Paper Reviewed
Almuhayawi, M.S., AbdElgawad, H., Al Jaouni, S.K., Selim, S., Hassan, A.H.A. and Khamis, G. 2020. Elevated CO2 improves glucosinolate metabolism and stimulates anticancer and anti-inflammatory properties of broccoli sprouts. Food Chemistry 328: 127102.

Writing as background for their study, Almuhayawi et al. (2020) say that "sprouts are the young seedling produced through seed germination and sprouting mechanism [and] are harvested and eaten before turning to true leaves." Furthermore, they note sprouts are "healthy foods due to the abundance of several nutrients that have positive impacts on human health, such as inducing antioxidant capacity and protecting against cancer and cardiovascular diseases." In this regard, broccoli (Brassica oleracea) sprouts number among those that are highly nutritious. And, according to Almuhayawi et al., they are of great interest "due to their antioxidant, anticancer and anti-inflammatory activities, given their high content of antioxidants, vitamins, minerals and glucosinolates and their hydroxylated derivatives."

In light of the above facts, plus the additional knowledge that "elevated CO2 is considered as an effective fertilizer to improve the nutritional and health-promoting values of plants," the six-member research team set out to investigate the ability of atmospheric CO2 enrichment to improve "the nutritive and health promoting values of broccoli sprouts." To accomplish this objective, they exposed seeds of three cultivars (Southern Star, Prominence and Monotop) to two levels of CO2 (ambient at 400 ppm or elevated at 620 ppm) in a controlled-environment setting. After nine days sprouts in each treatment were subjected to biochemical analyses in order to determine their nutritive and health-promoting values.

Results of the study revealed elevated CO2 increased sprout photosynthesis and growth in each of the broccoli cultivars. Fresh biomass, for example, ranged between 27% and 78% higher in the elevated CO2 treatments compared to control. What is more, Almuhayawi et al. report CO2 fertilization "enriched broccoli sprouts with health-promoting metabolites and bioactivites." In this regard, they note elevated CO2 "increased quinone reductase and glutathione-S-transferase enzyme activities and glucosinolates and sulforaphane levels, but reduced cyclooxygenase and lipoxygenase enzymes activity, [which] changes increased the anticancer and anti-inflammatory properties of [the] broccoli sprouts." Consequently, the authors conclude "broccoli sprouts grown under elevated CO2, besides their high nutritive values, are recommended as a potential functional food possessing significant anti-inflammatory and anticancer properties."