肉のトリメチルアミンに關する化學的研究

Abstract

1. Methods of colorimetric estimation of trimethylamine were discussed to determine the freshness of meats and meat products. The modified DYER's picrate method was found to be satisfactory as simplified determination of amines, and the CROMWELL's aconitic method_??_be available to determine trimethylamine in raw meat without distillation procedure. 2. During spoilage of meat and fish meat, changes of trimethylamine contents were determined by both colorimetric methods. In anaerobic condition, spoiled tunny meat produced more trimethylamine than the quantity attributable to its trimethylamine oxide content. 3. Colorimetric estimations of trimethylamine were carried out in fresh, cooked, and canned meats of tunny and bonito by both methods without distillation. In this case, colorimetric values increased in cooked and canned, compared to fresh meat. The similar increase was found also with aqueous extracts of meats. 4. The meats in which colorimetric values increase during heating seemed to have cor-relation with those which contain trimethylamine oxide. In the meats of tnnny, bonito, shark, and squid, colorimetric values increased, while in those of carp and pork they did not. 5. The colorimetric value of the distillate of deproteinized solution of cooked tunny meat increased as strongly as that of its filtrate by the picrate method, but scarcely did it by the aconitic method. 6. Thus the colorimetric estimation of trimethylamine in heated meat should be made by the aconitic method with its distillate of deproteinized solution. 7. When such a meat as pork which did not contain trimethylamine oxide was heated vith addition of it, reduction of trimethylgmin oxide to trimethylamine was recognized in a_??_light degree. Of course, this reducing power depended upon the degree of heating, was neasured by the ferricyanide method, where reduction by SH groups are measured inclusi-vely. 8. Trimethylamine was isolated from cooked meat of fresh tunny as its chloroaurate. Other amines than trimethylamine produced from cooked tunny meat were not yet identified, but siight degree seemed to be tertiary amines by the fact of increase of colorimetric value in the aconitic method.