Isolation of the active ingredient D-Limonene from citrus peel

The interest in oils, which has emerged with the effect of the interest in aromatherapy in recent years, is also the place where the world has passed. Within the scope of this thesis, the usage oils and active substances of citrus peel wastes have been studied. Within the scope of the study, it was aimed to enrich the D-Lemon, which is found at a high rate in citrus peel use oils, by using different methods. Different methods have been used for this enrichment process. First of all, the effects of extraction methods on the percentage of D-Limonene were examined. Oil production with the traditional method used for this purpose was obtained from the oils used by microwave assisted and supercritical CO2 extraction methods (for this purpose, different parameters were tested). Working parameters values with the Design-Expert program for the study in the supercritical CO2 extraction method. The optimum extraction method was aimed by looking at the percentage of D- Limonene of different extraction methods. Other methods used as enrichment process; cold crystallization, cold crystallization including metal plating and enrichment with column system. Within the scope of this study, the low D-Limonene ratio was obtained in the supercritical extraction method with a ratio of 16.19% at the operating parameter of 45°C-80 bar. The highest D- Limonene ratio was obtained with 85.43%, again by supercritical extraction method, at 60°C- 200 bar operating parameter. In the enrichment process of the column structure, product improvement was detected, but the desired level of efficiency could not be obtained. The oils obtained from four different citrus peels (orange, lemon, tangerine and grapefruit); Antioxidant determinations were made by DPPH, ABTS and CUPRAC methods. In the results of the analysis, the oil with the highest antioxidative value in the DPPH method was the orange peel oil with a sweeping effect of 61.59%, and the lowest antioxidant value was placed in the grapefruit peel operating oil with 11.97 sweep. In the DPPH method, the highest antioxidative value in supercritical studies was obtained with a scavenging rate of 40.57% at 30°C-80 bar operating parameters. The lowest scavenging was obtained with 9.58% scavenging at 60°C-80 bar operating parameters. In the ABTS method, the oil with the highest antioxidative value was found in orange peel launcher oil with 98% sweep propeller, the lowest value was determined in tangerine peel oil with 56% sweep. In the ABTS method, the parameter showing the highest antioxidative value in the oils obtained in supercritical studies was determined in the oils obtained at 60°C-200 bar. In the analysis made in the CUPRAC method, the oil showing the highest antioxidative value with an average trolox value of 12,283 mg/L is the use of lemon peel oil. In the supercritical studies performed in the CUPRAC method, the oil with the highest antioxidant value was determined in the oils obtained at 30°C-200 bar operating parameters.