Use of secondary raw materials from wine production

This bachelor thesis deals with using of grape pomace, waste from wine industry. It also deals with the determining of total phenolic substances in a grape pomace. The theoretical part focuses on the characteristic of grape, the chemical composition of wine, making of wine and mainly on use of secondary raw materials. It also describes phenolic substances, their division and finally something general about using experimental methods. In the experimental part a red grape pomace´s extraction was made. The extractions were made in different solvents, in a mixture ethanol-water (ratio 20:80; 40:60 and 60:40), also in a mixture glycerol-water (ratio 10:90; 20:80 and 40:60) and at the end in water. The extractions were made in a different time and the purpose was to optimize the extractions and to get the highest yield of phenolic substances, antioxidants. Time and economically side played an important role to find out and to choose the best solvent. In the results, as the best and the optimal extraction´s solvent on extraction of red grape pomace was chosen the mixture ethanol-water and ratio was 60:40. That mixture extracted the most phenolic substances and relatively in the shortest time. During the optimization of sample weight was found out that optimal sample weight is 4 g of grape pomace. At the end repeated extraction was made. It is obviously practically worthless. After second step of extraction, the concentration of phenolic substances is more than a half lower than at the first step