Effects of Soaking, Cooking, and Steaming Treatments on the Faba Bean Seeds’ Total Bioactive Compounds Content and Antioxidant Activity

Abstract

Faba bean (Vicia faba L.) is a winter-sowing grain legume with high-protein content utilized for human consumption and animal feeding. Faba beans contain high levels of polyphenol compounds with various nutritional benefits. Legume seeds, such as faba beans, are subject to different processing procedures before consumption, which decreases the levels of their bioactive compounds (polyphenols and flavonoids), resulting in a reduction in antioxidant activity. This study aimed to examine the influence of soaking, cooking, and steaming treatments on the total polyphenols, total flavonoid, and antioxidant activity levels of Broad (large) and Field (small) faba beans. Initially, the influence of the different extraction solvents on total phenolic content (TPC), total flavonoid content (TFC), and ferric reduction ability of plasma antioxidant activity (FRAP), variables were inspected, wherein the extraction efficiency. 70% acidic acetone treatment was found to be the best solvent for extraction. Then, we determined the soaking, cooking, and steaming effects on TPC, TFC, and FRAP levels compared to dry seeds as the control. It was found that the various processes resulted in a significant reduction in the level of these components in the processed seeds of both Broad and Field beans. Nevertheless, the soaking treatment resulted in the smallest reduction. In addition, steaming caused a more moderate decline among the cooking types. Therefore, to maintain a higher level of these three ingredients in the final product, it is better to steam the seeds than cook them.