Modification of Starches with Different Amylose/Amylopectin‐Ratios Using the Dual Approach with Hydroxypropylation and Subsequent Acid‐Thinning—Impacts on Morphological and Molecular Characteristics

Dissolution behaviour of corn starch with different amylose content in ionic liquids

The dissolution behaviour of three corn starches, including corn starch (CS), high amylose corn starch (HACS) and waxy corn starch (WCS) with different amylose content in 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) were studied by comparing their dissolution state in ionic liquids (ILs). Further, the structural and thermal properties of the regenerated starch were analyzed. WCS with the lowest amylose content had the fastest dissolution rate, the most extensive structural damage, and the lowest solubility and required the maximum energy for dissolution. In the process of dissolution-regeneration, the A-type crystalline structure of WCS and CS was completely destroyed and transformed into an amorphous structure, while the B-type crystalline structure of HACS transformed into an ordered V-shaped structure. And the thermal stability of starch was improved after dissolution-regeneration in ILs. Among the two kinds of ILs, [AMIM] Cl had a better ability to dissolve starch, causing minor damage to the starch.

Dual modification of various starches: Synthesis, properties and applications

The problems associated with native starches (NSs) and single modified starches were stated in order to justify dual modification of various starches. Broadly, there are two types of dual modification, i.e., homogeneous dual modification and heterogeneous dual modification. The combination of two physical modifications, e.g., (extrusion/annealing); two chemical modifications, e.g., (succinylation/cross-linking) and two enzymes modification (α-amylase/pullulanase) falls under the former classification and the latter classification is the combination of two of each of the differently stated modifications, e.g., acetylation/annealing, extrusion/succinylation, and microwave-assisted phosphorylation, etc. The classification, synthesis, properties and applications of dually modified starches were discussed. There is an attempt to elucidate the problems of each of the single modification in order to justify dual modifications. In dual modifications, the order of reactions, the reaction conditions, the medium of reaction, and the botanical sources of the various starches are very important parameters.