Effects of extrusion cooking on the dietary fibre content and Water Solubility Index of wheat bran extrudates

Instant study was an attempt to elucidate the suitability of wheat bran for extrusion cooking and to check the effect of different extrusion parameters on the dietary fibre profile as well as on water solubility index. Response surface methodology was used to optimise the extrusion parameters. From results, it was concluded that extrusion cooking had a positive effect on total and soluble dietary fibre. Whilst the insoluble dietary fibre decreased appreciably with the varying processing parameters, the decrease in insoluble fibre and increase in soluble fibre were probably due to disruption of covalent and noncovalent bonds in the carbohydrate and protein moieties leading to smaller and more soluble molecular fragments. Additionally, water solubility index was greatly enhanced by varying extrusion temperature and screw speed. Conclusively, the findings suggest the usefulness of extrusion cooking to beneficially modify the wheat bran for value addition. Extrusion cooking resulted in improved total and soluble dietary fibre content while Insoluble dietary fibre was considerably lowered with the effect of extrusion parameters. Additionally, water solubility index was enhanced by varying extrusion temperature and screw speed. The findings suggest that usefulness of extrusion cooking to beneficially modify the wheat bran for value addition. © 2015 Institute of Food Science and Technology.