Effects of Processing on the Dietary Fiber Content of Wheat Bran, Pureed Green Beans, and Carrots

The dietary fiber (DF) components of green beans and carrots were fractionated and analyzed utilizing methodology developed by Anderson and Clydesdale (1980). Samples of each vegetable were examined as purchased, after boiling for 30 min, and after retorting for 60 min. Also, a standard wheat bran, whose DF profile was previously determined by Anderson and Clydesdale (1980), was analyzed after toasting for 30 and 60 min and after boiling for 30 min. Results indicated that toasting significantly increased the “lignin” content of the bran and had little effect on the other components. Wet heat processing tended to first solubilize and then destroy the pectin substances in the pureed green beans, carrots, and wheat bran.