What you want to ask is why the pulp of grapefruit is pink after drying. With the passage of time, the combination of exocarpium citri grandis and air gradually aged, and flavonoids became more and more abundant, so the pulp was pink after drying. According to the data of the State Administration of Pharmaceutical Products, the Chinese herbal medicine "Exocarpium Citri Grandis" is a blindly qi-regulating medicine, and it is an immature or nearly mature dry skin of Rutaceae plant Huazhou pomelo.