Nutritional evaluation of the germ meal and its protein isolate obtained from the carob seed (Ceratonia siliqua) in the rat

Abstract

1. Evaluation of the germ meal (CGM) of carob seed (Ceratonia siliqua) and its protein isolate was carried out with weanling rats. Comparisons were made with casein, soya-bean meal, whole defatted egg and a soya-bean protein isolate (Promine-D) as protein sources. The growth-promoting effects and certain biological indices were evaluated using the protein efficiency ratio (PER), biological value (BV) and net protein utilization (NPU) bioassay procedures.2. The unsupplemented CGM had a PER of 1.66 ± 0.09 and an NPU of 0.58 ± 0.013. Addition of DL-methionine at 4, 8 and 12 g/kg diet resulted in a PER of 1.95 ± 0.11, 2.01 ± 0.11 and 1.90 ± 0.11 respectively. The corresponding BV values were 0.80 ± 0.003, 0.78 ± 0.015 and 0.74 ± 0.011, and those for NPU 0.69 ± 0.013, 0.66 ± 0.026 and 0.63 ± 0.020 respectively. The addition of amino acids improved the PER (2.24–2.59), BV (0.78–0.79) and NPU (0.71–0.73) values.3. The BV and NPU assays for the unsupplemented carob germ isolate were low (BV 0.36 ± 0.016, NPU 0.35 ± 0.015). Supplementation with amino acids resulted in a positive increase with values of 0.66 ± 0.013 and 0.64 ± 0.013 for BV and NPU respectively.