Physical, Functional, and Sensory Characteristics of Cereal Extrudates

Eleven cereals were processed in a twin-screw extruder to produce directly expanded extrudates. Physical and functional properties (gelatinization degree, bulk density, expansion ratio, water absorption index, water solubility index, and sensory characteristics (hardness, crispness, and bowl life) of cereal extrudates were determined. Relationships among different variables were analyzed by SPSS. Gelatinization degree positively and negatively correlated to starch and protein, respectively (p ≤ 0.01). The same relationship was observed with water absorption index at the same significance level. Water solubility index positively correlated to protein (p ≤ 0.05), negatively correlated to starch (p ≤ 0.01), amylose (p ≤ 0.01), and fat (p ≤ 0.05). Density and bowl life positively correlated to fat (p ≤ 0.01) and amylose (p ≤ 0.05), respectively. Gelatinization degree had a high correlation with water solubility index (p ≤ 0.05). As gelatinization degree increased, water solubility index decreased. Crispness positively correlated to bowl life (p ≤ 0.01).