Spatial and morphological influences on the fatty acid composition of Allanblackia parviflora oils

This study examined the relative influence of location and tree morphology on the fatty acid profiles of manually expressed seed (whole seed) and kernel (seed coat removed) oils of Allanblackia parviflora across its natural distribution range in Ghana.Using the same sampling framework as a companion study on oil stability, oils were extracted from seed and kernel materials collected from 157 trees sampled across 16 communities within three ecological zones.Fatty acid methyl esters were quantified by gas chromatography and evaluated in relation to ecological zone, community, tree morphological traits, soil properties, and oil yield.Analysis of variance (ANOVA) using SPSS version 23 was employed to assess differences in the chemical properties of seed (SO) and kernel (KO) oils among communities.Principal component analysis (PCA), conducted using the Plymouth Routines in Multivariate Ecological Research (PRIMER)/Permutational Multivariate Analysis of Variance (PERMANOVA) package, was used to explore relationships among oil stability parameters, fatty acid composition, tree morphological traits, and geographical variables.Both kernel and seed oils exhibited similar fatty acid profiles, dominated by stearic and oleic acids.Stearic acid content ranged from 42.8-61.5% (mean 55.3%) in kernel oils and from 42.7-59.9%(mean 54.5%) in seed oils, while oleic acid ranged from 37.4-55.3%(mean 43.2%) and 38.7-55.9%(mean 44.0%), respectively.Palmitic acid (PA) occurred at low levels (0.8-1.6%), whereas linolenic acid was present only in trace amounts (0.3-0.7%).Although substantial tree-to-tree variation was observed, fatty acid composition was not significantly influenced by tree morphology, soil properties, community, or ecological zone.Tocopherols were not detected in bulked kernel or seed oil samples.These results indicate that A. parviflora oil exhibits a stable and highly saturated-monounsaturated fatty acid profile across ecological and morphological gradients.Together with the oil stability findings reported in the companion manuscript, the results suggest that individual tree selection, rather than sitespecific factors, is likely to be more effective for the breeding, domestication, and commercial development of A. parviflora as a high-value indigenous oil crop.