Characterization of color, phenolic profile, and antioxidant activity of Italian pigmented rice varieties after different technological treatments

Abstract

Pigmented rice varieties are rich in antioxidant and anti-inflammatory compounds (e.g. anthocyanins and proanthocyanidins). Therefore, their consumption could exert beneficial effects, particularly in people suffering from chronic diseases (e.g., celiac disease). Pigmented rice is commonly consumed as brown rice, but technological treatments could be applied to reduce its cooking time and improve its nutritional value (vitamins and minerals). In this study, two relatively new pigmented varieties (Violet and Orange) were characterized in terms of phenolic content and antioxidant capacity and the impact of two technological treatments (e.g., milling and parboiling) on their phytochemical composition was evaluated. Two pigmented and one non-pigmented Italian varieties were included for comparison. Both technological processes affected the concentration of phenolic compounds and their relative antioxidant property. Although milling mainly reduced the phenolic content and the antioxidant activity, anthocyanins seem to be more affected by parboiling (reduction of 91.5%). Despite the effects of technological treatments on active compounds, pigmented varieties still represent an interesting antioxidant source when compared to the non-pigmented ones.