Acid treatment to improve psyllium functionality

Psyllium husks were treated with different concentrations of HCl in ethanol at ambient temperature to improve their gelling and water uptake properties. The acid-treated psyllium samples were examined and compared to the control, which was subjected to the same procedure without acid treatment, for their gelling properties, water uptake capacities, swelling volumes, and bile acid-binding capacities. The results showed that 0.36-1.44% HCl treatment in ethanol may significantly decrease the gelling, water uptake, and swelling capacities of psyllium without reducing their bile acid-binding abilities. Scanning electron microscopic (SEM) analysis showed that HCl treatment might reduce surface area of psyllium particle, which might contribute to their reduced water uptake capacity. The results from this study suggest that low concentration acid treatment in ethanol may improve psyllium functionality. (C) 2008 Elsevier Ltd. All rights reserved.