2.3. Biological assay
2.3.1. Experimental diets and treatments
Four experimental diets were formulated based on the chemical
composition of the by-products (Table 1) and in accordance
with recommendations of the American Institute of Nutrition
(AIN) (Reeves, Nielsen, & Fahey, 1993). The fibre in the control diet
(microcrystalline cellulose) was substituted with fibre derived
from the fruit by-products for the treatments. The following four
diets formed the treatments: CEL (treatment control, with cellulose),
AP (test treatment, with the addition of apple pomace) OB
(test treatment, with the addition of orange bagasse) and PFP (test
treatment, with the addition of passion fruit peel). All of the diets
were isocaloric and had the same contents of protein, lipids and
dietary fibre (Table 2).