The heating-cooling cycle to increase the RS (type 3) content of corn starch was as follows; steam heating at over 100°C for 30 min, and cooled at 4°C for 24 hours. The RS content in rice, corn starch, and experimental diets was measured using Megazyme RS assay kit (K-RSTAR, Megazyme, CT, USA), according to the manufacturer’s manual. The RS content of rice and corn starch was 2.33% and 6.69%, respectively, and the degree of starch degradation by amylase enzyme in vitro was 97.0% and 92.5%, respectively. The rice and corn starch with increased RS content were used as raw ingredients for each experimental diet.
Diets were prepared according to a previously described method with minor modifications [21 (link)]. The raw materials of the diets were commercially available as food products that were mixed, heated, molded, cut, dried, and cooled. The experimental diets used to evaluate nutrient digestibility were prepared separately using the same method; each experimental diet was supplemented with 0.5% chromium oxide.Table 1 lists the formulation ratios and chemical compositions of the diets used in this study.
Diets were prepared according to a previously described method with minor modifications [21 (link)]. The raw materials of the diets were commercially available as food products that were mixed, heated, molded, cut, dried, and cooled. The experimental diets used to evaluate nutrient digestibility were prepared separately using the same method; each experimental diet was supplemented with 0.5% chromium oxide.
