Food Additives and Digestive Enzyme. III. : Food Dyes and Tryptic Activity. (2)

Effect of food dyes on the amidase activity of trypsin was examined by using a synthetic substrate, Nα-benzoyl-L-arginine amide. Xanthene dyes strongly inhibited the tryptic activity, as shown previously in the case of hydrolysis of casein. The effects of xanthene dyes including fluorescein and its lower halogenated derivatives were also examined. From the experimental results, it was found that the extent of inhibition becomes stronger in the following order : fluorescein, 2', 7'-dichlorofluorescein<4', 5'-diiodofluorescein, 4', 5'-dibromofluorescein<eosine<3, 4, 5, 6-tetrachlorofluorescein<erythrosine<phloxine