The (poly)phenolic content and antioxidant capacity of apple varieties grown in or imported to Northern Ireland

Abstract

Apples have benefits to health through protection against chronic disease, largely attributed to their (poly)phenolic and antioxidant content. As this content is unknown in apples grown or available in Northern Ireland, thirteen common (poly)phenols, proanthocyanidins, ascorbic acid and antioxidant capacity were determined in 74 apple varieties. Varieties were categorized into five groups: imported dessert, locally grown dessert, culinary, locally grown cider, and Irish heritage apples. (Poly)phenol content ranged from 5.16 to 33.2 g kg−1 DW and ascorbic acid from 0.03 to 1.4 g kg−1 DW across all apples investigated. Lower concentrations of total flavanols, phenolic acids, dihydrochalcones, proanthocyanidins, ascorbic acid and antioxidant capacity were found in imported dessert apples when compared to locally grown dessert, culinary, locally grown cider and Irish heritage apples. Principal component analysis (PCA) located dessert and culinary apples in two distinct groups, while many heritage and cider apples were scattered throughout the plot, suggesting that these varieties may have unique bioactive profiles. The results indicate that many older Irish varieties are a rich source of bioactives worthy of commercial exploitation, while the culinary Bramley’s seedling variety contains the highest bioactive content currently available to consumers in Northen Ireland and possibly the wider UK market.