Chemical composition and antioxidant activity of two strawberry cultivars

The macro- and micro-chemical composition, as well as antioxidant activity of two strawberry cultivars, Marmolada and Clery, were studied. Results showed a noticeable difference in the sugar, protein and pectin contents. Clery had 6.92% and Marmolada 4.93% of total sugar. Also, protein and pectin contents were higher in the Clery cultivar. No significant difference was observed in acidity, as well as in ash and cellulose content. Marmolada had a higher content of total phenolics and flavonoids (228.04 mg GAE /100 g FW and 136.01 mg RE/100 g FW, respectively ). The anthocyanins content in Marmolada (32.0 mg CGE/100 g FW) was slightly lower than in Clery (36.0 mg CGE/100 g FW). The antioxidant activity was evaluated spectrophotometrically, using 2,2-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging activity assay. The DPPH free radical scavenging activity, expressed as EC50 value, of Marmolada (0.77 mg/ml )was higher than of Clery (0.83 mg/ml). There was a significant positive correlation (R2>0.90) between the concentration of phenolics/flavonoids/anthocyanins and DPPH radical scavenging activity of both strawberry cultivars. These results also showed that the antioxidant value of 100 g FW Marmolada and Clery is equivalent to 237.91 mg and 219.01 mg of vitamin C, respectively.