Effect of different thermal and non-thermal processing methods on chemical composition, quality indicators and apparent nutrient digestibility of full-fat soybean

Abstract

The aim of this research was to study the effect of thermal and non-thermal processing methods on chemical composition, quality indicators and apparent digestibility of soybean nutrients. For this, four processing methods (unprocessed, extruded, thermal, and gamma radiation) were applied on two soybean varieties (Katol & Caspian). Rations were formulated based on kinds of soybean (processed and unprocessed). The experiment was continued using 600 male Ross broiler chickens during 3 feeding phases (starter, grower, and finisher). Traits were measured and analyzed with the Lsmeans procedure by SAS software. The results showed the interaction effects of soybean varieties and processing methods were significant on the crude fiber, calcium, and phosphorus (p<0.05). The effect of soybean variety was significant on the crude protein, crude fiber, and phosphorus (p<0.05). Also, the effect of processing methods was significant on the dry matter, crude fiber, and phosphorus (p<0.05). The effect of soybean variety, processing methods, and their interaction were significant on urease activity, KOH protein solubility, and Protein dispersibility index (p<0.05). The results of the current study showed that the best soybean variety and the processing method is the Caspian and thermal, respectively.