A simple and sensitive electrochemical method for the determination of capsaicinoids in chilli peppers

Total capsaicinoids content is a main parameter that reflects the spicy degree of chilli peppers. Capsaicin and dihydrocapsaicin are the most abundant components in capsaicinoids, which are responsible for about 90% of the spicy taste of chilli peppers. The determination of capsaicinoids becomes important for the increasing demand for spicy foods by consumers. To analyze the capsaicinoids, a sensitive and simple electrochemical method was established in this study. The adsorptive stripping voltammetry (AdSV) method was used to enrich samples. The detection was performed using differential pulse voltammetry (DPV) method combined with the disposable unmodified screen-printed carbon electrode (SPCE). The results showed that capsaicin and dihydrocapsaicin had similar electrochemical behaviors. The linearity of capsaicinoids was from 0.16 to 16.37 mu mol/L at the optimal experimental conditions and the detection limit (LOD, S/N = 3) was 0.05 mu mol/L. The established electrochemical method presented satisfactory precision and accuracy and the variations were both below 8.9%. After a simple pretreatment of chilli pepper samples, the content of capsaicinoids could be finally determined. This method is sensitive, simple, cost-effective and with satisfactory selectivity for the capsaicinoids in chilli peppers, which provides a promising tool in food industry.