Ohmic heating and pulsed vacuum effect on dehydration processes and polyphenol component retention of osmodehydrated blueberries (cv. Tifblue)

• The combination of PVOD/OH treatments at higher temperatures intensifies mass transfer on osmodehydrated blueberries.
• Polyphenol components retention was greater at lower osmotic temperatures (30–40 °C).
• Osmotic treated samples improve the retention of polyphenols in contrast to untreated samples after drying.
• The PVOD/OH at 40 °C followed by air drying at 60 °C could be the best process to obtain a dehydrated blueberry.

Blueberries are highly perishable fruits; therefore, emerging technologies focus on improving the bioactive compound retention and extending the shelf life. The aim of this study was to evaluate the effect of ohmic heating and vacuum pulses on the dehydration processes and polyphenol compound retention of osmodehydrated blueberries (cv. Tifblue). The treatments were performed using a 65% (w/w) sucrose solution, an electric field of 13 V/cm (100 V) at 30 °C, 40 °C or 50 °C for 300 min, and air drying at 50, 60 or 70 °C to obtain dried blueberries. The moisture content, soluble solids and phenolic compounds were analyzed. The combination of ohmic heating/pulsed vacuum treatments intensifies mass transfer in osmodehydrated blueberries, especially at higher temperatures. Nevertheless, the polyphenol retention was greater at lower temperatures; hence, the application of an intermediate process temperature (40 °C) was selected as a pre-treatment prior to further drying. The treated samples improve the retention of polyphenols after drying compared with untreated samples. Therefore, the results of this research study suggest that the use of a pulsed vacuum and ohmic heating in the osmotic dehydration (PVOD/OH) treatment at 40 °C for 240 min and subsequent drying at 60°C could be the best process for dehydrating blueberries, considering that it improved mass transfer, achieved lower losses of phenolic components and reduced the drying time.Industrial relevanceBlueberries are an important fruit due their high bioactive compound content, especially polyphenols. Studies that involve emerging technologies application could add value to blueberries. Ohmic heating and pulsed vacuum as pre-treatments improve the efficiency of dehydration processes, focused toward bioactive compounds retention and achieving commercial viability. In this work have been applied PVOD/OH treatments at moderated temperatures and subsequently dried at 60 °C, obtaining promissory results.