The thermal decomposition of aneurin and co-carboxylase at varying hydrogen ion concentrations

Abstract

The rates of destruction of aneurin and co-carboxylase at 100[degree]C were detd. in phthalate, phosphate and mixed phthalate-phosphate buffers in pH range 2.4-7.4. Destruction was less rapid in phosphate than in phthalate buffers of equivalent molar conc. and pH; in a mixed buffer, phosphate appeared to have a protective effect. Atmospheric O2 had no effect nor did Al, Zn, Fe, and Sn at 2 p.p.m., but Cu at the same conc. caused marked acceleration. Destruction of aneurin appeared to be mostly non-oxidative in nature. Co-earboxylase was much more thermolabile than aneurin at the same pH. Percentage losses found accord well with published figures of losses found on cooking various foodstuffs.