Cross-linked and hydroxypropylated sweet potato starches
By WaferPaper.com on 08-04-2020
Starches are often modified to improve their functional properties for specific food applications. Cross-linking and hydroxypropylation are two important chemical modifications commonly used in the starch industry. Cross-links between starch chains reinforce the starch granule resulting in a good stability against heating, shear force and acid conditions. Even a very few cross-links can significantly change the paste and gel properties of starch.
For controlling the modification reactions and hence, to control and optimize the production and use of modified starches, it is necessary to be able to correlate the extent and location of cross-links along the starch backbone with the functionality obtained. Hence, the aim of this study was to investigate the level of modification and the position of substituents on glucose residues in cross-linked and/or hydroxypropylated sweet potato starches.
Nuclear magnetic resonance is an efficacious method to analyse level and substitution position of cross-linking and hydroxypropylation of sweet potato starch, even at the low level of substitution used for food applications. In their NVM study, the researchers noticed different forms of cross-linking, which suggests that low levels of intra-molecular cross-linking are present, both after crosslinking as well as after the hydroxypropylation. Hydroxypropylation occurred predominantly at the O-2 position of glucose for both single and dual modified starches; the reaction is slightly hindered by the presence of cross-links. These findings on substitution of dual modified starches may help to explain functional properties of such starches.