The Nutritive Value of Ten Inbred Lines of Faba Beans (Vicia faba L.) in Relation to their Content of Antinutritional Constituents and Protein Quality

Abstract

Ten mbred lines of tabe beans (Vicia {aha L.) selected according to their quality characters have been investigated for carbohydrates, proteins and antinutritional compounds. Digestible energy, Nbaiance trials with growing rats comprising determination of the protein digestibility and biological value were used as criteria in connection -n-ith comprehensive chemical-biochemical analysis.The chemical composition of the ten lines show-ed a considerable diversity as did the results from the rat trials. However, the content of i-icine and convieine in all of the investigated lines were below the level previously tound to have effect,^ on the nutritive value. Starch, protein and fibre were the quantitativeh-dominating seed constituents, and all showed great variation among the lines.The starch content was not correlated to the quaiity or nutritive value of the seed, whereas the prote-in content was negatively correlated to the biological value and net protein utilization. These correlations followed the content of essential amino acids, lysine, threonine .and methionine in the faba bean proteins. The content of the sulfur-containing amino acids cysteine and methionine are especially dominant factors for protein quality. A simple method for total sulfur determination was found nor to be a sufficiently reliable technique for evaluating the content of methionine and cysteine in the faba beans.Tannin, insoluble-and total dietary fibre are pnenolie aromatic compounds which were negatively eorrelated with the faba bean quality as expressed by digestible energy, the protein digestibility and the biological value of the faba beans. The results obtained have also revealed, that it is not sufficient to consider tannin as a group m relation to the faba bean quality. We need to separate and evaluate the different types of phenolics in relation to the variations in quality of faba beans. Some of the low molecular weight (LMW) phenolics in the faba beans seem to be involved in inhibitor)' effects on hydrolase enzymes, chymotr}'psin and try-psm. Trypsin and chymotrypsin from different animals were difterent in their sensitivity" to faba bean inhibitors and additional experiments are required to reveal details about these effects. It l:ias .also been revealed that iTuet-osans and LMW' carbohydrates (oligosaccharides) are important in relation to the quality of faba beans.Key words: Vieia faba -inbred lines -nutritive value -antinutritional compounds -protein quality -vieine -convieine -tannin -hydrolase inhibitors -trypsin -chymotrypsin -carbohydrates -fibres -fructosans -oligosaccharidesstarch Faba bean varieties h.ave a high yield capacity compared to other grain legumes (HA^STIN and STE^S-ART 1979, DANTUMA et al 1983), Thencarbo-hydrate content is high, but the nutritive value and quality are negatively affected by antinutritional and/or toxic compounds which occur m too-high concentrations m some faba bean lines. In addition, the content ol sulfurcontaming ammo acids is very low (BJERG et al, 1984 a, BJERG et al, 1984 c and ref...

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

“…These authors also found that the low-tannin varieties had higher average weights of 1000 seeds, even over 700 grams. 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%.…”

“…The crude protein content of the seeds was between 27.2 and 28.9% DM, which is slightly lower than that found in most European varieties (Bjerg et al, 1988). Caspar seeds had slightly less crude protein (27.2% DM).…”

Canola and Rapeseed

“…"Given as percent of dry matter. bReadily hydrolyzable carbohydrates, insoluble and soluble dietary fiber determined as described elsewhere (Bjerg et al 1988). The aromatic choline esters (Table 19-2) were present in group A.…”

“…The column was Licrosorb-NH z (150 x 4.6 mm), 20 JlI of the water effluent was injected for analysis, and the mobile phase was water modified with 62% acetonitrile for oligosaccharides and water modified with 80% acetonitrile for monosaccharides. Methods of analysis for determination of chemical composition have been described elsewhere (Bjerg et al 1988).…”

“…Feeding experiments comprising nitrogen (N)-balance trials with young growing rats, determination of biological values (BV) and true digestibility (TD), as well as long-term studies with mink, were performed according to established methods (Bjerg et al 1988(Bjerg et al , 1989.…”