Pectins of different resources influences cold storage properties of corn starch gels: Structure-property relationships

In this study, the structural characteristics of pectins with different degrees of esterification (DE) and their effects on retrogradation, freeze-thaw stability, and texture of corn starch gels during cold storage were analyzed. The low esterification pectin (LEP) had highly branched structure in globular sphere chain shape, molecular weight (M-w) of 4.45 x 10(5) Da, and intrinsic viscosity ([eta](w)) of 632.29 mL/g. The medium esterification pectin (MEP) showed linear structure in rigid chain shape, M-w of 1.58 x 10(5) Da, and [eta](w) of 554.43 mL/g. The high esterification pectin (HEP) had linear structure with a small side chain in flexible chain shape, M-w of 2.45 x 10(5) Da, and [eta](w) of 787.09 mL/g. The pectin samples, in particular LEP, inhibited retrogradation and improved the freeze-thaw stability of corn starch gels. However, HEP enhanced chewiness of starch gels better than others. Furthermore, retrogradation of starch gels was affected by branching degree, DE value, and [eta](w) of pectin, and freeze-thaw stability of starch gels was related to branching degree, DE value, and M-w. Also, the textural profile of starch gels was mainly related to branching degree, [eta](w), and DE values of pectin. These results provided new insights regarding the application of pectin in ready-to-eat starch-based foods.

Automated summary

This study investigated the structural characteristics of pectins with different degrees of esterification and their effects on the properties of corn starch gels. The results showed that low esterification pectin inhibited retrogradation and improved freeze-thaw stability of corn starch gels, while high esterification pectin enhanced the chewiness of starch gels. Additionally, the textural profile of starch gels was mainly influenced by the branching degree, intrinsic viscosity, and DE values of pectin.