Legumes as a source of natural antioxidants

Abstract

The following article summarizes the most up-to-date information available concerning endogenous bioactives and the antioxidant activity/radical-scavenging capacity of selected leguminous seeds, and extracts derived therefrom, as well as the impact of processing and seed germination on these bioactives. Biologically-active compounds of interest found in leguminous seeds come from many chemical classes and include phenolic acids as well as their derivatives, flavanols, flavan-3-ols, anthocyanins/anthocyanidins, condensed tannins/proanthocyanidins, tocopherols, and vitamin C. Research findings from over 100 references, many of which published only within the last 10 years, have been compiled and used in this review.

Phenolic Acid, Flavonoids and Antioxidant Activity of Common Brown Beans (Phaseolus vulgaris L.) Before and After Cooking

“…However, in a study by Diaz-Batalla et al [1], kaempferol was present at higher concentrations in raw beans (average of 52.3 μg g -1 of bean) compared to cooked beans (average of 27.2 μg g-1 of bean). Likewise, in a work by Amarowicz and Pegg [3], cooking promoted a reduction of this flavonoid by 5-71%. Romani et al [21], who assessed the levels of various flavonoids in Italians beans, did not detect even trace amounts of quercetin-3-glucoside and this flavonoid as not detected in the extracts evaluated in this study either.…”

“…The antioxidant activity of beans is due mainly to the reducing properties of polyphenols, which play an important role in the neutralisation or sequestration of free radicals and in the chelation of transition metals, acting against both the initiation and propagation of oxidative processes. The intermediates formed by the action of phenolic antioxidants are relatively stable due to the resonance of the aromatic rings in the structures of these substances [3].…”

“…It is known that the phenolic acids most commonly found in raw and cooked beans are gallic acid, vanillic, p-coumaric, ferulic, sinapic and chlorogenic acids and that they have great importance as precursors for the synthesis of other phenolic compounds in plants [3,5].…”

“…The main flavonoid representatives are quercetin and kaempferol in glycosylated forms. In raw and cooked beans, the main flavonoid representatives are catechin, kaempferol, quercetin, myricetin and procyanidins [3,5].…”

Determination of Phenolic Compounds in Adzuki bean (Vigna angularis) Germplasm

“…Flavonoids show differences and variations during ripening and harvesting (Raffo et al, 2004). The antioxidant activities of legumes depends on the variety of the plant and observed variously (Amarowicz and Pegg, 2008).…”