SEPARATION AND CHARACTERIZATION OF SIMPLE AND MALONYLATED ANTHOCYANINS IN RED ONIONS, ALLIUM-CEPA L

The colour of red onions is due primarily to anthocyanins present in t he epidermal cells of the scale leaves of the bulb. The occurrence of the four major anthocyanins, cyanidin 3-glucoside, cyanidin 3-laminari bioside, cyanidin 3-malonylglucoside and cyanidin 3-malonyllaminaribio side, was confirmed in four red onion cultivars, namely 'Mambo', 'Red Jumbo', 'Red Bone', and 'Red Granex'. In addition, four new minor anth ocyanin pigments were isolated and characterized from red onions. Two structures were determined by chemical and spectroscopic methods to be peonidin 3-glucoside, and peonidin 3-malonylglucoside, This is the fi rst report of the occurrence of simple and malonylated peonidin glucos ides in red onions. (C) 1998 Canadian Institute of Food Science and Te chnology. Published by Elsevier Science Ltd. All rights reserved.