Effect of thermal processing on the bioactive compounds, antioxidative, antinutritional and functional characteristics of quinoa (Chenopodium quinoa)

Abstract

Owing to their nutritional richness, quinoa (Chenopodium quinoa) is categorized as supergrain. The study was aimed to analyze the effect of thermal processing (moist heating – boiling and autoclaving; and dry heating – roasting and microwave processing) on total phenolic (TPC) and flavonoid contents (TFC), antioxidant activities, antinutrients and functional properties. All the processes brought significant (p < 0.05) changes in quality characteristics of quinoa. Boiling reduced TPC by 10.74% whereas other processes enhanced TPC and TFC by 29.68–105.4% and 5.12–26.45%, respectively. Similar trends were observed in various antioxidant assays and microwave processing exhibited highest antioxidant potency composite index (86.52). All the processes reduced the levels of phytates. Moist heating reduced saponin contents by 14–64% whereas dry heating increased them by 9–25%. These antinutritional components in raw and processed grains were found to be within safe limits. Water absorption capacities improved by 12.16–60.39%. Swelling power was enhanced upon dry heating (21.83%) but reduced during moist heating with a maximum reduction of 3.13% after boiling. Thermally processed quinoa exhibited significant reduction in emulsification properties and flour dispersibility. Therefore, thermal processing can be used to improve the potentiality of quinoa as functional food ingredient for providing technological and health benefits.