Response Surface Methodology-Optimized FL 0.1 @ZIF-8 Fluorescent Probe for High-Throughput Capsaicin Analysis in Chili Products

Capsaicinoids are a group of naturally occurring organic compounds responsible for the pungency of chili. This study aimed at exploring a novel approach with multivariate-assisted Response Surface Methodology–Box Behnken Design (RSM-BBD) optimized fluorescent probe (FL 0.1 @ZIF-8) for the detection of capsaicin. The probe was solvothermally synthesized and characterized using XRD, FTIR, and SEM to confirm the successful incorporation of fluorescein (FL) into ZIF-8. The experimental parameters, including pH, concentration of the probe, and reaction time, were systematically optimized via RSM-BBD to enhance the sensitivity of FL 0.1 @ZIF-8. The results demonstrated a quenching response of FL 0.1 @ZIF-8 emission with capsaicin. The limit of detection (LOD) and limit of quantification (LOQ) were calculated and found to be 1.5 μM and 4.9 μM, respectively. The outcome of the study identifies efficient electronic factors as major contributors to the development of FL 0.1 @ZIF-8 with promising possibilities for the detection of chili hotness for food pungency evaluation, quality control, and assurance in the food industry.