PULSED ELECTRIC FIELD (PEF) IMPACT ON ACTINIDIA KOLOMIKTA DRYING EFFICIENCY

Actinidia kolomikta (Maxim. and Rupr.) Maxim fruits are very beneficial for the health, but their wide use is limited by short shelf life. One way of fruit preservation is drying, but Actinidia fruits have quite firm skin, which results in a long drying time. Pulsed electric field (PEF) is a promising nonthermal food stuff processing method, based on a very short time (s to ms range), but high-voltage (1-10kV/cm) treatment, allowing increased mass transfer from plant tissues. In this study PEF-pretreated A.kolomikta fruits were dried in a fluid bed hot air dryer. The weight difference after PEF pretreatment of the fruits was 13%, after 3h of drying, with a 5-kV/cm strong electric field strength, pulse width of 20s, pulse repetition rate of 20Hz and a total treatment time of 120s. PEF pretreatment did not influence the color parameters or ascorbic acid content of A.kolomikta fruits. Practical ApplicationsActinidia kolomikta (Maxim. and Rupr.) Maxim show high frost resistance (up to -30C during the dormant period), and exhibit short growth and maturation time; therefore, they could be cultivated in colder climate countries. A.kolomikta fruits are healthy and valuable, but their wide use is limited by its short shelf life. One way of fruit preservation is drying, but Actinidia fruits have quite firm skin, which results in a long drying time. In this study, we presented pulsed electric field (PEF) pretreatment in order to increase the drying efficiency of A.kolomikta fruits. Using PEF pretreatment, the same dryness could be reached almost two times faster. This allowed for the saving of time and energy, while fruit quality parameters (color parameters and ascorbic acid content) remained unchanged. Thus, PEF pretreatment prior to drying is a promising technology for increased quality of A.kolomikta fruit preservation.