Phenolic composition, antioxidant capacity and inhibitory effects on α-glucosidase and lipase of immature faba bean seeds

Abstract

Immature faba bean seeds of five varieties were investigated for changes in phenolic composition, antioxidant capacity and inhibitory effects on α-glucosidase and lipase at three edible stages (S1, S2 and S3). Phenolics and antioxidant capacity in seed coats were significantly higher than those in cotyledons, and the highest was found of FD18 at stage S3. While phenolic content in cotyledons decreased steadily with the harvest time delayed. Eight phenolic compounds were confirmed with epicatechin and catechin prominent and their levels showed a great variability depending on varieties, maturation stages and plant parts of faba bean seeds. Unexpectedly, the inhibitory effects of purified phenolics on α-glucosidase were even stronger than that of the positive control acarbose, and the inhibitory effects on lipase in the cotyledons declined gradually from stage S1 to S3. Significant positive correlations between phenolics from seed coats and antioxidant capacity, and phenolics from cotyledons and the enzyme inhibitory effects were observed. Overall, the immature faba bean seed, especially its seed coat, has great potential as a functional food.

Effect of Thermal Processing on Color, Phenolic Compounds, and Antioxidant Activity of Faba Bean (Vicia faba L.) Leaves and Seeds

“…Several studies have quantified TPC in faba tissues. Lu et al [ 6 ] evaluated the distribution of TPC in seed coats (ranged from 1.62 to 4.71 mg GAE/g d.w.) and cotyledons (ranged from 0.03 to 0.27 mg GAE/g d.w.) of five immature faba bean varieties. Randhir et al [ 46 ] reported the increase of TPC (around 1.1 to 2.5 mg GAE/g fresh weight) in faba bean sprouts in 8 days.…”

“…Previous studies evaluating the antioxidant activities of faba tissues have mainly focused on different genotypes of seeds, seed coats and cotyledons, sprouts and pods [ 6 , 46 , 57 ]. The antioxidant activity of faba leaves has been verified as higher than several commercial vegetables such as asparagus, broccoli raab, spinach and cabbage [ 4 ].…”

“…However, there were no significant correlations between Vc content, TPC, TFC and antioxidant activity for faba seeds. This could be explained by the antioxidant activity of faba seeds mainly originating from the seed coat rather than the cotyledon [ 6 ], with the seed coat only forming a small proportion of the whole seed.…”

“…Faba seeds have been studied extensively and widely used in the food and pharmaceutical industries due to its properties on enhancement of nutrition or reduction the complications and progression of certain diseases [ 6 , 7 , 8 ]. Faba leaves have also gained attention as an unconventional vegetable, with several studies providing significant results on characterizing their phytochemicals and proximate nutritional values [ 4 , 9 , 10 , 11 ].…”

Faba beans with enhanced antioxidant activity ameliorate acetic acid-induced colitis in experimental rats

“…These results are consistent with those reported previously for faba bean seeds. 69,70 Interestingly, the G + L + Se, L + Se and Se treatments, respectively, increased the TPC, TVC and antioxidant capacity in faba bean seeds as compared to the untreated beans (control group).…”