Heat-stability of the (anti-dermatitis, “anti-pellagra”) water-soluble vitamin B2

Abstract

Vitamin B2 was more stable in acid solution (pn 5.0-3.0) than in alkaline solution ([rho]H 8.0-10.0). An extract made with boiling acetic acid (0.01%) was found more suitable for experimental material than yeast itself. At [rho]H 5.0 yeast suffered no loss in vitamin B2 potency on heating for 2 hrs. at 90-100[degree] but the potency was decreased about 50% on heating for 4-5 hours at 123[degree] C. When the reaction of the extract was alkaline ([rho]H 10.0-9.5) about 1/3 of the vitamin B2 was lost in 10 days at room temp. An extract ([rho]h 8.3) heated for 2 hrs.'' at 98-100[degree] lost about 50% of its potency and 4-5 hrs.'' heating at 122-125[degree] C. destroyed 75-100%.