1. Nestlé Research Center, 101 Avenue Gustave Eiffel, F-37390 Notre Dame d'Oé, France; Nestlé Research Center, Nestec Ltd., Vers-chez-les-Blanc, P.O. Box 44, CH-1000 Lausanne 26, Switzerland; and Nestec Ltd., Avenue Nestlé 55, CH-1800 Vevey, Switzerland