Novel applications of fresh cheddar cheese in extruded pet food snacks

Cheese trim is a lower value co-product obtained during slicing, cutting, and cubing operations with the potential to be used in pet snacks. In this study, pet snacks were formulated with fresh cheddar cheese trims at different concentrations (25%, 30%, and 35%). The extrusion variables including water content, temperature, screw speed, and feed rate were explored and optimized using the expansion ratio of the extruded snack. The results demonstrated that the best conditions were temperature 125°C, water content 18%, and screw speed 400 rpm. The pet snacks extruded using 25% cheese had the lowest bulk density (0.402 g/cm 3 ), the highest porosity (40%), and highest hardness (273 N). Additionally, results exhibited high hardness and did not fracture during texture analysis. The nutritional profile ranged from 10.4-12.1% for protein, 9.4-11.2% for fat, and 65-71% for carbohydrates. The mineral profile met the requirement for nutrition recommended for pets except for iron, which was lower compared to commercial pet snacks. This study reports on the high potential for fresh cheese as an ingredient in extruded pet snacks, which can add value to the co-product.