Agroaldea
Orange and other citrus juices are considered healthy products due to their high content of antioxidant compounds., that help reduce harmful free radicals in our body, But new research indicates that its benefits are greater than previously thought.
The antioxidant activity of citrus juices and other foods is undervalued. A new technique developed by researchers from the University of Granada to measure this property yields values ten times higher than those indicated by current analysis methods..
The results suggest that the tables on the antioxidant capacity of food products used by dietitians and health authorities should be reviewed..
To study these compounds in the laboratory, Techniques are used that simulate the digestion of food in the digestive system., in such a way that only the antioxidant capacity of those substances that are potentially absorbed in the small intestine is analyzed.: the liquid fraction of what we eat.
“The problem is that the antioxidant activity of the solid fraction – the fiber – is not measured., because it is assumed that it is not used; but this insoluble part reaches the large intestine and the intestinal microbiota can also ferment it and extract even more antioxidant substances, that we can evaluate with a new method”, explains the professor from the University of Granada, José Ángel Rufián Henares.
His team has developed a technique called 'global antioxidant response' (GAR, for its acronym in English), which also simulates in vitro the gastrointestinal digestion that occurs in our body, but taking into account the 'forgotten' antioxidant capacity of the solid fraction.
The method, details of which are published in the journal Food Chemistry, includes assessments of various physical-chemical parameters, like the color, fluorescence or the relationship of the concentrations analyzed with that of indicator compounds such as furfural.
When applying the technique to commercial and natural orange juices, tangerines, lemons and grapefruits, It has been proven that its values skyrocketed. For example, in the case of the orange one, goes beyond 2,3 millimoles Trolox/liter (trolox antioxidant capacity units) recorded with a traditional technique at 23 mmol Trolox/L indicating the new GAR method.
“The antioxidant activity is, on average, about ten times greater than what everyone said until now, and not only in juices, but in any other food that is analyzed with this methodology”, Rufián Henares stands out, that points out its possible application: “This technique and the results derived could serve dietitians and health authorities to better establish the values of the antioxidant capacity of foods”.
With the help of this method, Scientists have also created a mathematical model to classify juices depending on their natural and storage conditions., which allows us to ensure that the raw materials and the sterilization and pasteurization processes are correct.
——