Characterizing Phenolic Compounds in Fava beans

Fava beans are a good source of polyphenols and are located in different parts of the plant. Phenolic compounds are thought to contribute to the overall antioxidant activities of plant foods. However, there is a lack of information on the phenolic composition of the seeds (beans) of some edible varieties. This has led a team of researchers based in Chile and Spain to use high performance liquid chromatography (HPLC) to identify the composition of a variety of immature fava seeds.¹

Chile is one of the largest exporters of fava beans in the world and beans are often eaten in an immature seed state when they are still tender and young. The team selected 10 varieties for analysis. All varieties were grown in the same field and during the course of one season.

To obtain precise information on the phenolic composition, samples were analysed by HPLC with diode-array detection and mass spectrometry (HPLC–DAD–MS). Phenolic compounds were identified by ultraviolet (UV) spectra and electrospray ionization mass spectrometry (ESI-MS) spectrometric data.

Significant differences in the content of these compounds were found among the fava bean varieties. Reina Mora and Alargá contained the highest concentration of total phenolics and Luz de Otono the greatest content of condensed tannins. In addition, Alargá had the highest concentration of proanthocyanidins and Super Aguadulce Anasac had the highest number of flavanols and flavones.

The team concluded that additional studies were needed to corroborate their findings. The influence of environmental conditions would be a good indicator of phenolic composition in this type of annual crop. Ultimately, it was established that there was ample room for selection studies that could produce varieties for increased nutritional value, taste, and ease of production.