Effect of sonication on the content of bixin, norbixin, total phenols and antioxidant activity of extracts of five achiote accessions

Pigments obtained from achiote seeds are highly demanded worldwide, being the bixin the second most important natural pigment. Due to this, the study of methods and conditions that allow to improve traditional processes for their extraction from achiote seeds is of particular interest. In some cases, the functional activity of the obtained extracts is also evaluated. In this work we study the effect of a sonication treatment on the extraction of functional compounds of achiote seeds, as well as the antioxidant activity of such extracts, in comparison to a traditional maceration extraction. Sonication has shown some advantages such as being simple to apply, reducing extraction times and increasing extraction yields. The comparisons are made in hydrophilic and hydrophobic extracts obtained from 5 accessions of achiote from Yucatan, Mexico. When applying sonication, the content of polyphenols (18-25%) and norbixin (25-55%) in the extracts was increased, as well as the antioxidant activity of the hydrophilic (18-22%) and hydrophobic (10-20%) phases; however, the sonication had no effect on the content of bixin, the latter being the main product of commercial interest. These results suggest that sonication extraction can be a valuable alternative for obtaining extracts with higher contents of functional compounds or enhanced norbixin contents from achiote seeds.

Keywords: Bixa orellana; sonication; bixin; norbixin; antioxidant activity.