Physicochemical and functional characterization of dietary fibres from four Indian temperate rice cultivars

Abstract

The health benefits associated with the consumption of fibre rich foods has diverted the focus of researchers towards development of functional foods with the incorporation of dietary fibre. Keeping this fact into consideration, dietary fibre was extracted from non-pigmented (SR-4, K-39, Mushq Budij) and pigmented (Zhag) rice cultivars of Kashmir and evaluated for physicochemical and functional properties. Zhag fibre revealed the highest total dietary fibre (76.90 g/100g), insoluble fibre (75.32 g/100g) and α-amylase inhibitory activity (61.73 g/100g). SR-4 dietary fibre had the highest soluble fibre content (1.40 g/100g), water holding (1.40 g/g) and oil holding (5.74 g/g) capacities. At neutral pH condition, cholesterol binding capacity was revealed to be the highest for SR-4 dietary fibre (9.30 mg/g). The Fourier transforms infrared spectra (FTIR) of dietary fibres revealed prominent peaks at 3250.0 cm−1, 2950.0 cm−1, 2846.0 cm−1 and 1600 cm−1 regions which were ascribed to stretching oscillations of –OH and –CH2 groups of cellulose or hemicelluloses and aromatic hydrocarbons of lignin polymer. The scanning electron micrographs of dietary fibres revealed presence of stripped fibrils. Results indicated that studied rice cultivars can be valuable sources of dietary fibres with several functional properties.