Antioxidant activity of two grape types

There is a growing body of evidence that a healthy diet, which includes lots of fresh fruits, vegetables, and whole grains, is highly beneficial in preventing the development of chronic degenerative diseases, such as, e.g. cardiovascular diseases. This favorable influence on the human health is associated with the high content of antioxidants, found often in high quantities in the fresh produce. In particular, grapes are known to contain large concentrations of polyphenols, phenolic acids, anthocyanins, and flavonoids, which all belong to an important class of naturally occurring antioxidants. Many of them have been found to reveal, among others, strong antioxidative activity, free radical scavenging capacity, anti-inflammatory and anticancer activities, protective action against Alzheimer’s disease, prevention of urinary bladder dysfunctions, as well as potential antiviral activities.

In our proof-of-concept study we compared, using Electron Paramagnetic Resonance (EPR) spectroscopy, the antioxidant activity of two grapes varieties, i.e. red and white grapes. Specifically, we implemented a well-known spin probe, TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, 50 mM), as a paramagnetic target for the antioxidant reactivity of the freshly-prepared juices of red and white grapes. As shown below, we could easily identify the faster decay, as a function of time, of the EPR signal of TEMPOL exposed to the antioxidant reactivity of the red grape juice.


It is then quite obvious to expect that the red wine has similar advantages over white wine!