Differences in bioactive compounds between red cabbage grown as microgreens or to mature plants under organic conditions

Abstract

There is increasing demand for healthy and organic foods, particularly for microgreens, which have strong flavour and aroma linked to their bioactive components. Microgreens are young vegetables that are harvested after the seeds have germinated but before the true leaves emerge. Studies comparing the quality and bioactive components of microgreens with those of their mature plant counterparts are limited. Therefore, in this study, the same red cabbage variety (Brassica oleracea var. capitata f. rubra cv. ‘Stampa F1’) was used to produce microgreens and to grow cabbage to maturity under organic conditions. Supplementary blue and red LED lights were used alongside daylight to cultivate the microgreens. The mature red cabbage had higher concentrations of vitamin C (443.8 mg 100 g−1), total phenolic compounds (318 mg GAE 100 g−1 fw), FRAP (1375.8 mmol TE 100 g−1 fw) and DPPH (1202.6 mmol TE 100 g−1 fw) than the microgreens. Notably, the total flavonoid concentration in the microgreens exceeded that in the mature cabbage. Cultivation of microgreens under blue LED lighting resulted in increased concentrations of total phenolic compounds (221 mg GAE 100 g−1 fw), total flavonoids (63.9 mg QE 100 g−1 fw), FRAP (1184.4 mmol TE 100 g−1) and DPPH (257.4 mmol TE 100 g−1), compared with those grown under red LED lighting. Cultivation of microgreens under LED lighting facilitated expeditious sprout production, and although the nutritional values were generally higher in the organic mature red cabbage, it was acknowledged that red cabbage microgreens can also make a significant contribution to human nutrition.