Comparative amino acid composition and quality parameters of Moringa oleifera testa and cotyledon

Abstract

Introduction: Moringa oleifera is a drought-resistant plant, widely used in the tropical region. The leaves and stems have been extensively utilised in foods and neutraceuticals preparation, with less attention to the seeds. In this study, amino acid (AA) compositions of M. oleifera testa and cotyledon were examined comparatively. Methods: Samples were separately defatted, hydrolyed, and neutralised. The AA solution was purified by cation-exchange solid-phase extraction, derivatised and analysed by gas chromatography. Results: Glutamic (acidic amino acid) and phenylalanine (essential amino acid, EAA) were the most concentrated in both samples. Total EAA (g/100g crude protein, cp) was higher in cotyledon (51.0) than testa (41.9). Predicted protein efficiency ratios (P-PERs) were higher in testa (0.605-1.530) than cotyledon 0.286-1.460). EAA index ranged between 0.951-1.13 (soybean comparison) and 83.0-96.9 (egg comparison) with corresponding biological value of 78.7-93.9. The following AA had scores >1.0 in comparison to whole hen’s egg, testa: glycine (Gly), glutamic acid (Glu), phenylalanine (Phe), histidine (His), and cysteine (Cys); cotyledon (Gly), proline (Pro), Glu, Phe, His, arginine (Arg) and Cys. In comparison with requirements of pre-school children, six AA (6/9 or 66.7%) had scores >1.0 in each sample. In provisional AA scoring pattern, isoleucine (Ile) (1.25) and Phe + tyrosine (Tyr) (1.68) had scores >1.0 in testa while methionine (Met) + Cys, Phe+Tyr, and tryptophan (Trp) in cotyledon. However, tryptophan and lysine were the limiting AAs in testa and cotyledon, respectively. Conclusion: The study showed that both anatomical parts would complement each other in terms of amino acid supply.