Extraction, characterization and spontaneous gelation mechanism of pectin from Nicandra physaloides (Linn.) Gaertn seeds.

Nicandra physaloides (Linn.) Gaertn seeds (NPGS) could be manually scrubbed to obtain water-soluble pectin, which forms gel at room temperature without additives. The extraction, characterization and spontaneous gelation (SG) mechanism of the pectin were studied. The results showed that the pectin was located on the surface of NPGS and easily to be dissolved. Chemically, the pectin was low methoxy pectin with esterification degree of 46.93%, Gal-A content of 65.80%, and average molar weight of 631.15 kDa. The SG occurred at the pectin concentration of 1.5%, it can be destroyed by urea and SDS, however, EDTA cannot. In addition, KCl and NaCl induced the gelation of 1.0% pectin solution and the ions of K, Mg, Ca and Na were detected in the pectin. Hydrogen bonding, electrostatic and hydrophobic interaction contributed to the SG. This study could promote the commercial applications of the pectin in the field of edible colloids and cosmetics.