Proximate composition and fatty acid analysis of Lablab purpureus (L.) legume seed: implicates to both protein and essential fatty acid supplementation

The high mortality rate in Bangladesh is related to poverty, which results in protein malnutrition, essential fatty acid deficiency and lacks in adequate vitamins, minerals and calorie. Exploring new food items with improved dietary nutrition factors may, therefore, help to decrease the mortality rate in the poor countries like Bangladesh. Accordingly, the present study was a proximate composition and fatty acid analysis of L. purpureus seed—a legume seed which is given no careful attention locally, though it might be a good source of valuable nutrition factors for both animals and humans. The purpose of the study was, therefore, to generate awareness that L. purpureus could also act as a good source of food components essential for good health. Proximate analysis revealed that the seed powder contained 8.47 ± 0.52% moisture; 3.50 ± 0.0.07% ash; 1.02 ± 0.06% total fat; 23.95 ± 0.15% total protein; 1.21 ± 0.16% total dietary fiber; 61.86 ± 0.70% total carbohydrate and 352.4 ± 2.66 kcal/100 g energy. Phytic acid content (%) was 1.014 ± 0.048. Major fatty acid composition (%): the essential fatty acid linoleic acid (C18:2, ω-6) was 9.50 ± 0.68, while the linolenic acid (C18:3, ω-3) was 1.95 ± 0.18. Palmitic acid (C16:0), stearic acid (C18:0) and oleic acid (C18:1) were, respectively, 2.96 ± 0.19, 0.77 ± 0.04 and 1.10 ± 0.06. Lignoceric acid (C24:0) was 0.11 ± 0.007%. Monounsaturated palmitoleic acid (0.006 ± 0.0), docosapentaenoic acid (DPA, C22:5, ω-3) and nervonic acid (0.002 ± 0.0) were present in trace amounts. Arachidonic acid (AA, C20:4, ω-6), eicosapentaenoic acid (C20:5, ω-3), and docosahexaenoic acid (C22:6, ω-3) were not detected. The fatty acid profile, thus, suggests that essential omega-6 fatty acid linoleic acid (C18:3, ω-6) and omega-3 linolenic acid (C18:3, ω-3) were the major polyunsaturated fatty acids (PUFA) present in L. purpureus seed. In addition, the seed contained high amount of proteins. Finally, these results suggest that L. purpureus seed could be used as a good source of quality food components, including protein and essential fatty acids.