High apparent ileal digestibility of amino acids in raw and germinated faba bean (Vicia faba)- and chickpea (Cicer arietinum)-based diets for rats

The effects of germinated faba bean (Vicia faba minor var Alameda) - and chickpea (Cicer arietinum kabuli var Athenas)-based diets on performance, N utilisation, amino acid Heal digestibility and plasma concentrations were studied in growing male Wistar rats. Raw and germinated faba bean and chickpea seed meals were incorporated in essential amino acid-supplemented and energy-equalised diets as the only sources of protein. A lactalbumin-based diet equalised in protein (100g kg(-1)) and digestible energy (15.5 kJ g(-1)) with the test diets was used as control. Weight gains, gain/feed ratios, N retention and NPU values of animals fed raw or germinated legumes were lower than those of rats given the control (lactalbumin) diet, while faecal dry weights were higher. However, N retention and NPU values of rats fed germinated faba bean diets were higher and faecal dry weights lower than those of animals fed non-germinated faba bean diets. Liver and thymus fresh and dry relative weights were lower than controls for all legume diets, whilst small intestine, caecum. and colon relative weights were higher than controls for non-germinated faba beans and chickpeas either germinated or not. Caecum and colon fresh and dry relative weights of rats fed germinated faba bean seeds were lower than those of rats fed non-germinated faba beans and not different from controls. Except for aspartic acid and proline in rats fed raw faba bean diets, apparent ileal digestibilities of amino acids were not different or higher in rats fed legume diets as compared with controls. Except for arginine, apparent Real amino acid digestibility was higher for germinated than for non-germinated faba bean seeds. The amounts of glycine, arginine and ornithine in plasma significantly increased whilst those of threonine, alanine, leucine and lysine decreased with respect to controls in faba bean- or chickpea-fed rats, either germinated or not. We conclude that (a) germination of faba bean seeds gave rise to a significant (P<0.01) but limited improvement in performance, N retention and apparent Real digestibilities of some amino acids in growing rats compared with non-germinated seeds, while there was no detectable effect in the case of germinated chickpea seeds, and (b) the apparent ileal amino acid digestibility of essential amino acid-supplemented diets based on faba bean or chickpea meals, either germinated or not, is similar or even higher than controls. (C) 2002 Society of Chemical Industry.