The effects of myo-inositol supplementation on nutritional, physicochemical quality and hygiene of cat foods

Objective. Feed hygiene is a critical component of animal and public health, particularly due to the risk of viral contamination in pet food. This study evaluated the impact of dietary myo-inositol supplementation on the nutritional composition, physicochemical properties, and viral inactivation efficiency in commercial dry and wet cat foods. Materials and Methods. Feed samples were supplemented with varying concentrations of myo-inositol (0, 12.5, 25, and 50 mg/100 g), and the survival of murine norovirus-1 (MNV-1)—a surrogate for feline calicivirus—was assessed at room temperature (22 °C) and refrigeration (4 °C) over 30, 60, and 120 minutes. Results. While proximate nutritional content was unaffected by inositol supplementation or storage conditions, physicochemical differences such as pH, water absorption index (WAI), and water solubility index (WSI) were significantly influenced by food type, with dry food exhibiting higher WAI and WSI, and wet food showing higher pH. Myo-inositol supplementation led to a dose-dependent decrease in viral viability, with significant reductions in virus half-life observed at higher inositol doses and longer storage durations. The half-life of MNV-1 ranged from 31.1 to 346.4 minutes in dry food and 23.7 to 71.3 minutes in wet food, decreasing notably with 50 mg/100 g myo-inositol at 22 °C. The IC₅₀ values of myo-inositol varied with food type and storage conditions, reaching zero in wet food after 60–120 minutes. Conclusions. These findings highlight the potential of myo-inositol as a natural feed additive to improve viral inactivation in pet foods without altering nutritional or physicochemical quality, thus contributing to enhanced feed safety and hygiene.