PROCESS FOR OBTAINING AN EXTRACT OF PHENOLIC COMPOUNDS FROM MARC OF THE RED GRAPE VITIS VINIFERA AT LOW TEMPERATURES FOR APPLICATION IN FOODS AND BEVERAGES DESTINED FOR HUMAN AND ANIMAL CONSUMPTION

摘要

Process for obtaining an extract of phenolic compounds from marc of the red grape Vitis vinifera at low temperatures applicable as an ingredient in foods and beverages suitable for human and animal consumption. Lyophilised fermented or unfermented marc is employed in said process. The extraction solvent is a 50:50 ethanol:water mixture acidified to pH 2 through the addition of citric acid in a proportion of 30 - 50 g/l of extraction solvent. The extraction is carried out at a temperature of 2 - 10°C with continuous stirring at 500 - 1000 rpm for a period of 4 - 8 hours using an extraction ratio of lyophilised marc:extraction solvent of 1:8. The juice from the extraction is separated from the marc of extraction, being pressed to obtain a pressed juice. The extraction and pressed juices are mixed and subsequently purified by centrifuging, followed by filtration for the removal of precipitated solids. The extract is stabilised with the addition of guar gum in a proportion of 0.7 - 1.0 g/l of extract.