most fruits and vegetables belong to alkaline foods, and the acidity and alkalinity of foods are not classified according to taste, but determined according to the PH value of ash dissolved in water after food burning. The sour taste of fruits is due to the acidity and citric acid in fruits.

Notes on the attributes of fruits

Fruits can generally be divided into three categories: cold, warm and sweet. Cold fruits include oranges, tangerines, water chestnuts, bananas, Sydney, persimmons, watermelons, etc. People with weak constitution should eat with caution. Warm fruits include dates, chestnuts, peaches, apricots, longan, litchi, grapes, cherries, pomegranates, pineapples, etc. People with hot and dry constitution should eat them in moderation. Ganping fruits include plum, plum, coconut, loquat, hawthorn and apple, which are suitable for people of all systems.