A comparative effect of different pretreatment techniques on the pomegranate juice yield and other physico-chemical parameters with an insight into the flow behavior of juice and morphological elucidation of arils

Abstract The study aimed to enhance pomegranate juice yield through different pretreatments aiming to reduce waste generation and biomass valorization. Effect of different pretreatments on physicochemical properties and average viscosity of juice, along with morphology of arils was evaluated. Pretreatment conditions were standardized/ optimized based on selected parameters. Optimum ultrasound pretreatment conditions were obtained at a power and treatment time of 39% and 15 min, respectively. Further, the characterization and comparative evaluation of juices extracted under standardized conditions were performed. Ultrasonication (82.15%) yielded maximum juice followed by enzymatic (81%), microwave (79.12%) and conventional (75.5%) methods. Juice extracted after ultrasonication showed highest viscosity (7.50 cP), total phenolic content (3816.85 mg GAE/L), tannins (2058.47 mg CE/L), turbidity (33.45) and titratable acidity (12.71 g/L). Antioxidant activity (65.50%) and total soluble solids (16.41°Bx) were maximum in enzyme pretreated sample with minimum viscosity (4.63 cP). Overall, ultrasound increased the juice recovery, phenolic content and tannins by 8.81%, 39.75% and 32.8%, respectively, with the least color change (ΔE = 2.16) compared to the conventional method, while enzymatic pretreatment excelled in improving antioxidant activity (14.45%) and reducing viscosity (27.76%). Morphological evaluation of arils revealed maximum cell disruption following ultrasonication. Aril's morphology was affected by different pretreatments, which influenced juice yield and quality attributes. The findings support sustainable juice processing by reducing waste and valorizing aril biomass, offering promising industrial applications. Graphical abstract