Comprehensive analysis of phytochemical extraction of betalains from Beta vulgaris L. pomace using conventional, enzyme-assisted and ultrasonic-assisted methods

Abstract

Beetroot pomace, rich in bioactive components, offers versatile applications in betalain extraction through various methodologies, including ultrasonic-assisted extraction (UAE), conventional extraction (CE), and enzyme-assisted extraction (EAE). In CE, accurately weighed pomace powder (PP) was homogenized with deionized water, forming slurry which underwent conventional heating at 30–60 °C for 20–60 min. EAE involved mixing pomace powder with xylanase enzyme and distilled water under various time-temperature conditions. UAE utilized amplitudes of 20, 30 and 40% for durations ranging from 10 to 60 min. The comparison of UAE, EAE and CE methods demonstrated that UAE exhibited elevated levels of betalains, total phenols, flavonoids, minerals and total antioxidants, which were confirmed through FTIR, LCMS and SEM analyses. Optimizing UAE conditions significantly enhanced phytochemical extraction from beetroot pomace, with betacyanins, betaxanthins and total betalains increasing by 54, 11 and 36%, respectively, compared to EAE and CE. Total phenols (193.26 mg GAE/g) and antioxidant activity (53.23%) were also notably higher, demonstrating UAE’s superior extraction efficacy. SEM analysis confirmed enhanced porosity in UAE-treated pomace, supporting its efficient utilization. Conclusion, UAE demonstrates superior extraction efficacy over EAE and CE methods.