Influence of plant maturity on anthocyanin concentrations, phenolic composition, and antioxidant properties of 3 purple basil (Ocimum basilicum L.) cultivars

• Plant maturity affects total and individual phenolic concentrations in purple basil.
• Plant maturity has a significant effect on total and individual anthocyanin levels.
• Plant maturity also influences measured antioxidant properties.
• Phenolic composition affects antioxidant properties more than anthocyanin content.

We have determined the effect of plant maturity on total and individual anthocyanin concentrations, phenolic acid content, and antioxidant capacities in three purple basil (Ocimum basilicum L.) cultivars. Plant maturity significantly influenced total phenolic content (with values ranging from 3.30 to 20.08 mg/g dry weight, DW) and average concentrations of individual phenolics, including caftaric (0.08–0.85 mg/g DW), chicoric (0.13–3.55 mg/g DW), and rosmarinic (1.31–21.31 mg/g DW) acids. Cultivar and plant maturity significantly affected the total anthocyanin content (2.07–9.72 mg/g DW) and the concentrations of the four most abundant individual anthocyanins. Plant maturity also had a significant effect on measured FRAP (ferric reducing antioxidant power) reducing capacities (3.50–28.73 mmol/100 g DW), and phenolic acid concentrations were found to have an important influence on basil antioxidant properties. Overall, the cultivar and the maturity of basil at the time it is harvested play critical roles in the herb’s phenolic and anthocyanin composition as well as its antioxidant properties.