Ultrasonic depolymerization of pomegranate peel pectin: Effect of sonication time on antioxidant, α-amylase inhibitory, and prebiotic properties
Sahar Bachari, Maryam Ghaderi‐Ghahfarokhi, Hassan Ahmadi Gavlighi, Mehdi Zarei
Abstract
This study aimed to investigate the effects of ultrasonic treatment time (5–30 min) on the structural characteristics, antioxidant, α-amylase inhibitory, and prebiotic properties of pomegranate peel pectin (PPP). The extracted PPP was rich in galacturonic acid (64.27 %) and exhibited a high degree of esterification (DE, 61.7 %), with an average molecular weight ( Mw ) of 135.6 kDa. The Mw , particle size, and DE of ultrasonic-treated PPPs (U-PPPs) significantly decreased compared to the PPP. FTIR analysis revealed that the intensity of the peak at ∼1730–1720 cm −1 weakened with prolonged treatment time. The total phenol content, antioxidant activity, and α-amylase inhibition of U-PPPs were enhanced compared to PPP. Both PPP and U-PPP treated for 30 min promoted the growth of Bifidobacterium longum and Lactobacillus casei , with U-PPP-30 showing a greater preference over PPP and inulin. In conclusion, ultrasonic treatment represents a promising approach to depolymerization aimed at enhancing the biological activities of pectin. • Pomegranate peel pectin (PPP) was degraded using ultrasonic treatment. • Degree of esterification and molecular weight were reduced in sonicated samples. • FTIR analysis confirmed the ultrasonic did not change the primary structures of PPP. • Ultrasonic treatment improves α-amylase inhibitory and antioxidant activity of PPP. • The prebiotic potential of PPP was enhanced upon ultrasonic treatment for 30 min.