Why does white flour have better keeping qualities than whole wheat flour?

This statement is incorrect. Whole wheat flour actually has better keeping qualities than white flour.

Whole wheat flour contains the entire wheat kernel, including the bran, germ, and endosperm. The bran and germ contain natural antioxidants and other compounds that help to preserve the flour and prevent it from spoiling. White flour, on the other hand, is made only from the endosperm of the wheat kernel, and it does not contain these beneficial compounds. As a result, white flour is more susceptible to spoilage than whole wheat flour.