Many foods with sour taste, such as lemon, citrus, carambola, vinegar, etc. When it enters the human body, the organic acids in food are decomposed into carbon dioxide, water and most cations, and most of the metabolites are alkaline substances, so it belongs to alkaline food.

According to the degree of alkalinity, common alkaline foods in daily life can be divided into the following categories:

1. Strongly alkaline food: wine, tea, kelp, grapes, oranges, persimmons, cucumbers, carrots, etc.

2. Moderately alkaline foods: protein, soybeans, tomatoes, spinach, bananas, strawberries, lemons, prunes, etc.

3. Weakly alkaline foods: tofu, potatoes, Chinese cabbage, cabbage, rape, red beans, pears, apples, etc.

General alkaline foods include vegetables, fruits and beans. From the point of view of nutrition, the reasonable combination of acidic food and alkaline food is the guarantee of good health.

However, some alkaline foods are special. For example, although vinegar tastes acidic, it will produce carbon dioxide and water in the process of human metabolism, and will not produce acidic substances, so vinegar is also an alkaline food.