Why does pastry fl our typically absorb less water than cake fl our? Why is this desirable when making thin, crisp cookies? In what way is fl our treated with potassium bromate or ascorbic acid...

Why does pastry fl our typically absorb less water than cake fl our? Why is this desirable when making thin, crisp cookies?

In what way is fl our treated with potassium bromate or ascorbic acid similar to naturally aged fl our? In what way is it different?