Evaluation of the Phenolic Profile and Antioxidant Capacity of Landraces and Modern Tunisian Durum Wheat Genotypes Under Organic Farming System.

The consumption of whole wheat has increased due to its nutritional benefits, particularly its richness in phenolic compounds. This study evaluated the influence of the farming systems (organic and conventional) and the diversity of thirteen Tunisian durum wheat varieties (landraces and modern genotypes) on the phenolic profile and antioxidant capacity. UHPLC-MSn analysis allowed the identification of eight phenolic acids, mainly in bound form, while p-coumaric acid was the only compound detected in its free form. The results showed a highly significant effect of both the farming system and the variety on the bound and total fractions of all identified acids, on the total phenolic content and on the total antioxidant capacity, highlighting a combined genetic and environmental influence on their accumulation. On average, antioxidant capacity measured using the FRAP assay reached 2.70 mmol Fe/100 g under conventional farming and 2.90 mmol Fe/100 g under organic farming, indicating a slight increase in the organic system. The varieties Jenah Khotifa and Chili exhibited the highest values, reaching 3.65 mmol Fe/100 g and 3.38 mmol Fe/100 g, respectively, in the organic system, and 3.04 mmol Fe/100 g for Chili in the conventional system. Genotype and farming system influence phenolic profile. Organic farming enhanced the accumulation of bioactive compounds and increased antioxidant capacity, particularly in landraces Chili, Biskri, and Jenah Khotifa, compared to modern varieties. These findings highlight the value of traditional genotypes and organic farming in improving the functional quality of Tunisian durum wheat, while preserving local cereal biodiversity and enhancing nutritional quality.