Abstract:

The non-expansive extrusion process of instant oat noodles from a blend of oat and wheat flours using a double-screw extruder was investigated. Differential scanning calorimetry and Brabender farinograph were used to examine effects of mass ratio of oat to wheat flours, amount of water added to their blend, and extruder screw speed and barrel temperatures at areas Ⅱ and Ⅲ on rehydration time and gelatinization degree of instant noodles. Results showed that the optimum processing conditions were as follows: mass ratio of oat to wheat flours 40%, amount of water added to their blend 40%, extruder screw speed 210 r/min, and extruder barrel temperature 90－95 ℃ (Ⅱ) and 110－115 ℃ (Ⅲ). The gelatinization degree and rehydration time of instant oat noodles processed under the optimum conditions were 94.6% and 8 min, respectively.

Key words: instant oat noodles, non-expansive extrusion, double-screw extruder, gelatinization degree, rehydration time