HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kyuma, K. Articles by Kawaguchi, K. Search for Related Content PubMed Articles by Kyuma, K. Articles by Kawaguchi, K. Agricola Articles by Kyuma, K. Articles by Kawaguchi, K.

Oxidative Changes of Polyphenols as Influenced by Allophane¹

ABSTRACT

Oxidative changes of polyphenols as influenced by allophane were studied in relation to humus-forming processes in Ando soils. A chestnut tannin-containing substrate was incubated for varying lengths of time with an allophanic material, and changes in the shape of ultraviolet (UV) and infrared (IR) spectra and in neutralization capacity of the polyphenols were traced with time. As compared with control materials, the allophanic material adsorbed large amounts of organic carbon (8 to 10 times as much at the end of 22 weeks), and the adsorbed organic matter kept incubated for only 2 weeks showed the following features: (1) No sharp peaks in UV spectrum at the 280 mµ region which is characteristic of tannin, (2) High optical density (about 20 times as high at 400 mµ as that of tannin), (3) High neutralization capacity (416 me. per 50 g. carbon, which is about 3 times as high as that of tannin), and (4) Strong 5.8 to 5.9 µ band in IR spectrum instead of a weak shoulder as for tannin. All these remarkable changes occurring in a very short period of time suggested that allophane might have some catalytic effect on oxidative changes of polyphenols, and a manometric determination of oxygen absorption confirmed this supposition. Such catalytic effect exerted by allophane would have great significance in humus formation and accumulation in Ando soils.

¹ Contribution from the Dept. of Agricultural Chemistry, Kyoto Univ., Kyoto, Japan. Part of the dissertation submitted by the senior author in partial fulfillment of the requirements for the Ph.D. degree, Kyoto Univ., 1961. The authors are grateful to Professor R. J. McCracken, North Carolina State College, for reading the manuscript and giving helpful suggestions. Presented before Div. S-3, Soil Science Society of America, Aug. 21, 1962, at Ithaca, N.Y.

² Research Associate and Professor of Soils, respectively.

Received for publication September 3, 1963. Accepted for publication October 10, 1963.