Indena exploits new technology to refine bilberry extract

The company says that its characterisation method provides an effective solution to a well-known issue in determining the active constituents of bilberry extracts and could have similar uses for a variety of other berry-based active extracts.

Because of their antioxidant-rich composition, these extracts are widely used as ingredients in cosmetics formulations for skin care applications, dietary botanicals and by the pharmaceutical market for the treatment of vascular and vision disorders.

The main actives, accounting for many of the beneficial properties of these extracts, are anthocyanins - the natural pigments responsible for the red, pink, mauve, purple, blue or violet colouring of most flowers and fruits.

Formed by a flavonoid molecule conjugated with a sugar, it is these compounds that act as potent antioxidants and phosphodiesterase inhibitors, thus being particularly effective in helping capillary resistance and permeability in both topical and oral applications.

Anthocyanidins, which are usually present in low quantities in the bilberry extract, are anthocyanins without the sugar moiety and are quick to degrade when there has been incorrect extract production or storage.

Until now, the most common method for evaluating anthocyanins has involved UV-visible spectrophotometry, which allows the quantification of anthocyanins. Although widely used, the company says that this method lacks in specificity and does not allow the identification of each anthocyanin.

As a consequence, it is impossible to detect anthocyanins extracts produced from similar plant materials, including other berry fruits such as raspberry, blackberry, blackcurrant and elderberry.

Indena​, which specialises in active ingredients derived from medicinal plants, says that its extensive research has led to the conclusion that the best technique for the standardization of anthocyanin extracts is High-performance Liquid Chromatography (HPLC). This method allows the evaluation of individual anthocyanins, but is hard to reproduce and does not allow for the complete separation of all the constituents.

In order to simplify the UV-visible and the HPLC procedures the extract is often modified by acidic hydrolysis. The company says that this method is far from satisfactory as it distorts the extract's natural balance. Moreover, this procedure does not allow the quantification of the real content of free anthocyanidins, which are markers of extract degradation.

Recently introduced into the Italian Pharmacopoeia, Indena's new HPLC method is claimed to overcome all of these analytical issues. As a result of its good reproducibility and its high specificity, the method can ultimately identify the botanical raw materials used for manufacturing and evaluating the composition of the extracts, thus providing a high degree of product consistency and quality.