Correlation Study of Multi-Element Composition and Oxidative Stability of Ziziphus Lotus Lam. Seed Oils Collected from Different Regions of Tunisia
摘要
The main objectives of this study were to identify the effect of geographic origin on the mineral composition of cold-pressed Ziziphus lotus Lam. seed oil samples obtained from twelve regions in Tunisia using inductively coupled plasma-optical emission spectrometry and to analyze their oxidative stability (Rancimat test). Results show that magnesium (8.45–18.79 mg.kg− 1 of oil) and calcium (6.90–12.43 mg.kg− 1 of oil) had the greatest concentration values among the macro-elements, while potassium had the lowest values (0.01–0.10 mg.kg− 1 of oil). Regarding microelements, iron was the main essential trace element in all studied Ziziphus lotus seed oil samples, whereas the toxic trace elements (Pb, Hg, and Cd) were detected in low concentrations below the allowed standard values. On the other side, the oxidative stability results indicated a significant negative correlation with iron content (r = -0.879). Ziziphus lotus seed oil derived from Mehdia and Sousse were the most resistant to the oxidation process. Principal component analysis revealed distinct variations among samples from different geographic origins, which can be related to the unique regional characteristics. Compared to samples from rural and urban areas, Ziziphus lotus seed oils from industrial location exhibited a significant high content of cadmium, zinc, chromium, nickel, and mercury. These findings highlight the impact of geographical origin on the mineral composition and oxidative stability of Ziziphus lotus seed oil, suggesting the usefulness of geographical profiling to ensure the quality and safety of seed oils, and their potential applications in the food, pharmaceutical, and cosmetics industries.