Impact of pulsed electric field pretreatment on quality parameters of aronia and haskap berry juices

This study examined the effect of pulsed electric field pre-treatment at three intensities (1.78, 5.3, and 10.7 kJ/kg) on the yield and physicochemical properties of aronia and haskap juices. PEF significantly increased juice yield by 18.0% points in aronia (from 39.3% to 57.3%) and 30.6% points in haskap (from 29.2% to 59.8%) at 10.7 kJ/kg. Physicochemical properties were also affected: pH, total soluble solids, and viscosity increased, while both juices retained pseudoplastic flow behaviour. PEF induced significant colour changes, with total colour difference increasing progressively with treatment intensity. PEF enhanced sugar extractability, increasing total sugars from 169.4 to 210.0 g/L in aronia (mainly glucose and sorbitol) and from 115.2 to 142.1 g/L in haskap (mainly glucose and fructose). Organic acids increased by 26-27%, with higher citric, malic, and quinic acids. Phenolic compounds, especially anthocyanins, increased from 8.60 to 15.12 g/L in aronia and from 5.65 to 10.18 g/L in haskap, along with increases in flavonols and total phenolics. Correlation analysis revealed strong positive relationships between juice yield, sugar content, total acids, and phenolic compounds in aronia, while moderate positive correlations were observed between these parameters in haskap. Overall, PEF at 10.7 kJ/kg effectively improved yield and compositional quality of both aronia and haskap juice.