The source of grapefruit extract is the dried outer peel of mature or near-mature grapefruits. The naringin in it can inhibit the free radical chain reaction of self-oxidation of catechol, that is, naringin has antioxidant properties. It can also be used as a raw material for synthesizing new sweeteners such as dihydro-naringenin chalcone and new hesperidin dihydrochalcone, which are high in sweetness, non-toxic and low in energy, as well as having the function of inhibiting the enzyme aldose reductase in the eyes. It can also regulate mixed, oily and other skin types. It is one of the main raw materials for cosmetics and perfumes. The naringin contained in grapefruit extract has the effect of improving body immunity and inhibitory effects on aldose reductase in the eyes.