Pulsed Electric Field-Assisted Recovery of Phenolic Compounds From Haskap (Lonicera caerulea L.) Pomace: Influence of...

This study investigated the effect of pulsed electric field (PEF) treatment on cell disintegration and phenolic extractability from haskap (Lonicera caerulea L.) pomace generated after juice processing. Pomace samples were subjected to 16 PEF conditions combining electric field strengths of 1.0 and 1.5 kV/cm, pulse frequencies of 5 and 10 Hz, and specific energy ranging from 1 to 12.3 kJ/kg. Cell membrane permeabilization was quantified using the cell disintegration index (Z_p), whereas phenolic compounds were profiled by HPLC-PDA-mass spectrometer (MS). One-way analysis of variance (ANOVA) revealed significant differences among treatments for Z_p and all phenolic groups. Moderate to high-intensity treatments (1.5 kV/cm, 5-10 Hz, 5-12.3 kJ/kg) produced the highest Z_p values (0.10-0.12) and resulted in the greatest enhancement of phenolic extraction, particularly anthocyanins, flavonols, flavanols, and hydroxycinnamic acids. Anthocyanins exhibited the strongest response, with up to a 2.6-fold increase compared to the untreated control. Multivariate and regression analyses identified electric field strength and pulse frequency as the main factors influencing cell disintegration and phenolic extraction. In contrast, specific energy showed mainly nonsignificant or negative regression coefficients, suggesting it was not a relevant predictor of phenolic extractability under the tested conditions. These findings provide quantitative insight into PEF process optimization for enhanced phenolic extraction from haskap berry pomace.