Evaluation of applewood extract as a natural antioxidant in emulsified meat products.

The growing demand for natural and sustainable food additives has driven research into alternatives to synthetic antioxidants. This study investigates the potential of applewood extract (AE), a polyphenol-rich product obtained through ultrasound-assisted extraction, as a natural antioxidant in emulsified meat products, with particular focus on liver pâté. The antioxidant capacity of AE was tested both individually and in combination with sodium nitrite (NaNO₂), a commonly employed stabilizer in the preparation of liver pâté. These results were subsequently compared to formulations containing NaNO₂ and butylated hydroxytoluene (BHT), an extensively utilized synthetic antioxidant.

Liver pâté formulations were stored at 4 °C for 10 weeks, with analyses conducted at six time points. Primary oxidation products, hydroperoxides, were quantified using the FOX assay, while secondary oxidation products were profiled using HS-SPME-GC-MS. Additionally, the evolution of the polyphenolic compounds in AE-treated  meat products was evaluated by UPLC-DAD. pH changes were also monitored to assess the overall quality of the product.

In both formation of hydroperoxides and secondary oxidation products, the control formulation, which included BHT and NaNO₂, exhibited the highest oxidative stability, maintaining minimal oxidation levels throughout the storage period. Liver pâté stabilized with NaNO₂ individually showed limited antioxidative protection after 4 weeks of storage, leading to oxidative degradation. The combination of AE and NaNO₂ demonstrated improved oxidative stability compared to the use of NaNO₂ as individual stabilizing agent, although it was less effective than the control. UPLC-DAD analyses revealed a time-dependent decline in polyphenolic content in AE-treated liver pâté, indicating that polyphenols were actively consumed during the oxidative process.

These findings demonstrate the potential of AE as a natural antioxidant, particularly when combined with nitrite, offering a more sustainable approach to enhancing the oxidative stability of emulsified meat products.