Response surface methodology (RSM)-based statistical modeling and optimization of the ultrasound-assisted extraction of saffron bioactives

The present study was carried out for the extraction of bioactive compounds from saffron stigma using the ultrasound-assisted extraction. Process parameters were optimized by using response surface methodology (RSM). The percentage of methanol (0–100%), duration of sonication (min), and varied holding temperatures (°C) were kept as independent variables to optimize the extraction of crocin, picrocrocin, and safranal, three main components of saffron. High-performance liquid chromatography (HPLC) was employed to assess the concentration of crocin, picrocrocin, and safranal in saffron extract. The final data included four models: linear, linear squares, linear interactions, and complete quadratic. With R 2 values of 0.90, 0.92, and 0.80 for crocin, picrocrocin, and safranal, respectively, the full quadratic model was determined to be the most effective. Response surface analysis revealed that the ideal conditions for the extraction of crocin, picrocin, and safranal were methanol concentration of 52.59, sonication time of 4.34 min, and holding temperature of 68.78 °C respectively. The empirical quantities of E1cm%1 λmax for crocin, picrocrocin, and safranal, contents were 523.531, 2656.59, and 11,035.61 respectively. The total phenolic content (103.063 ± 0.00 mg GAE/100 g) and total flavonoid content (98.25 ± 0.01 mg QE/100 g) of optimized extracts were higher under ultrasound-assisted extraction conditions than the total phenolic content (94.311 ± 0.00 mg GAE/100 g) and total flavonoid content (92.210 ± 0.02 mg QE/100 g) of conventionally extracted samples (CES). The higher DPPH activity (88.08%) was observed in the optimized ultrasonically extracted sample than in conventionally extracted samples (80.00%). Our data revealed that ultrasound-assisted extraction increased the recovery of these valuable bioactive components; moderate methanol concentrations, high temperatures, and short durations had a remarkable influence on bioactive component extraction efficiency. Our discoveries regarding extraction conditions are relevant for both industrial and analytical applications.