Nutritional evaluation of protein and starch of mature Canavalia gladiata seeds

Evaluation of true digestibility (TD), biological value (BV) and net protein utilisation (NPU) of diets made with raw and processed seed flour from mature Canavalia gladiata seeds were carried out with male Sprague-Dawley rats. The weight gain of the rats fed with diets containing raw whole seed and raw cotyledon alone were significantly lower (P = 0.05) than that of the group fed with the reference diet. Processing the cotyledons (dry-autoclaved or roasted) significantly (P < or = 0.05) increased the weight gain of the rats when compared to the weight gain of rats fed diets prepared with raw seed flour. NPU of raw (whole seed 13.8; cotyledon 27.6) was significantly lower (P < or = 0.05) than the reference diet (79.5). The NPU of processed samples was also significantly lower (P < or = 0.05) when (dry-autoclaved 25.1; roasted 25.1) compared to the reference diet fed group (79.5). The BV of the processed samples (dry-autoclaved 31.1; roasted 37.7) was significantly lower (P < or = 0.05) than that of raw (53.6) cotyledon. In contrast TD increased (P < or = 0.05) with processing (dry-autoclaved 80.9; roasted 65.9) when compared to raw cotyledon (51.4). In vitro protein digestibility for the raw whole seed and cotyledon was 71.7 and 70.1% respectively. In vitro starch digestibility of raw and processed cotyledon flour samples indicated dry-autoclaved sample to have the highest digestibility.