Caracterização e optimização do teor em manoproteinas dos vinhos: influência na estabilização físico-química e características sensoriais

Doutoramento em Engenharia Alimentar - Instituto Superior de AgronomiaMannoproteins interact with several wine compounds and they seem to enhance the product sensory characteristics. This way, it was essential to understand more deeply the behaviour and the interactions established by mannoproteins through the industrial wine production process. The mannoproteins release in a white wine was studied, evaluating two different bâtonnage methods by comparing mannoproteins profile and content. The wines submitted to wood barrel bâtonnage presented a higher polysaccharide concentration and a better body mouth-feel. Subsequent to this work, the impact of fining and tartaric stabilization processes on the released mannoproteins was studied. Bentonite, gelatine and static cold tartaric stabilization removed high molecular weight mannoproteins and diatomaceous earth filtration removed mannoproteins with no selectivity. The interaction between mannoproteins and red wine phenolic compounds was also evaluated, by adding commercial mannoprotein enriched products and by adding winery produced yeast lees. Mannoproteins did not show an interaction with colour compounds but they seemed to delay the polymerization reaction of proanthocyanidins with a polymerization degree between eight and fourtee