(P07-002-24) Effect of Phenolic and Fiber Profile of Biofortified Cowpea on Glucose Tolerance in Anemic Rats Fed High-Fat/High-Sugar Diet

Objectives: To evaluate the relation between the phenolic and fiber profile of biofortified and conventional cowpea beans (Vigna unguiculata L. Walph) on glucose tolerance in anemic rats fed high-fat/high-sugar diet (HFHS).

Methods: The biofortified cowpeas BRS Arace and BRS Tumucumaque and the conventional BRS Pajeu were cooked in pressure pan with deionized water (1:2, w: v), freeze-dried, and ground to produce flours. Then, dietary fibers, resistant starch, and the phenolic profile were determined. For in vivo study, during 21 days (depletion phase), 12 young male Wistar rats receiving an iron-free diet and others 48 rats received a diet free of iron and rich in fat and sugar (HFHS). Then, in the repletion phase (35 days), animals were divided into five groups (n=12): NS (normal diet+ferrous sulfate-FS); HS (HFHS+FS); HA (HFHS+ Arace); HT (HFHS+ Tumucumaque); and HP (HFHS+Pajeu), containing 12ppm iron. At the end of the experiment, to determine glucose tolerance test (iGTT), a 50% D-glucose solution (2 g/ kg body weight) was administered in the intraperitoneal cavity, and blood samples from tail were taken and glycemia levels was detected at 0, 30, 60, 90 and 120 minutes. The incremental area under the curve was calculated. The project was approved by CEUA/UFES (protocol n. 013/2022). Data were analyzed by ANOVA and post-hoc Newman-Keuls (p < 0.05).

Results: The Pajeu had highest values of resistant starch (4.04 %), followed by Tumucumaque (3.26 %), and Arace (2.52 %). All beans had similar content of total dietary fiber, however Pajeu showed highest content of soluble fiber. Chlorogenic and ferulic acids were more present in Arace beans. Catechin and gallic acid were most present in digested cultivars, unlike rutin and quercetin, which were predominant in flour beans. The p-coumaric acid was detected in all digested cultivars and was more predominant in conventional Pajeu beans. The NS group had the lowest iGTT, followed by HA group. The HS, HT, and HP had similar values of iGTT.

Conclusions: The composition of phenolic compounds, mainly rutin, and quercetin, may have directly influenced the reduction of glycemic peaks, but types of fiber did not have a major influence on glycemic values. The results indicate the benefits of cowpea biofortification on glucose metabolism.

Funding Sources: FAPES and CAPES