Influence of Sodium and Maturity Stage on the Antioxidant Properties of Cauliflower and Broccoli Sprouts

Abstract

Sprouts are very rich in antioxidants (e.g. phenolic compounds) and their consumption is beneficial for humans’ health. The sprouts’ antioxidant properties are correlated to conditions of growth and maturity stage. The present study reveals the influence of maturity stage (5-, 7- and 9-day-old) and two sodium salts, NaCl and Na₂SO₄ (10 mM and 100 mM) on the antioxidant capacity and total phenolic content of cauliflower and broccoli sprouts. The analysed sprouts’ extracts were obtained in two phases, using ethanol 70% with 0.01% hydrochloric acid. In the case of cauliflower, the 7 days germination leads to the highest total phenolic content and radical scavenging capacity. Broccoli sprouts revealed the most enhanced DPPH radical scavenging capacity and total phenolic content at 5-day-old. The two sodium salts, generally, had positive effects on global antioxidant status. It is highlighted both for broccoli and cauliflower, the stimulating effect of 100 mM Na₂SO₄ on the total phenolic content and soluble dry weight, but the DPPH radical scavenging activity was more important in the case of NaCl, than Na₂SO₄ treatments, except for cauliflower sprouts treated with 100 mM Na₂SO₄. In conclusion, germination under adequate salt stress is a protocol to be considered in order to improve antioxidant properties of broccoli and cauliflower sprouts, despite the non-convenient effects on the germination and sprouts growth. Further researches are needed to optimize the level and time periods of such treatments.