Technological possibilities of grape marc cell walls as wine fining agent. Effect on wine phenolic composition
Abstract
Fining is a technique that is used to remove unwanted wine components that affect clarification, astringency, color, bitterness, and aroma. Fining involves the addition of adsorptive or reactive material in order to reduce or eliminate the presence of certain less desirable wine components and to ensure that a wine remains in a particular stable state for a given period of time Recently concerns have been raised about the addition of animal proteins, such as gelatin, to wine due to the disease known as bovine spongiform encephalopathy (Mad Cow disease). Although the origin of gelatins has been moved to porcine, winemakers are asking for substitute products with properties and application protocols similar to the traditional animal-derived ones, making the use of plant-derived proteins in fining a practically viable possibility. As a consequence, various fining agents derived from plants have been proposed, including proteins from cereals, legumes, and potato. Also, particular attention should be paid to the proteins involved in celiac disease and food allergy, since they may be indicated in the label of foods, including wine, in order to inform susceptible individuals. Although wine fining materials are removed by precipitation and/or filtration, it is not possible to completely exclude the presence of residual traces of those materials in the fined wine. One option that has not been explored concern to grape cell wall material. Cell wall material is composed mainly of polysaccharides and small quantities of proteins, and lignin, and their use as red wine fining agents could be considered. It is clear that fiber or purified CWM derived from fresh grapes could not be commercially interesting since grapes are a valuable product but those products derived from the pomace obtained after fermentation and devatting could be an interesting way of adding value to this by-product. In this work, the properties of pomace derived cell wall material as regard the reduction of polyphenolic content in red wines have been studied and the results compared with different commercial fining products.
Issue: Macrowine 2016
Type: Poster
Authors
*University of Murcia