Ultrasound-Assisted Extraction of Pectin from 'Saba' Banana Peel Waste: Optimization and Rheology Study

Abstract

This study utilized 'saba' banana peel waste as a source of pectin for gelling and thickening applications. Peel wastes were dried, powdered, mixed with acidified solvent, and subjected to an ultrasound-assisted extraction. Significant factors for the extraction of pectin were screened and optimized using Response Surface Methodology. The predicted optimum extraction conditions were 60% amplitude, pH 5, and 20 minutes with predicted and actual yields of 4.6% and 4.8%, respectively. The gelling ability of the ultrasound-extracted pectin (UEP) was evaluated, and results showed that the strength of the gel is directly proportional to the concentration of UEP. Moreover, the concentration of acidifier also affects gel strength – 1% glucono-delta-lactone being the most appropriate concentration of acidifier. UEP was also applied to a commercial orange juice and subjected to an in vitro digestion. Results showed that UEP increased the beverage's apparent viscosity during different digestion stages.