To investigate the copigmentations of glutathione and gallic acid on purple yamanthocyanins, the effects of glutathione and gallic acid on the degradation rate, thermal stability and color difference of anthocyanins were studied. The results showed that glutathione and gallic acid could effectively inhibit the degradation of anthocyanin, and the optimal addition amount was 0.03% and 0.2%, respectively. Under that additive quantity condition, the thermal degradations of purple yam anthocyanin in 50 ℃, 70 ℃ and 90 ℃ water bath were in accordan...