Impact of nanoemulsion of Ajwain-cardamom essential oils on Mortadella sausage quality during chilling (4°C) storage.

Essential oils application as natural preservatives is challenging owning to low solubility and stability to harsh conditions, while incorporation of essential oils into nanoemulsion systems can effectively improve these issues. Therefore, the nanoemulsion of ajwain (C. copticum) and cardamom essential oils were fabricated through self-emulsification technique and evaluated their size, ζ-potential, antioxidative and antibacterial activities. The effect of double nanomulsion on the textural and sensorial properties of Mortadella sausage was also examined under chilling temperature (4 °C). Our goal was to improve the chilling storage of Mortadella sausage by using ajwain and cardamom nanoemulsion as natural preservative. By increasing the ajwain essential oil in the nanoemulsion, the protein and moisture of sausage increased, while the fat content decreased (17 %). Furthermore, nanoemulsion of ajwain and cardamom essential oils showed particle size less than 100 nm and PDI<0.5 revealing the stability of nanoemulsions. Moreover, double nanoemulsions exhibited higher antibacterial activity against S. aureus and IC₅₀ DPPH value (107 ppm). The nanoemulsion had a greater effect on the textural properties of Mortadella, reduction in hardness (∼5300 g), and chewiness (∼2500 g mm). Ajwain/cardamom nanoemulsion also increased the sensory properties, particularly taste and acceptance of the Mortadella. Consequently, Ajwain/cardamom nanoemulsion not only improve the storage of mortadella sausage at chilling temperature due to their antioxidant and antimicrobial properties, but also has a positive effect on the red color and textural properties created a special herbal aroma, taste and odor in the Mortadella samples, which ultimately contributed to the customer-friendly product. The appropriate dose of these nanoemulsion can develop meat products at lowest amount of nitrite in Mortadella sausage formulations, although, further research should be conducted on the mechanism of action AEO/CEO nanoemulsion concerning appearance and nitrite reduction in the meat products.