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 works, 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 agitation extraction. Sonication has shown some advantages such as being simple to apply, reducing extraction times and increasing extraction yields. The comparisons were made in hydrophilic and hydrophobic extracts obtained from 5 accessions of achiote from Yucatan Peninsula, Mexico. When applying sonication, time of extraction was reduced (33%), the content of polyphenols in the hydrophilic phases was increased (18-25%) as well as the norbixin content in the alkaline extracts (70-85%). A similar behavior was observed in 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 some of the studied accessions had the potential to be used commercially and that sonication extraction can be a valuable alternative for obtaining extracts with higher contents of functional compounds or enhanced norbixin contents from achiote seeds.