Gelatinization of starch

Gelatinization of starch refers to the process in which starch granules swell, split, and form a homogeneous paste solution in water at a suitable temperature (different temperatures of starch from various sources, generally 60 to 80 ° C). The essence of gelatinization is the hydrogen bond break between the ordered and disordered (crystalline and amorphous) starch molecules in the starch granules, which is dispersed in water to become a colloidal solution. The gelatinized starch is beneficial to be decomposed by enzymes. , its viscosity increases. XPC China Feed Industry Information Network - based on feed, serving animal husbandry

The process of gelatinization can be divided into three stages: XPC China Feed Industry Information Network - based on feed, serving animal husbandry

(1) Reversible water absorption stage, moisture enters the amorphous part of the starch granules, the volume is slightly expanded, at this time cooling and drying, the particles can be restored, and the phenomenon of birefringence remains unchanged; XPC China Feed Industry Information Network - based on feed, serving animal husbandry

(2) Irreversible water absorption stage, as the temperature rises, water enters the gap of starch crystallites, irreversibly absorbs a large amount of water, and the phenomenon of birefringence gradually blurs and disappears. It is also called “dissolution” of crystals, and the starch granules swell to the original volume of 50-100. Double; XPC China Feed Industry Information Network - based on feed, serving animal husbandry

(3) The starch granules finally disintegrate, and the starch molecules all enter the solution. XPC China Feed Industry Information Network - based on feed, serving animal husbandry

The gelatinized starch is also known as alpha-starch. The freshly prepared gelatinized starch slurry is dehydrated and dried to obtain an amorphous powder which is easily dispersed in cold water, that is, "soluble α-starch". XPC China Feed Industry Information Network - based on feed, serving animal husbandry

Method for determining starch gelatinization: optical microscopy, electron microscopy, light propagation, viscosity measurement, measurement of swelling and solubility, analysis of enzymes, nuclear magnetic resonance, laser light scattering, and the like. At present, there are few companies that have mastered the method of measuring the degree of starch gelatinization in the aquafeed industry, and basically adopt the enzymatic method (debranching enzyme). XPC China Feed Industry Information Network - based on feed, serving animal husbandry