Production of antioxidant dietary fibre powder from cabbage outer leaves

White cabbages have been reported to contain high amount of dietary fibre (DF) and bioactive agents with high antioxidant activity. However, outer leaves of cabbages are discarded and treated as wastes and may only be used for fertilizer or animal feed. It is interesting to transform the residue into a value added product. The production of dietary fibre powder associated with antioxidant activity produced from cabbage outer leaves was developed in this study. The effects of hot-water blanching and hot air drying temperature (70-90 degrees C) on the quality of dietary fibre powder produced from cabbage outer leaves were investigated. The quality of interest was measured in terms of proximate composition and visual colour. The dominant antioxidant substances, i.e. phenolic content and vitamin C, as well as total antioxidant activity, as determined by beta-carotene bleaching method, were also evaluated. The information obtained could provide a guideline for industrial application. (C) 2009 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.