Abstract
The inhibitory effects of the mixed azo-dyes on pepsin activity for casein digestion were studied, using amaranth, new coccine and tartrazine, in the various ratios of the mixture. The results obtained are summarized as follows.
1) Lower pepsin activity was found when higher concentration of the food dyes was used for the experiment, except for extremely low concentration.
2) The highest inhibitory effect on pepsin activity was obtained by new coccine. The inhibitory effect by tartrazine was generally low.
3) In the many cases of high concentration of the food dyes, the inhibitory effects of the mixture of the food dyes on pepsin activity were lower than that of new coccine only, and higher than that of tartrazine only.
4) The most remarkable inhibition on pepsin activity was shown in a mixture of the food dyes which is a ratio of amaranth: new coccine: tartrazine=15: 70: 15.
5) In the mixture of the food dyes of the high ratios in amaranth or tartrazine, the increased inhibitory effect on pepsin activity was not found.
