Comparison of ultrasound assisted and Kelavenger extraction methods on efficiency and antioxidant properties of Fennels oil essence and its optimization by response surface methodology

ABSTRACT: Today, Fennel essence is used as Flavor-giving, antimicrobial, antioxidant ingredients in food products such as chocolate, liquors, drinks, bread, pickles, confections, cheese, and medicine. So in this research, optimization of conditions for water- assisted extraction of fennel essence with (different combinations of sound time and intensity) and without applying ultrasound was studied. Experimental design included use of central complex design and statistical response surface methodology. optimum conditions for extraction of fennel essence ( including the highest efficiency and ferric reducing activity and the least rate of free radical scavenging activity) were determined with sound intensity of 100 and sound time of 12.61. Comparison of the findings from water-assisted extraction method with and without applying ultrasound showed a direct relationship between the rate of extraction and use of ultrasound waves. So that, the extraction rate with applying ultrasound was increased significantly compared to that of water-assisted extraction method without applying ultrasound (Kelavenjer). Increasing sound intensity increased extraction rate of antioxidant substances with Ferric reducing activity of plasma (FRAP) and decreased the extraction rate of antioxidant substances with free radical scavenging activity (DPPH). Also, increasing the time of sound-giving decreased the extraction rate of antioxidant substance with Ferric reducing activity of plasma (FRAP) and increased the extraction rate of antioxidant substances with free radical scavenging activity (DPPH). This finding shows that these two variables show opposite behaviors regarding extraction of antioxidant compounds with different properties.