Fatty Acid Composition, Isoflavone and L-3,4-dihydroxyphenylalanine (L-dopa) Contents in Different Parts of Faba Bean (Vicia faba) Genotypes

The faba bean, one of the few crops that produces L-3,4-dihydroxy-phenylalanine (L-dopa) naturally, is also a good source of fatty acids and isoflavones. This study analyzed fatty acids, L-dopa and isoflavones in the leaves, immature pods and seeds of selected high-yielding faba bean genotypes spring-sown in Korea. The most abundant fatty acids in the leaves, immature pods and seeds were linolenic acid (58.6-63.7%), linoleic acid (46.9-58.9%), and linoleic acid (45.7-63.6%), respectively. The L-dopa content was highest in the leaf for all the faba bean genotypes except PI430715 and PI614810 where it was highest in the immature pods. The α-linolenic acid and L-dopa contents of the seed and immature pod of the PI430715 and PI614810 genotypes were the highest of all the genotypes. Four isoflavones (daidzin, genistin, daidzein and genistein) were detected with levels of daidzin and genistin generally higher than those of daidzein and genistein in each part of the faba bean. The L-dopa content was correlated (P ≤ 0.05) with those of five fatty acids (oleic, gondoic, phytanic, α-linolenic, and behenic acid). Overall, the PI430715 and PI614810 faba bean genotypes with their higher L-dopa and α-linolenic acid contents were the most functional. This study may help identify optimal genotypes for breeding new cultivars which provide functional compounds to treat Parkinson’s disease or use in foods.