EFFECT OF HEAT TREATMENT ON NUTRITIONAL VALUE OF WINGED BEAN (Psophocarpus tetragonolobus) AS COMPARED TO SOYBEAN II. AMINO ACIDS DIGESTIBILITY

The effect if heat treatment (autoclave) in amino acid digestibility of winged bean determined using intact cockerels had been investigated. The winged beans were autoclaved at $120^{\circ}C$ for 45 or 90 min, respectively, and the soybean were autoclaved for 45 min. The treated winged bean and soybean were fed to 3 intact cockerels, which had been previously starved for 24 h. Excreta were collected individually for 49 h. The amino acids contained in the diets and excreta were determined to measure the digestibility values. Apparent and true digestibilities of all amino acids except histidine of unheated winged bean were significantly (P < 0.05) lower than those of heated winged bean and soybean. Heat treatment significantly (p < 0.05) improved amino acid digestibility of winged bean, However, over heating (90 min if autoclaving) destroyed lysine, cystine and arginine of winged bean. The true digestibility values of all amino acids of winged bean heated for 90min were the same as those values of treated soybean. However, true digestibilities of glycine, alannine, phenylalanine and lysine of treated soybean were significantly (p < 0.05) higher than those of winged bean heated for 45 min.