Role of Extraction Conditions in the Recovery of Some Phytochemical Compounds of the Jujube Fruit

In this study, the combined effects of various experimental parameters (solvent concentration, extraction temperature, pH, extraction time, and light conditions) on the recovery of phytochemical compounds from the jujube (Ziziphus jujuba var vulgaris) fruit were investigated in a batch system using a 25 full-factorial design. The independent variables were coded at two levels and their actual values were selected based on the results of single-factor experiments. Total Phenolic Content (TPC), Total Monomeric Anthocyanin Content (TMAC), and vitamin C content values were used for the determination of phytochemical compound content in jujube extract. The results showed that pH, extraction temperature, and solvent concentration were the most significant (P< 0.05) factors affecting the TPC, TMAC, and vitamin C content. The optimal extraction conditions of phytochemical compounds were found to be as follows: ethanol concentration of 60%, pH of 3, extraction time of 180 min, extraction temperature of 25°C, and absence of light. In the optimized conditions, the maximum experimental values for TPC, TMAC, and vitamin C content were 164.51 mg gallic-acid equivalents per gram of dry weight (mg GAE g-1 DW), 52.94 mg cy-3-glu 100 g-1 DW, and 137.12 mg LAA 100 g-1 DW, respectively. The high content of phytochemical compounds in the jujube extract indicates that jujube extract might be considered as a potential source of nutraceuticals in the future.