**Background:** The growing global demand for protein and the environmental impact of conventional meat production have spurred interest in alternative protein sources, including edible insects. House crickets (Acheta domesticus) are a promising candidate due to their high protein content (42–75% dry matter), favorable amino acid profile, and lower environmental footprint compared to livestock. However, consumer acceptance in Western countries remains low. Incorporating insect flour into hybrid meat products, where insects are not visually identifiable, may help overcome neophobia. Previous studies have shown that insect flours can replace up to 20% of meat in sausages without major technological drawbacks, but challenges remain regarding texture and oxidative stability. This study aimed to evaluate the effects of cricket flour (CF) addition on the functional properties of CF itself, and on the texture and oxidative stability (lipid and protein) of hybrid pork sausages during storage.
**Methods:** Freeze-dried and ground house cricket flour was characterized for protein solubility (pH 2–10; NaCl 0–2.5 M), water-holding capacity, and gel-forming ability. Four sausage formulations were prepared: a control (35% lean pork, 20% pork fat, 42.5% ice water, 2% salt, 0.5% phosphate) and three hybrid sausages with CF added at 1%, 2.5%, and 5% on top of the base recipe. Sausages were cooked at 75°C until core temperature reached 72°C. Rheological properties of raw batter were measured via temperature ramp (20–80°C). Cooked sausages were analyzed for color (L*, a*, b*, ΔE*), texture profile analysis (hardness, springiness, cohesiveness, chewiness, resilience), and fracturability. Lipid oxidation was assessed by TBARS (mg malondialdehyde/kg sausage), and protein oxidation by carbonyl content (DNPH assay), free thiol content (DTNB method), and tryptophan fluorescence intensity over 14 days of storage at 4°C in the dark. Statistical analysis used two-way ANOVA with storage days and CF% as fixed factors, and Pearson correlations between oxidation markers.
**Key Results:** CF protein solubility was lowest at pH 5 (isoelectric point) and increased significantly at pH <4 and >6. Water-holding capacity of CF was ~2 g/g and increased with NaCl concentration. Gel formation occurred at CF concentrations ≥10% at pH 6.8 after heating at 70°C. Proximate analysis showed CF contained 56.0 ± 0.5% protein, 23.5 ± 0.5% crude fat, and 8.1 ± 0.8% chitin. In sausages, moisture decreased from 68.7% (control) to 65.8% (CF-5.0%), while protein increased from 7.1% to 9.4%. Rheological measurements showed all CF sausages had lower storage modulus (G′) at 50–80°C compared to control, indicating weaker gel formation. Color analysis showed significant darkening with CF: L* decreased from 74.8 (control) to 66.0 (CF-5.0%), while a* and b* increased. Total color difference ΔE* was 4.1, 6.5, and 9.7 for CF-1.0%, CF-2.5%, and CF-5.0%, respectively. Texture was markedly impaired: hardness dropped from 743.9 g (control) to 271.0 g (CF-5.0%), springiness from 0.9 to 0.5, cohesiveness from 0.7 to 0.4, chewiness from 475.7 N to 56.8 N, resilience from 0.4 to 0.1, and fracturability from 14.9 to 7.4. For lipid oxidation, TBARS values on Day 0 were higher in CF sausages and increased dramatically from Day 7 to 14, with a significant storage day × CF% interaction (p < 0.001). For protein oxidation, carbonyl content increased with CF addition (from 1.5 to 2.6 nmol/mg protein on Day 0, p < 0.001), while free thiols decreased (from 127.0 to 76.4 nmol/mg protein on Day 0, p < 0.001). Tryptophan fluorescence intensity was higher in CF sausages on Day 0 but decreased rapidly during storage. Significant positive correlation was found between TBARS and carbonyls (r = 0.566, p < 0.01), and negative correlations between free thiols and TBARS (r = −0.640, p < 0.01) and carbonyls (r = −0.854, p < 0.01).
**Clinical Implications:** This study provides important technological data for the development of hybrid meat-insect products. The results demonstrate that cricket flour addition, even at low levels (1–5%), negatively affects sausage color, texture, and oxidative stability during storage. The weakened gel structure is attributed to interference from insect cuticular components (chitin, quinone-tanned scleroproteins) and potential polyphenol oxidase activity. The accelerated lipid and protein oxidation, particularly after one week of storage, is linked to the high polyunsaturated fatty acid content of cricket flour (46.8%) and increased protein content with susceptible amino acid residues. These findings suggest that for commercial application, additional strategies—such as enzymatic modification (e.g., transglutaminase), optimized drying methods, or inclusion of antioxidants—are needed to improve texture and retard oxidation in hybrid sausages containing insect ingredients.