Short-time acoustic and hydrodynamic cavitation improves dispersibility and functionality of pectin-rich biopolymers from citrus waste.

Pectin is a valuable biopolymer used as a natural, clean label additive for thickening and gelling. However, industry faces issues with dispersibility and stability of pectin formulations. To address these issues, the effect of short processing time (30-180 s) with hydrodynamic (HC) and acoustic cavitation (AC) on the dispersibility and gelling functionality of mandarin pectin-rich polysaccharide (M-PRP) was investigated. Short-time processing with HC and AC did not affect polymer composition. HC, but not AC, decreased polydispersity index (PDI) from 0.78 to 0.68 compared to the control. Electron and atomic force microscopy showed that HC and AC decreased aggregation of fibrous and matrix polymers. Both treatments increased apparent viscosity significantly from 0.059 Pa s to 0.30 Pa s at 10 (-s). The pectin dispersions showed good gelling capacity upon addition of calcium (final conc. 35 mM). HC and AC treatments for 150 s led to gels that were 7 and 4 times stronger (as measured by peak force) than the control with more homogeneous, less porous structures. In conclusion, short-time HC and AC can improve the dispersibility and functionality of citrus pectin without affecting composition, and are promising technologies to facilitate the use of pectin in industry applications.