2.4. Conventional heating
Conventional heating treatments were performed in a glass cell, and the cell content was heated by heat exchange with hot water in the jacket. The glass cell used was similar to the one employed for ohmic heating but had a 5.5 cm diameter. The time/temperature conditions were the same for both processes, and the product was cooled in the same manner. Temperature was monitored using type T thermocouples which were inserted in the center of the cell.
For the evaluation of conventional heating on anthocyanin degradation, only the central level of the design was analyzed; therefore, only blueberry pulp containing 10 g/100 g solids content was used.