1. Division of Food Sciences, University of Nottingham, Sutton Bonington, Loughborough LE12 5RD, United Kingdom, Nestl'e Product Technology Center, Lebensmittelforschung GmbH, Postfach 671; D-78221 Singen, Germany, and Nestl'e Research Center, PO Box 44, CH-1000 Lausanne, Switzerland