Initial stages of minimal processing of red beets result in significant loss of bioactive compounds

Abstract

This study aims to detect the main stages in which bioactive compounds are lost during minimal processing of red beet and to comprehend more deeply the influence of each processing stage in the quality of minimally processed beet. Samples of beets were collected during the stages of preparation of this minimally processed produce, analyzed for betalains (betacyanins and betaxanthins) and phenolic compounds content, as well as polyphenoloxidase (PPO) activity, and performed anatomical analysis. Initial stages of minimal processing of red beet result in significant losses of bioactive compounds. Peeling accounts for one-quarter of betacyanins losses. Betaxanthins were expressively reduced at the first sanitation, resulting in almost half decrease. Anatomical sections have shown that cells of the cortical parenchyma are smaller and vascular parenchymal tissue was characterized by larger cells, well visible intercellular spaces and containing single vacuole. In conclusion, initial stages result in bigger losses of betalains and phenolic compounds during minimal processing of red beet. These stages promote PPO leaching, as its location in organelles is compromised by cell decompartmentalization. However, because these stages are essential for minimally processed produce, strategies aiming to reduce losses should focus on other factors.