Biochemical properties, organic acid composition, and mineral content of black ( <i>Morus nigra</i> L.), white ( <i>M. alba</i> L.), and red ( <i>M. rubra</i> L.) mulberry genotypes

Mulberries (Morus spp.) represent a fruit crop of considerable agricultural, economic, and medicinal importance. In the present study, 22 genotypes belonging to M. nigra (black mulberry), M. alba (white mulberry), and M. rubra (red mulberry) were evaluated for their pomological traits, biochemical composition, and mineral content. Among the investigated genotypes, ‘Çınar-4’ exhibited the highest soluble solids concentration (43.9%), whereas ‘Çüngüş−5’ produced the largest fruits (5.00 g, 27.18 mm in length). The genotype ‘Sur-3’ displayed the maximum total phenolic content (98.02 mg GAE 100 g−1 FW) and antioxidant capacity (17.3 µmol Trolox g−1 FW). Multiple regression analysis (MRA) identified total phenolic content (β = 0.56, p ≤ 0.001) and chlorogenic acid (β = 0.35, p ≤ 0.05) as the major determinants of antioxidant potential. Principal component analysis (PCA) indicated that the first three principal components accounted for 54.73% of the overall variance. Heat map analysis (HMA) further separated the genotypes into distinct clusters, with ‘Silvan-1’ emerging as the most mineral-dense genotype, particularly rich in potassium and calcium. Collectively, these findings provide an in-depth characterization of the biochemical and nutritional diversity within mulberry germplasm, underscoring their value for functional food development and genetic improvement strategies. In particular, ‘Sur-3’ is highlighted as a superior candidate for its elevated phenolic and antioxidant profile, while ‘Silvan-1’ is distinguished by its exceptional mineral composition.