Determination of total antioxidant and total phenolic component in extracts prepared from hass and fuerte avocado leaves grown in Alanya

This research was carried out to determine the optimal extraction method to obtain the total phenolic substance and flavonoid content and antioxidant effect of Hass (AH) and Fuerte (AF) avocado leaves grown in Alanya. For the analysis of bioactive components of Hass and Fuerte variety avocado leaves, extracts were obtained by 4 different methods: infusion (AHI, AFI), maceration (AHM, AFM), Soxhlet (AHS, AFS) and sound wave assisted extraction (AHU, AFU). The phenolic component and flavonoid amounts of the prepared extracts were calculated, besides the determination of total antioxidant activities in the leaves was carried out with the use of scavenging effect of 1,1-diphenyl-2-picrylhydrazil (DPPH●) radical, scavenging effect of 2,2'-azino-bis (3 ethylbenzthiazoline-6-sulfonic acid) (ABTS+●) radical, and determination of ironreducing antioxidant power (FRAP) methods. Obtained results were evaluated with oneway analysis of variance and Tukey-HSD test (p<0.05). The highest amount of total phenolic substance in avocado extracts was found in AHS, AHU, AHM and AFS extracts, while the highest amount of flavonoids was found in AFM, AFS and AHS extracts. In addition, as a result of the antioxidant activity experiments carried out, it was determined that the avocado leaf extracts showed the highest efficiency in the experimental setup in which the ABTS+● radical was used. According to these results, It was determined that AHU and AHS extracts of 'Hass' type leaves of avocado and AFU and AFS extracts of 'Fuerte' leaves showed the highest level of ABTS radical scavenging effect. In addition, it has been observed that the extracts have a weak effect in the DPPH system; although it is not as effective as trolox, it has been observed that the extracts had high activity in FRAP system and in this system extracts that prepared by the Soxhlet method from the leaves of the 'Fuerte' and 'Hass' type of avocado showed the highest activity.