Extracting Blueberry Pigments with Compressed Fluid Technology

A recent study by multiple research facilities in Portugal, introduced a dynamic compressed fluid-based separation process that combines carbon dioxide and ethanol in order to explore the isolation of portisins (a variety of bluish phenolic pigments [1]) previously hemi-synthesized from blueberry surplus anthocyanins.

While the performance of the two-step separation process is like centrifugal partitional chromatography (CPC) and conventional reversed-phase liquid chromatography (RPLC) in terms of portisins content in the extract, process throughput, process efficiency, and total solvent used. However, the process discussed in the study decreased the total solvent used, albeit with a decrease in the throughput and efficiency (2,3)

Blueberries contain vitamins and minerals which provide health benefits. For example, blueberries are rich in vitamin K, which helps promote heart health, and is also important in bone health and blood clotting. In addition, blueberries are thought to have the highest levels of antioxidants (which help protect against free radicals, harmful molecules your body makes in response to things that can damage cells) of any common fruit or vegetable. Blueberries also lower blood pressure and cholesterol levels. Furthermore, studies have shown that regularly eating blueberries can help improve insulin sensitivity in type 2 diabetes patients (4).

A compressed fluid is defined as a fluid under mechanical or thermodynamic conditions that force it to be a liquid. At a given pressure, a fluid is considered compressed if it is at a temperature lower than the saturation temperature (where a liquidcontains as much thermal energy as it can without boiling). The term emphasizes that the pressure is greater than the saturation pressure for the given temperature (5,6).

While several studies have shown that there are potential health benefits associated with blueberry compounds, the work presented in this paper expands on those studies by showing a technique which, by isolating portisins, could then be used as natural colorants in a variety of functional foods. This not only increases blueberry by-product value, but additionally coincides with the growing call for natural and sustainable ingredients by consumers.

As stated earlier, the process outlined in the article performed the task at hand with a decrease in the throughput and efficiency due to the reduction in the amount of total solvent used. However, the authors state that the choice of the best separation technology depends on the application, as these techniques result in different portisins purities, and believe that their study furthers to a scalable, more sustainable process in the production of natural colorants, specifically focusing on blue pigments, and that the technique can lead to a variety of industrial applications.

Fresh blueberries on the bush: © Andris Tkachenko - stock.adobe.com

References

1. Portisins. Wikipedia. https://en.wikipedia.org/wiki/Portosin (accessed 2024-05-22).

2. A. N.; Oliviera, J.; Bronze, M. R.; Matias, A. A. Compressed Fluid-Based Technology for Downstream Isolation of Bluish Anthocyanin-Derived Pigments Obtained from Blueberry Surplus. Food Funct. 2024, Advance Article. DOI: 10,1039/D3FO04813F (accessed 2024-05-22)

3. Howard, G. New Method to Extract Blueberry Pigments Using Compressed Fluid Technology. Natural Science News 2024.https://naturalsciencenews.com/article/2474 (accessed 2024-05-22).

4. Health Benefits of Blueberries. WebMD. https://www.webmd.com/diet/health-benefits-blueberries (accessed 2024-05-22).

5. Compressed fluid. Wikipedia. https://en.wikipedia.org/wiki/Compressed_fluid (accessed 2024-05-22).

6. Boiling point. Wikipedia. https://en.wikipedia.org/wiki/Boiling_point (accessed 2024-05-22).