Towards the Reuse of Sauce By-Product: Combining Analytical Chemistry and Chemometrics to Develop New Sustainable Products

Food waste valorization represents a critical challenge and opportunity for sustainable food systems. This study investigated the reuse of sauce production by-products through two approaches: (i) solvent-free recovery of an oil-rich fraction and (ii) development of polymeric films for potential edible or biodegradable packaging. Centrifugation recovered approximately 10 g per 100 g of by-product. The recovered oil was characterized for total polyphenols and fatty acid composition, showing a profile consistent with vegetable oils (mainly olive oil), with minor contributions attributable to cheese and meat components. A full factorial design was used to prepare and test films and to study the effects of the three ingredients used, namely pectin, carvacrol, and sauce by-products, on their mechanical, surface, and antibacterial properties. Chemometric analysis based on principal component analysis (PCA) and regression-based modeling (multiple linear regression and response surface analysis) was applied to identify the relationships among the responses and the most influential factors. Among the tested formulations, N3 (low pectin and by-product; high carvacrol) showed the most favorable overall balance, combining the strongest antibacterial activity (mean inhibition halo diameter of 14.8 mm and 17.8 mm against Escherichia coli ATCC 11229 and Staphylococcus aureus ATCC 6538, respectively) with favorable mechanical performance, including the highest maximum force (0.53 ± 0.01 MPa) and elastic modulus, (6.8 ± 0.01 MPa) and intermediate elongation (12 ± 3%) and work at maximum force (11.9 ± 0.9 N mm).