The influence of o-phosphoric acid and of sodium hydroxide on wheat starch extrusion cooking with a Creusot-Loire BC 45 twinscrew extruder has been investigated under various process conditions by employing regression analysis. Phosphoric acid (0-1.5% w/w) and sodium hydroxide (0-4% w/w) contents, feed moisture (15-60%) and mass temperature before the die (130-190°C) at constant screw speed (150 rev/min) and feed rate (18 kg d.m./h) were chosen as independent variables. An increase in phosphoric acid content and a decrease in feed moisture increased water solubility index and starch breakdown, as followed by HPLC, and decreased water absorption ability. Under similar conditions, an increase in sodium hydroxide level and moisture content usually increased water absorption ability. Starch breakdown was in this case less pronounced than in an acid environment. The presence of alkali also significantly increased browning.
|Journal||Lebensmittel-Wissenschaft & Technologie|
|Publication status||Published - 1985|
|MoE publication type||A1 Journal article-refereed|