Grape seed extract: additive and functional ingredient
Grape seed extracts (GSE) can be used as functional ingredients due to their beneficial effect on human health but they are sensitive to high temperatures and have strong astringency and bitterness. Microencapsulation can provide an individual package for ingredients like GSE, acting as a barrier which retards the damage and prevents unpleasant tastes. Several studies have been done to evaluate the possibility of using GSE to substitute synthetic antioxidants and antimicrobials with positive results and no impact on the sensory profile of the products. On the other hand only a few articles deal with the use of GSE as functional ingredients and in these cases because of the concentration of the extract, there is a need to mask the taste of the GSE.
Around 48 million tons of grapes are intended for the production of wine a year, and marcs represent 20% of the total, generating about 5-9 million tons of wine by-products. It represents a considerable pollution from the chemical demand of oxygen and the biochemical demand of oxygen points of view (1). Grape seeds are the part of the marcs that has the greatest amount of total phenolic compounds, being mainly flavan-3-ols and condensed tannins (2). It is known that polyphenols present in the grape seeds have a beneficial effect on human health; their free radical scavenging property protects cells from lesions caused by these highly reactive molecules. Other beneficial effects from polyphenols on human health are: anti-inflammatory and anti-allergenic properties, reduction of the risk of cardiovascular diseases, and cancer chemopreventive properties (3). With regards to the bioavailability of polyphenols present in the grape seeds, flavan-3-ol monomers are quite well absorbed from the small intestine. However, absorption of dimers is less efficient than that of flavanol-3-ol monomers, as is evidenced by 6- to 50-fold lower peak plasma value ...