Standardization of acid concentration and solvent ratio for modification of psyllium husk (Plantago ovata F.)

Abstract

Native psyllium husks were treated with different concentrations (0.50, 0.55 & 0.65%) of HCl in ethanol for three different psyllium husk – solvent ratios @1:2, 1:4 and 1:6 (w/v) and compared to the native & control psyllium husk sample at 37oC temperature to reduce gel hardness and improve functional properties viz., hydration capacity, oil absorption capacity & water up-taking rate. The results highlighted that acid modification with concentration of 0.65 % HCl in the ethanol solvent for solvent ratio of 1:6 (w/v) as PSH: Solvent ratio significantly decrease the hydration capacity, oil absorption capacity & water up-taking rate of psyllium. Scanning electron microscopic (SEM) examination showed that 0.65 % HCI treatment in ethanol for ratio of 1:6 (w/v), reduce surface area of psyllium husk particle resulting in reduced water uptake capacity. Similarly the proximate composition, dietary fibre profile and textural profile analysis of the aforesaid treatment also revealed decrease in hardness and adhesiveness for gelling properties without affecting the dietary fiber and arabinoxylan contents. The results from this investigation suggests that 0.65 % HCI treatment in ethanol for ratio of 1:6 (w/v) improve functional properties of psyllium husk as required for exploration in the value addition of processed food products.