Properties and extraction of pectin-enriched materials from sugar beet pulp by ultrasonic-assisted treatment combined with subcritical water

Pectin-enriched material (PEM) was extracted from sugar beet pulp using subcritical water combined with ultrasonic-assisted treatment. Optimisation of the reaction parameters for maximum extraction yield of PEM was carried out using response surface methodology. Optimum modification conditions were as follows: liquid/solid ratio 44.03, extraction temperature 120.72 °C, extraction time 30.49 min and extraction pressure 10.70 MPa. Under optimal conditions, the maximum yield of PEM was 24.63%. The composition of the PEM was determined. The data showed that the contents of galacturonic acid and arabinose were 59.12% and 21.66%, respectively. The flow behaviours were investigated by a rheometer. The effects of PEM on the pasting and thermal properties of maize starch were also conducted. The results showed that the addition of PEM increased pasting temperature and decreased other pasting parameters. Increasing PEM concentrations resulted in increased gelatinisation temperature and enthalpy.