Lipid Oxidative Stability of Fresh Pork Sausages Enriched With Peixinho Da Horta ( <i>Stachys byzantina</i> K. Koch) Extracts Obtained via Natural Deep Eutectic Solvents (NADES)

The growing interest in natural alternatives to synthetic additives underscores the importance of plant-based antioxidants. This study investigated the use of peixinho da horta (Stachys byzantina K. Koch) extract in fresh pork sausages. Five formulations were developed: one control with synthetic antioxidants (LC), one without antioxidants or extracts (LS), and three with natural extract at concentrations of 0.5% (LP1), 1.0% (LP2), and 2.0% (LP3). Physicochemical properties, including pH, color, water-holding capacity (WHC), cooking weight loss (CWL), and lipid oxidation, were evaluated at three time points: Day 0 (24 h after production), Day 9, and Day 16. Significant differences were observed across all parameters. CWL ranged from 12% to 36.52%, and WHC ranged from 73.69% to 86.36%, with LP3 showing the highest CWL and lowest WHC. pH values ranged from 5.11 to 5.81, and although L* values remained similar, significant differences were observed for a* and b* values. For oxidative stability, LP1 and LP3 performed similarly to the control (LC), with thiobarbituric acid-reactive substance (TBARS) values ranging from 0.09 to 0.12 mg MDA kg^-1. Among the formulations with natural extracts, LP1 (0.5%) was the most promising, offering oxidative stability comparable to the synthetic antioxidant while maintaining desirable physicochemical characteristics. The use of peixinho da horta extract as a natural antioxidant enhanced oxidative stability, improved color retention, and reduced reliance on synthetic additives. These findings highlight the potential of using natural extracts like peixinho da horta in the development of healthier, more sustainable meat products.