Food spoilage has been a common problem throughout history and is mostly due to the activity of microorganisms and enzymes during the storage period of food; Therefore, preservative chemicals are used to prevent or delay corruption. Sodium benzoate is a common preservative with antibacterial and antifungal properties that is used in a wide range of foods, including mayonnaise. Studies showed adverse biological effects of this substance on the body of animals. Plant essential oils have antibacterial and antioxidant activity and can be used to control the growth of pathogenic microorganisms and food spoilage agents. In this study, the effect of pure and encapsulated essential oil of clove on the shelf life of mayonnaise and the possibility of replacing sodium benzoate,was investigated.For this purpose, nanostructured lipid carriers were produced by combining two methods of high shear homogenization and ultrasonic, using glyceryl behenate as solid lipid, olive oil as liquid lipid and lecithin and tween 80 as emulsifier. Particle size, polydispersity index, encapsulation efficiency and encapsulation loading for nanostructured lipid carrier formulas with solid lipid ratio of 2, 5 ,8% and clove essential oil ratio of 10 ,20 % was estimated. The formulation with solid lipid ratio and clove essential 8 and 20%, respectively, and size and polydispersity index, encapsulation efficiency and encapsulation loading, respectively, 67.10 ± 1.86 nm, 0.43 ± 0.02,% 99.30 ± 0.17,% 19.86 ± 0.06 were selected as the optimal formula and were discussed in the continuation of the research.Field emission scanning election microscopy images showed the presence of nearly spherical to oval particles with an average diameter of less than 100 nm, which was almost a confirmation of the results obtained from the dynamic light scattering method. The results of infrared spectroscopy indicated that no chemical reaction occurred between the essential oil and the nanocarrier. Thermal gravimetric analysis showed the reduction of thermal stability of nanostructured lipid carrier after adding essential oil and differential scanning calorimetry analysis showed complete entrapment of essential oil in lipid carrier. Antioxidant activity of pure and encapsulated essential oils was measured at concentrations of 100, 200, 400, 600, 800 and 1000 ppm of essential oil. Antioxidant activity increased with increasing essential oil concentration.Also, measuring the antioxidant activity of pure and encapsulated essential oils over a 22-day period showed an improvement in the antioxidant activity of encapsulated essential oils. The minimum inhibitory and bactericidal concentrations of essential oils in both pure and encapsulated states were 3,000 and 6,000 ppm for Escherichia coli and 1500 and 3000 ppm, respectively, for Staphylococcus aureus. The results showed a favorable and stable inhibitory effect of encapsulated clove essential oil during the shelf life of mayonnaise and the possibility of replacing sodium benzoate with it. The results of sensory eva‎luation showed that mayonnaise containing encapsulated clove essential oil had an acceptable acceptance.

ميلاد فتحي

صبيحه سليمانيان زاد، علي نصيرپور

هاجر شكرچي زاده، رسول كوثر