Physicochemical analysis of Psophocarpus tetragonolobus (L.) DC seeds with fatty acids and total lipids compositions.

Psophocarpus tetragonolobus (L.) DC. is a tropical legume with potential nutritional properties. In present study, the physical properties and proximate composition of the seeds were evaluated. Besides, the physico-chemical properties of fatty oil from fully mature seeds were also studied. The fatty oil compositions of immature, mature and fully mature seeds were evaluated by GC-FID, GC/MS and (1)H-NMR. The study revealed that, fatty oil from fully mature seeds contained high proportion of unsaturated fatty acids (75.5 %), whereas immature seeds contained higher percentage of saturated fatty acid (61.3 %). In addition, unsaponification matter (0.25 %) of fatty oil was identified as stigmasterol (66.4 %) and β-sitosterol (25.1 %). Total lipids of fully mature seeds were extracted and isolated as neutral, glyco- and phospholipids. Overall, the fatty oil of fully mature seeds was enriched with mono-unsaturated fatty acids (38.6 %) and poly-unsaturated fatty acids (36.9 %) without trans-fatty acids, thus meeting the edible oil standard.