Effects of particle size and heating time on thiobarbituric acid (TBA) test of soybean powder

► TBARS of powder studied upon the particle size and heating time during TBA test. ► Fractional conversion model described changes in TBARS during heating. ► The particle size affected to the TBARS in the TBA-MDA reaction during TBA test. ► A diffusion model including the surface area of particle described the TBARS. ► The average transfer coefficient calculated will be useful to estimate the TBARS.