Profiling of mineral elements and heavy metals in argan leaves and fruit by-products using inductively coupled plasma optical emission spectrometry and atomic absorption spectrometry

Argan leaves along with fruit by-products serve, since ancient times, as animal feed as well as incorporated into other food products. Most of research works conducted on argan tree were devoted to oily fraction and little is known about by-product. In this study, thirteen elements including macro, micro-elements as well as heavy metals were quantified in argan leaves, cake and pulp using inductively coupled plasma optical emission spectrometry and atomic absorption spectrometry. Sampling was carried out over 4 localities. Analyses of variance revealed that locality, by-product type and their interaction affect significantly data variability, while by-product was the main variability source. These outcomes were confirmed by principal component analysis, which allowed a clear discrimination among localities and by-products. Our samples were found to be rich in macro and micro-elements but lower levels of heavy metals demonstrating higher nutritional value on one hand and lack of toxicity concerns of argan by-products.