Enhancement of phenolics, flavonoids and glucosinolates of Broccoli (Brassica olaracea, var. Italica) as antioxidants in response to organic and bio-organic fertilizers

A field experiment was carried out to study the effect of organic and bioorganic fertilizers on growth parameters, yield and the quality of two broccoli cultivars (Calabrese and Southern star). Bio-organic fertilizers gave better results for all vegetative growth parameters for Southern star cultivar compared to Calabrese cultivar. Total phenolic content (TPC), total flavonoid content (TFC) and total glucosinolates content (TGsC) were almost higher in Calabrese cultivar as a result of organic fertilizer treatment. The antioxidant activities of both cultivars were evaluated and Calabrese cultivar showed the higher1, 1-diphenyl-2-picrylhydrazyl DPPH. scavenging activity expressed as IC50 (its concentrations for 50% inhibition) (16.56 μg/ml) compared to Southern star (19.42 μg/ ml). In addition, Calabrese cultivar showed the higher chelating power (75.36 μg/ml) than Southern star (72.43 μg/ml) at (30 μg/ml) when the organic fertilizer was applied. The results indicated that there is a good margin for enhancing antioxidant compounds of broccoli for economic production using organic fertilization. This study indicated the potential application of broccoli as a potent natural source of antioxidants as nutraceuticals.