The possibility to prevent nutrition-related diseases that include scavenge of free radicals and to block chain reactions is very important and significant for human well-being. The aim of this study was to analyse different basil extracts, determine the relationship between total phenolic/flavonoid content and antioxidant activity in order to optimize its application in industry. The extraction involved different solvents (ethanol, methanol and water), extraction time (10 and 30 min and 24, 48 and 72 h), plant fragmentation level (0.3 and 2 mm) and the presence or absence of light. Antioxidant activity was investigated by applying spectrophotometric method and measuring the total phenolic and flavonoid content and DPPH radical scavenging activity. The content of total phenolics varied from 5.2 to 185.6 mg of gallic acid equivalents per gram of a dry extract and flavonoids ranged from 0.2 to 35.0 mg of quercetin per gram of a dry extract. All extracts presented a scavenging capacity and IC50 values of DPPH radical inhibition ranged from 0.04 to 12.99 μg/ml. The evaluation of experimental data for eighty basil extracts was performed by chemometric analysis showing good correlation between yield and total phenolic compounds, as well as flavonoid content and inhibition of the DPPH radical.
Keywords: Antioxidants; Basil; Chemometrics; Cluster analysis; Principal component analysis; Scavenging capacity.