n-hexadecane with uranyl loaded/anchored microporous zeolites and ozone

The selective oxidation of higher n-alkanes at moderate temperature and pressure conditions is challenging. The scope of microporous molecular sieve materials as catalysts in the ozone initiated functionalisation of higher n-alkanes is investigated at 20 ± 1 °C and ∼1 atm. In the ozone initiated oxidation of the higher hydrocarbons hexadecane, tetradecane or dodecane with uranyl loaded silica or zeolite-Y (Na-Y) or ZSM-5 catalysts lead to the keto-isomers as main products, where oxygen is introduced into carbonaceous site of the product molecule, and small amounts of organic acids were produced. This paper emphasises the effect of microporous catalysts, the conversion, reaction products, yields and selectivity on ozonation of higher alkanes (e.g. hexadecane). A plausible mechanism for the ozonation of higher alkanes with new heterogeneous uranyl anchored zeolite catalysts is proposed. Using uranyl anchored/loaded microporous zeolite catalysts and ozone as oxidant higher normal alkanes are successfully oxidized to ketones, but with the moderate/reasonable selectivity.

Effect of essential oil of Citrus cinensis cv new hall – Citrus aurantium (indigenous in Greece) upon growth of Yarrowia lipolytica

The effect of essential oil from Citrus cinensis cv new hall – Citrus aurantium (indigenous in Greece) upon growth of the dimorphic non-conventional yeast Yarrowia lipolytica strain ACA-DC 50109 was studied. The microorganism was aerobically cultivated in batch mode in carbon-limited media. The essential oil was added into the culture medium in different quantities while the control experiment was carried out without addition. The essential oil caused a relatively important decrease of the highest concentration of biomass produced. Additionally, biomass yield on glucose consumed was significantly decreased with the addition of the oil on the cultivation medium. Moreover, the addition of the essential oil considerably increased the lag time of the culture. In all trials, a remarkable drop the pH value of the medium was observed due to the biosynthesis of small amounts of organic acids. Given that one principal component of this membrane is the one of cellular lipids, it was assumed that the extraction and the analysis of cellular lipids could provide information about the microbial behaviour. Total lipids were extracted, methanolyzed and analyzed with the aid of G.L.C. In the control experiment, the culture conditions did not favour accumulation of storage lipid inside the yeast cells and, hence, lipid produced corresponded to 5–9% (wt/wt) in dry cell mass. Similar concentrations of cellular lipids were produced when essential oil was added in various amounts. When essential oils were added, an increase of lower aliphatic chain saturated fatty acids was observed, suggesting an alteration in the membrane function.

Hydrogen Bonding in Alcoholic Beverages (Distilled Spirits) and Water−Ethanol Mixtures

The hydrogen-bonding properties of water-ethanol of alcoholic beverages and water-ethanol mixtures of the corresponding ethanol contents were examined on the basis of OH proton NMR chemical shifts and the Raman OH stretching spectra of water and ethanol. Japanese shochu, an unaged distilled spirit of 25% (v/v) alcoholic content made from various grains, was provided for the samples; it is a high-purity spirit as it contains only small amounts of dissolved components, like typical vodka, gin, and white rum. The hydrogen-bonding structure in shochu containing some acids was found to be different from that of the water-ethanol mixture with corresponding ethanol content. It was concluded that, by the presence of small amounts of organic acids, the water-ethanol hydrogen-bonding structure was strengthened, at the same time, the proton exchange between water and ethanol molecules was promoted in shochu, compared with the water-ethanol mixture. The NMR chemical shifts of fruit cocktail drinks suggested that the hydrogen bonding of water-ethanol in the solution was developed by organic acids and (poly)phenols from fruit juices.

Gold mobilizing fluids in the Witwatersrand Basin: composition and possible sources

Crush-leach data were obtained, using High Performance Gradient Ion-Chromatography and Capillary Electrophoresis, on individual generations of aqueous fluid inclusions in hydrothermal quartz from three different auriferous conglomerate horizons (reefs) in the late Archaean Witwatersrand Basin, South Africa. These data, supplemented by oxygen isotope analyses of hydrothermal quartz and in combination with microthermometric analyses, help to constrain the chemical composition, pH, temperature of formation and the possible source of the mineralizing fluid which, in places, was capable of mobilizing some of the primarily detrital gold in the fluvial Witwatersrand sediments. The dominant cations in the aqueous fluid inclusions are Na+ and Ca2+, with Cl− or HCO 3 − being the dominant anion, whereas K+, Mg2+, and SO 4 2− are subordinate. Most fluid inclusions have elevated NH 4 + concentrations which are directly correlated with those of N03. In a number of samples small amounts of organic acids (formate, propionate, and acetate) were also detected. A largely meteoric source is inferred for the gold-mobilizing fluids in the Witwatersrand reefs because of a lack of Br in the fluid, a composition distinctly different from that of seawater, the presence of organic acids, and δ18Ofluid values around O%o. The fluids are ascribed to hydrothermal infiltration triggered by the 2020 Ma Vredefort impact which also created a secondary permeability in the form of a dense network of micro-fractures preferentially in the conglomerate beds of the already metamorphosed Witwatersrand rock sequence. This fluid differs from the regional metamorphic fluid in the basin by having a considerably higher pH (5.7–7.2). The difference in pH might explain why the older, fairly acidic metamorphic fluid was apparently less capable of mobilizing the gold as gold solubility reaches its peak at the pH calculated for the fluid ascribed to the impact.

FTIR Analysis of Aerosol Formed in the Photooxidation of 1,3,5-Trimethylbenzene

ABSTRACT The composition of aerosol generated in the photooxidation of 1,3,5-trimethylbenzene was investigated in a smog chamber experiment. The relative concentrations of alcohols, carboxylic acids, organonitrates, carbonyl groups, nitroaromatics, aliphatic C—H and aromatic C—H in the aerosol were estimated through analysis of infrared spectra. Based on model compound calibrations it was estimated that a typical molecule in the aerosol contained three carbonyl groups, six aliphatic C—H bonds, and one hydroxyl group. Small amounts of organic acids (one molecule in ten) and organonitrates (one molecule in four) were observed. About 5–10 wt% of the aerosol mixture was aromatic and these structures contained nitro and hydroxyl groups. This information on aerosol chemical functionality was coupled with gas-phase chemistry mechanisms to propose potential aerosol formation pathways.

Carboxylic Elastomers

Abstract Carboxyl groups can be introduced into elastomers by adding olefinic acids to suitable emulsion systems prior to polymerization. In general, such carboxyl groups elevate the elasticity temperature range, impart superior filming properties, increase resistance to swelling by hydrocarbon solvents, and render the polymers susceptible to cross-linkage, gelation, and vulcanization by polyvalent reagents. In vulcanization recipes based on sulfur but containing polyvalent metal salts, the presence of as little as 1 per cent of a carboxylic monomer is recognizable through its influence on vulcanizate properties. Carboxylic elastomers can be cross-linked by reactions of the carboxyl groups. Salt formation with zinc oxide, without pigmentation, gives stocks having stress-strain properties equaling or surpassing those of black-pigmented sulfur-cured vulcanizates of analogous noncarboxylic polymers. Several divalent metal oxides and other salts can be used as vulcanizing agents. The metal oxide vulcanizates possess excellent stress-strain properties, but poor compression sets. Certain vulcanizates are improved by the inclusion of small amounts of organic acids. An excess of organic acid causes devulcanization. Carbon blacks function principally as loading rather than reinforcing pigments.

Ether-Soluble Organic Acids and Buffer Properties of Citrus Peels

1. The concentrations of ether-soluble organic acids are much lower in peels of citrus fruits (oranges, grapefruit, and lemons) than in juice samples of corresponding pulps. The high pH values of the peel saps indicate that most of the organic acids are present in the salt form and not in the free state. The amounts of citric and malic acids in the expressed saps agreed satisfactorily with the total organic acids titrated between pH 7.8 and 2.6. The organic acids precipitated from the peel sap with lead acetate agreed with the total organic acids titrated between pH 7.8 and 2.6 on a water solution of the ether extract. The citric and malic acids values of the ether extract agreed substantially with similar values of the lead acetate precipitate. The ether liquid extraction method is satisfactory for the isolation of organic acids from citrus-peel saps. 2. The total nonvolatile organic acids were extracted from dried peel of citrus fruits with absolute ether at pH 1. The organic acid content consisted chiefly of citric, malic, and oxalic acids. The citric acid content is very low in comparison with the concentrations of malic and oxalic acids. The oxalic acid is present in the peel as insoluble calcium oxalate, with the exception of a trace occurring in the peel sap. 3. The titration curves of peel saps of citrus fruits (navel and Valencia oranges, grapefruit, and lemons) show that these systems contain comparatively small amounts of organic acids and their salts. In the absence of these constituents, the pH values of the peels are high, and these systems consequently have only a slight buffer capacity.

Studies on the Nature of the Action of Organic Accelerators for Rubber Vulcanization. X. The Action of Organic Acids on Rubber Sols

Abstract In continuation of the previous communication, the author has examined the influence of small amounts of organic acids, such as butyric, valeric, propionic, chloroacetic, bromoacetic, p-bromobenzoic, and o-iodobenzoic acids, on the viscosity of dilute benzene-rubber sols. The results are briefly summarized as follows: