Cultivar selection bridged with innovative processing: a new strategy to preserve and maximize antioxidant activity in blueberry juice.

摘要

The importance of consuming pigmented fruits rich in polyphenols and anthocyanins in our everyday diet is related to the well established protective effect exerted by fruits and vegetables, naturally rich in antioxidant compounds, on health, in particular on degenerative chronic diseases. In order to enrich a diet with antioxidant compounds without resorting to concentrated extracts, the development of new strategies is required to obtain high quality horticultural products retaining their natural abundance of these bioactive compounds. In order to obtain a blueberry (Vaccinium corymbosum) fruit juice rich in nutritional and biological compounds, the combined effect of cultivar and processing technology on the physical and chemical properties, phenolic compound contents and antioxidant activity of the final fruit juice were studied in 5 highbush blueberry cultivars (Berkeley, Coville, Bluecrop, Bluegold and Bluechip) from the same geographic location and individually processed into juice. The effect of an initial steam blanching step on raw fruits was also tested. This innovative technological step, not contemplated in traditional juice processing, was introduced in order to inactivate oxidative enzymes responsible for an early degradation of phenolic compounds. Results showed that the introduction of a blanching step was effective in improving phenolics recovery from fruits to juice, leading to a product characterized by a higher antioxidant activity, being this healthy improvement dependent on the tested blueberry cultivar.