1. U.S. Department of Agriculture, Agriculture Research Service, Arkansas, Children's Nutrition Center, 1120 Marshall Street, Little Rock, Arkansas 72202, Arkansas Children's Hospital Research Institute, Brunswick Laboratories, 6 Thacher Lane, Wareham, Massachusetts 02571, Universita' Degli Studi Urbino, Instituto di Chimica Biologica, Urbino, Italy, University of Arkansas, Department of Food Science, Fayetteville, Arkansas 72704, and USDA, ARS, Western Human Nutrition Research Center, Davis, California 95616