Pre-Cooked Fiber-Enriched Wheat Flour Obtained by Extrusion: Rheological and Functional Properties

Abstract

Extrusion processing was utilized to pre-cook wheat flours substituted with 0, 10, 20, and 30% wheat bran in order to enhance their rheological properties and functionality with regards to production of cookies and tortillas. Two extrusion conditions, low-temperature-low-shear (LTLS), and high-temperature-high-shear (HTHS) were studied for pre-cooking the flours. Results showed that for all flours, as % bran increased, RVA peak viscosity (PV), mixograph peak time (PTM), and peak height (PH) decreased. At all bran levels, PV, and PH were significantly lower for pre-cooked flours as compared to uncooked. As the percent bran and storage time (4 to 16 d) increased, the quality of cookies (weight and spread factor) and tortillas (specific volume, rollability, and extensibility) deteriorated for both uncooked and pre-cooked wheat flours. The quality of cookies and tortillas from pre-cooked flour were either similar or inferior to those from uncooked flour.