Natural procyanidins were extracted from Vitis vinifera seeds and fractionated by FPLC (Fast Protein Liquid Chromatography). Selected procyanidins were then isolated purified and identified in order to study their transformations in model wine solutions characterized by different conditions of temperature (12, 22, 32 and 32°C), pH (2.0, 3.2, 3.6 and 4.0) and acetaldehyde content (0.0%, 0,02% and 0,2%). Transformation of flavanols at each level of acetaldehyde appeared to be a first-order kinetic reaction. The rate constants and the half-life times for all procyanidins decreased with increasing levels of acetaldehyde. Higher degradative constant rates and lower half-life times were pointed out at the lowest pH value (2.0). Low temperatures increased half-life time of all studied compounds, while high temperatures increased transformation rate of procyanidins. Results pointed out that trimeric structures are the most sensitive to all the factors assayed. We suggest you to read the entire article. Original title: Influence of Acetaldehyde, pH and Temperature on Transformation of Procyanidins in Model Wine Solutions