SummaryThe Villavecchia test was adapted for the quantitative determination of sesamol in sesame oil. Of the several aromatic aldehydes tested, furfural, in the presence of aqueous sulfuric acid (sp. gr. 1.37 at 15°C.), proved to be the most suitable for the quantitative measurement of the color produced with sesamol.The oil, dissolved in iso‐octane (10 g. per 100 ml.), is shaken with dilute aqueous‐alcoholic potassium hydroxide to remove the free, but not the bound sesamol. The modified Villavecchia test is applied to a) the original iso‐octane solution of the oil, b) the iso‐octane solution after extraction with alkali, and/or c) the aqueous‐alcoholic extract. The optical densities, read at a wavelength of 518 mμ, correspond to the total bound, and free sesamol, respectively.The method was applied to the determination of free, bound, and total sesamol in a number of crude, refined, bleached, and deodorized sesame oils. Agreement between the values for total and free plus bound sesamol was close. Four crude sesame oils of different origins had total contents of sesamol ranging from 0.13 to 0.17%, of which nearly all was in the bound form. The yields of added sesamol varied from 95 to 106%.

SummaryThe red skins of peanut kernels contain a catecholtype tannin. The purified tannin represented about 7% of the weight of the skins. Much smaller quantities of phlobaphene and so‐called “leuco‐anthocyanic chromogen” were isolated from the skins. Some evidence of the presence of traces of a flavonic‐type pigment was obtained.Spectrophotometric investigations of the isolated tannin, phlobaphene, and “leuco‐anthocyanic chromogen” indicated a close relationship of the three pigments.The tannin gave a water‐soluble red pigment when refluxed with alcoholic hydrochloric acid. This pigment exhibited certain properties which are indicative of an oxonium‐type structure.The elementary analyses and certain properties of the isolated tannin and related pigments were considerably different from those reported by previous investigators. The amorphous nature of these substances makes chemical investigation difficult.

A previously described method for the determination of free and bound sesamol and sesamin in sesame oil was found to be inapplicable in the analysis of sesamin concentrates, because of the low solubility of the sesamin concentrate in isooctane and the presence of an iron-containing substance in the sesamin concentrate.The method was modified by using a mixed solvent (chloroformiso-octane) to dissolve the sesamin concentrate and by centrifugation in the phasic separation of free and bound sesamol to remove substances that interfere with normal color development in the Villavecchia reaction.The accuracy of the spectrophoto-SESAMOL occurs free and in bound form (sesamolin) in sesame oil. In the form of sesamolin, sesamol is combined with an unidentified substance, samin (C13H14O5), from which it is liberated by acid hydrolysis and hydrogenolysis (3). In addition to

Summary A new method for the determination of sesamin in sesame oils is described. It is based on the measurement of the ultraviolet absorption of sesame oil following the removal of sesamol by treatment with alkali and correction for the absorption resulting from the presence of sesamolin. The advantages of the new method over the previously described colorimetric method are discussed. The accuracy of the method is attested by a comparison of the determined values with those for known added amounts of sesamin in cottonseed and sesame oils. When applied to four crude oils, the content of sesamin was found to range from 0.50 to 0.96%. Ultraviolet absorption spectra curves are reported for sesamin, sesamolin, sesamol, and sesame oil.