Ultrasound and microwave maceration techniques have been utilised to lower production costs and reduce processing time, while also preventing the degradation of nutrients like phenolics and vitamin C and preserving physical properties such as colour and viscosity. In this study, the effects of several traditional (cold, enzymatic, and thermal) and innovative (ultrasonic and microwave) maceration methods on some quality parameters of aronia juice were investigated. Microwave maceration significantly impacted the soluble solids content of the analysed juices and resulted in noticeably darker juice samples compared to the controls, with lower L*/lightness (20.1) and b*/blue-yellowness (−3.2) values and an increased a*/redness value (1.7). Different maceration methods also significantly impacted the rheological properties of the treated juices, among which MW treatment consistently showed a higher viscosity. Sorbitol and fructose were the main sugars identified, while malic acid and quinic acid accounted for 85% of the total acid content. Significant increases in the total sugar and acid concentrations were obtained in the juice samples from ultrasonic, microwave, and enzymatic maceration, while thermomaceration had no significant effect. The concentration of total phenolics ranged from 6.45 g/L in the thermomaceration samples to 9.86 and 14.07 g/L in the ultrasonic and microwave samples, respectively. The obtained results suggest that ultrasonic and microwave technologies were superior in terms of colour improvement and the extraction of sugars, acids, and phenolic compounds compared to traditional maceration methods. Ultrasound and microwave technologies present possible approaches to the improvement of aronia juice production in comparison to traditional methods.

This study researched the combined effects of heat treatment and varying concentrations of the pectolytic enzyme on the improvement of yield, color, and extraction of sugars, acids, and bioactive compounds of the ‘Merlot Kanthus’ grape juice. Application of low (0.05 IU/mL) and high (0.09 IU/mL) enzyme treatment substantially increased the yield of unpasteurized and pasteurized juice. Color intensity significantly improved in the pasteurized juice with a high enzyme concentration (CIRG 4.4) and the pasteurized juice without enzymes (4.5). No considerable differences in the total sugar concentration between the treatments were observed; however, the concentration of organic acids was improved by 27 and 13% in unpasteurized and pasteurized juice with a high enzyme concentration, respectively. A total of 78 individual phenolic compounds were identified, and the treatment with a high enzyme concentration had the most notable effect on the total anthocyanins, improving their concentration by 33.6% and increasing the concentration of 18 individual compounds. The heat treatment increased flavonol concentration by 41%. Overall, heat and enzyme treatment, mainly the high enzyme concentration, had a very favorable effect on the parameters of the analyzed ‘Merlot Kanthus’ grape juice, with a significant increase in the yield of bioactive components.

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.

Pulsed electric field (PEF) and high-pressure processing (HPP) are non-thermal treatments, developed to ensure preservation of food products whilst maintaining taste and valuable nutrients. In this study, we investigated their potential for the inactivation of 3 commercial exogenous pectinases (polygalacturonase, pectin transeliminase, pectin esterase) commonly used in juice processing for clarification of juices. The inactivation of these enzymes after processing is mandatory by European law. Clear apple juice was treated with both non-thermal processing methods, as well as with thermal pasteurization as the standard method. For HPP, 3 pressures (250, 450, and 600 MPa) and different holding times (from 2 to 12 min) were tested. For PEF, 3 electric field intensities (10, 13, and 15 kV/cm) and different specific energy values (from 121 to 417 kJ/kg). Standard thermal pasteurization resulted in a complete inactivation of all tested pectinases. HPP treatment only showed marginal effects on polygalacturonase and pectin transeliminase at the highest pressure and holding times, which are beyond levels used in industrial settings. For PEF, dependence upon high electric field strength and specific energy values was evident; however, here too, the effect was only moderate at the levels attainable within the scope of this study. Assuming a continued linear relationship, usable results could be achieved in an industrial setting, albeit under more extreme conditions.

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.

This study evaluated the effects of pectinase-assisted maceration (0, 100, and 200 ppm ROHAPECT ^® MC) and pasteurization on juice yield, colour characteristics, sugars, organic acids, and phenolic compounds in aronia ( Aronia melanocarpa L. cv. ‘Nero’) and haskap ( Lonicera caerulea L. cv. ‘Aurora’) juices. Berry mashes were preheated to 50 °C and incubated with pectinase for 1 h prior to pressing. Enzymatic maceration significantly improved juice yield in both fruits, with increases of 5.6% in aronia and 11.0% in haskap at the highest enzyme concentration. Total sugars increased by 13.3% in aronia and 9.5% in haskap compared with the thermomacerated control, while total organic acids increased by 16.8% and 11.8%, respectively. Enzymatic treatment also significantly affected colour parameters, generally increasing lightness and redness in both juices. The sum of quantified phenolic compounds increased by 6.5% in aronia and 5.7% in haskap following treatment with 200 ppm pectinase. Anthocyanin concentration was not significantly affected in aronia juice but increased by 5.1% in haskap at the highest enzyme concentration. Principal component analysis further demonstrated that enzyme concentration was the main factor affecting the phenolic composition of both juices, whereas pasteurization had a less significant effect. Overall, pectinase-assisted maceration enhanced juice yield and improved the extraction of sugars, organic acids, and phenolic compounds in both aronia and haskap juices. However, differences in concentration of individual phenolic subclasses, particularly anthocyanins, indicate that the effectiveness of enzymatic maceration is dependent on the characteristics of the fruit matrix.