The effect of optimizing the extraction method of some of the orange varieties over time on its antioxidant strength by ultrasound-maceration method

Sour tree is the local tree in the northeen part of Iran. Nowdays using its peel as by products has gained attention. In this study the effect of extraction method like sonication with diffrent solvents like ethanol, methanol, ethanol/water (50:50), methanol/water (50:50), and water has been evalutaed. Total phenolic content was measured due to the Folin–Ciocalteu method and antioxidant activities of each extract has been evaluated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH), b-carotene bleaching and finally the effects of the concentrations of the extracts and temperature on the oil was done. The result showed that in both ripened and raw sour orange the correlation between solvent and extract concentraion was not significant (p> .05) but the effect of extract concentration on 2,2-diphenyl-1-picrylhydrazyl ,Total phenol and b-carotene bleaching was significant(p<.05) .the effect of solvent sort on above tests was also significant(p<.05). In continue the results showed that in both ripened and raw sour orange the total phenol values don’t have any significant diffrences which has been extracted by different solevents.the highest phenolic values was about 1082.80 μg/mg gallic acid equivalent. the result also showed that water-ultrasound method for extraction in both cases showed the lowest DPPH values in ripened and raw sour oranges,respectively 53% and 59.2%. ethanol-water solvent also showed the highest values for above test for both type of sour orange69.72% and 75.16% .At the end it has been cleared that there are three important factors like ripness,solvent and extracted molcules nature which affect phenolic compounds and antioxidant activities.

Keywords:

DPPH , Folin–Ciocalteu , sonication , extraction