This is difficult to distinguish. Generally, the identification of adulterated sweet potato starch is as follows: the sweet potato starch sold in the market is refined by elutriating the starch contained in sweet potatoes, and the adulterer is fine powder mixed with dried sweet potatoes. Identification can be made from the following two aspects:

1. Sound identification: pinch a little powder with your thumb and forefinger and twist it back and forth. Pure starch is smooth and delicate, making a squeaking sound; Adulterated starch is rough and stagnant.

2. Water test: take a small amount of starch, put it in a glass of clear water, stir and let it stand for a while, and the pure starch will precipitate quickly, and the water on it will still be clear; The water on adulterated starch is turbid.

I hope it helps you.