Comparison of Tyrosinase Biosensor and Colorimetric Method for Polyphenol Analysis in Different Kinds of Teas

Abstract

We report the content of polyphenols expressed as chlorogenic acid equivalents, in a variety of commercially available samples of yerha mate. The 48% of analyzed samples presented a 92 ± 8mg of extracted chlorogenic acid equivalents per gram of dry base. Composites exhibited a lower extracted amount. Results from samples contained in tea bags are higher, indicating dependence on milling degree. The extracted chlorogenic acid, expressed as m g /g was evaluated hy three methods in an unique yerba mate sample; hiosensor (89.2mg/ g ). Folin (90.2 mg-g ). and high-performance liquid chromatography (HPLC) analysis(21.0mg g ). Biosensing system validation was peformed. Repetitiveness of genuine replicates was consistent with nature of the samples. Discrimination between yerba mate and other plants can be done using principal component analysis (PCA) and the corresponding physical and chemical descriptors. Flavor and taste alterations can be studied by means of analytical methods that involve low-cost instrumentation. It has been observed that some green tea samples present remarkable differences depending on the specie.