Volatile and Antioxidant Compounds of Beetroot Powder Obtained by Dehumidified Air Spray Drying of Cloudy Juice

Abstract

The aim of this study was to evaluate the quality of cloudy beetroot juice powders with or without a carrier obtained by spray drying using an innovative method of dehumidified air that enabled drying in low temperatures and, consequently, with a reduced carrier content. Phenolic content, betacyanin content, antioxidant activity and the content and types of aromatic compounds of the produced powders were examined. Powders obtained at a lower temperature (90 °C) without carriers were characterized by the highest share of aromatic volatile compounds, the highest content of betalains and polyphenols and the highest antioxidant activity. The addition of carriers (including the variant with added pomace as a natural type of carrier) did not indicate the protection of the active substances present in the juice. The powders obtained with carrier addition compared with those without the carrier addition were characterized by lower antioxidant activity, lower content of betalains and polyphenols and a lower amount of aromatic volatile compounds. No significant differences were found in the content of bioactive and aromatic compounds between powders obtained using different carriers (skim milk powder, Nutriose, maltodextrin and kleptose).

Keywords

• spray drying
• dehumidified air
• beetroot
• aromatic compounds
• antioxidant activity