Extraction of acesulfame potassium from sweetened foods using a K₃PO₄-PEG aqueous two-phase system

Aqueous two-phase systems (ATPS) offer a sustainable and residue-free approach for food processing. Herein, a stable PEG-K₃PO₄ ATPS was developed and its phase behavior shown to depend on PEG molecular weight, temperature, and pH. The system enabled efficient recovery of acesulfame potassium (Ace-K), which preferentially partitioned into the PEG-rich phase through electrostatic and hydrophobic interactions. Applied to real samples including cola, Babao congee, and oral solutions, the method achieved recovery rates of 94.58–110.92 % with detection and quantification limits of 0.22 and 0.67 mg/L, respectively. This phosphate-PEG ATPS provides a safe, efficient, and cost-effective platform for sweetener recovery and detection in food and pharmaceutical products. • A green phosphate-PEG ATPS for sweetener recovery. • Phase behavior tuned by PEG size, temperature, and pH. • Electrostatic–hydrophobic effects drive Ace-K selectivity. • Safe, efficient, zero-residue extraction for real samples.