Antioxidant effects of Satureja montana L. essential oil on TBARS and color of mortadella-type sausages formulated with different levels of sodium nitrite

This study aimed to evaluate the effect of adding winter savory (Satureja montana L.) essential oil (EO) at concentrations of 7.80, 15.60 and 31.25 μl/g on color and lipid oxidation (TBARS) in mortadella-type sausages formulated with different sodium nitrite (NaNO2) levels (0, 100 and 200 mg/kg) and stored at 25 °C for 30 days. The EO was extracted by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Twenty-six chemical compounds were identified; the most prominent of which were thymol (28.99 g/100 g), p-cymene (12.00 g/100 g), linalool (11.00 g/100 g) and carvacrol (10.71 g/100 g). Among the nitrite levels tested, a concentration of 100 mg/kg of sodium nitrite appeared to be sufficient for the formation of the characteristic red color. The use of EO at concentrations exceeding 15.60 μl/g adversely affected the color of the product by reducing redness (a∗) (p ≤ 0.05) and increasing yellowness (b∗h∗). The EO antioxidant activity was confirmed by β-carotene bleaching method and DPPH assay. Reduced values of thiobarbituric acid reactive substances (TBARS) (p ≤ 0.05) were observed in mortadellas formulated with the lowest concentrations of EO without added nitrite. This significant effect on lipid oxidation was also observed in samples containing EO and reduced amounts of sodium nitrite. The results suggest possible benefits from the combined use of EOs and minimal amounts of sodium nitrite in cured meat products.

► DPPH and β-carotene bleaching methods confirmed the antioxidant effect in vitro. ► Essential oil inhibited effectively the lipid oxidation in mortadella-type sausages. ► The synergistic effect of low sodium nitrite levels and essential oil was observed. ► High levels of essential oil and nitrite can promote undesirable changes in product (characteristic color). ► Savory essential oil can be used combined with minimal doses of nitrite, to meet the consumer demand for natural additives.