Optimized extraction technology of glutathione from ‘Haidao 86’ germ rice by response surface methodology

Glutathione is an important functional component of ‘Haidao 86’, which has many important physiological functions in organisms and is widely used in medicine and other industries. In this study, the effects of four extraction methods (hot water extraction, formic acid extraction, ethanol extraction, and sulfuric acid extraction) on the yield of glutathione in ‘Haidao 86’ germ powders were studied by high‐performance liquid chromatography, and the yield of glutathione in hot water extraction was the highest. The effects of material–liquid ratio, temperature, pH, and time on the extraction rate of glutathione from ‘Haidao 86’ were investigated by single‐factor experiment and Box–Behnken combined experiment. The results showed that the order of influence on GSH yield was pH, temperature, material–liquid ratio, and time, and the interaction of extraction time and pH had a significant influence on glutathione yield of ‘Haidao 86’ germ powders. The optimum parameters for hot water extraction of glutathione from ‘Haidao 86’ germ powders were determined as follows: material–liquid ratio of 1:12, pH value of 2.8, temperature of 84.9°C, time of 14 min, and the extraction rate of glutathione was 139.68 mg/100 g. It provided the scientific proof for the development and industrial production of functional products of ‘Haidao 86’.