Abstract
Rheological characteristics, i.e., farinograph and extensograph test in dough, specific-volume, hardness, sensory-properties, and the physicochemical-properties of toast-bread containing four levels (0-15%) of Portulaca oleracea leaf-powder (PLP) based on flour weight were determined. The water absorption and development-time of the dough sample increased with the addition of PLP. The increase in the PLP content in the dough sample from 10% to 15% showed significant differences in dough-stability. The energy and extensibility of dough increased for 5 and 10% and then decreased for 15% PLP substitution levels at dough resting time 45, 90, and 135 minutes after production. The specific-volume decreased and the pressure force reversely increased stepwise by 5 up to 15% dosage. Sensory-evaluation indicated that 10% of PLP in the bread is the most acceptable-level, more enriched-bread variants were less acceptable mainly owing to having less significant colour and sensory indices (p < 0.05), meanwhile dough water-absorption and specific-volume had no significant difference compared to less enriched bread samples (p > 0.05). As expected, the colour changed, too, from light brown (the control) to dark green (for 15% the PLP in bread). The moisture, dietary-fiber, protein, ash, and fat content significantly increased in the toast-bread, reflecting the enhancement levels.
Keywords:
Portulaca oleracea leaf powder; toast bread; dough rheology; bread physico-chemical properties; bread staling