Effect of sodium and starch reduction on nutritional, physicochemical, and sensorial properties of mortadella added with Agaricus bisporus and Pleurotus ostreatus by-products.

High sodium intake is a major global health concern, driving the search for alternatives in processed foods (Riis, Lassen, Bjoernsbo, Toft, & Trolle, 2022). Edible mushroom stems, which account for up to 20 % of mushroom production, are rich in umami compounds. This study evaluated for the first time the use of Agaricus bisporus and Pleurotus ostreatus stem flours (ABSF and POSF) as partial replacements for sodium chloride, sodium tripolyphosphate, and starch in mortadella. Formulations containing 2.75 % and 4.25 % of ABSF (MAB, MAB) or POSF (MPO, MPO) were assessed for their chemical, physicochemical, microstructural, and sensory properties of mortadella. The results demonstrated that the reformulated products maintained or improved protein content and achieved a significant reduction in residual nitrite levels (P < 0.05), suggesting improved product safety. POSF incorporation preserved texture, color, and aroma, while ABSF led to darker coloration and lower emulsion stability in the mortadellas. ABSF and POSF addition revealed significantly lower overall acceptability (P < 0.05) in sensorial analysis. However, despite sodium reduction, all formulations achieved similar salinity perception, indicating the potential of mushroom by-products as natural flavor enhancers. Microstructural analysis confirmed successful integration of flours into the protein matrix. These findings support the industrial application of mushroom stem flours as cost-effective, sustainable ingredients to develop clean-label, reduced‑sodium meat products. Their use can contribute to circular economy strategies by valorizing mushroom by-products and meeting consumer demand for healthier, reformulated foods. Further research should address microbiological safety and optimization of formulation to improve sensory profiles for large-scale production.