ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 80 Number 2
Comparative evaluation of some binding agents for water stability and nutrient retention in aquaculture diets. (128)
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.
Keywords: Aquaculture; Binders; Diets; Water stability; Nutrient retention; Africa