Use of alternative technologies for the inactivation of contaminated microorganisms and decomposition of pesticides in sour cherry juice

Effects of pulsed electric fields (PEF) (PEF1; 24.7kV/cm electric field strength and 655 µs treatment time and PEF2; 24.7 kV/cm electric field strength and 327 μs treatment time), ultrasonication (US) (1200 W, 35 kHz, 3 min) and ozone (O3) (20.2 g/m3, 3 min) alone as well as in different combinations (PEF1, PEF2, O, US, PEF1+O, PEF2+O, PEF1+US, PEF2+US, PEF1+O+US, PEF2+O+US) on physical and chemical properties of sour cherry juice, inactivation of four different microorganisms inoculated and decomposition of five different pesticides contaminated were implemented in this research. Depending on the dose and the treatment time (PEF+O, PEF+US, PEF+O+US) different amount of changes were detected on pH, titratable acidity, Brix, conductivity, color (L*, a*, b*), hue, chroma, total color difference, total antioxidant capacity, total phenolic content, total monomeric antocyanin content, turbidity and total ascorbic acid content of the sour cherry juice samples. Results from sensory analysis showed that there were no significant changes on the quality properties of sour cherry juice when pulsed electric fields or ultrasonication proses were used. On the other hand ozone application can be caused unwanted effect in some properties. Significant amount of changes on measured attributes of sour cherry juice were observed with both increased dose and treatment time. On the other hand, significant amount of reduction both on Escherichia coli O157:H7, Pseudomonas syringae subs. syringae, Penicillium expansum and Bacillus cereus and chlorpyrifos-ethyl, cyprodinil, pyraclostrobin, malathion and tau-fluvalinate pesticides contaminated on sour cherry juice were occurred. While ozone alone and in combination with other processes were effective in pesticide decomposition; PEF alone and in combination with other processes were effective on microbial inactivation. Therefore, it was concluded that ozone and PEF can successfully be applied on the products that both microbial inactivation and pesticide decomposition were targeted. It is suggested that future studies will focus on the determination of the potential of the alternative technologies used in this research on pasteurization of fruit as well as vegetable juices preferred by consumers.