2. The "pearl" in bubble tea, commonly known as "powder yuan", is a powder yuan product made of starch as the main raw material, of which cassava starch is the most commonly used one. In addition, some wheat protein and food additives will be added to enrich the taste.

3. The cassava flour officially sold in the market is white, tasteless and odorless. All of them are detoxified, boiled in water and cooled to be transparent. Cassava starch has a high viscosity and Q-elasticity because of its large molecular weight, which forms a network structure between molecules after boiling and cooling.

4. As for the increased wheat protein, it is a kind of protein, except wheat allergy, which will not bring harm to human body. But eating too much may not be easy to digest, especially for people with poor gastrointestinal function, such as children and the elderly. In addition, when drinking "pearls", it is also recommended to chew slowly.