Comparative fatty acid profiling of Aesculus spp. seeds: Multi-year insights into lipid composition and valorization potential

The genus Aesculus (horse chestnut) represents a valuable yet underexplored source of phytochemicals, particularly regarding the lipid fraction of its seeds. This study investigated the fatty acid composition of seeds from three Aesculus taxa: Aesculus hippocastanum pure (AHP), Aesculus hippocastanum hybrid (AHH), and Aesculus × carnea (AXC). Lipids were extracted and analyzed using GC-MS over a four-year observation period to assess both qualitative and quantitative variability. A total of 17 fatty acids (C14–C22) were identified across the samples. The lipid profiles of AHP and AHH showed a high degree of qualitative overlap, each containing 16 fatty acids, whereas AXC exhibited only 10 fatty acids, lacking shorter-chain components (C14–C15). Quantitatively, AHH displayed the highest proportion of saturated fatty acids (12.4 %), compared to AHP (9.0 %) and AXC (10.0 %), with corresponding unsaturated fractions of 87.6 %, 91.0 %, and 90.0 %, respectively. These values were consistently higher than those reported in the literature from other geographic areas. Principal component analysis (PCA) highlighted distinct clustering among the three cultivars, with AXC sharing more compositional similarities with AHH than with AHP. Specifically, AXC and AHH both loaded positively on PC1, indicating comparable fatty acid profiles, while AHP was clearly separated along the negative axis of PC1. These findings expand current knowledge on Aesculus seed lipid composition and offer a compositional basis for exploring multiple potential valorization pathways.