Madrid: Gazpacho, the popular salad in soup form native to Spain, may be a vegetable-packed dish, but scientists have found that the vitamin and nutrient levels of its ingredients may drop during preparation.

The study, released by the Spanish Foundation for Science and Technology last week, found that some vitamin C and other organic acids get lost once they've been chopped and purified into soup consistency.

Gazpacho is a traditional Spanish soup, eaten cold throughout the summer months. The soup is prepared by blending red peppers, tomatoes, cucumbers, garlic, onions, bread, olive oil and vinegar.

In their experiment, scientists out of Complutense University of Madrid and the University of La Laguna measured the ingredients separately post-prep and found that red pepper had the highest vitamin C content, followed by tomatoes and then the gazpacho itself.

"We found that the gazpacho showed a lower ascorbic/dehydroascorbic acid ratio than the vegetables used to prepare it," explained Elena Mar ­a Rodr ­guez, co-author of the study. "This suggests that some of the vegetables' antioxidant capacity is lost."

To maximize nutritional value, it's advised to chop vegetables into larger chunks. The more finely they're chopped, the more surfaces are exposed to the air, which zaps vitamins and minerals.
Peeling fruits and vegetables also decreases their antioxidant properties, many of which are found in the skins.

Meanwhile, another study published in the American Journal of Lifestyle Medicine found that adding more tomatoes to a diet decreased the risk of cancer, osteoporosis and cardiovascular disease.

Tomatoes are the biggest source of lycopene, a powerful antioxidant that, unlike most nutrients, has even greater bioavailability after it's been cooked and processed. In other words, cooking tomatoes actually boosts some of their cancer-fighting abilities.