Preparation and characterisation of surface active pectin from soya hulls by phosphate assisted subcritical water combined with ultrasonic treatment
Summary Surface active pectin was efficiently extracted from soya hull using phosphate assisted subcritical water combined with ultrasonic treatment (PASW UT) The physicochemical and functional properties of soya hull pectin (PSHP) were evaluated. Compared to pectin prepared by traditional acid extraction (ASHP) the yield and purity of PSHP were significantly increased, as well as PSHP also contained more protein moiety and displayed better emulsifying and foaming properties. However, the emulsifying and foaming properties of protein depleted soya bean hull pectin (PDSHP) were markedly decreased as compared to PSHP, which was supported by data of dynamic interfacial tension of pectins, suggesting that the emulsifying and foaming capacity of PSHP should be mainly ascribed to the existence of more extensin, as evidenced by the results of hydroxyproline content. In further comparison with commercial sugar beet pectin (SBP) the PSHP exhibited similar emulsifying properties with SBP over the pH range of 2 6. Moreover, the foam ability and stability were even higher than those of SBP, especially at pH 4.0. These findings suggest that PASW UT could be used as an effective strategy to prepare novel surface active pectin from soya hull.