The Composition of Pectin: A Preliminary Report on the Determination of Galacturonic Acid in Pectin

Dore, W. H.

doi:10.1021/ja01412a032

Cited by 14 publications

(6 citation statements)

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“…Denny (16) obtained evidence that the coloration of apple juice by oxidation involves two different reactions and two different chromogens, as follows Chromogen A reversible, rapid dark brown oxída_ (4) reduced to relatively tion Products colorless compounds by addition of both thiourea and pineapple juice Chromogen B not reversible, slow -y thiourea inhibits but pineapple juice does not light brown oxida-( 5)…”

Section: Enzyme-catalyzed Oxidative Discolorationmentioning

confidence: 99%

Color Retention in Fruit Products

Joslyn¹

1941

Ind. Eng. Chem.

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Section: Enzyme-catalyzed Oxidative Discolorationmentioning

confidence: 99%

Color Retention in Fruit Products

Joslyn¹

1941

Ind. Eng. Chem.

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“…The carbon dioxide evolved in heating was absorbed in a potash bulb (after purification in the train of absorbents recommended by DORE) and deter-mined by weighing. The pectin value of the uronic acid found could be calculated knowing that each molecule of carbon dioxide collected corresponded to one molecule of uronic acid and assuming that this formed part of a tetragalacturonie-galactose-arabinose complex or its methyl esters (7,12,13). The volatile substances other than carbon dioxide which may be produced during the respiration of plants have recently received considerable attention.…”

Section: Analytical Proceduresmentioning

confidence: 99%

The Balance Sheet of Metabolites For Potato Discs Showing the Effect of Salts and Dissolved Oxygen on Metabolism At 23° C1

Steward¹,

Stout²,

Preston³

1940

Plant Physiology

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IntroductionThis paper presents a summarv of the effects of various salt and oxi-gen treatments so chosen that they comprise a range of conditions of peculiar interest to the student of salt accumulation.In any account of plant metabolism important processes may evade recognition unless a balance sheet of the principal metabolites can be prepared. Such balance sheets have rarely been attempted although the work of RAISTRICK et al. (31) on fungi is a notable exception. The work of RAISTRICK was concerned, however, with the use of organisms under standardized nutritional conditions to effect organic synthesis and transformations; it did not describe the effect on the metabolism of a given organism of a range of external and nutritional conditions. There is nieed of more attention to balance sheets of plant metabolism and especially so with reference to the vexed problems of respiration. Deviations from the familiar equations C6H1206 + 602 = 6CO2 + 6H20 + 674,000 cal. and C6H1206 = 2C2H50H + 2CO2 + 25,000 cal. often tacitly accepted as representative of plant respiration, are multiplying. The work of GANE and others (11,16,17) has demonstrated the production of volatile substances other than carbon dioxide and large discrepancies between respiration and the simple equations above may be encountered. For example, ARCHBOLD and BARTER (1) observed that the loss of sugar and acid in respiring apples exceeded by 17 to 30 per cent. the carbon dioxide evolved. On the other hand, DASTUR and DESAI (10) founid that in the respiration of rice the carbon dioxide evolved exceeded the utilization of sugar and they believe that acids formed durino the synthesis of protein form the source of the carbon involved. Again Luidegardh (23) states that in excised wheat roots 30 to 60 per cent. more glucose disappears than is accounted for by respiration and he tacitly assumes that the discrepalne is a measure of the sugar used in growth. In experiments with excised roots HOAGLAND has observed cases in which a very rapid disappearance of sugar occurred anid carbon dioxide productioni conitinued after the cells seemed to be free of sugar.2 1 This is the second of a series of papers on The Biochemistry of Salt Absorption by Plants. The authors are inidebted to PROF. HOAGLAND for proof-reading this paper.2 Results privately comlmunicated. PLANT PHYSIOLOGY From our present standpoint the outstanding fault in the above equations is lack of any implication that respiration concerns substances other than carbohydrates or that aerobic respiration and nitrogen metabolism are mutually dependent processes in plants.The variation between replicate samples of standard potato discs is small (47) and the effect of metabolism on the constituents of the tissue can be obtained by difference between the composition of the initial and final, experimentally treated, batches of discs. It is possible, therefore, to draw up a balance sheet with reference to any metabolite, e.g., carbohydrate, the fate of which is known with sufficient certainty so that its pr...

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“…According to Reithel and Wither (77) carbon dioxide may form from ascorbic acid reactions. Degradation of pectin produced carbon dioxide in investigations by Dore (2).…”

Section: Literature Citedmentioning

confidence: 99%