Evaluation of Starch Components, Pasting and Functional Properties of PleurotusTuberregium Flour from Air Dried Sclerotia
- Pleurotus tuberregium sclerotia, Air-dried flour, Resistant starch, Pasting properties, Dispersibilty index, Amylose, Amylopectin, Set back ratio, Stability ratio, Gelatinization temperature.
Pleurotus tuberregium is one group of mushroom that produce edible sclerotia and is used for various culinary and medicinal purposes. Flour was produced from the air dried sclerotia and starch components, pasting and functional properties were evaluated. It had a total and resistant starch contents of 73.63% and 12.37% respectively while its amylose content was 20.03%. Its amylose and resistant starch contents classified it as regular and high resistant starch flour. Its pasting properties revealed it had pasting temperature and peak time of 60.16ºC and 5.97min respectively. Results on breakdown viscosity, set back viscosity and set back ratio revealed a high tendency of the flour to retrograde after gelatinization and when shear stress is applied. It had low swelling capacity, moderate dispersibility index and high gelatinization temperature with values of 4.17g/g, 53% and 94ºC respectively. This therefore suggests that flour from air dried Pleurotus tuberregium sclerotia can be utilized in food formulations where high resistant starch is relevant for nutritional purposes and as thickeners in food products. However, there is need for technological modification to improve its pasting properties so as to generate flour with a high stability ratio and a low set back ratio and so withstand retrogradation and with improved resistance to shear stress.