Comparative analysis of nutritional value and antioxidant activity in sweet and bitter almonds

In this study, four cultivars of almonds including bitter and sweet almonds from the northern regions of Morocco have been studied in terms of chemical composition, bioactive content, and antioxidant activity. Our research revealed that almonds are rich in minerals, and they displayed low levels of primary oxidation by-products and excellent stability. The fatty acid composition was dominated by oleic and linoleic acids, with slight variations between regions and almond cultivars. The analyses of unsaponifiable fraction revealed that the sterol component of almond oil was mainly composed by β-sitosterol and Δ-5-avenosterol (with regional differences), meanwhile α-tocopherol was the predominant among tocopherols. Furthermore, a significant presence of phenolic compounds was observed, particularly in Al Hoceima Beldi sweet almonds, with a gallic acid equivalent of 47.15 mg GAE/g in methanol extract and a total tocopherol content of 558.53 mg/kg. These results highlighted the strong antioxidant potential of Al Hoceima Beldi sweet almond oil, which showed good antioxidant activity for 2,2-Diphenyl-1-picrylhydrazyl (DPPH) with an IC50 value of 63.47 μg/mL and a high concentration of samples for 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (19.48 mg TE/g extract). In conclusion, the research supports the cultivation and consumption of these sweet almond cultivars in recognition of their significant contribution to human well-being. Bitter almonds have medicinal benefits but are toxic and unsafe for consumption.