Comparison of the effects of alkaline extraction and ultrasound methods on Physicochemical and functional properties of quinoa protein isolate

In recent years much attention has been paid by researchers to the quinoa due to diverse functional properties, high nutritional value and gluten-free feature rather than other protein grains. The quinoa protein can be used as a nutritional supplement and a valuable food source for babies, children and adults in the formulation of sauces, sausages, soups, etc. The aim of this study has been comparing the effects of both alkaline extraction and ultrasound methods on the physicochemical and functional properties of quinoa protein isolate. Physicochemical properties includes Moisture content, fat, protein, carbohydrate, ash, weighted efficiency and color (L*,a*,b*), and functional properties including water and oil absorption capacity, foam production capacity and its stability, emulsifying capacity and its stability were examined . The results of the experiments showed that ultrasound assissted extraction without any effect on protein amount created higher extraction efficiency. It also showed the higher water absorption capacity (2/76 ml/g) and fat absorption capacity (4/63 ml/g) than the alkaline method. The alkaline method had better functions in foamability (foam production capacity 10/08% and its stability 38/88%) and emulsification properties (emulsifying capacity 17/57% and its stability 62/04%). The results have been showed that produced protein isolates have good functional properties and can be a substitute for other protein sources in different food formulations.Keywords: foam, emulsifying capacity, color properties, extraction efficiency, gluten free