Abstract:

The physicochemical properties of sweet potato pectin extracted by sodium polyphosphate were investigated. The
results showed that the viscosity of sweet potato pectin extracted by sodium polyphosphate was (27.46 ± 0.46) mPa·s, the
degree of esterification (58.22 ± 1.46)%, and the degree of gelation (151.15 ± 1.32)%, which were all higher than those of
the pectin extracted by hydrochloric acid and similar to those of apple pectin. As observed under electron microscopy, the
pectin extracted by polyphosphate was fluffier than that extracted by hydrochloric acid. The infrared spectra showed that
both pectins extracted from sweet potato had typical functional groups of pectin, but the wavenumbers varied somewhat in
the fingerprint region. This study demonstrates that sodium polyphosphate-extractable pectin from sweet potato has a wider
range of application in the food industry.

Key words: sodium polyphosphate, sweet potato pectin, physicochemical properties