Recent advantage in electrochemical monitoring of gallic acid and kojic acid: a new perspective in food science

Phenolic compounds have outstanding features for health, such as immune system defense and preventing fatal diseases like cardiovascular diseases, stroke, diabetes, and cancer. They are the most prevalent antioxidants in the diet and come in various forms, distinguished by the presence of hydroxyl groups on aromatic rings. Two important phenolic compounds are gallic and kojic acid. Gallic acid is widely used in the food and pharmaceutical industry as a food additive, antitumor, anti-viral, and anti-mutagenic agent. Kojic acid is a natural tyrosinase inhibitor clinically used to cure human skin hyperpigmentation and has antibacterial and antifungal properties. Therefore, kojic acid is used in food and cosmetic products. For the detection of gallic and kojic acid, many conventional techniques have been utilized, such as high-performance liquid chromatography and mass spectrometry. However, electrochemical methods provide simple, low-cost, fast, and a wide range of concentration analyses for these phenolic acids. Through the development in materials science, modification of an electrode surface with alternative materials such as conductive polymers, molecularly imprinted polymers, or nanoparticles ensures versatile, selective electrochemical sensors for monitoring gallic and kojic acid. They offer simplicity regarding sensor preparation, measurement, and cost-efficiency. Therefore, the present review highlights the recent developments in developing electrochemical sensors for monitoring gallic and kojic acid.