How amylose differs from amylopectin in structure and properties

Amylose: It is the main component of starch granules together with amylopectin (generally accounting for 20-25), and is a long-bond compound with only -1,4-bond linked to glucopyralose, also known as -amylose. It does not swell in water and dissolves, but it cannot form a typical paste with hot water, and it reacts blue with iodine when cooled, with a molecular weight of about 50,000.

It is obtained from the soluble part of starch dissolved in warm water or dilute acid and precipitated with alcohol, in which there are also very few -1,6- branches, which can be completely hydrolyzed to maltose under the combined action of -amylase and -amylase (cutting 1,4 bonds) and isoamylase in malt.

Properties of amylose.

Amylose has anti-swelling properties, poor water solubility, and is insoluble in fat;

Amylose does not produce insulin resistance;

The gelatinization temperature of amylose was higher, and the glutinous starch was 73, while the amylose was 73.

Amylose has good film-forming and strength, but its adhesion and stability are worse than those of amylopectin.

Amylose has similar properties to fiber, and the film made of amylose has good transparency, flexibility, tensile strength and water insolubility, and can be applied to the production of sealing materials, packaging materials and water-resistant and pressure-resistant materials.

Amylose is a chain-like compound formed by the binding of glucose to a -1,4-glycosidic bond, which can be hydrolyzed to maltose by amylase. The content in starch is about 10-30%. It can be dissolved in hot water without being a paste. It is blue when exposed to iodine.

Amylopectin, also known as gum starch, is relatively large in molecule and generally consists of several thousand glucose residues. Amylopectin is insoluble in water, and its molecule has many non-reducing ends, but only one reducing end, so it does not show reduction. Amylopectin reacts with iodine to produce a brown reaction.

In food starch, the content of amylopectin is higher, generally 65%-81%.

In addition to the -1,4-glycosidic bond between the glucose molecules in amylopectin, there are also -1,6-glycosidic bonds attached to each other. So with branches, there is one branch out of about 20 glucose units, and only the peripheral branched chains can be hydrolyzed by amylase to maltose. It is insoluble in cold water, and expands into a paste when it reacts with hot water.

In case of iodine, it is purple or reddish-purple.

Glycogen is the storage form of carbohydrates in animals, also known as animal starch, which is divided into two types: liver glycogen and muscle glycogen, which are completely composed of glucose. The function of liver glycogen is to regulate blood sugar concentration and maintain a certain blood viscosity, muscle glycogen is related to muscle activity energy, muscle glycogen through anaerobic respiration to produce dextrolactic acid through anaerobic respiration, and release energy for muscle use. Glycogen and iodine are brownish-red in color, and exhibit maximum absorption at 430 490 nm.

Amylose is a polysaccharide chain connected by A-(1,4) glycosidic bond of D-glucosyl, there are about 200 glucose groups in the molecule, the molecular weight is 1 2 105, the degree of polymerization is 990, the spatial conformation is coiled into a helix, and each rotation is 6 glucose groups.

In addition to the sugar chain of a-(1,4) glycosidic bond, there are also branches connected by a-(1,6) glycosidic bond, which contains 300 400 glucose groups in the molecule, the molecular weight is 2 107, the degree of polymerization is 7200, and each branch is also coiled into a spiral. Starch reacts with iodine in color, amylose is blue, and amylopectin is reddish-brown.

Properties of amylose.

1.Amylose has anti-swelling properties, poor water solubility, and is insoluble in fat;

2.Amylose does not produce insulin resistance;

3.The gelatinization temperature of amylose was higher, and the glutinous starch was 73, while the amylose was 73.

4.Amylose has good film-forming and strength, but its adhesion and stability are worse than those of amylopectin.

5.Amylose has properties similar to fiber, and the film made of amylose has good transparency, flexibility, and tensile strength.

and water insolubility, which can be applied to the production of sealing materials, packaging materials and water-resistant and pressure-resistant materials.

Properties of amylopectin:

It has excellent sustained release, thickening, bonding and water retention capabilities. Nutrition facts. Strong swelling properties. It is easy to gelatinize and does not form a gel.

First, the structure is different:1. Amylose is a polysaccharide chain connected by A-(1,4) glycosidic bond of D-glucosyl, there are about 200 glucose groups in the molecule, the molecular weight is 1 2 105, the degree of polymerization is 990, and the spatial conformation is coiled into a spiral, and each rotation is 6 glucose groups;

2. The amylopectin molecule is relatively large and consists of thousands of glucose residues. In addition to the 1,4-glycosidic bond between the glucose molecules in amylopectin, there are also 1,6-glycosidic bonds attached to each other, so they have branches.

Second, the color of the reaction with iodine is different:1. Amylose is blue;

2. Amylopectin is reddish-brown.

Third, the nature is different:1. Poor adhesion and stability of amylose;

2. Strong adhesion and stability of amylopectin.

Uses of Amylopectin:1. It is widely used as a sustained-release agent and carrier. Such as: medicine, flavors, dyes and other fields.

2. Used as adhesive and thickener.

2. As a moisturizer and thickener, it is used in the field of personal care products.

The difference between amylose and amylopectin is:1. Different definitions1. Amylose refers to D-glucosyl to A-(1,4) glycosides.

Bond-connected polysaccharide chains.

2. Amylopectin refers to polysaccharides with a structure of dendritic branches.

Second, the water solubility is different1. Amylose is relatively easy to dissolve in water.

2. Amylopectin is insoluble in water.

Third, the speed of digestion is different1. Amylose is digested quickly.

2. The digestion rate of amylopectin is slow.

1. The solution is differentAmylose: The solution is easy to polymerize and settle and form a semi-solid gel.

Amylopectin: The solution is not easy to polymerize and settle, and does not form a gel.

2. The water solubility is differentAmylose: Amylose is relatively soluble in water.

Amylopectin: Amylopectin is insoluble in water because it is relatively large in the year.

3. The characteristics are differentAmylose: Amylose does not produce insulin.

resistance; The gelatinization temperature of amylose was higher, and the glutinous starch was 73, while the amylose was 73.

Amylopectin: When the starch paste is cooled, the amylopectin weakens the tightness of the reassociation of the starch molecular chain due to its branching structure, and shows good anti-aging ability. It has excellent sustained release, thickening, bonding and water retention capabilities.

Nutrition facts. Swelling.

Strong performance. It is easy to gelatinize and does not form a gel.

The above content reference: Encyclopedia - Amylose.

Encyclopedia - Amylopectin.

The difference between amylose and amylopectin is as follows:

1. Different definitions, amylose refers to D-glucose.

The base is A-(1,4) glycoside.

Bond-connected polysaccharide chains. Amylopectin refers to polysaccharides that have a dendritic branching structure.

2. The water solubility is different, amylose is easier to dissolve in water, and amylopectin is difficult to dissolve in water because it is larger in the year. Amylose is more soluble than amylopectin, a monosaccharide of amylose.

It is connected by -1,4 glycosidic bonds, and amylose is connected by -1,6 glycosidic bonds in addition to -1,4 glycosidic bonds.

3. The digestion speed is different, the digestion speed of amylose is fast, and the digestion speed of amylopectin is slow.

4. The arrangement of glucose molecules is different, amylose is not easy to form a paste after boiling, and it is a gel after cooling, and its macromolecular structure is neatly arranged in glucose molecules. Amylopectin is easy to form a paste and its viscosity is large, but it cannot be a gel after cooling, and the structure of glucose molecules is not neatly arranged.

5. The color of iodine is different, amylose is blue when iodine-potassium iodide solution is present, and amylopectin is purple. Amylose is more viscous than amylopectin.

As follows:

First, the molecular weight is different.

1. Amylose: The molecular weight of amylose is smaller than that of amylopectin, and the molecular weight is in the range of 3 160,000.

2. Amylopectin: The molecular weight of amylopectin is larger than that of amylose, and the molecular weight is in the range of 101 million.

Second, the cohesion and precipitation are different.

1. Amylose: Due to the relatively regular molecular arrangement of amylose, the molecules are easy to rearrange each other. Therefore, in cold aqueous solution, amylose has strong coagulation and precipitation properties.

2. Amylopectin: The molecule of amylopectin is large, and the spatial hindrance of each branch chain reduces the intermolecular force. And because of the action of the branched chains, the water molecules.

It is easy to enter the microcrystalline beam of amylopectin, which hinders the coagulation of amylopectin molecules and makes amylopectin not easy to coagulate.

Third, the crystal structure is different.

1. Amylose: The particles of amylose are small, the degree of association between molecular chains and molecular chains is large, and the microcrystalline beam crystal structure formed is compact and the crystalline area is large.

2. Amylopectin: Amylopectin is glucose at the branch end.

The chains are arranged in parallel and are connected into bundles by hydrogen bonds to form a microcrystalline beam structure. Therefore, the crystalline area in amylopectin is small, and the crystal structure is not very compact.