2.5. Determination of turbidity and solubility

Turbidity: the samples were dissolved in deionized water to prepare the required concentration, and stirred magnetically at room temperature for 30 min[15]. The absorbance was measured by spectrophotometer (Lambda 1050 UV/VIS/NIR, PerkinElmer, Waltham, USA) at 600 nm with deionized water as blank control.

Solubility: quinoa protein was dispersed in the distilled water (1% w/w) and then centrifuged at 10,000 g for 30 min at 10 ℃, solubility of quinoa protein was expressed as a percentage of the total protein[16].