Citation: Hussain, A.N.; Geuens, J.; Vermoesen, A.; Munir, M.; Iamonico, D.; Marzio, P.D.; Fortini, P. Characterization of Seed Oil from Six In Situ Collected Wild Amaranthus Species. Diversity 2023, 15, 237. https://doi.org/10.3390/d15020237 Academic Editors: Kalina Danova, Antoaneta Trendafilova and Jesús Fernando Ayala-Zavala Received: 23 November 2022 Revised: 31 January 2023 Accepted: 4 February 2023 Published: 8 February 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). diversity Article Characterization of Seed Oil from Six In Situ Collected Wild Amaranthus Species Amara Noor Hussain 1, * , Jeroen Geuens 2 , Ann Vermoesen 2 , Mamoona Munir 3 , Duilio Iamonico 4 , Piera Di Marzio 1 and Paola Fortini 1 1 Department of Bioscience and Territory, University of Molise, Fonte Lappone, 86090 Pesche, Italy 2 Centre of Expertise on Sustainable Chemistry, Karel de Grote University of Applied Sciences and Arts, Salesianenlaan 90, 2660 Antwerp, Belgium 3 Department of Botany Rawalpindi Women University, Satellite Town Rawalpindi, Islamabad 46300, Pakistan 4 Department of Environmental Biology, University of Rome Sapienza, Piazzale Aldo Moro 5, 00185 Rome, Italy * Correspondence: a.noorhussain@studenti.unimol.it Abstract: Six Amaranthus species (A. cruentus, A. hybridus, A. hypochondriacus, A. muricatus, A. tuber- culatus, and A. viridis) were collected in Italy (wild habitats) from crops and roadsides. Amaranth seed oil was extracted to obtain fractions rich in squalene. Squalene, free fatty acid, tocopherol, and sterol composition and content were investigated in detail. An analysis of variance and prin- cipal components was performed. The oil content in the seed ranged from 5.17% (A. muricatus) to 12.20% (A. tuberculatus). The quantity of squalene in the oil varied from 3.43% (A. muricatus) to 6.09% (A. hypochondriacus). The primary sterols were beta-sitosterol, brassicasterol, campesterol, and stigmasterol. The main tocopherols in all the samples were alfa-tocopherol, beta-tocopherol, and delta-tocopherol. Our results exhibited that the smallest seeds (A. tuberculatus) have the high- est percentages of oil and squalene, whereas the largest seeds size (A. muricatus) show the lowest percentages. There is also evidence that the samples growing at lower altitudes show the highest concentration of fatty acids. According to our results, the six wild Amaranthus species exhibited similar characteristics to commercial species. This study confirms that the site of the collection has an impact on the oil and squalene content of the Amaranthus species. Keywords: Amaranthus; fatty acids; Italy; seeds; squalene; statistical analysis; tocopherols; sterols 1. Introduction The genus Amaranthus L. (Amaranthaceae Juss.) comprises 65–70 species, of which approximately half are native to the Americas [1]. Some taxa are used as ornamentals, food, and medicines, and they are able to spread due to cultivation, negatively impacting agricultural and natural ecosystems [1–3]. Taxonomically, this genus is complex due to its high phenotypic variability, which has resulted in the current nomenclatural disorders and misapplication of several names [4–9]. Amaranthus species have the C4 photosynthetic pathway, which allows them to proliferate at high temperatures and light levels, tolerate drought, and aggressively compete with warm-season plants for light, moisture, and nutritive substances. All these characteristics make Amaranth a valuable plant, particularly in parts of the world with scarce water resources [10]. The interest in Amaranth seeds, both for their use in the food field (human and animal nutrition) and their application in the industrial field, is increasing, mainly because its seeds are a source of minerals and vegetable oil rich in essential fatty acids, vitamins, and unsaponifiable substances, particularly squalene [11]. Squalene is a biochemical antecedent of sterols and occurs naturally as a triterpenoid. It has a significant role in medicine, cosmetics, and therapeutic applications. Recently, it has also had a significant role in drug design as an antioxidant and anticarcinogen [12]. Additionally, it is also used to reduce cholesterol levels among Diversity 2023, 15, 237. https://doi.org/10.3390/d15020237 https://www.mdpi.com/journal/diversity