Antinutritional factors in faba beans (Vica faba L.) as affected by breeding toward the absence of condensed tannins

Abstract

The effect of genetic removal of condensed tannins on the levels of other antinutritional factors in faba beans (Vicio faba L.) has been studied by comparison between partners of six near-isogenic pairs for trypsin inhibitor activities (TIA), concentrations of lectins and pyrimidine glucosides (vicine and convicine), seed weight, and the proportion of testa thereof. Each near-isogenic pair consisted of two lines which were genetically almost identical, apart from the absence [tannin-free (TF)] or presence [tannin-containing (TC)] of condensed tannins. Within these pairs no effect of tannin content was observed on cotyledon-bound TIA or lectin concentrations. Seeds of the TF lines showed higher levels of pyrimidine glucosides, lower seed weight, and lower proportion of testa as compared to the TC lines of the same near-isogenic pair. Methanolic extracts from testa of exclusively the TC lines showed significant TIA with both porcine and bovine trypsin. This TIA was completely inhibited by 1% poly(vinylpyrrolidone). These data indicate that condensed tannins are responsible for the testabound TIA. The observations are discussed in relation to the consequences of breeding faba beans, free of condensed tannins, for the agricultural characteristics and for the nutritional quality of the crop.

The chemical composition and nutritive value of low- and high-tannin faba bean varieties

“…This shows that the antitrypsic activity of faba beans determined by the method of Kakade et al (1974) resulted to a large extent from their content of phenolic compounds. A similar conclusion can also be drawn from the results of Helsper et al (1993).…”

“…The share of seed hull was inversely proportional to the weight of the seeds (from 12.8% in Caspar to 14.3% in Tinos) and was within the 13-15% limits given by other authors as characteristic of faba beans (Bjerg et al, 1988;Wang and Uberschar, 1990). According to Helsper et al (1993) the proportion of faba bean hulls may range from 11.6 to 15.7%.…”

Evidence for Protein–Tannin Interaction in Legumes: Implications in the Antioxidant Properties of Faba Bean Tannins

“…Although the selection of lines with reduced tannin content through breeding seems to be a possible way to improve the nutritional quality of legume proteins, recent characterization of tannin-free cultivars obtained from Vicia faba suggested that alterations in some seed properties (i.e. decrease in seed weight, increase in pyrimidine glucosides), consequent to tannins removal, should be carefully evaluated (8,9). Tannins are considered to be involved in the plant defence mechanism to environmental attack, likely because of the recently reported antioxidant properties (10)(11)(12).…”

A Comparative Study on Nutritional Composition, Mineral Content and Amino Acid Profile of the Skin of Four Different Animals

“…The value of ratio of Na/K of goat and pig skins (0.55, 0.57 respectively) were lower than 0.6, the value that favours non-enhancement of high blood pressure disease in man while that of dog and cane rat were higher. Although for normal retention of protein during growth and for balancing fluid a K/Na ratio of 1.0 is recommended [31], the high value of K/Na ratio (1.27, 1.83, 1.76 and 1.57 for dog, goat, pig and cane rat respectively) obtained in the present report suggests that bringing the ratio down would require the consumption of food sources rich in Na. The Ca/Mg value obtained for the present skin samples (2.52, 2.57, 2.60 and 2.17 for dog, goat, pig and cane rat respectively) were fairly higher than the 1.0 recommended.…”