Rapid detection of benzoic, sorbic, and dehydroacetic acids in processed foods using surface-enhanced Raman scattering spectroscopy

Abstract

Benzoic acid (BA), sorbic acid (SA), and dehydroacetic acid (DHA) are among the most common food additives that are classified as antimicrobial preservatives. However, their consumption in excess can lead to damage to the human liver and kidneys. At the present time, no rapid method has been developed for the simultaneous detection of these preservatives in processed foods. In this study, an expedited process based on surface-enhanced Raman scattering (SERS) and solid-phase extraction (SPE) has been developed to determine the content of the preservatives in processed seafood, minced fish, and cheese products. The effect of local heating on SERS spectra at the center of the droplet, which was deposited onto silver nanopillar arrays used as the SERS substrate, was examined. A recirculating flow, manifested as twin vortices merging within the droplet, brought the preservative molecules down to the droplet’s center, resulting in an increase in the SERS signals. Furthermore, the screening efficiency of the detection method for the three preservatives was experimentally evaluated in real samples. The experimentally determined Raman bands of the added BA, SA, and DHA were compared with amounts obtained by the conventional method of high-performance liquid chromatograph (HPLC).