Effect of Vinegar on the Oxidative Stability of Mayonnaise During its Storage

Mayonnaise is an emulsion of oil that is susceptible to lipid oxidation, which can cause spoilage and the formation of harmful compounds. This study aims to evaluate the impact of Syrian apple and grape vinegar on the oxidative stability of mayonnaise and compare the use of natural antioxidants to synthetic ones such as butylated hydroxyanisole and butylated hydroxytoluene. The study measured total phenol content, radical scavenging activity, and identified some phenolic compounds by High Performance Liquid Chromatography (HPLC). The rancidity of mayonnaise was examined using peroxide value and thiobarbituric acid number. The fatty acids content in the mayonnaise samples was examined using gas chromatography. Vinegar samples containing high concentrations of phenolic antioxidants showed high ability to scavenge free radicals. The antioxidants in vinegar protected the mayonnaise samples from primary and secondary oxidation, and there was no statistically significant difference between the ratio of unsaturated fatty acids in the samples containing vinegar at the beginning and at the end of the storage period. The study shows the significance of using vinegar to protect mayonnaise from deterioration and increase its shelf life, in addition to its role as a dressing.

The Oxidative Stability of Chia Seed Oil Enriched with Oregano (Origanum vulgare L.) and Yarrow (Achillea millefolium) Extracts

Oxidative stability of chia seed oil enriched with oregano (Origanum vulgare L.) and yarrow (Achillea millefolium) extracts at different concentrations (600, 1200, and 1800 ppm) was evaluated under accelerated oxidation conditions for 5 days. The total phenolic compounds and antioxidant activity of oregano extract were higher than the yarrow extract. With decreasing concentrations of extracts and increasing time, the oxidative stability of chia seed oil decreased significantly ( $p<0.05$ ). At the first day, the acid value of chia seed oil did not show a significant difference, and the highest acid value was related to the control sample at the end of the storage period. The oil containing 1200 and 1800 ppm of oregano extract had the lowest acid, peroxide, anisidine, and Totox values. In the rancimat, the highest oxidative stability index (OSI) was shown in the sample containing 1800 ppm oregano extract, followed by yarrow extract. Our findings showed the potential of oregano and yarrow extracts by improving the oxidative stability of chia seed oil, especially at 1200 and 1800 ppm. At similar concentrations, oregano extract was more successful than yarrow extract in reducing the oxidation rate.

Valorizing the usage of olive leaves, bioactive compounds, biological activities, and food applications: A comprehensive review

Olive oil production is a significant source of economic profit for Mediterranean nations, accounting for around 98 percent of global output. Olive oil usage has increased dramatically in recent years, owing to its organoleptic characteristics and rising knowledge of its health advantages. The culture of olive trees and the manufacture of industrial and table olive oil produces enormous volumes of solid waste and dark liquid effluents, involving olive leaves, pomace, and olive oil mill wastewaters. These by-products cause an economic issue for manufacturers and pose major environmental concerns. As a result, partial reuse, like other agronomical production wastes, is a goal to be achieved. Because these by-products are high in bioactive chemicals, which, if isolated, might denote components with significant added value for the food, cosmetic, and nutraceutical sectors, indeed, they include significant amounts of beneficial organic acids, carbohydrates, proteins, fibers, and phenolic materials, which are distributed differently between the various wastes depending on the olive oil production method and table olive agronomical techniques. However, the extraction and recovery of bioactive materials from chosen by-products is a significant problem of their reasonable value, and rigorous detection and quantification are required. The primary aims of this review in this context are to outline the vital bioactive chemicals in olive by-products, evaluate the main developments in extraction, purification, and identification, and study their uses in food packaging systems and safety problems.

The Role of Thyme (Zataria multiflora Boiss) Essential Oil as Natural Antioxidant on the Lipid Oxidation in Mayonnaise

Nowadays, essential oils are considered substitutes for synthetic additives in food products. Since lipid oxidation is the main chemical process affecting mayonnaise deterioration, in this research, the antioxidant activity of essential oil of thyme (Zataria multiflora Boiss) was determined for oxidative stability of treated mayonnaise (homogenized) during 6 months of storage. The antioxidant activities of the essential oil of thyme (0–150 μg/g) were investigated by the DPPH method. Then, the efficiency of this essential oil (144.4 μg/g) as a natural antioxidant in mayonnaise was studied by following analysis: peroxide, anisidine, Totox, and thiobarbituric acid. GC analysis of the essential oil resulted in the identification of forty compounds. The essential oil is characterized by a high number of monoterpenes such as thymol and carvacrol. Regarding antioxidation, the investigated essential oil strongly reduced the DPPH radical (IC50 = 144.4 μg/ml). This study confirms that the essential oil of thyme possessed antioxidant properties in vitro. The results showed that the treatments containing essential oil and TBHQ significantly reduced the oxidation ( $p<0.05$ ), while the control sample was oxidized faster. The essential oil had a significant effect on taste, odor, and overall acceptance, but no significant difference was observed in color and texture. The results of the present experiments suggest that essential oil of thyme (Z. multiflora) can be used as a source of natural antioxidant for the application in food industries to prevent lipid oxidation particularly lipid-containing foods such as mayonnaise. Therefore, it can used as a natural antioxidant and flavoring compound in foods such as mayonnaise.

ANTIBACTERIAL AND ANTIFUNGAL EFFECT OF ACHILLEA MILLEFOLIUM ESSENTIAL OIL DURING SHELF LIFE OF MAYONNAISE

The importance of food-borne disease and consumer demands for avoiding synthetic food preservatives shifted the research interest to natural food preservatives such as essential oils which have antimicrobial activity. Also, spoilage of foods by fungi is a major problem, especially in developing countries. The aim of this study was to evaluate the efficiency of Achillea millefolium essential oil as natural food preservative in high fat and low fat mayonnaise kept at 4°C for 6 months. Mayonnaise samples were divided into four experimental treatments, namely: EO (essential oil in concentrations of 0.45-7.2 mg/ml), BS (sodium benzoate and potassium sorbate in concentration of 0.75 mg/ml), Cmo (control: no preservative with added microorganisms) and C (control: no preservative and no added microorganisms). The results showed that of essential oil of Achillea millefolium had influence against all of the tested microorganisms in mayonnaise and all of the pathogens and fungi did not grow in mayonnaise, whereas in the control samples all of the microorganisms grew. The maximum cell counts of bacteria and fungus in low fat mayonnaise were approximately lower than the high fat mayonnaise or resistance to inactivation of microorganisms appeared to be greater in high fat mayonnaise than in low fat mayonnaise (p< 0.05). Also, BS samples exhibited antimicrobial properties against tested species during storage. In conclusion the essential oil of Achillea millefolium would lead to control food pathogenic organisms and food spoilage organisms and therefore, it can be used as natural preservative in food industry such as mayonnaise.