Short-term germination of faba bean (Vicia faba L.) and the effect on selected chemical constituents

Abstract

Selected chemical compounds of five faba bean (FB) cultivars; Snowdrop (low tannin), Taboar (high tannin), Snowbird (low tannin), Fabelle (low vicine & convicine), and Malik (high tannin) that were grown in North America (3 production years) were determined. The effect of short-term germination (24 h, 48 h, and 72 h) on the levels of phytic acid, vicine/convicine (v/cv), oligosaccharides, and total phenolics were evaluated. On average, FB contained 2% phytic acid and there was no difference between the 5 cultivars. Fabelle presented the lowest level of v/cv of 1 and 0.4 mg/g, respectively while the others had 7.27–10.82 and 3.53–3.93 mg/g, respectively. No significant difference was found among cultivars for oligosaccharides content. Content of total phenolics differed significantly (p ≤ 0.05) between FB cultivars. Snowdrop and Snowbird had the highest total phenolic content of 48.4 and 48.3 mg/g, respectively, while Fabelle had the lowest level of 10.8 mg/g. All cultivars showed significantly (p ≤ 0.05) reduced contents of raffinose (100%), stachyose (60%), verbascose (80%) at 72 h. Germination had no significant effect on phytic acid, vicine (except Snowbird), and convicine levels. At 48-h, Snowdrop and Snowbird seeds only showed 17-18% reduction (p ≤ 0.05) in total phenolic content. Germination between 48 to 72 h is an option to produce FB seeds with very low levels of oligosaccharides.