Optimization of ultrasound-assisted pectinase extraction process parameters for peppermint leaves using response surface methodology: a dataset of total flavonoid yield and antioxidant activity

This dataset comprises the complete experimental data for optimizing the ultrasound-assisted pectinase extraction (UAEE) of total flavonoids from peppermint (Mentha canadensis L.) leaves and evaluating the antioxidant activity of the resultant extracts. The data were generated through systematic laboratory experiments conducted at Bozhou Key Laboratory of Biosynthesis of Effective Components of Medicinal Plants between 2025 and 2026.Data generation followed a sequential methodology: (1) Single-factor experiments to preliminarily assess the effects of four key parameters (pectinase addition, time, temperature, liquid-to-solid ratio) on total flavonoid yield. (2) A Box-Behnken design (BBD) of response surface methodology (RSM) with 29 experimental runs (4 factors, 3 levels) was executed using Design-Expert software (version 13) to model and optimize the process. (3) Triplicate verification experiments were performed under predicted optimal conditions. The total flavonoid yield (expressed as g per 100 g dry weight, g/100 g DW) was determined for all extraction trials using a spectrophotometric method. For the final optimized extract, in-depth analysis included: (i) qualitative profiling of flavonoids via UHPLC-MS (Shimadzu Nexera UHPLC LC-30A system coupled with an AB SCIEX TripleTOF 5600+ high-resolution mass spectrometer); raw data were acquired using Analyst TF software and processed with PeakView software for compound identification; (ii) quantification of four major flavonoid compounds (hesperidin, diosmin, linarin, acacetin) via an external standard method; and (iii) assessment of in vitro antioxidant activity through DPPH and ABTS radical scavenging assays, with results expressed as half-maximal inhibitory concentration (IC₅₀ in mg/mL, reported as mean ± standard deviation from triplicate measurements).The dataset comprises the following key files (all in CSV format):Single_Factor_Pectinase_Results.CSV: Raw absorbance and calculated flavonoid yield for experiments varying pectinase addition.Single_Factor_Time_Results.CSV: Raw absorbance and calculated flavonoid yield for experiments varying ultrasonic time.Single_Factor_Temperature_Results.CSV: Raw absorbance and calculated flavonoid yield for experiments varying temperature.Single_Factor_Liquid_to_Solid_Ratio_Results.CSV: Raw absorbance and calculated flavonoid yield for experiments varying the liquid-to-solid ratio.BBD_Design_Matrix_and_Results.CSV: Experimental design matrix and corresponding flavonoid yields for the 29 RSM runs.RSM_Model_Analysis.CSV: Key statistical analysis results of the RSM model, including ANOVA, model fitness statistics (R², Adjusted R²), and regression coefficients.Verification_Experiment_Results.CSV: Results from the triplicate verification experiments under optimized conditions.UHPLC_MS_Flavonoids_Positive.csv: Tentatively identified flavonoids from UHPLC-MS analysis in positive ion mode.UHPLC_MS_Flavonoids_Negative.csv: Tentatively identified flavonoids from UHPLC-MS analysis in negative ion mode.UHPLC_MS_Flavonoids_Combined.csv: Consolidated list of flavonoids identified from both positive and negative ion modes.Quantification_Four_Flavonoids.CSV: Calibration curves and calculated concentrations of the four target flavonoids.DPPH_Assay_Data.CSV: Raw absorbance readings and calculated radical scavenging rates for the DPPH assay.ABTS_Assay_Data.CSV: Raw absorbance readings and calculated radical scavenging rates for the ABTS assay.Standard_Curve_Data.CSV: Absorbance data used to generate the rutin calibration curve for total flavonoid quantification.The dataset is complete with no missing values. Measurement errors are expressed as the standard deviation of replicate determinations.