Watermelon can be called "the king of summer", which is refreshing and thirst-quenching, sweet and juicy, and it is a good fruit in summer. Watermelon contains a lot of substances such as glucose, malic acid, fructose, protein amino acids, lycopene and vitamin C besides fat and cholesterol, so it is a kind of food with high nutrition, purity and food safety. The sugar content of pulp meat is generally 5-12%, including glucose, fructose and sucrose. Sweetness increased with the increase of sucrose in the late ripening stage. Watermelon pulp: protein, glucose, sucrose, fructose, malic acid, citrulline, glutamic acid, arginine, phosphoric acid, lysine, propionic acid, ethylene glycol, betaine, adenine, sucrose, carotene, tomato hydrocarbon, hexahydrotomato hydrocarbon, vitamins A, B and C, and volatile components contain various aldehydes. Watermelon seeds: containing fatty oil, protein, vitamin B2, starch, pentosan, propionic acid, urea, sucrose, etc. Watermelon skin: Watermelon skin is rich in vitamins C and E. The efficacy of watermelon: 1. Watermelon juice also contains a variety of important chemical components that are beneficial to health and beauty. It contains citrulline, alanine, glutamic acid, arginine, malic acid, phosphoric acid and other amino acids with skin physiological activity, as well as important metabolic components such as adenine, sugars, vitamins, minerals and other nutrients. These components of watermelon are most easily absorbed by the skin, and have good moisturizing, sunscreen and whitening effects on facial skin. Method: Wipe your face with melon juice, or cut off the green skin outside the watermelon, and slice it with the white skin inside for 15 minutes. 2. Because watermelon has diuretic effect, and the water content is high, the amount of urination will increase after eating watermelon, thus reducing the content of bile pigment and making the stool smooth, which has a certain effect on treating jaundice. In addition, the diuretic effect of watermelon can also make salt excrete and reduce edema, especially leg edema. For women whose legs are numb and swollen due to sitting in front of the computer for a long time, watermelon is a natural leg-beautifying fruit.