Analytical chemistry examination of grape pomace extract

Introduction: Wine-growing has long-standing traditions in Hungary. The most large- and small-scale wine producers that process heavy amounts of grapes, look at pomace as waste. The basis of our work is that polyphenol-type compounds are found exactly in those plant segments, which are used to produce pomace. Objective: Our research tried to support the assumption that pomace does contain varied types and high level of polyphenol.Our research question was also expanded to examine the level of polyphenol in food supplements made of pomace substances.We have compared three different kinds of food supplements – each of them were free available for consumers – and their levels of polyphenol compounds. Method: The first step was to prepare an extract from the raw pomace and the three types of purchased food supplements. The extract tinctures have been strained at each case, then analysed first bythe HPLC (High Performance Liquid Chromatography) method, second by the NALDIMS (Nanoassisted laser desorption-ionization mass spectrometry) method. The received data was evaluated with the softwares belonging to the measurement equipment. Results: NALDI-measurements support the high level of polyphenol-type compounds defined by our research team in pomace extract. Level of polyphenol-type compounds was the highest in this sample of all measured samples. The level of polyphenol-type compounds in the other samples, the analysedfood supplements were far lower. During HPLC-measurements, three polyphenol-type compounds have been examined, these were resveratrol, quercetin, and rutin.Resveratrol concentration was only possible to be defined in case of pomace extract; the level was 0,04019 mg/l. No polyphenol-levels were possible to be detected in any other analysed sample, including the food supplements too.