Effects of seed pre-soaking on bioactive phytochemical levels of wheat and barley microgreens grown under hydroponics versus organic soil conditions

Abstract

This study was conducted to examine the effects of seed pre-soaking on bioactive phytochemicals in barley and wheat micro-greens grown under two different growing media, i.e., hydroponics and organic soil. Microgreens were cultivated for 12 days in a plant growth chamber consistent with the following: light-dark interval (12/12 hours), light-dark temperature (20/15°C), light intensity (150 µmol•m–2•s–1), and relative humidity (60%). Both wheat and barley microgreens grown in organic soil from pre-soaked seeds showed increased levels of bioactive compounds, especially carotenoids, flavonoids, phenolics, total vitamin C, and anthocyanins. Antioxidant activities [2,2-diphenyl-1-picrylhy-drazyl, 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, nitrite scavenging activity, and super-oxide dismutase (SOD)-like activity] and antioxidant enzymes (catalase activity, glutathione reductase, and guaiacol peroxidase activity) were highest in both barley and wheat microgreens grown in organic soil from pre-soaked seeds.