Contents lists available at ScienceDirect Microchemical Journal journal homepage: www.elsevier.com/locate/microc Chemical composition and mineralogical residence of sesame oil from plants grown in different Yemeni environments Faez Mohammed a,b, ⁎ , Nada Abdulwali c , Dominique Guillaume d, ⁎⁎ , Noël Tenyang e , Roger Ponka f , Kamal Al-Gadabi a , Rahma Bchitou b , Abdul Hafeedh Abdullah g , Khalid Mohammed Naji h a UniversitySana'a, Faculty of Education –Arhab, Sana'a, Yemen b Laboratory of Nanostructure, Process Engineering and Environment, Department of Chemistry, Faculty of Science, University Mohammed V-Agdal Rabat, Morocco c Laboratoire des Matériaux Nanotechnologie et Environnement, Université Mohamed V Agdal, Faculté des Sciences, Av. IbnBattouta, BP 1014 Rabat, Morocco d Institut de ChimieMoléculaire de Reims, School of Medicine-Pharmacy, CNRS-UMR 7312, 51 Rue Cognacq Jay, 51100 Reims, France e University of Maroua, Faculty of Science, Department of Biological Sciences, P.O. Box 814, Maroua, Cameroon f University of Maroua, The Higher Institute of The Sahel, Department of Agriculture, Livestock and By-Products, P.O. Box 46, Maroua, Cameroon g University Hodeidah, Faculty of Education – Hodeidah, Yemen h Department of Chemistry, Faculty of Science, Sana'a University, Sana'a, Yemen ARTICLE INFO Keywords: Cold-press oil Oil quality ICP-OES Yemen ABSTRACT Sesame seeds collected in eight provinces of Yemen were used to prepare cold-pressed sesame oil over three consecutive years. After ascertaining the nutritional quality and compliance with official norm of each batch of oil, mineral composition was determined by ICP-OES. No major and significant variations were detected over three years indicating the high reproducibility of Yemeni sesame oil composition as a function of its geographic origin. Three physico-chemically distinct sub-groups were identified. A subgroup includes sesame oil from Al Bayda, Marib, Ibb, and Taiz; a second is constituted by sesame oil from Abyan, Shabwa, and Hadhramount while sesame oil from Hodeida presents its own specificity. Calcium content was between 3.02 and 9.66 mg/kg, this cation making up 50% of the total mineral content. The two other most abundant minerals were potassium (0.824–4.251 mg/kg) and magnesium (0.811–4.742 mg/kg). Potentially toxic metal (Cd, Pb, Cu, Sn and Zn) content was very low in all samples. Principal component analysis showed that Abyan oil presents a unique metal-content profile. The precise geographic origin of Yemeni sesame oil can be determined by element content analysis. 1. Introduction Sesame (Sesamum indicum L.) oil is probably the most ancient oil seed crop known to human kind, it has been cultivated in Asia and Africa for 2000 years [1]. It is still highly valued as a traditional healthy food ingredient [2,3]. Several other outputs have also recently been envisioned for this oil [4]. The quantity and the quality of the oil contained in sesame seeds have been shown to depend on ecological factors such as climate, soil type and on cultivars and maturity of plant [5]. Oxidative stability of sesame oil is superior to that of other vege- table oils although it contains nearly 85% unsaturated fatty acids [6–8]. Bioactive components, such as lignans, pinoresinol, tocopherols, le- cithin, myristic acid, and linoleate have been identified as the major antioxidants responsible for the reduction of oxidative rancidity and deterioration of sesame oil [9,10]. A group of phenolic compounds has also been correlated with the oil nutritional and organoleptic proper- ties, as well as its remarkable oxidative stability [11,12]. Sesame oil consists majoritarily of fatty acids whose distribution varies with the species of sesame seed [13,14]. Main fatty acids are palmitic acid (16:0; 7.0–12.0%), stearic acid (18:0; 3.5–6.0%), oleic acid (18:1; 35–50%), linoleic acid (18:2; 35–50%). Vegetable oil quality is generally assessed by the determination of physico-chemical parameters [15–17]. Another important quality cri- terium of vegetable oils is its metal content [18–20], which can be analyzed by ICP-OES [21,22], and whose presence results from en- dogenous factors connected with the plant metabolism, and exogenous factors due to contamination during the agronomic techniques of pro- duction, as well as systems and materials of packaging and storage [23,24]. Recent studies have focused on the composition of locally produced https://doi.org/10.1016/j.microc.2018.04.011 Received 5 March 2018; Received in revised form 11 April 2018; Accepted 11 April 2018 ⁎ Correspondence to: F. Mohammed, UniversitySana'a, Faculty of Education – Arhab, Sana'a, Yemen. ⁎⁎ Corresponding author. E-mail addresses: Faez89@hotmail.fr (F. Mohammed), dominique.guillaume@univ-reims.fr (D. Guillaume). Microchemical Journal 140 (2018) 269–277 Available online 03 May 2018 0026-265X/ © 2018 Published by Elsevier B.V. T