1. Milk can be drunk with fresh juice. Caking may occur when milk is mixed with some juices because the acidic components in the juices make it easier for the large casein molecules in the milk to combine with each other to form precipitates. However, this clumping phenomenon will not affect the body's absorption of nutrients, because milk will encounter a large amount of gastric acid after entering the stomach and will also agglomerate. There is no essential difference between juice agglomeration and gastric acid causing milk to agglomerate.

2. Why does milk and juice clump together? When milk encounters the acid in fruits, it will clump into a bean-like shape. This is a manifestation of the denaturation of the protein in the milk, mainly because the casein molecules are usually in a free state. If acid or alkali is added, the free casein molecules will become unstable and the molecules will combine with each other, thus making the milk appear lumpy.