Comparative evaluation of amino acid composition and volatile organic compounds of selected Nigerian cucurbit seeds
ABSTRACT Amino acid composition and volatile organic compounds (VOCS) of five Nigerian cucurbits namely:
Luffa aegyptiaca (Mill.), Citrullus lanatus (Thunb. Matsum), Cucurbita maxima (Duchesne, ex Lam), Cucumis
metuliferus (E.Mey. ex Naudin) and Momordica balsamina (L.) were investigated using Amino acid Analyzer
and Gas Chromatography-Mass Spectrometry (GC-MS). The proportion of essential amino acids ranged from
22.75- 30.23 g/100 g protein with the highest content in M. balsamina with 30.23 g/100 g protein and the least
in C. lanatus with 22.75 g/100 g protein. High content of leucine was found in C. maxima and M. balsamina
with 7.04 and 6.11 g /100 g protein respectively. The GC-MS analysis revealed the presence of thirty-one
compounds, the most abundant classes of organic compounds in L. aegyptiaca comprised of esters with
65.17% and Fatty Acids (FA) had 32.62% while hydrocarbons amounted to 29%. In C. lanatus, seven
compounds were identified dominated by FA and hydrocarbons with 91.5 and 7.25% respectively.
In C. maxima, ten compounds were identified dominated by FA (52.24%) and hydrocarbons (43.46%). In
C. metuliferus, FA had 30.74% while aromatic compounds and alcohol had 9.18 and 0.68%, respectively.
Among the five seeds studied, the most abundant compounds identified were linoleic acid methyl ester in
L. aegyptiaca with 63.72%. Cis-cis linoleic acid is most abundant in M. balsamina (62.03%) totaling the fatty
acid portion to 86.41%. These results suggest the potential of the seeds as a source of amino acids and fatty
acids that could be useful in food and feed fortification strategies. The unique VOCS could be useful as
biomarkers for delimitation of the studied species.