Sodium gluconate, also known as sodium pentahydroxyorganic acid, is a white crystalline particles or powder, its relative molecular mass is 218.14, the melting point is about 206 ℃, 10% aqueous solution pH 6.2 ~ 7.8, soluble in water, slightly soluble in alcohol, insoluble in ether, has a certain salty taste.
Sodium gluconate, as a new type of functional flavoring seasoning, can give food acidity, improve food flavor, prevent protein denaturation, cover up undesirable bitter and astringent taste, instead of salt to produce low-sodium, sodium-free food. And it has non-toxic, non-deliquescent, better stability and chelating properties, and raw materials from a wide range of characteristics, has attracted people's attention, some of the new preparation technology and application of endless.
What are the uses of sodium gluconate
1, used in the food industry
(1) Sodium gluconate can be used to replace table salt: relevant studies have shown that excessive intake of sodium induces high blood pressure. Low-sodium salt food has become a hot spot of research in today's food industry. The salt flavor of sodium gluconate is close to that of table salt, and the molecular weight of sodium only accounts for 10.5%, compared with table salt, the former sodium amount is only 1/4 of the latter, and compared with other low-sodium salts, sodium gluconate has the advantages of non-irritation, no bitter taste, salt pungency, etc., which makes it the best substitute for table salt. It is now widely used in salt-free soy sauce, bread and other food fields.
(2) Sodium gluconate can improve food flavor: In the food industry, flavor is the most important indicator of the sensory function of food. At present, the production and application of flavor substances has become a hotspot for the majority of food researchers and producers. In recent years, it has been found that sodium gluconate has the effect of masking the bitter taste of food, shielding the odor, improving the presentation, etc., which has a significant effect on the improvement of food flavor. By adding sodium gluconate to low-fat cheese, the original bitterness and astringency of low-fat cheese were eliminated, and the overall taste was improved. By comparing the flavors of lactone tofu made with sodium gluconate and gypsum as coagulant, it was found that the tofu ordered with sodium gluconate was more tender, with higher flavor and nutritional value.
(3) Sodium gluconate can enhance the nutritional properties of food: With the continuous improvement of people's living standards and health care awareness, the nutritional and flavor requirements of food have been gradually improved. As a multifunctional food additive, sodium gluconate can not only improve the flavor of food, but also enhance the nutritional properties of food.
2, used in medicine
Sodium gluconate has an important role in maintaining extracellular osmotic pressure and volume, regulating acid-base balance, exerting the normal function of neuromuscular, and effectively preventing the occurrence of hyponatremia syndrome.
3, as a water reducing agent
By adding water reducing agent, water to cement ratio (W/C) can be reduced. Adding sodium gluconate can get the following effects:
(1) In the case of water to cement ratio (W/C) remains unchanged, adding sodium gluconate can improve workability. At this time, sodium gluconate is acting as a plasticizer. When the amount of sodium gluconate is below 0.1%, the degree of improvement of workability is proportional to the amount added;
(2) When the cement content remains constant and the water content in the concrete can be reduced (i.e., W/C is reduced). When the addition of sodium gluconate is 0.1%, the amount of water can be reduced by 10%.
(3) The water and cement contents are reduced in the same proportion, and the W/C ratio remains unchanged. At this time, sodium gluconate is used as cement reducing agent.
4, used as steel surface cleaning agent
Steel surface such as platinum plating, chromium plating, tin plating, nickel plating to adapt to the special purpose, the surface of the billet need to be strictly cleaned, so that the plating material and the surface of the steel firmly combined, cleaning agents in the addition of sodium gluconate will achieve a very satisfactory result.
5, as a glass bottle special cleaning agent
Sodium gluconate as the main formula for the glass bottle professional cleaning agent can improve the descaling force is not strong, easy to block the nozzle and pipeline of the bottle washing machine; the bottle sticker and bottle neck rust staining power is not ideal; after washing the trace residue on the safety of food is not ideal (eg, phosphate residue); washing water discharge into the public health (does not comply with the national regulations of the standard).
6, used as a water quality stabilizer
Sodium gluconate has excellent corrosion and scale inhibition, is widely used in water quality stabilizer. It has obvious coordination effect, applicable to molybdenum, silicon, phosphorus, tungsten, nitrite and other formulations; corrosion inhibition rate increases with temperature; scale inhibition ability, calcium, magnesium, iron salts have a strong complexing ability; as circulating, cooling water corrosion and scale inhibitor to achieve the extermination of public health.
Sodium gluconate synthesis method
Industry generally to contain glucose substances (such as grains) as raw materials, using fermentation method from glucose to produce gluconic acid, and then by sodium hydroxide to neutralize, you can get sodium gluconate, but also electrolysis and oxidative synthesis. Most of our country adopts chemical oxidation method-hypobromous oxidation method to produce synthesis.
Based on the different types of fermentation enzymes used, the fermentation method can be divided into two bells, one is to use the enzyme of AspergillusNiger, another acid, and another method with the help of glucose dehydrogenation to form lactone, and then the ester decomposition.
Sodium gluconate can also be obtained directly from glucose fermentation. At this time, the composition of the fermentation substrate can be as follows: glucose 250~350g/L, magnesium sulfate heptahydrate 0.2~0.3g/L, diammonium hydrogen phosphate or urea 0.4~0.5g/L. This substrate must be sterilized. During the fermentation process, the temperature is controlled at 30-32 degrees, pH is controlled at 5.5-6.5 by means of 30%-50% sodium hydroxide, and the fermentation process lasts for 40-100 h. Then, microorganisms are removed by filtration and washing, and the activated charcoal is decolourized, and then filtration is performed, and the finished product is obtained by concentrating the result or spray drying.