Evaluating polyphenol profile and antioxidant activity in relation to seed morphology in a collection of red lentils

Red lentils may have either a reddish-brown or grey seed coat with different pigmentation patterns, and cotyledons varying from yellow to orange-red depending on the genotype. This class of lentils is widely consumed for their nutritional and functional properties the latter being largely attributed to antioxidant polyphenols. However, the relationship between seed morphology and polyphenol composition remains poorly characterized. In this study, 59 red lentil genotypes were analyzed to investigate associations among seed color, polyphenol profiles, and antioxidant capacity. Total phenolic content and individual flavonoids were quantified, and antioxidant activity was assessed both in extracts and directly on whole-meal flour. ANOVA revealed significant variability among genotypes for all traits. Three-way ANOVA highlighted that different tegument pigmentation patterns were strongly associated with individual flavonoids and antioxidant capacity, while cotyledon color was influenced by total polyphenol content and gallic acid levels. Multivariate analyses (PCA, OPLS-DA) confirmed these relationships by achieving high classification accuracy for color classes based on combined biochemical and physical data. Overall, the results showed that morphological features of red lentils can be valuable tools for accelerating breeding programs for selecting and developing varieties rich in functional compounds.