Amino acids, fatty acids and mineral elements composition of <i>Roystonea regia</i> and <i>Ptychosperma macarthurii</i> palm kernels

Abstract

Roystonea regia and Ptychosperma macarthurii are exotic palm species widely grown in Nigeria as ornamentals. The kernels of R. regia and P. macarthurii were subjected to amino acids, fatty acids, and mineral elements analyses in this study. Glutamic acid (13. 64 and 14.00 g/100 g), aspartic acid (9.72 and 9.50 g/100 g), arginine (8.68 and 7.49 g/100 g), and leucine (7.23 and 7.98 g/100 g) were the dominant amino acids in R. regia and P. macarthurii seeds. The percentage yields of kernel oils were 13.9 and 1.7% for R. regia and P. macarthurii, respectively. Gas chromatograph facilitated the identification of thirteen fatty acids, mainly comprised of oleic acid (25.19 and 35.64%), linoleic acid (57.88 and 45.60%), and palmitic acid (9.6 and 10.03%) in R. regia and P. macarthurii, respectively. The analysis also revealed the high unsaturated nature of fixed oils of R. regia (83.63%) and P. macarthurii kernels (81.66%). Calcuim, copper, iron, zinc, magnesium, manganese, sodium, and potassium were also detected in the kernels; majorly, calcium (71.5 mg/L) and magnesium (23.1 mg/L) in P. macarthurii kernels, whereas sodium (24.6 ppm) and potassium levels (50.1 ppm) were higher in R. regia kernels. These results reveal the high amino acids, fatty acids, and mineral elements content of R. regia and P. macarthurii kernels. These unexploited palm fruits could be properly utilized as animal feed, edible oil, or for other industrial purposes with the knowledge of its nutritional value and fixed oil content.