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Flash point: 202.243oC.

Refractive index: 1.362.

Storage conditions: 2-8oC.

Chemical Properties:

It is the most widely distributed monosaccharide in nature.

Glucose contains five hydroxyl groups and one aldehyde group, and has the properties of polyols and aldehydes.

It is easy to decompose when heated under alkaline conditions.

Should be kept tightly closed.

It is rapidly absorbed after oral administration, and is utilized by tissues after entering the human body.

1mol of glucose releases 2870KJ energy after complete oxidation reaction of the human body. Some of this energy is converted into 30 or 30 or, and the rest of the energy is dissipated in the form of heat energy to maintain the body temperature, and can also be converted into glycogen or fat storage through the liver or muscle.

(1) The aldehyde group in the molecule is reducible and can react with silver ammonia solution: CH2OH(CHOH)4CHO+2Ag(NH3)2OH-water bath heating→CH2OH(CHOH)+2Ag↓+3NH3+H2O, oxidized into Ammonium Gluconate.

(2) The aldehyde group can also be reduced to hexanol.

(3) There are multiple hydroxyl groups in the molecule, which can undergo esterification with acid.

(4) Glucose undergoes oxidation reaction in the body, releasing heat (C6H12O6+6O2 (oxygen)+6H2O==+12H2O+energy).

(5) Glucose can be obtained by hydrolysis of starch under the catalysis of enzymes or sulfuric acid.

(6) Plant photosynthesis: +6H2O (chlorophyll, sunlight catalysis) - C6H12O6+6O2.

(7) Reaction equation of glucose and newly prepared copper hydroxide:

CH2OH(CHOH)4CHO+2Cu(OH)2-heating->CH2OH(CHOH)+Cu2O↓+2H2O.

(8) Glucose is decomposed into water and carbon dioxide under certain conditions.

(9) Hydrolysis of maltose: C12H22O11+H2O—catalyst→2CH2OH(CHOH)4CHO.

(10) Hydrolysis of starch and cellulose: (C6H10O5)n+nH2O—catalyst→nCH2OH(CHOH)4CHO.

Preparation method of glucose:

1. The saccharide aqueous solution obtained by partial hydrolysis of edible corn starch with food-grade acid and/or enzyme is purified and concentrated. Due to the different degree of hydrolysis, the amount of D-glucose contained can vary greatly. Made from corn starch, it is called "corn syrup".

2. Glucose can be obtained from starch by hydrolysis of hydrochloric acid or dilute sulfuric acid. It can also be prepared from starch under the action of starch saccharification enzyme.

Glucose Isomers:

Allulose; fructose; sorbose; tagalose; inositol.

Glucose chiral isomer:

Allose; altrose; mannose; gluose; idose; galactose; talose.

Glucose Optical Isomers:

α-D-glucofuranose.

β-D-glucofuranose.

α-D-glucopyranose.

β-D-glucopyranose.

Storage of Glucose:

Under dry conditions, glucose has good stability, and the aqueous solution can be sterilized by autoclaving.

Overheating can cause a drop in the pH of the solution and caramelization.

Glucose bulk products should be stored in dry, low temperature airtight containers.

Glucose verifies the aldehyde group:

Glucose verification:

⒈ The glucose solution reacts with the freshly prepared copper hydroxide suspension to form a brick red precipitate. (yellow precipitate is formed when the concentration is high)

CH2OH(CHOH)4CHO+2Cu(OH)2---heating→CH2OH(CHOH)+Cu2O↓+2H2O.

Note: (1) The newly prepared 2Cu(OH)2 suspension should be prepared as needed and should not be stored for a long time.

Chapter 155: Looking for Glucose (3)