Characteristics of pectin from black cherry tomato waste modified by dynamic high-pressure microfluidization

- Effect of DHPM on pectin from black cherry tomato pomace were investigated.
- Physicochemical properties of pectin, particle size, microstructure and esterification degree were changed by DHPM.
- DHPM treatment under 160 MPa could not break the main chain of pectin.
- Pectin treated by DHPM at the pressure of 120 MPa maintained the apparent viscous but fluid property changed.
- DHPM is an alternative modified method of pectin for food additives usage.

The present work aimed at better understanding of the effects of dynamic high pressure microfluidization (DHPM) on physicochemical properties and rheological property of pectin extracted from black-cherry tomato pomace. It was found that DHPM effectively increased the average particle size of pectin, as the result of foamed filiform parts formation in micro-structure. Galacturonic acid with esterified structures were observed according the nuclear magnetic resonance (NMR) spectroscopy and relatively independent of the pressure of DHPM, while degree of esterification (DE) was slightly increased when the pressure was higher than 40 MPa. Solutions of pectin treated by DHPM were consistent with the power's law model at low shear rate (shear rate < 1 s−1) and sweep frequency (f < 1 Hz). DHPM treatment significantly decreased (p < 0.05) the apparent viscosity (η) and consistency index (K) of pectin. Moreover, phase angle (δ) of pectin treated by DHPM decreased, that indicated better fluidity and higher consistency for the solutions. Additionally, effects of DHPM at 120 MPa were noticed, DPPM resulted in particle size decreasing and there were no significant changes (p < 0.05) of η. However, flow behavior index (n) and tanδ indicated that character of pectin solutions changed compared to pectin without DHPM treatment.