EXTRACTION TIME INFLUENCE ON THE PHENOLIC AND CAROTENOID LEVEL, AND THE DYNAMICS OF ANTIOXIDANT ACTION OF CHOKEBERRY DRY RESIDUE

Abstract

This study aimed to analyze the extraction time influences on some phenolics and carotenoids determined in the chokeberry dehydrated residue. In addition, the dynamics of the DPPH· radical reduction under the influence of the different amounts of chokeberry extract and reaction time were registered. For this purpose, fruits belonging to the ’Melrom’ and ’Nero’ cultivars grown in the experimental plots of the Research Institute for Fruit Growing Maracineni-Arges were harvested at full maturity, in the middle of August 2021 and pressed for juice extraction. The resulting pomace was subjected to convective dehydration at 45ºC. Values of 12286.11-16560.88 mg GAE/100g DW for TPC, 6567.96-9428.90 mg GAE/100 g DW for TTC, and 3293.74-5109.63 mg CE/100 g DW for TFC were registered. Lycopene and -carotene ranged between 0.78-1.43 mg/100 g DW and 0.21-0.37 mg/100 g DW. Longer ultrasound treatment led to higher TPC and TFC, while TTC decreased after 60 minutes. Raising the extraction time by at least 24 hours resulted in higher amounts of carotenoids. The lowest remanent radical activity (A=20.55%) was determined for the 50 and 60 µL extract doses. In this case, A% was minimal after 20 minutes of the DPPH reduction reaction (12.62-12.94 %), but not significantly different compared to the values determined after the first 8 minutes of the reaction (17.59-19.11 %).