Comparison of the effect of sodium benzoate and peppermint essential oil on physicochemical, microbial, sensorial and rheological properties of Mayonnaise sauce

In this research the substitution of sodium benzoate with peppermint essential oil (PEO) was investigated as preservative of Mayonnaise sauce. Firstly, the chemical compounds of PEO was analyzed by gas chromatography-mass spectrometry (GC-MS). After that, the effect of addition of PEO at the levels of 1, 2 and 3% on the physicochemical, sensorial, microbial and rheological properties of Mayonnaise sauce during one month storage was investigated at 10 days intervals. Results of chemical tests indicated that the peroxide value (lower than 10 meq.kg-1) and acidity (0.7 –1.2 %) of all samples are in standard range. Also, the pH of samples was in standard value (lower than 4.1). The counts of Salmonella and E.Coli were negative for all samples. Total count test revealed that the microbial growth was decreased during storage time by increasing of PEO content. Also, the desirability and total acceptance of PEO containing samples was acceptable. According to the results of rheological test, the produced sauces had solid viscoelastic behavior with storage modulus higherthan loss modulus. By considering all properties, the sample containing 2% of PEO was the best sauce. Therefore, we can introduce the Mayonnaise sauce containing peppermint essential oil as a new natural and functional product.