Protease produced by Lactobacillus brevis enhanced nutritional values of African yam beans and demonstrated improvement in the growth and blood indices of albino rats

This study evaluates the nutritional values of African yam bean hydrolyzed with protease from Lactobacillus brevis and afterward assess its effect on the growth and blood parameters of albino rats. The nutritional compositions of AYB hydrolyzed with partially purified protease from L. brevis were determined by standard chemical methods. The protease-hydrolyzed AYB was thereafter formulated into feeds with different inclusion levels (20, 40 and 60%), which was used to feed albino rats for 27 days. After the feeding trial, the blood of anesthetized albino rats was collected using the cardiac puncture method, and the hematological parameters were determined by standard biochemical methods. The AYB hydrolyzed with partially purified protease had the highest percentage crude protein with a value of 31.2% when compared with boiled, soaked and boiled, and raw sample with the values of 20.9, 20.9 and 19.9%, respectively. The treatment of AYB with purified protease also resulted in an increase of vitamins and some essential amino acids when compared with unhydrolyzed AYB. The group of rats fed with 60% hydrolyzed AYB had the highest percentage average weight gain of approximately 144%, while the values recorded for the groups fed with commercial feed and unhydrolyzed AYB were approximately 86 and 101%, respectively. The hematological analysis revealed that the hemoglobin (Hb) and packed cell volume (PCV) of the group fed with 40% hydrolyzed AYB of 14 g/L and 38% respectively, were significantly higher than the rats fed with commercial feed with values of 10 g/L and 32%, respectively. Thus, enzyme-hydrolyzed AYB might be a suitable alternative to animal protein with good functional properties.