optimization of extraction conditions by ultrasound-assist on the ratio of flavonoids, anthocyanins content and antioxidant and antimicrobial activity of punica granatum var. pleniflora (persian golnar) extract

This study aimed to investigate the effect of type of solvent (1: ethanol and 2: water), time (3, 6, 9 min), and power (100, 200, 300 w) of ultrasound assist in the extraction rate of flavonoids, anthocyanins, ic50 as well as the antimicrobial effect of the extract of punica granatum. var. pleniflora (pgp). in order to design treatments, analysis, and optimization of dependent variables the full factorial design is used.  the result of multiple optimizations of independent variables revealed that the highest amount of flavonoids in pg) extract (9.0502 mg/ml) and the amount of anthocyanin (5.3669 μmol/g) and the lowest ic50 value or the highest rate of free radical scavenging in (pgp) (8.0452 mg/ml) with 88.97% desirability were observed at 300 w for 9 min by using methanol as a solvent. the highest mean values of minimum inhibitory concentration (mic) and minimum bactericidal concentration (mbc) of pgp extract obtained by ultrasound pretreatment were 625 and 3750 μg/ml respectively against clostridium perfringens. the optimized predicted treatment by ultrasound pretreatment had a greater antimicrobial effect on staphylococcus aureus with the largest diameter of the growth inhibition zone (14 mm) compared to e. coli and c. perfringens. the results showed that the extract obtained from pgp could be introduced as an antioxidant source in marketable foods