Insights into date seed oil composition: Geographical variability and potential applications

Abstract

Date fruit (Phoenix dactylifera L.) processing generates substantial quantities of date seeds, constituting a potential source of valuable oil yet currently considered waste. This study aimed at characterizing date seed oil (DSO) as a prospective approach for date seed valorization while investigating the influence of geographical origin on its composition. Samples from three Moroccan palm groves (Allougoum, Alnif, and Errachidia) and four non-Moroccan samples were analyzed. Liquid and gas chromatography were applied to determine the chemical composition. The prevalent fatty acids were oleic acid (Ol), ranging from 40.8% to 50.2%, followed by lauric acid (La, 14.0%–24.2%), myristic acid (My, 9.0%–12.6%), palmitic acid (Pa, 9.0%–11.6%), linoleic acid (7.1%–10.7%), and stearic acid (St, 2.4%–4.8%). Major triacylglycerols identified included LaOlLa, LaOlMy, LaOlPa, LaOlOl, MyOlPa, MyOlOl, and PaOlOl. Notably, DSO contains significant tocochromanol (424–760 mg kg⁻¹) and phytosterol content (3422–4827 mg kg⁻¹), with specific phytosterols identified for the first time. Multivariate analysis employing principal component analysis and hierarchical cluster analysis, supplemented by heatmaps, underscored the influence of geographical origin on DSO composition. Moroccan samples exhibited distinctive profiles rich in St, Ol, Pa, PaOlSt, MyOlPa, PaOlPa, γ-tocotrienol, and δ-tocotrienol, leading to a differentiation from non-Moroccan oils. Challenges in classifying DSO within selected Moroccan palm groves were discussed, emphasizing the necessity to consider major and minor compounds, along with date varieties, in geographical effect studies.

Practical Applications: By delving into the chemical properties and potential applications of DSO, this research strives to contribute to sustainable and economically viable approaches for utilizing agricultural waste products.