Quantification of total polyphenol content in wine lees by conventional optical and photoacoustic spectroscopy

The He-Ne laser (632.8 nm) and photoacoustic spectroscopy (PAS), a variant of the photothermal methods, were combined with Folin-Ciocalteu colorimetry method to determine total phenolics in wine lees. Utilising this we found that polyphenol content nine selected lees varied from 1305 3907 mg/L. gallic acid equivalent was determined by means spectrophotometry using 765 nm as analytical wavelength. original assay modified for PAS measurements. Since does not need dilution, filtration steps reagent used directly on samples. Using colour reaction process reaction, showed linear behaviour between PA signal; results which gave determination coefficients 0.9946 0.9936, while limit detection 232.6 mg/L both cases.