Modified starch
Starch can be hydrolyzed by dilute acids (e.g. dilute sulfuric acid) (requiring heat) or enzymes: (C6H10O5)n(starch) + nH2O → nC6H12O6(glucose).
Classification of modified starch
At present, there are more than two thousand varieties and specifications of modified starch, and the classification of modified starch is generally based on the treatment method.
(1) Physical denaturation: pre-dextrinized (α-ized) starch, γ-ray, ultra-high frequency radiation treated starch, mechanical grinding treated starch, moist heat treated starch, etc.
(2) Chemical denaturation: denatured starch obtained by treatment with various chemical reagents. There are two major categories: one is to make the molecular weight of starch decrease, such as acid-decomposed starch, oxidized starch, baked dextrin, etc.; the other is to make the molecular weight of starch increase, such as cross-linked starch, esterified starch, etherified starch, grafted starch, etc.
(3) Enzymatic denaturation (biological modification): various enzymes treat starch. Such as α, β, γ-cyclodextrin, maltodextrin, straight chain starch, etc.
(4) Compound denaturation: denatured starch obtained by using two or more treatment methods. Such as oxidized cross-linked starch, cross-linked esterified starch, etc. The modified starch obtained by compound denaturation has the respective advantages of two kinds of modified starch.
In addition, modified starch can also be classified according to the production process route, such as dry method (such as phosphate starch, acid soluble starch, cationic starch, carboxymethyl starch, etc.), wet method, organic solvent method (such as carboxy starch preparation generally using ethanol as solvent), extrusion method and drum drying method (such as natural starch or modified starch as raw material to produce pre-dextrinized starch), etc.
The difference between starch and dextrin: dextrin is manufactured from starch, the difference between the two is the difference in molecular weight, just like the relationship between protein and peptide.