Physicochemical, texture, color, and sensory evaluation of insect-based jerky-style pet treats formulated with varying ratios of crickets (Gryllodes sigillatus) and chicken liver

Abstract

The rapid increase in pet ownership and the continued humanization of companion animals have intensified the search for sustainable, functional ingredients that can be incorporated into the pet treats without compromising quality, safety, or consumer acceptance. Cricket meal (CM), a nutrient-dense and environmentally efficient protein source, and chicken liver (CL), a highly palatable co-product of the poultry industry, offer a promising combination for developing hybrid jerky-style pet treats. However, limited research has explored how varying CM:CL ratios influence physicochemical traits, color stability, texture, and sensory perception; key factors driving both product performance and pet owners purchasing decisions. Therefore, this thesis conducted three integrated studies to evaluate the effects of formulation composition on the physicochemical properties, instrumental color characteristics, and sensory acceptance of insect-based jerky-style pet treats. Formulating significantly influenced moisture-related traits, with higher CM inclusion producing the driest products and lower CL inclusion resulting in slightly higher water activity values, although all samples reached 0.85 of aw, ensuring microbial stability. Texture analysis showed no differences among treatments for bending behavior; however, greater CL inclusion increased firmness during shear force testing, while toughness remained similar across formulations. Instrumental color responses demonstrated that CM:CL ratios affected lightness, redness, and yellowness over time. Treats with 50% CM were lighter and redder initially but exhibited greater color variation during storage, whereas higher CM levels produced darker, more color-stable products. ΔE values indicated perceptible changes withing first days post-production, yet overall differences among treatments remained within visually acceptable limits. Sensory evaluation with 101 pet owners revealed no significant differences in hedonic, appearance, texture, or purchase intent among formulations, indicating that varying CM:CL ratios did not influence overall acceptance. Check-All-That-Apply descriptors suggested that higher CL samples were perceived as more meaty and pleasant, while higher CM samples were associated with darker and smoky notes, though these differences did not affect liking scores. Consumer perception data further showed openness toward insect-based treats, particularly among younger owners who associated them with sustainability and nutrition. Overall, varying the proportion of CM and CL influenced physicochemical and color attributes but did not affect consumer acceptance. These findings demonstrate that insect and co-product hybrid formulation can produce high-quality, jerky-style pet treats, supporting the use of sustainable and underutilized ingredients in the pet food industry.