Physical fruit traits, proximate composition, fatty acid and elemental profiling of almond [Prunus dulcis Mill. DA Webb] kernels from ten genotypes grown in southern Morocco

Abstract

This study was carried out with the aim to evaluate physical fruit traits, proximate composition, elemental content, and fatty acid profiling of almond kernels from ten genotypes (sweet and bitter) grown under various agro-ecological conditions (Tafraout, Igherm, Taliouine, Tiznit and Essaouira) in southern Morocco. During the ripening stage, samples (almond kernels) belonging to these genotypes were subjected to physical fruits measurements (weight, length, width, and thickness). Proximate composition determination (crude protein, crude oil, ash and moisture) was carried out on the powder of kernels for each genotype. Carbohydrates as well as energy value were calculated. Elemental profiling of almond kernels consisted of ten macro and microelements was determined as well as the fatty acids composition of almond extracted oil. The results of this study showed wide variations among the investigated genotypes in terms of crude protein (17.14 ± 2.14 to 25.12 ± 1.23 g/100 g), oil content (51.12 ± 2.99 to 56.26 ± 3.22 g/100 g), ash content (5.11 ± 0.45 to 6.79 ± 0.52 g/100 g), moisture content (2.55 ± 0.38 to 4.34 ± 1.16 g/100 g), carbohydrates (13.34 ± 1.54 to 18.59 ± 2.22 g/100 g) and energy value (549.80 ± 37.04 to 591.03 ± 38.56 kcal/100 g DM). A similar trend was observed in the case of mineral profiling. K (9796.08 ± 793.49 to 14 197.84 ± 1150.03 mg/kg) was the major mineral in all genotypes. This was followed by P (8190.75 ± 663.46 to 11 061.68 ± 895.96 mg/kg), Ca (3067.53 ± 248.47 to 5404.93 ± 437.79 mg/kg) and Mg (4002.85 ± 324.22 to 5101.72 ± 413.23 mg/kg), while Na, Cu, Fe, Zn, Mn and B were detected in small quantities. Our results revealed six fatty acids with a dominance of oleic acid, which varied widely among the studied genotypes and extraction technique. Solvent extraction performed better in terms of oil content. The studied genotypes showed a great pomological potential that could be exploited for their fruits such as for breeding purposes.