Extraction and characterization of jujube fruit phenolic components with traditional and current methods

In this thesis study, it was aimed to optimize the extraction of phenolic compounds from jujube fruit, which has a high phenolic content, by traditional, ultrasound and microwave-assisted methods using the response surface methodology, to compare the extraction methods and to determine some bioactive properties of the obtained phenolic extracts. For this purpose, in the first stage of the study, time (120-1440 minutes), temperature (40-80℃), and solvent concentration (40-100%) for traditional extraction (TE) conditions; time (5-20 minutes), sonicator power (50-200Watt), duty cycle (10:6-10:10 sec:sec) and solvent concentration (40-100) for ultrasound-assisted extraction (UAE) conditions; time (30-180 seconds), microwave power (300-600Watt) and solvent concentration (40-70%) for microwave-assisted extraction (MAE) conditions were optimized using the independent variables. The extraction conditions providing the maximum total phenolic substance content for all extraction methods was determined as response. The optimum extraction conditions for TE were determined as extraction time 1410 minutes, extraction temperature 80℃ and methanol concentration 40%; for UAE were determined as the extraction time was 20 minutes, the duty cycle was 10:7 sec:sec, the sonicator power was 130 Watt and the methanol concentration was 40%; for MAE were determined as the microwave power was 300 Watt, the extraction time was 127 seconds and the methanol concentration was 43%. In the second stage of the study, extraction efficiency, pH, total titratable acidity, total phenolic substance, total anthocyanin, total flavonoid substance, ascorbic acid, antioxidant capacity (TEAC and FRAP) and compositions of phenolic and flavonoid components of the extracts obtained under optimum extraction conditions has been determined. When the bioactive properties of the extracts produced under optimum extraction conditions were examined, the highest total phenolic substance was in MAE as 3.3455±0.0843 mgGAE/g, the highest total flavonoid substance in UAE as 1671.1111±25.4587 mg/kg, the highest ascorbic acid in UAE as 2.2489±0.0589 mg/100g, and the highest total flavonoid substance in UAE as 1671.1111 mgQE/kg, the highest trolox equivalent antioxidant capacity in MAE as 3449.79±133.1608 mgTE/kg, and the highest iron (III) reduction antioxidant power in TE as 670±10.1835 mgTE/kg were detected. According to the LC-MSMS analysis results, different amounts of cathechin, succinic acid, cyanidin chloride, rosmarinic acid, salicylic acid, rutin, oxalic acid and quercetin dihydrate were detected in the extracts.