The effect of methanol extract of Clove as a natural preservative in Mayonnaise sauce preservation

Due to the harmful effects of chemical preservatives and the prevalence of the idea of green consumption, the need for research on the antimicrobial effects of natural preservatives and plant essential oils on the growth of important food microorganisms in laboratory and food models has increased. Plant extracts are a natural source of antioxidants. The need for natural antioxidants in the food and pharmaceutical industries has led to extensive scientific research in recent decades. Due to the harmful effects of chemical food preservatives, the use of natural preservatives is increasing (Dabbagh et al., 2011). Essential oils are aromatic oily liquids derived from various components of the plant. The antimicrobial properties of essential oils have been known for many years and today the approach of the general public as well as other national and international organizations responsible for food hygiene in the use of various natural preservatives instead of chemicals leads to a greater desire for scientific knowledge. This material has been. Phenolic compounds are responsible for the antimicrobial properties of plant essential oils. Therefore, the higher the amount of phenolic substances in essential oils, the higher their antimicrobial properties. These substances include carvacrol, eugenol and thymol (Barzegar et al., 2008). Clove is one of the plants that contains volatile and non-volatile compounds. Clove contains 10-13% of tannins, which have a chemical composition such as gallotanic acid. It also contains 2% triterpene and oleanolic acid (Milind et al., 2011). Clove has strong antioxidant activity that is comparable to the antioxidant activity of synthetic antioxidants such as butyl hydroxyl anisole and pyrogallol (Dorman et al, 2000). In recent years, food manufacturers have paid close attention to the use of natural preservatives of plant and microbial origin instead of chemical preservatives in their products. This is on the one hand due to the high tendency of consumers to use processed foods without preservatives or even possible with natural preservatives, and on the other hand, more and more attention of health authorities to this issue (Shafiei et al., 2014).

After preparing the plant sample powder, essential oil was extracted by steam distillation with the help of Clevenger device for 3 hours, and 150 g of clove powder was used in each essential oil extract. To prepare the extract, 60 g of clove powder in 1200 ml of 96% ethanol was placed in the dark at 30 ° C for 48 hours. Then, using Whatman 42 filter paper, plant powder residues were separated from the solution and extracted again by the previous method. The solution obtained from both stages was added on top of each other and the concentration operation was performed using a concentrator in a rotating vacuum at a temperature of 50°C (Zabetian Hosseini et al., 2013). After extraction, extract compounds were determined by GC-Mass method. Minimum mortality and inhibitory tests of clove extract were also performed for national standard bacteria and then used in mayonnaise formulation. Samples of mayonnaise with concentrations of zero (control), 0.1, 0.3, 0.5 and 0.7% and with other raw materials including olive oil (44%), vinegar 4% (12%), 4.5% sugar, a mixture of egg yolk powder and emulsifiers (2.22%), starch (2%), salt 10% (1.5%), mustard powder (0.4%), xanthan gum (1/1) Guar gum (0.1%), citric acid (0.15%), sodium benzoate (0.04%), potassium sorbate (0.035%) and water (32.975%) were formulated. After preparing the final mixture, it was homogenized for 5 minutes using a high-speed homogenizer (1000 rpm). It should be noted that one kilogram of sample was prepared for each treatment and kept at 4 ° C for 5 months (Janine Passos Lima da et al., 2012). Sauce samples were evaluated and tested at production time intervals, first, second, third, fourth and fifth months. Microbial tests, peroxide number evaluation, emulsion stability, viscosity, colorimetric and sensory were performed for the treatments. The results of the research were evaluated with Minitab software version 16.

The studied clove extract had the highest percentage of eugenol with 5.85%, eugenol acetate with 1.3% and heptacosan with 1.8%, respectively. In the study of the percentage of compounds derived from clove essential oil, the highest percentages were observed: eugenol with 86.36%, beta-cariophylline with 66.7%, alpha-hemolen with 1.87% and eugenol acetate with 1.14%, respectively. The clove extract and essential oil used had inhibitory effect on the growth of Lactobacillus plantarum, Saccharomyces cerevisiae and Penicillium glaucoma. Increasing the amount of clove extract significantly reduced the initial microbial population as well as during storage. Mayonnaise treatment with clove extract at 0.7% also had the lowest population of Lactobacillus, mold and yeast, total number of microorganisms and Salmonella. The use of clove extract significantly inhibited the peroxide index during the storage period and also reduced the emulsion stability. With increasing the concentration of clove extract, the brightness index (L*), redness (a*) and yellowness (b*) of mayonnaise treatments increased significantly and during storage the brightness and redness index decreased but the yellowness index increased significantly. With increasing the use of clove extract and also over time, the pH decreased significantly. With increasing the ratio of shear rate to shear stress in mayonnaise treatments and with increasing the use of clove extract, the viscosity had a decreasing trend and mayonnaise treatment with 0.7% compared to the control treatment and other mayonnaise treatments had the lowest viscosity index. Sensory evaluators announced the 0.5 and 0.7 treatments as having the lowest score and the mayonnaise treatment with 0.1% as the optimal treatment during the storage period.

Due to the health of food against compounds and pathogens and maintaining the nutritional value of the desired food along with the elimination of pathogens, the use of natural antioxidant extracts such as clove extract as an antioxidant to prevent spoilage in food Perishable like mayonnaise seems essential. Analysis of the obtained results proved the antimicrobial effect of clove essential oil in mayonnaise product. Therefore, it can be claimed that mayonnaise contains clove essential oil, a completely natural and useful new product that, while eliminating the use of chemical preservatives, can maintain the shelf life of the product to an acceptable level and lead to the introduction of a new product as a flavored sauce with desirable nutritional properties.