The effects of different temperature and time conditions during retorting of canned cat food on physicochemical characteristics and palatability were examined. For this purpose, lacquer cans containing an unprocessed loaf-type commercial cat food were heated in a pressurised retorting system at three specified temperature-time profiles (113°C/232 min, 120°C/103 min and 127°C/60 min) to equal a similar lethality (F0 value = 30). Physicochemical properties (viscosity, texture, particle size, pH) were determined, and a 10 d three-bowl palatability test was performed with ten European shorthair cats. Retorting at 113°C/232 min resulted in differences in all the physical parameters examined (<viscosity, firmness, adhesiveness, and > particle size). Significant pH differences were observed (6·53, 6·63 and 6·66 for T113/232, 120 and 127°C, respectively). Preference ratios were 0·38, 0·31 and 0·31 for T113/232, 120 and 127°C, respectively (P = 0·067). It can be concluded that different retorting temperature-time profiles with equal F0 value significantly affect physical characteristics and tended to affect palatability of moist cat food.
Keywords: Canned food; Cats; F0, lethality value; Palatability; Texture; Thermal processing; Viscosity.