Ziziphus lotus (L.) Lam. almonds nutritional potential: Evidence from proximate composition, mineral, antioxidant activity, and lipid profiling reveals a great potential for valorization

Ziziphus lotus (L.) Lam. ( Z. lotus ) is used in Morocco for various purposes such as nutrition, health, and cosmetics. Its fruits are eaten fresh and Z. lotus almonds (ZLA) are underutilized biomass and usually considered as waste left after fruit consumption. The purpose of this study was to evaluate the nutritional potential of nine Moroccan origins of ZLA. They were subjected to proximate composition, elemental, fatty acid, and sterol oil profiling, total flavonoid (TFC), phenolic content (TPC), condensed tannins (CT), and antioxidant activity (AA). As findings, significant differences were observed in ZLA-measured traits according to geographical origin. ZLA had important energy value (439.31 ± 6.55–494.24 ± 0.67 kcal/100 g) associated to ash (3.77 ± 0.09–9.62 ± 0.48%), oil content (26.22 ± 0.15–31.04 ± 0.19%), proteins (26.18 ± 0.01–31.20 ± 0.03%), and carbohydrates (28.29 ± 0.60–38.94 ± 0.02%). Major macro-elements were K (5581.02 ± 20.66–6752.93 ± 93.62 mg/kg), P (5400.24 ± 24.60 6528.88 ± 88.45 mg/kg), Mg (1133.39 ± 38.91–3083.68 ± 68.34), and Ca (936.03 ± 17.20–2777.01 ± 4.23 mg/kg). The main fatty acids were oleic (60.00 ± 0.1–69.99 ± 0.1%), linoleic (10.66 ± 0.1–20.10 ± 0.1%), and palmitic (9.00 ± 0.1–10.22 ± 0.1%). The main sterols were β-sitosterol (65.94 ± 0.28–71.99 ± 0.82%), stigmasterol (10.96 ± 0.30–16.20 ± 0.26%), and campesterol (8.36 ± 0.10–9.52 ± 0.20%). Similar trends were observed for TPC (5.13 ± 0.08–10.33 ± 0.32 mg GAE/g DW), TFC (8.25 ± 0.20–12.66 ± 0.29 mg QE/g DW) and AA with FRAP (9.11 ± 0.04–43.67 ± 2.43 mg TE/g DW), ABTS (5.73 ± 0.01–5.92 ± 0.01 mg TE/g DW), and DPPH (46.83 ± 0.07–94.03 ± 0.00%), and CT (3.02 ± 0.38–7.05 ± 0.00 mg CE/g DW). ZLA composition was influenced by geographical origin and can be considered a new source of edible oil, proteins, minerals, and natural antioxidants. Graphical Abstract