Grape Seeds
Grape
Vitis vinifera L.
Grape seeds are a part of grape pomace from winemaking by-products. Grape seeds represent 5% of the weight of the whole grape but represent a range of 40 to 50% of solid wastes of the winemaking process. The oil content of the grape seed is ranged around 10 to 15% of seed weight with about 70% of linoleic acid (C18:2), 16% for oleic acid (C18:1), and palmitic acid (C16:0) 10%.
By-Products
Amount per 100 g
| Dry matter | 93 g |
| Protein | 17.1 g |
| Minerals | 3 g |
| Total dietary fiber | 35.1 g |
| Carbohydrates | 3.6 g |
| Lipids | 7 to 20 g |
| Ash | 2.4 g |
There is also a high content of chemical components with biological importance due to antioxidant activity. Among them, phytosterols, tocopherol, tocotrienols, flavonoids, phenolic acids and carotenoids are the most important.
The polyphenolic part contains a heterogeneous mixture of monomers, oligomers and polymers:
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Total phenols 8.58 g GAE / 100 g of DM
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Total flavonoids 8.36g catechin equivalent / 100 g DM
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Condensed tannins 6.41g catechin equivalent / 100 g DM
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Proanthocyanidins 5.95 g cyanidin equivalent / 100 g DM
Grape seeds, according to the varieties, are rich in flavanols with high antioxidant activity. Some studies also found trans-resveratrol in some grape varieties (Isabel, Sangiovese, Negro Amaro), between 1 and 3.75 mg/100 g DW.
Grape seeds are rich in fatty acids, especially PUFA (C18:2) which is associated with the promotion of cardiovascular health by down-regulated low-density lipoprotein cholesterol production. Studies have also reported anti-tumor and antioxidant effects in fractions rich in tocotrienols as well as improving insulin sensitivity.
By-Products
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