Cereal Chem 66:103-106   |  VIEW ARTICLE

Influence of Wheat Bran Particle Size on Vitamins A and E and Cholesterol in Rats.

T. S. Kahlon, F. I. Chow, C. A. Hudson, F. T. Lindgren, and A. A. Betschart. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

Six groups of rats were fed diets that contained either 5% cellulose, 10% cellulose, 22% whole wheat bran, 20.7% coarse (1.29 mm) wheat bran, 21.8% medium (0.75 mm) wheat bran, or 21.4% fine (0.3 mm) wheat bran. A group was sacrificed at time zero. Apparent digestibilities of fat and nitrogen were significantly lower in bran diets compared with cellulose diets. After five weeks, plasma cholesterol was not significantly affected by any of the bran or cellulose diets. Liver values as well as five-week liver storage of retinol equivalents were similar in rats fed bran diets compared with those fed the 5% cellulose diet, which indicates that the bioavailability of vitamin A was not impaired by bran diets. Liver alpha-tocopherol values as well as five-week storage of vitamin E were significantly lower in rats fed all high-fiber diets compared with cellulose, suggesting impairment of vitamin E bioavailability by high-fiber diets. This impairment of liver storage or total liver vitamin E was significantly greater with whole wheat bran or coarse bran diets than with the high-cellulose diet. These results indicate that 20% wheat bran diets decrease fat and protein digestibility and impair vitamin E bioavailability.