Purple, high β-glucan, hulless barley as valuable ingredient for functional food

Barley (Hordeum vulgare L.) stands out for its high content on bioactive compounds although it is not frequently found in human food. In this study, a purple hulless barley genotype was used to explore its food potential. β-glucans, arabinoxylans, anthocyanins and other phenolic components were determined in biscuits containing different proportions of whole barley flour and pearling fractions and compared to biscuits prepared with 100% refined (control) and 100% whole wheat flour. Barley biscuits were richer in bioactive compounds, showed higher in-vitro antioxidant capacity and lower estimated glycemic index with slight changes in physical properties. Baking did not affect β-glucans and arabinoxylans while it increased most of the phenolic compounds and antioxidant capacity. Barley anthocyanins were thermally unstable and exhibited high degradation rates but were partially stabilized by tartaric acid. Biscuits baked with 100% flour from purple barley grains fulfill the health claim of “high in fiber”. A single biscuit provides more than 0.75g of β-glucans. Thus, one serving of four biscuits satisfies the 3g of β-glucans per day target to display the label of “reduces blood cholesterol and risk of heart disease”. This work was funded by project AGL 2015-69435-C3-1 from the Spanish Ministry of Economy and Competitiveness. Mariona Martínez-Subirà was supported by a pre-doctoral fellowship (BES-2016-078,654/AGL 2015-69435-C3-1).