For people with strong digestive ability, most of the enzymes in vegetables and fruits are killed in the stomach, because the pH value of gastric juice is as low as 2, and the enzymes in vegetables and fruits can hardly move below pH3. For people with insufficient gastric juice and poor digestive ability, enzymes in vegetables and fruits can play a role to some extent. However, these enzymes are not necessarily beneficial. Protease helps protein digest, amylase helps starch digest, but oxidase destroys many vitamins.
The food that really helps digestion is not so much raw vegetables and fruits as fermented food, such as unheated yogurt, fermented bean curd, fermented glutinous rice and fermented soybean. Because enzymes in microorganisms often have high activity and strong heat and acid resistance, the effect is much better than that in vegetables and fruits.
On the other hand, when the body temperature is 37℃, the activity of digestive enzymes in human body is the highest. If you eat a lot of cold vegetables and fruits, the activity of enzymes in your stomach will decrease. If the body is strong and has strong heat production, the activity of enzymes can be improved by accelerating the blood circulation in the stomach; If the body is weak and afraid of cold, the heat production ability is poor, and the blood circulation is not good, eating more raw and cold food is easy to cause abdominal distension, abdominal distension and other discomfort.
At the same time, raw vegetables contain more unmelted fiber, which has a certain stimulating effect on the stomach.