Cricket protein hydrolysate as a sustainable functional ingredient in dog diets: Effects on palatability, health parameters, and antioxidant shelf-life stability

Abstract

Background and Aim: Insect-derived proteins are gaining attention as sustainable pet food ingredients, but the use of cricket protein hydrolysate (CPH) in canine diets remains underexplored. This study evaluated the effects of CPH on diet palatability, physiological responses, and antioxidant potential for shelf-life extension in commercial dog food. Materials and Methods: Thirty-two healthy adult dogs were assigned to four diets containing 0%, 2%, 4%, or 6% CPH for a 30-day feeding trial. Palatability was assessed through a two-bowl preference test, while biochemical, hematological, and fecal parameters were measured pre- and post-trial. Antioxidant efficacy was evaluated by monitoring acid value (AV) and peroxide value (PV) during accelerated storage (55°C for 46 days, simulating 12 months). Nutritional adequacy was confirmed through proximate and amino acid analysis. Results: The 2% CPH diet significantly improved palatability, with a 57% increase in intake compared to control (p < 0.05), whereas higher inclusions (4% and 6%) reduced acceptance due to bitterness from hydrophobic peptides. All health parameters remained within reference ranges, though the 6% CPH diet lowered serum glucose (87.0 vs. 112.0 mg/dL; p < 0.001) and increased blood urea nitrogen (11.0 mg/dL; p = 0.0023). Antioxidant activity increased with CPH level, with 6% CPH reducing PV by 33% after 46 days (p < 0.05). CPH lacked certain essential amino acids, notably tryptophan, requiring complementary protein supplementation. Conclusion: CPH is a multifunctional ingredient that can enhance palatability and oxidative stability in dog diets at moderate inclusion (2%). High inclusion levels improve antioxidant capacity but may impair sensory acceptance and alter metabolic markers. Long-term safety, allergenicity, and flavor-masking strategies warrant further study.