Quantification of the association constant of caffeic acid‐cyclodextrin complex using a novel micro‐conductometric sensor for bitter taste masking of caffeic acid

Abstract

Abstract Caffeic acid (CA), a member of the hydroxycinnamic acid family, has garnered attention in the medical community for its wide‐ranging health benefits. However, its application in pharmaceutical and nutraceutical products has been hampered by its distinctly bitter taste, which deters many consumers. This study investigates the taste‐masking of caffeic acid (CA) using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD). A CA micro‐conductometric sensor was developed. This advanced technology demonstrated remarkable sensitivity, capable of detecting CA at concentrations as low as 10 −5 M, with a rapid response time between 10 and 50 seconds. The binding constant of the CA‐HP‐β‐CD complex was determined to be 240±24. 1 H NMR spectroscopy analysis provided concrete evidence of the formation of a 1 : 1 inclusion complex between CA and HP‐β‐CD. These findings collectively suggest that HP‐β‐CD is highly effective in masking CA's bitterness, thereby significantly enhancing its palatability.