Relationships between total anthocyanins, antioxidant activity and quality traits in purple and blue wheat genotypes

Pigmented wheat genotypes are increasingly valued for their enhanced nutritional and functional properties due to their anthocyanin content. However, whether grain colour can reliably predict anthocyanin accumulation across genetically diverse pigmented wheat breeding materials remains unclear. This study investigated advanced purple durum wheat lines derived from Ethiopian germplasm and blue bread wheat lines to evaluate the relationships among total anthocyanin content, antioxidant activity (ABTS and DPPH assays), colour parameters (L*, a* b*) and technological quality traits (protein and gluten-related parameters). Substantial variation was observed in anthocyanin content, antioxidant activity and technological characteristics. Anthocyanin content was positively associated with antioxidant activity in both genetic backgrounds, confirming its contribution to the antioxidant potential of pigmented wheat. In purple durum wheat, colour parameters showed significant associations with anthocyanin accumulation (p < 0.05), whereas no significant relationships were detected in blue bread wheat, despite its generally higher anthocyanin levels. Technological quality traits showed no consistent relationship with anthocyanin accumulation across the analysed materials, although genotype-specific associations were observed for selected gluten-related parameters. Overall, these results indicate that the relationship between grain colour and anthocyanin accumulation is genotype-dependent, suggesting that colour-based phenotyping cannot be universally applied across pigmented wheat germplasm.