Effect of Soymilk Residue Substitution for Flour of Some Dishes on Antioxidant Activity and Urethane Induced Mutation in Drosophila melanogaster

Abstract

Four dishes, namely glutinous rice balls in coconut milk (Bua-loi), crisp crackers (Khao-kriep), fried radish cake (Khanom-puk-kad) and cookies that have soymilk residue (SR) substituted for flour as well as their traditional corresponding ones were determined for antioxidant activity and total phenolic content. The antioxidant activity of each SR- substituted samples seemed to be the same as of its corresponding traditional one. Only the phenolic content of SR- fried radish cake increased. The samples were evaluated for their modulating effect on urethane induced wing spots of Drosophila melanogaster in somatic mutation and recombinant test (SMART). Firstly, three day-old trans-heterozygous larvae (mwh flr⁺/ mwh TM3) were transferred to the Drosophila medium containing each sample substituted for corn flour; it was found that none was mutagenic. In the antimutagenicity study, each sample was subjected to the same procedure as that of the mutagenicity study except the medium used in bringing up the larvae had each sample substituted for corn flour and 20 mM urethane substituted for deionized water. The number of urethane induced wing spots on flies from both SR substituted samples and their corresponding traditional ones were reduced. Overall data suggested that the substitution of SR in each dish should be benefit to the consumers because it had increased antimutagenicity. The antimutagenicity might be due to some components of each sample modulated the expression of urethane mutagenicity.