Fatty Acid Profile and Squalene, Tocopherol, Carotenoid, Sterol Content of Seven Selected Consumed Legumes

Legume seeds (Fabaceae) of seven species Cyamopsis tetragonoloba (guar), Glycine max (soybean), Lablab purpureus (lablab-bean), Macrotyloma uniflorum (kulthi bean), Phaseolus vulgaris (common bean), Trigonella foenum-graecum (fenugreek) and Vigna unguiculata (cowpea) were studied. The oil yield ranged from 1.2 to 20.2% dw, in the lablab-bean and soybean, respectively. The polyunsaturated fatty acids (PUFA) constituted the largest part (46–78%) of total fatty acids in studied legumes. γ-Tocopherol was the predominant tocopherol (T) homologue (61–95%) in most of the tested legumes with the exception of fenugreek (α-T, 97%) and cowpea (γ-T and δ-T, nearly equal). The β-sitosterol was the main sterol (51–56%) in most legumes. While in cowpea, lablab-bean and kulthi bean the main sterols were β-sitosterol and Δ5-stigmasterol (28–37% and 14–42%, respectively). Squalene was detected only in kulthi bean and lablab-bean (58 and 284 mg/100 g oil). The total concentration of carotenoids, tocochromanols, and sterols in the studied legumes was 0.2–9.2, 12.4–276.0, and 350–8,542 mg/100 g oil, respectively. Based on the levels of minor lipophilic compounds of this study, C. tetragonoloba, T. foenum-graecum and G. max seem to have a better nutritional value compared to P. vulgaris, V. unguiculata, L. purpureus, and M. uniflorum.