PSV-11 - The effect of fermented co-products on sensory characteristics of extruded dog kibble

Abstract: To promote sustainability, the pet food industry could use fermented co-products from ethanol and beer production as ingredients. However, these ingredients may impact the appearance, smell, and taste of the final product. The aim of this study was to analyze the sensory characteristics of extruded dog kibble produced with fermented co-products. Four diets were evaluated: a control diet with no fermented co-products (CON), a diet containing 3.5% brewer's dried yeast (BDY), a diet with 17.5% distiller's dried grains plus solubles and 2.5% brewer's dried yeast (DDGS+BDY), and a diet with 17.5% corn fermented protein (CFP). Five human trained panelists rated various characteristics of the product in terms of appearance, texture, aroma, and flavor from 0 to 15 (0 = none; 15 = extremely high). Results were analyzed using the sensory package in XLSTAT, and for significant attributes (P < 0.05), sample effects were assessed using Fisher LSD. For appearance, DDGS+BDY was browner than the other treatments (P < 0.05), and all treatments had similar porosity (P > 0.05). For texture, all treatments had similar ratings for particle amount, toothpacking, and oily mouthcoating (P > 0.05). The CFP was harder than DDGS+BDY (P < 0.05), and DDGS+BDY had lower fracturability than CON and BDY (P < 0.05). The aroma characteristics including grain, cardboard, metallic, and overall intensity were similar for all treatments (P > 0.05). The BDY had less oxidized oil aroma than CON and CFP (P < 0.05). The CFP had less barnyard aroma than DDGS+BDY (P < 0.05), but was more brothy than DDGS+BDY (P < 0.05). The CON had a less intense vitamin aroma than BDY and DDGS+BDY (P < 0.05). In terms of flavor, barnyard, fish, brothy, salt, bitter, and metallic flavors were similar for all treatments (P < 0.05). Treatment CFP had stronger grain flavor than BDY (P < 0.05). Vitamin flavor was less intense for CON than DDGS+BDY and CFP (P < 0.05). Cardboard flavor was stronger for DDGS+BDY than BDY (P < 0.05), and oxidized oil flavor was less intense for DDGS+BDY than CON (P < 0.05). In addition to producing a nutritionally balanced product, the pet food industry must also accommodate the preferences of human consumers. For this reason, the final product must contain sensory characteristics that appeal to pet parents. Overall, the fermented ingredients evaluated did not seem to negatively impact the food sensory properties, resulting in desirable texture, aroma, and flavor profiles.