Optimization of Phenolic and Flavonoid Extraction From Bee Bread Using Response Surface Methodology and Central Composite Design, and Evaluation of Antimicrobial Activity.

Bee bread is a remarkable apicultural product recognized for its abundant proteins, minerals, vitamins, and phenolic compounds, which enhance its notable biological activity. This study aimed to optimize the extraction conditions to maximize the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant capacity (DPPH) with conventional extraction of bee bread using response surface methodology (RSM) with Central Composite Design (CCD). The phenolic profile of the optimal extract was evaluated by high-performance liquid chromatography (HPLC). Antibacterial activity of the optimal extract was evaluated against Staphylococcus aureus, Escherichia coli, and Salmonella Enteritidis by using the microdilution method. The optimal conditions were determined to be 30°C temperature, 40 mL/g solvent-solid ratio, 66.729% solvent concentration, and 19.996 h time. The TPC, TFC, and DPPH results of the optimal extract were found to be 26.860 ± 1.08 mg GAE/g, 2.300 ± 0.46 mg QE/g, and 3.043 ± 0.26 mg AAE/g, respectively. HPLC analysis showed that quercetin, kaempferol, and hesperidin are the main phenolic compounds of the optimal extract. The optimal extract had minimum inhibition concentration (MIC) values of 12.5 mg/mL against S. Enteritidis, 25 mg/mL against E. coli, and > 25 mg/mL against S. aureus. In conclusion, this study demonstrated that the recovery of antioxidant and phenolic compounds from bee bread can be significantly enhanced by RSM.