Abstract

This study investigated the antioxidant capacity and the levels of enhanced total carotenoids (TCAR), tocopherols (TOC) and phenolic (TPC) and protein (PC) contents in whole grains of wheat plants irrigated 10 and 20% (v/v) seawater (SW) in response to water extracts of microalgae Spirulina maxima (SME) and Chlorella ellipsoida (CEE) and exogenous plant growth enhancers of ascorbic acid (Vit. C) and benzyladinin (BA) treatments. Significant differences (P < 0.05) in amounts of TCAR (ranged 80 to 140 µg/g), TOC (ranged 50.4 to 115 µg/g), TPC (ranged 0.80 to 2.96 mg/g) and PC (ranged 9.34 to 13.79 %) in wheat grains among all treated plants were observed. The levels of their compounds increase related to irrigation-SW combined with algal treatments. The ethanolic extracts of grains of SW-stress plants treated with algal extracts exhibited high antioxidant capacity based on scavenging of DPPH and ABTS radicals than other samples. This activity remarked correlation with levels of antioxidant compounds present in these extracts. The electrophoretic profiles (SDS-PAGE fingerprint) of grains protein of treated samples exhibited similar pattern that in controls samples. It is concluded that the application of algal extracts to wheat plants irrigated SW lead to increase antioxidative components and protein content; hence consumption of these whole grains may render beneficial health effects.

Key words: Microalgae, antioxidant activity, phenolics, proteins, seawater.