Abstract
Three carbohydrate derivatives (starches) from paddy rice (RS), sorghum grain (SS), and cassava starches (CS) were incorporated as binding agents at 2% inclusion and compared with organic hydrocolloid sodium carboxymethylcellulose (CMC) as reference binder in isocaloric-isoproteic 40% crude protein diets. The diets were observed in the laboratory for water stability and nutrients retention for 30 min at 5-min intervals. The diet treated with CS was not significantly (P > 0.05) different from the reference diet in water stability within the set time. The CMC-based diet was superior in water stability with 100.00, 98.64, and 97.53% at 5, 15, and 30 min of immersion, respectively. The CS-based diet ranked second with 96.97, 92.84, and 85.34%, respectively; and the least stability was recorded in the SS-based diet with 92.00, 73.10, and 54.23% for the same period of observation. There was a decreasing trend in nutrient retention with increasing time of immersion in water. However, there was no significant (P > 0.05) difference in nutrients (proteins and lipids) retention in RS and SS, but they were significantly (P < 0.05) different from CMC and CS. It was observed that the rate at which the proteins were leached was significantly (P < 0.05) higher than the lipids in all binder-based diets. Based on the results of this study and the unavailability and unaffordable cost of CMC in African countries, CS is recommended at 2% inclusion as a local binding agent in aquaculture diets.
