Non-volatile Organic Acids Research Articles

Simultaneous Analysis of Volatile and Nonvolatile Organic Acids by Gas Chromatography

The gas chromatographic conditions were studied to analyze volatile and nonvolatile organic acids simultaneously as 1-butyl ester. Eleven columns were surveyed for the separation of eleven organic acid 1-butyl esters, viz. formate, acetate, propionate, butylate, lactate, oxalate, succinate, fumarate, malate, tartarate and citrate.The 1m.×3mm. I.D. column of 20% Silicone DC 550 on Diasolid L was selected as optimum column for the separation of acid esters. Of all these acid esters, only succinate and fumarate could not be separated from each othr.For the simultaneous estrification of volatile and nonvolatile organic acids, enough ammonium hydroxide was added to make the medium basic, and the basic medium was evaporated to dryness and esterified with 1-butanol and slightly excess of hydrocloric acid. The esterified acids were chromatagraphed on the column of 20% Silicone DC 550.

The Influence of a Short Period of Evaporative Cooling on the Distribution of 14C in Potato Plants1

Abstract Potato plants (Solarium tuberosum L. cv. Irish Cobbler) which were intermittently misted fixed more 14CO2 than nonmisted plants. Most of the 14C was found in the sugar fraction with the greatest activity translocating to the top of the plant. The highest 14C in the nonvolatile organic acid fraction was found in the leaf which was fed 14CO2. The radioactivity of the free amino acid fraction was highest in tubers of misted plants, but was highest in the 14CO2 fed leaf of the nonmisted plants.

NONVOLATILE ORGANIC ACIDS IN GUAVA

ABSTRACT— The nonvolatile organic acids of guava were extracted and isolated. TLC of the acids showed the presence of 6 acids, 5 of the acids identified as lactic, malic, citric, ascorbic and galacturonic. GLC of the methyl esters of the guava acids confirmed the presence of malic, citric and lactic acid. Quantitative determinations using succinic acid as an internal standard showed citric and malic acid to be present in almost equal amounts and lactic acid in much lesser amount in cultivated guavas. In wild guavas, citric acid was the predominant acid, with lesser amounts of malic and lactic acids.

Non-volatile Organic Acid and Sugar Composition of Saskatoon Berries (Alnifolia sp.) During Ripening

Malic, oxalic and citric acids are the only non-volatile organic acids present in ripening Saskatoon berries (Alnifolia sp.) in measurable concentrations. The levels of these acids, as well as the levels of glucose, fructose and sucrose are reported for three varieties of Saskatoons presently being cultivated at the Canada Department of Agriculture Research Station at Beaver-lodge, Alberta. Results indicate that the organic acids content of Saskatoons is comparable to that of apples, and that the fructose levels in the berries may decrease fairly rapidly after ripening.

A mixed silica gel—cellulose support for thin-layer chromatography of non-volatile organic acids

A mixed silica gel—cellulose support for thin-layer chromatography of non-volatile organic acids

Nonvolatile Organic Acids Produced by Sclerotinia sclerotiorum in Synthetic Liquid Media

SUMMARYSclerotinia sclerotiorum (Lib.) D By. grew well and produced sclerotia on a glucose-salts liquid medium (pH 4.1-4.3 in stationary culture). Culture filtrates and mycelia + sclerotia were analyzed separately for organic acids by paper, silicic acid partition and thin-layer chromatography. Oxalic, succinic, malic, fumarie and glycolic acids were detected in the medium and cellular extracts. The pH of the filtrates reached a minimum of 3.4 and contained maximum amounts of the dicarboxylic acids after 2 weeks growth of S. sclerotiorùm. The quantity of these acids decreased and glycolic acid increased with longer incubation. Increasing the pH of the medium increased the amount of oxalic acid produced.When S. sclerotiorum was grown on a mannitol-salts medium, growth of mycelia was depressed, no sclerotia were produced and the pH of culture filtrates increased. Only malic, oxalic and glycolic acids were found in culture filtrates. The maximum amount of malic acid was detected after 2 weeks of growth. Oxalic and glycolic acids increased slowly throughout the growth period. More total organic acid was produced on the glucose medium than on the mannitol medium.

Changes in the organic acids of Jonathan apples during cool storage in relation to the development of breakdown

Changes in oxalacetic, α-ketoglutaric and pyruvic acids, non-volatile organic acids, and titratable acidity of Jonathan apples during storage at −1° were examined. A storage treatment which increased the rate of water loss and significantly delayed the development of breakdown did not affect the amounts or changes with time of any of the acids. The results indicate that, in contrast with published data, in our results there is no direct causal relationship between oxalacetic acid and breakdown.

Gas-chromatographic resolution of nonvolatile organic acids in peaches

Gas-chromatographic resolution of nonvolatile organic acids in peaches

The Non-volatile Organic Acids of Some Fresh Fruits and Vegetables

The concentrations of citric, malic, and quinic acids were determined in several fresh fruits and of these acids and succinic and 2-pyrrolidone-5-carboxylic acids in a number of fresh vegetables. The peel of eggplant was found to have a very high content of quinic acid.

Ionic Balance in Different Tissues of the Tomato Plant in Relation to Nitrate, Urea, or Ammonium Nutrition

An investigation was carried out to study the cation-anion balance in different tissues of tomato plants supplied with nitrate, urea, or ammonium nitrogen in water culture.Irrespective of the form of nutrition, a very close balance was found in the tissues investigated (leaves, petioles, stems, and roots) between total cations (Ca, Mg, K and Na), and total anions (NO(3) (-), H(2)PO(4) (-), SO(4) (--), Cl(-)) total non-volatile organic acids, oxalate, and uronic acids. In comparison with the tissues of the nitrate fed plants, the corresponding ammonium tissues contained lower concentrations of inorganic cations, and organic acids and a correspondingly higher proportion of inorganic anions. Tissues from the urea plants were intermediate between the other 2 treatments. These results were independent of concentration or dilution effects, caused by growth. In all tissues approximately equivalent amounts of diffusible cations (Ca(++), Mg(++), K(+) and Na(+)), and diffusible anions (No(3) (-), SO(4) (--), H(2)PO(4) (-), Cl(-)) and non-volatile organic acids were found. An almost 1:1 ratio occurred between the levels of bound calcium and magnesium, and oxalate and uronic acids. This points to the fact that in the tomato plant the indiffusible anions are mainly oxalate and pectate. Approximately equivalent values were found for the alkalinity of the ash, and organic anions (total organic acids including oxalate, and uronic acids).The influence of nitrate, urea, and ammonium nitrogen nutrition on the cation-anion balance and the organic acid content of the plant has been considered and the effects of these different nitrogen forms on both the pH of the plant and the nutrient medium and its consequences discussed.

Quantitative Gas Chromatography of Nonvolatile Organic Acids: Evaluation of the Internal Standard Method.

Quantitative Gas Chromatography of Nonvolatile Organic Acids: Evaluation of the Internal Standard Method.

Metabolism of acetate-1-14C in rice leaves

Abstract The presence of large quantities of non-volatile organic acids which are members of the TCA cycle has been found in a variety of plant materials. It is now generally accepted that these acids serve as respiratory substrates and the TCA cycle participates in the metabolism of these substances in plant tissues.

Changes in the non-volatile organic acids of tomato fruit during ripening.

AbstractA study has been made of the individual non‐volatile organic acids in ethanolic extracts of tomato fruit during ripening. Whole fruit of three varieties and the outer walls and locular contents of one variety each at five stages of ripeness from mature green to full red were analysed.No trace of many of the K rebs‐cycle acids could be detected. Maximum citric acid concentrations were found at either the green‐yellow or yellow‐orange stage of ripeness according to variety. Malic acid concentrations and the malic/citric acid ratio decreased progressively as the fruit ripened. Glutamic acid increased approximately ten‐fold and aspartic acid more than doubled from the mature green to red stage of ripeness, but changes in pyrrolidonecarboxylic acid (PCA) during ripening were not statistically significant.In general, similar trends were observed in whole fruit and in the outer walls and locular contents, but malic, citric, glutamic and aspartic acid concentrations were higher in the locular contents than in the outer walls at all stages of ripeness.Alcohol‐insoluble solids (AIS) decreased markedly between the green and green‐yellow stages and then more slowly with further ripening.

Studies on the non-volatile organic acids in mulberry leaves

Studies on the non-volatile organic acids in mulberry leaves

Changes in the non‐volatile organic acids of ryegrass during air‐drying

AbstractExperiments have been carried out to determine the nature of the changes in the nonvolatile organic acids of ryegrass during air‐drying. Malic acid increased and citric and succinic acids decreased throughout most of the drying period. Quinic acid tended to increase. Aspartic acid was not detected in the fresh grass, but appeared early in the drying. Increases in glutamic and aspartic acids were less than those expected from the protein breakdown. Pyrrolidonecarboxylic acid has formed during the latter part of the drying.

NON-VOLATILE ORGANIC ACID AND pH CHANGES DURING THE FERMENTATION OF DISTILLER'S WORT

The only non-volatile organic acids found in significant amounts in distiller's wort were citric and malic acids. During the fermentation of penicillin-treated wort by yeast, the levels of citric and malic acid remained unchanged, succinic acid appeared and small amounts of lactic acid were also found. Without added penicillin, citric and malic acids disappeared, succinic acid was produced as before and lactic acid appeared in large amounts especially towards the end of the fermentation period of 65 hr. After 16 hr. fermentation, the pH of penicillin-treated wort had fallen from 5·6 to 3·6; by 40 hr. it had risen to 4·2 and by 65 hr. to 4·4; without added penicillin the changes up to 40 hr. were similar but the final pH at 65 hr. was 3·8. These pH changes are considered to be due first to the production of organic acids and loss of wort buffering power during the period of rapid yeast growth, secondly, to a period of yeast autolysis which returns to the fermenting liquor phosphate buffering capacity and, finally, to wash lactic acid.

The organic acids in banana leaves

The concentration of total non-volatile organic acids in eleven banana leaf samples was found to be 93·2 (± 10·2) m-equiv./100 g dry weight ; with a twelfth sample containing only 57·5 m-equiv. The leaf tissue represented three cultivars of banana and various stages of plant maturation, grown either in the tropics or the greenhouse. Oxalic acid constituted 83 per cent of the total acidity, malic acid about 2 per cent and “citric peak” acidity (citric acid plus certain phosphates) about 9 per cent. The remaining acidity consisted of a series of acids, each present in trace quantities. These included glutamic, aspartic, glutaric, glyceric, glycolic, glyoxylic, shikimic, succinic, pyruvic, malonic, and α-ketoglutaric acids. At least nine trace acids, including five keto acids, remain unidentified. Approximately 50 per cent of the oxalate in field-grown leaves is in water-soluble form; the greenhouse leaves contained 28 per cent soluble oxalates. The results are compared with those obtained with the leaves of temperate-zone plants.

The Formation of Succinic Acid during Alcoholic Fermentation

During alcoholic fermentation by yeast there is an increase in total acidity and a change in the constituent organic acid composition of the fermented medium. The formation of acetic acid, widely referred to as volatile acidity, is generally recognized as a normal by-product of alcoholic fermentation. In bacteria-free fermentations, the amount of acetic acid formed does not exceed 0.03 to 0.04 g per 100 ml. By far the largest increase in acidity during fermentation is brought about by the formation of nonvolatile organic acids, and it generally varies between 0.1 to 0.4 g per 100 ml but averages about 0.2 g per 100 ml. Three strains of <i>Saccharomyces cerevisiae</i> widely used in California for commercial wine fermentations were studied using dormant yeast, cake or proliferating yeast slurry. The net increase of nonvolatile organic acidity was not influenced by the yeast strain. The highest rate of increase of nonvolatile organic acidity took place during the early stages of fermentation; after the fermenting medium reached 4 to 5% alcohol, the rate of increase leveled off gradually. The net increase in nonvolatile acidity was not significantly influenced by the initial pH of the fermenting medium. However, the percentage increase in nonvolatile acidity was highest with media of low initial total acidity. With most grape juice fermentations, qualitative changes in the nonvolatile acid composition of the resulting wine are obscured by the over-all decrease in total acidity brought about by the precipitation of potassium acid tartrate. Significant amounts of organic acids, not present in the grape, are formed during fermentation and perhaps influence wine quality. At least two new organic acids are formed during fermentation, which constitute the bulk of the nonvolatile organic acidity increase. Of these, about 90% is due to one acid and about 10% to the second. On the basis of paper chromatagraphy, radiochromatagraphy, infrared absorption spectroscopy, melting point, and other traditional methods of organic chemistry, it was determined that the predominant nonvolatile organic acid formed during fermentation is succinic acid (90%). Lactic acid appears to be the other acid formed in significant amounts (10%).

Organic Acids in the Ripening Banana Fruit

The nonvolatile organic acids undoubtedly play a role in fruit ripening as they do in many other metabolic processes. As an approach to defining this role in the banana fruit, information is needed on the nature of these acids and on the changes which occur during ripening. Earlier reports (23) indicate the presence of malic, citric, oxalic, and tartaric acids in the banana fruit, with malic acid being the principal acid. Lulla and Johar (13) found only malic and citric acids in 9 varieties of bananas from India. Wolf (25) found the same 2 acids plus an unknown fraction in Colombian bananas. Steward et al. (20) have recently reported the presence of 30 organic acids in alcoholic extracts of the banana fruit. Malic and citric acids were predominant; the other acids occurred in trace amounts. These workers also detected 22 keto acids by extraction of the phenylhydrazones. There is little quantitative information available on the organic acids in bananas or on the changes which occur during ripening. The malic acid concentration has been reported to vary between 0.8 and 7.5 meq/100 g fresh weight (23) and to increase three to sevenfold during ripening (2, 8). Pyruvic, a-ketoglutaric,-and oxaloacetic acids also increase during the ripening (2). The present study was undertaken to confirm the identity of the nonvolatile organic acids of the banana fruit and to determine the concentration of these acids throughout ripening.

Chemotaxonomic investigations in asphodeleae and aloineae (liliaceae)

Seven species from two genera ( Aloe, Kniphofia) of the tribe Aloineae and eight species from four genera ( Eremurus, Asphodelus, Asphodeline, Bulbine) of the tribe Asphodeleae were investigated with regard to the presence of 1,8-dihydroxyanthraquinone derivatives and non-volatile organic acids in roots and leaves. Anthraquinones were found in all the genera investigated, except Kniphofia. Isocitric acid was detected only in species of Aloe. The results are discussed in relation to taxonomic arrangements of the taxa investigated. The plant in which homonataloin was demonstrated to be present and which was called Aloe africana in a preliminary communication has now been found to be Aloe speciosa Baker.