Effect of the thermal treatment and high pressure processing for the preservation of purees from two different cherry cultivars ('Pico Negro' and 'Sweetheart') grown in "Valle del Jerte" (Spain)

The effect of hydrostatic high pressure processing for the preservation of cherry purees was compared to the traditional thermal treatment of pasteurization. Two cherry cultivars ('Pico Negro' and 'Sweetheart') were assessed in order to evaluate the cultivar suitability for each type of processing. Purees were manufactured with ascorbic acid (0.5% w/w) to avoid quality damages during the blending process. They were treated at 400 and 600 MPa for 3 min in a semi-industrial high pressure equipment. In the thermal treatment, purees were heated at 80 degrees C for 5 min. The changes in the microbiology, and bioactive compounds content (phenolic and anthocyanin compounds) were evaluated in the purees from the two cultivars after processing (thermal and high pressure treatment). Both treatments (high pressure and thermal treatments) reduced pathogens and spoilage counts of microorganisms in both cultivars ('Pico Negro' and 'Sweetheart'). In addition, the anthocyanins contents were better preserved by high pressure processing than by the thermal treatment while phenolic compounds content were well maintained by both methods. Results indicate that the high pressure processing could be a suitable alternative to obtain cherry-derived products with better nutritional quality than by traditional pasteurization.