The upmarket company says that the new sweet naturally contains more flavonol antioxidants than any other food. Antioxidants are known to fight free radicals, which have been linked to heart disease, cancer and other age-related diseases.
The chocolate is processed in a gentle way to preserve two to three times more of the natural antioxidants in cocoa. Choxi+ comes in four flavours - dark, milk, dark chocolate with oriental mint and milk chocolate with sweet orange.
Prestat claims that Choxi+ dark chocolate contains almost 20 times as many antioxidants as blueberries, and two squares of the chocolate provides the same amount of antioxidants as 1lb of Brussels sprouts, or over 5lb of apples.
A spokesman for the company said that the health benefits of Choxi+, priced at 1.99 pounds per 70g or 75g bar, means no one need ever feel guilty about enjoying a few squares of chocolate again.
"We're saying that chocolate is good for you and not straying too far from there. And if you're going to be eating chocolate, this is the best chocolate you can get," the Daily Mail quoted Bill Keeling, owner of Prestat chocolates, as saying.
"Although Choxi+ is a great product, it can't replace the nutrients and fibre found in fruit and vegetables, so you should still be eating your five a day and of course, sadly, it does contain calories. That's why we're calling Choxi+ 'positive indulgence'.
"It should still be considered a treat but it's a treat that is much better for you than chocolate has ever been before," he added.