According to the study carried out by a team of researchers from the Faculty of Pharmacy and Food Sciences of the University of Barcelona (UB), the Biomedical Research Centre on the Network of Physiopathology of Obesity and Nutrition (CIBERobn) and the Biomedical Research Centre on the Network of Diabetes and Associated Metabolic Diseases (CIBERDEM), cooking the vegetables from the sofrito with virgin olive oil favours the absorption and release of the bioactive compounds from their traditional ingredients (garlic, onion and tomato).
The study, led by Rosa M.ª Lamuela, allows for an in-depth study of the mechanisms by which gastronomy could play a relevant role in the healthy effects of the Mediterranean diet. The results are published in the scientific journal Molecules.
The Mediterranean diet, characterised by a high consumption of phytochemicals from vegetables, fruits and legumes, has been correlated with improvements in cardiovascular and metabolic health. This association is mainly based on the results of the PREDIMED study, in which Lamuela also participated.
However, the health effects of this diet have been difficult to reproduce in non-Mediterranean populations. Possibly, according to the researchers, due to differences in cooking practices. Therefore, they are currently trying to evaluate whether Mediterranean gastronomy can bring health benefits, not only because of the food they eat, but also because of how it is cooked.
In this context, the aim was to evaluate the effect of extra virgin olive oil on the bioactive compounds of tomato, onion and garlic, ingredients traditionally used in the preparation of sofrito, one of the key culinary techniques in the Mediterranean diet.
According to the researchers, sofrito contains 40 different phenolic compounds and a high carotenoid content, and its consumption is associated with an improvement in cardiovascular risk parameters and insulin sensitivity.
"Cooking vegetables with virgin olive oil encourages bioactive compounds, such as carotenoids and polyphenols that are present in vegetables and sautéed vegetables, to move towards olive oil, which facilitates the absorption and bioactivity of these compounds.
The study has also discovered a new characteristic of olive oil. Until now, it had been described that this type of oil and the onion have the capacity to produce isomers (molecules with the same molecular formula but with different properties) of carotenoids, variants that are more bioavailable and have greater antioxidant capacity. However, in this work it has been proved that oil has a fundamental role in this process, not only in carotenoids, but also in polyphenols, which pass from vegetables to oil.
These results could explain why previous studies of this group had already found that the presence of oil increases the anti-inflammatory effect of tomato sauce.