摘要:The effects of food dyes on tryptic hydrolysis of casein were studied in vitro. The assay methods used were as follows : xanthene derivatives (erythrosine, eosine, phloxine, rose bengal) by Kunitz's method, tartrazine by direct Anson's method, and azo derivatives (amaranth, new coccine, ponceau 3R, ponceau SX, sunset yellow FCF) naphthol yellow S, and indigo carmine by indirect Anson's method using gel filtration. From the experimental results, it was found that all dyes tested inhibit in some extent tryptic activity at the concentration of 10-3M, and the inhibition by xanthene dyes is especially strong. Consequently, the dosage of these food dyes is preferable to be limited for use as food additives. As one of the causes of inhibition, the formation of inactive complex compound of enzyme-dye was assumed. This assumption was proved to be valid from the spectrophotometric data of trypsin-rose bengal complex and its precipitation at high concentration.