Evaluation of the differences in phenolic compounds and antioxidant activities of five green asparagus (<i>Asparagus officinalis</i>L.) cultivars

Abstract

Phenolic compounds and total antioxidant activities were analysed in five green asparagus cultivars (Grande, Altas, UC800, UC301 and UC157). In addition, the colours as well as the lignin, amino acid, and microelement contents of the asparagus cultivars were assessed. Cultivar ‘Grande’ had the best greenness (a*=-12.47), the highest vitamin C (59.1 mg/kg) and microelement contents (282.3 mg/kg) and the lowest lignin content (0.92%). Cultivar ‘UC301’ had the highest amino acid content (3.95 g/kg), and cultivar ‘UC157’ had the highest total phenolic and total flavonoid contents. Correlations were determined to evaluate the relationship between phenolic compounds and total antioxidant activity. Phenolic compounds, particularly rutin, are major contributors to the antioxidant activity of green asparagus, with a correlation coefficient of r=0.977-0.982. A principal component analysis was then performed to investigate the interrelationships between the parameters and the investigated cultivars. The results showed that cultivars ‘UC157’ and ‘Grande’ had high total phenolic and rutin contents and consequently high antioxidant activity. The cultivar had a marked influence on bioactive constituents, particularly the phenolic compound content and composition, and on the antioxidant activity of green asparagus, which may provide a basis for improved health benefits and breeding programs.