Prospective study on the quality and functionality of berry fruits

Trabajo presentado a las III Jornadas Científicas CIAL Fórum, celebradas del 22 al 23 de noviembre de 2018 en el Instituto de Investigación en Ciencias de la Alimentación (CIAL).

Currently, the World Health Organization recommended the daily intake of 400 g of vegetables and fruits to prevent numerous chronic diseases such as cancer, diabetes, obesity and heart diseases. However, the consumed amount is estimated to be lower to the established limit. An alternative could be the consumption of fruits that contain the highest concentrations of several bioactive compounds which can promote beneficial effects on the health reducing the risk of suffering degenerative phatologies. In this regard, berry fruits are an interesting source of polyphenols and functional carbohydrates, such as pectins. Pectins consist of a linear chain of partly methoxylated (1→4)-linked α-D-galacturonic acid (GalA) units that may be interrupted by rhamnose units bearing sugar side chains, arabinans and/or arabinogalactans. In Medicine, these complex polysaccharides also play an important role lowering glucose serum and stimulating the immune response. Nonetheless, the most striking application of pectins is in the food industry as gelling, emulsifying and thickening agents in jams, jellies, sauces and canned foods, being citrus the most used sources. Previous works have carried out a chemical characterization of strawberry, blueberry, raspberry, blackberry and red currant focusing only on the recovery of phenolic compounds. However, to the best of our knowledge, hardly any studies have analysed the composition of these fruits to evaluate them as a source of pectin. In this work, an investigation on the content of GalA, protein, sugar composition and total phenolic compounds have been carried out. All fresh fruits contained pectin; the highest and lowest contents of GalA were found in raspberry (1.6% dry matter) and blueberry/red currant (0.5% dry matter). Raspberry and blackberry presented 2-fold greater protein than blueberry (7.3% - 4.2%). With respect to polyphenols, the concentrations were similar for all samples except for red currant (~1400 vs 800 mg/100g dry matter). These results underline the possibility of extracting pectin from strawberry, blueberry, raspberry, blackberry and red currant, being the particular importance the extraction of this polysaccharide in the by-products derived from juice elaboration industry.

The authors thank to the funding granted by the Ministry of Science, Innovation and Universities through the project AGL2014-53445-R.

Peer reviewed