Abstract:Taking passion fruit peel as research object，pectin was extracted from it by steam explosion，and compared with traditional acid extraction method.The results showed that the steam pressure was 0.6 MPa，the pressure maintaining time was 120 s，and the pectin extraction rate was 18.84%，which was 81.15%higher than the traditional acid extraction method.Observing the residue of the steam explosion process by scanning electron microscope revealed many porous structures and potholes.The Pectin extracted by steam explosion and acid methods belonged to high-methoxyl pectin.Compared with acid extraction，the pectin extracted by steam explosion with a simultaneously lower esterification degree（DE），lower molecular weight，higher total phenolic content and higher DPPH radical scavenging activity.Moreover，there were certain differences in functional group composition and thermal properties according to Fourier transform infrared spectra（FTIR）analysis.In addition，rheological analysis showed that the pectin solutions had shear-thinning characteristics and as the frequency increased，the energy storage （G'）and loss （G''）modulus increased.Hence，the steam explosion process was an efficient pectin extraction method and had good application prospects.