Instant Controlled Pressure Drop as Blanching and Texturing Pre-Treatment to Preserve the Antioxidant Compounds of Red Dried Beetroot (Beta vulgaris L.)

Abstract

Red beetroot is rich in bioactive compounds such as polyphenols, flavonoids, betaxanthins, betacyanins, among others. According to selected processing methods, the bioaccessibility of these compounds could be either enhanced or decreased. This study evaluated the effect of four different drying conditions: (1) Traditional Drying (TD), (2) Swell Drying (SD), (3) DIC Blanching + Traditional Drying (BTD), and (4) DIC Blanching + Swell Drying (BSD) on the antioxidant content and the antioxidant activity of red beetroots. Obtained results showed that in all the cases, by comparing to Traditional Drying (TD), the coupling of a DIC Blanching pre-treatment to a Swell Drying treatment (BSD) maintained or enhanced the preservation of the Total Phenolic Compounds (TPC), the Total Flavonoids Compounds (TFC), the Betanin Concentration (BC), the Trolox Equivalent Antioxidant Capacity (TEAC), and the Free Radical Scavenging Activity by DPPH (IC50) of red beetroots. Various studies have shown that thanks to the expanded and porous structure triggered by the Swell Drying process, it has been possible to achieve better antioxidants extraction and better whole quality. Hence, by coupling DIC as a blanching–steaming pre-treatment, it was possible to preserve better the antioxidant content and the antioxidant activity of red dried beetroots.

An Overview on Food Applications of the Instant Controlled Pressure-Drop Technology, an Innovative High Pressure-Short Time Process

“…Many other fruit and vegetable products have been submitted to swell-drying, such as broccoli [13], okra pods [56], and beetroots [57], among others. In all the cases, it has been highlighted that DIC treatment easily intensifies the drying kinetics, reduces energy, and achieves the desired quality attributes of final products (e.g., preservation of bioactive molecules and microstructure expansion).…”

A review on instant controlled pressure drop technology – a strategic tool for extraction of bioactive compounds

“…Besides the extraction of plant secondary metabolites, DIC can be used as a pre‐treatment for blanching‐steaming and assists in deactivation of heat resistance enzymes, peroxidase and polyphenoloxidase. Interestingly, fresh food material pre‐treated with DIC prior to convective air‐drying resulted in reduced drying time, and subsequently preserved nutritional and sensorial properties of dried products (Alonzo‐Macías et al ., 2020).…”