Influences of different decontamination methods on surface pesticide residues and quality of dried star anise

Pesticide residues on dried star anise remain major barrier to product safety and quality; current washing practices unfortunately fail to balance decontamination efficiency with retention of bioactive compounds. Suitability of emerging decontamination media, in particular alkaline electrolyzed water (ALEW), for star anise has nevertheless not been assessed. The present study therefore compared use of ALEW with use of conventional methods at ambient and high-temperature conditions to decontaminate star anise; four representative fungicides were tested. Quality of dried star anise was then determined in terms of color, rehydration behavior, shikimic acid and volatile oil contents. ALEW treatment at ambient temperature provided superior pesticide reduction (9.3–14.7%) compared with other treatments; such treatment also led to enhanced rehydration capacity and color. Unexpectedly, high-temperature soaking markedly reduced effectiveness of ALEW and caused significant losses of shikimic acid and volatile oils. Machine learning modeling identified support vector regression as most accurate tool to predict influences of pH, soaking temperature and soaking time of ALEW on pesticide residues decontamination and reveals distinct parameter sensitivities among different pesticides. Short-duration, ambient ALEW treatment offers practical and quality-preserving solution for pesticide control in star anise processing, with clear implications for sustainable spice manufacturing.