PSLBI-7 Coating extruded kibble with increasing levels of free fatty acids does not decrease palatability or impact e-nose odor profiles

Abstract Complete uncoated extruded kibble was coated with 5% by weight premium poultry fat (5,000 ppm Naturox, 0.57% FFA; Tyson, Springdale, AR) spiked with 0, 5, 10, 15, or 20 percent free fatty acids (Oleic acid, Millipore Sigma. Burlington, MA), and 3% liquid chicken-based palatant (Tyson, Springdale, AR). Kibbles were then utilized in oral palatability (n = 20 dogs; 10 male, 10 female), aromatic palatability (n = 20 dogs; 10 male, 10 female), and apparent total tract digestibility (ATTG; n = 36 dogs; 18 male, 18 female). Kibble odors were by ultra-fast gas chromatography e-nose (AlphaMOS, Toulouse, France), and SPME GC-MS (MUMC, Columbia, MO). In the aromatic palatability trials, there were no significant differences in first approach (P ≥ 0.21), percent interaction time (P ≥ 0.16), or interaction ratio (P ≥ 0.94). In the oral palatability trials, there were no significant differences in first approach (P ≥ 0.26), first bite (P ≥ 0.50), percent consumed (P ≥ 0.15), or intake ratio (P ≥ 0.59). There was a significant increase in fat digestibility among diets coated with 20% FFA compared with the uncoated diet (P = 0.02), with intermediate diets showing a slight numerical increase but no significant difference. However, there was no significant difference in protein, carbohydrate, or dry matter digestibility (P ≥ 0.06). Principle component analysis of e-nose peaks showed minimal odor changes between samples (DI = -3). SPME GC-MS analysis identified 16 compounds correlated with FFA percentage (r2 ≥ 0.50). When used to coat kibble, poultry fat with up to 20% FFA did not appear to negatively impact palatability or overall odor profile, though it did modify specific volatile compounds.