Characterization of extruded whole grain cereals enriched with Indian horse chestnut flour

Abstract

This study explores the development of a fibre-rich breakfast cereal utilizing Indian Horse Chestnut Flour (IHCF) combined with traditional whole grains, including whole wheat flour, barley flour, and corn flour. The research focuses on optimising key extrusion process variables—feed moisture content (10–18%), barrel temperature (70–150 °C), screw speed (290–380 rpm), and IHCF concentration (1.75–4.75%) to enhance the cereal’s quality attributes. Comprehensive measurements and analyses were conducted to determine the optimal conditions, focusing on water absorption capacity, bulk density, sectional expansion, water solubility index, porosity, rehydration ratio, hardness, and overall product acceptability. Extrudates rich in IHCF were also evaluated for rheological and Fourier Transform Infrared (FTIR) spectroscopy. Statistical analysis revealed significant impacts of these variables on the cereal’s physical properties. Under optimal conditions (12% feed moisture, 130 °C barrel temperature, 380 rpm screw speed, and 2.5% IHCF), the breakfast cereal exhibited superior expansion, porosity, and rehydration ratios, along with desirable hardness, achieving an overall acceptability score of 77.1. Further, an increase in feed moisture content corresponded with improved pasting properties in the optimized extruded flours. The rheological assessment indicated that the storage modulus (G′) of both extruded and native flours surpassed the loss modulus (G″), with samples at higher moisture content displaying the highest flow index but the lowest consistency coefficient. FTIR spectroscopy analysis underscored a reduction in peak intensity during extrusion, indicating notable structural modifications in the cereal constituents. This research presents significant advancements in the measurement and characterization of breakfast cereals, underscoring the potential of IHCF as a nutritious ingredient in the food industry.