Acerola pulp was supplied by Mais Fruta Company (Jarinu, SP, Brazil). The product presented high moisture content, approximately 92%, pH value of 3.3 and soluble Roxadustat molecular weight solids of 7.2 °Brix. The experimental setup, described in details by Mercali, Jaeschke, Tessaro, and Marczak (2012), comprises a power

supply, a variable transformer (Sociedade Técnica Paulista LTDA, model Varivolt, São Paulo, SP, Brazil), a stabilizer (Forceline, model EV 1000 T/2-2, São Paulo, SP, Brazil), a data acquisition system, a computer and an ohmic cell. The ohmic cell was a 400 ml water jacket glass vessel. The electric field frequency used was 60 Hz. The electrodes were made of platinum, with cross-sectional areas of 7.0 cm2. The cell was placed

on a magnetic stirrer plate (Instrulab, Model ARE, Brazil) for agitation of the product during heating. The kinetic experiments were conducted at 75, 80, 85 and 90 °C. Samples were withdrawn at various heating times (0, 15, 30, 45, 60, 75 and 90 min). In order to eliminate the heating time as a variable during the experiments, the time–temperature histories in conventional and ohmic processes were matched using the following control strategy. A temperature-controlled water bath (Lauda, model T, Germany) was connected to the ohmic cell to heat the sample at one degree above the desired temperature of the study. When this temperature was reached, the pump was turned off. The water in the jacket was removed while the temperature of the sample gradually decreased. When the sample reached the desired Selleck CH5424802 temperature, the first sample,

Thalidomide associated with time zero, was collected. Then, the ohmic heater was turned on using 25 V to maintain the desired temperature inside the cell during 90 min. Although one of the advantages of ohmic heating over the conventional process is that food exposure to heat is significantly reduced due to more rapidly temperature increments, this heating procedure was necessary to evaluate the non-thermal effects of electricity during the thermal treatment. Fig. 1 presents plots of temperature against time for ohmic and conventional heating experiments conducted at 75 and 90 °C. The time–temperature histories at 80 and 85 °C showed a similar plot behaviour. The conventional heating process was carried out in the ohmic cell without the presence of the electrodes. The same thermostatic water bath (Lauda, model T, Germany) was used to heat the samples. The experiments were conducted at the same range of temperatures (75–90 °C) and the samples were withdrawn at same heating times (0–90 min). The monomeric anthocyanin content of the samples was analyzed by UV–Visible spectroscopy using the pH-differential method (Lee, Durst, & Wrolstad, 2005). Briefly, the samples were centrifuged (Cientec, model 500R, Piracicaba, SP, Brazil) at 5 °C (10 min, 3000×g).