Healthy antioxidants can be extracted from pine bark

The pulp industry constantly produces great amounts of biomass in the form of pine bark.  Today, this bark is mainly used to produce energy, but the fact is that bark, and above all pine bark, contains many useful chemical substances that can be used in commercial industrial contexts.

— There is a low concentration of antioxidants in the bark, but it is still interesting, both from a sustainability point of view and an economic point of view, to be able to reuse these antioxidants before the bark is combusted, says Kerstin Sunnerheim, senior lecturer at Mid Sweden University.

Today, antioxidants are extracted mainly by means of different types of chemical processes that require solvents and other chemicals. Together with researchers from Uppsala University, a research team at Mid Sweden University has investigated different environmentally friendly methods to extract the antioxidants.

 The purpose has been to develop a fast, effective and environmentally sustainable method that extracts the greatest possible share of antioxidants.

—Using regular water and ethanol in combination with high temperature and high pressure, we have discovered an environmentally sustainable method to extract antioxidants from pine bark, says Kerstin Sunnerheim.

The method that proved to be the most effective one is the PFE method, (pressurised fluid extraction) in combination with the pressurized fluids water and ethanol. Among other things, the antioxidant resveratrol was extracted, an antioxidant usually connected with grapes and wine.  

Antioxidants are interesting within a number of commercial fields. In the pulp industry, for instance, they can be added in order to prevent paper from turning yellow and in the food industry, they are often added because of their preservative effect.