Grape seed components

Dietary intervention with crude MegaNatural-AZ grape seed extract significantly reduced (by 30-50%) Alzheimer s disease-type cognitive deterioration in mice by prevention of amyloid formation in the brain [8]. However, it is essential to determine which components of the extract exhibited bioactivity in the transgenic... 

In a companion study, M. Palma et al. studied the extraction of grape seeds with pure SF CO2 and analyzed the derivatized extracts by GC-MS. These extracts were found to contain volatiles such as aliphatic aldehydes in addition to fatty acids and sterols. Even though we used similar conditions for our SF extraction and GC-MS analysis, we were unable to detect any similar volatile compounds. To further investigate the presence of volatiles in the cranberry seed extract, we adapted a solid phase microextraction (SPME) method from the work of Jelen et al. who had earlier developed it for the characterization of volatile compounds in different vegetable oils. SPME followed by gas chromatog[raphy was performed on the headspace of the cranberry seed extract to test for the presence of volatile compounds. The GC trace failed to show the elution of any components for either the SF or Soxhlet extract. 

In dry white wines, the total phenol content is between 50 and 250 mg/1, or less than 10% of the value in red wines. It is even lower in sweet wines, made from grapes affected by noble rot. Indeed, the development of Botrytis cinerea is accompanied by a large-scale breakdown of the phenolic compounds in the skins. Only tyrosol remains, as well as the components from seeds (gaUic acid, catechin and procyanidins). Although their deep yellow color might seem to indicate the contrary, these wines always have a very low tannin content. 

Moreover, apart from these main components, grapes contain secondary metabolites such as flavonoid and non-flavonoid phenolic compounds, sesquiterpenes, and melatonin. Most of the grape s medicinal value can be attributed to its seed and skin, which researchers have found to be rich in nutritional value due to the presence of polyphenolic antioxidants. At least 500 different types of antioxidants have been found in various parts of this fruit [4]. 

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