1. Department of Agriculture and Food Western Australia, P. O. Box 1231, Bunbury, Western Australia 6230, Australia, Muresk Institute, Curtin University of Technology, PMB 1, Margaret River, Western Australia 6285, Australia, The Australian Wine Research Institute, P. O. Box 197, Glen Osmond, South Australia 5064, Australia, and School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia