Protein Bioavailability – Lowering in Rats Fed High Dietary Fiber from Cereal and Nata De Coco

Abstract

The comparative effects of 6 different high dietary fiber diets and casein diet on protein bioavailability (protein efficiency ratio, net protein utilization, biological value and digestibility) were investigated by feeding male Sprague – Dawley rats with diets containing unpolished rice, mung bean, sweet corn, nata de coco, milk powder, sugar (formula 1); pumpkin, mung bean, unpolished rice, nata de coco, milk powder, sugar (formula 3); oat, sweetpotato, kidney bean, nata de coco, milk powder, sugar (formula 5); formula 2, 4, 6 containing the same raw materials as formula 1, 3, 5 but without milk powder and sugar. Six experimental diets and control diet (casein) were prepared from 6 formulas by AOAC, contained 10 ± 0.3% test protein, 8% oil, 5% water, 5% mineral, 1% vitamin, 1% cellulose, 35% sucrose, 35% corn starch and different dietary fiber. Total dietary fiber in diet 6 was the highest with it being 20.01g/100 g but the casein diet was the lowest with 6.58 g/100 g whereas in diet 1-5 the dietary fiber ranged from 8.41 to 13.22 g/100 g . The value of protein efficiency ratio in diets 1-7 was 2.44, 1.89, 2.29, 1.66, 2.55, 1.88 and 2.50 respectively whereas net protein utilization and digestibility in diets 1-7 were 63.81 – 77.45 and 70.05-95.52 respectively. Net protein utilization and digestibility in the casein group showed the highest values of 77.45 and 95.52 respectively. The range of biological values in diet 1-7 was 80.29 – 91.76 . The results indicate the highest dietary fiber diet showed the highest content of feces and decreased the value of net protein utilization and digestibility.