Effect of different processing methods on the nutritional characteristics and tannin content of fababean seed (Vicia faba minor)

In the last years, because of their high protein content, the demand of legume seeds is significantly increased. In the centre and southern Italy fababean (Vicia faba minor) can play an important role as alternative protein source in ruminant nutrition. In this trial has been studied the effect of different treatments (flaking, cooking, dehulling, germination) on the in vitro digestibility and tannin content of fababean seeds. The in vitro OM and NDF digestibility of seeds were significantly (P<0.05) improved by dehulling and flaking. The in vitro OM digestibility of dehulled fababean (99.27%) showed higher values (P<0.05) than the other treated seeds as well as in vitro NDF digestibility (90.33%, P<0.05). Germination of fababean reduces the in vitro digestibility of OM and NDF. Cooking in water was more effective in reducing tannins than other treatments. Compared to the untreated the cooked has significantly (P<0.05) reduced the tannin content over 55% (2.71 g/kgDM vs. 6.10 g/kgDM). Germinated fababean did not affect the tannin content of seeds. The results from this trial suggest that thermal treatments applied to fababean seeds in order to reduce the tannins must be evaluated according to the cost/benefits ratio because this factors in seeds is low (<10 g/kgDM).