月: 2023年1月

What Is Succinic Acid?

Succinic Acid is classified as a dicarboxylic acid because it has two carboxyl groups in its molecule. The name succinic acid is derived from its discovery in the dry distillation of amber.

This compound is widely used in the synthesis of various compounds, and its demand is increasing as an important raw material for the chemical industry.

Industrially, it is produced by hydrogenation of maleic anhydride, which is derived from petroleum.

Succinic acid is also produced in living organisms as a metabolite of the citric acid cycle. This has led to widespread attempts to produce petroleum-derived bio-succinic acid using bacteria and cyanobacteria.

Physicochemical Properties of Succinic Acid

Succinic Acid (IUPAC name: butanedioic acid) has the molecular formula C4H6O4, and molecular weight 118.09. It has a melting point of 185-187°C.

It is soluble in water and ethanol, and insoluble in diethyl ether. The taste is umami, and it is also bitter and acidic.

Uses of Succinic Acid

Succinic acid is used in a wide range of applications.

In the food industry, it is used as an umami additive, flavoring agent, and acidity regulator.

In industry and pharmaceutical manufacturing, succinic acid is used as an intermediate in the production of polymers such as polyester and polyurethane, resins, dyes, and in the synthesis of various pharmaceuticals.

1. Unique Umami Taste and Use as a Food Additive

Succinic acid is a well-known umami component found in shellfish such as clams. Its sodium salt, sodium succinic acid, exhibits a stronger umami taste than free carboxylic acid. It is also produced by alcoholic fermentation and is a component of the flavor of wine and beer.

2. Use as an Industrial Product and Medicine

Succinic acid is industrially used as a raw material for synthesizing various compounds. Polybutylene succinate, a biodegradable plastic, is a typical example of a compound synthesized from succinic acid.

Succinic acid is also used as a pH adjuster in pharmaceuticals, plating agents, and bath salts.

3. Buffering Action and Use as a PH Adjuster

Succinic acid is a type of organic acid, and its mixture with conjugate base has a buffering effect and is used as a pH adjuster in cosmetics.

Role of Succinic Acid in the TCA Circuit

Succinic acid is an important intermediate in the TCA circuit and is deeply involved in the energy metabolism of many oxygen-breathing organisms; in the TCA circuit, succinic acid catalyzes succinate dehydrogenase to give fumaric acid, during which the coenzyme FAD is reduced to produce FADH2.

Structure of Succinic Acid

Succinic Acid is a dicarboxylic acid compound with two carboxylic acids in its structure. It has the molecular formula C4H6O4, molecular weight 118.09, and is designated butanedioic acid in IUPAC nomenclature.

Succinic acid is a four-carbon linear molecule with two carboxyl groups (-COOH). The two carboxyl groups make it highly acidic and soluble in water.

Succinic acid also behaves as a strong acid because the carboxyl groups release a proton.

Other Information on Succinic Acid

How Succinic Acid is Produced

In industrial production, succinic acid is prepared by contact hydrogenation of maleic anhydride, which is maleic acid or its dehydrated cyclide.

Succinic acid is an intermediate in the TCA circuit, so it can also be produced by fermentation using microorganisms. However, its productivity is low and it has not yet been put to practical use.

What Is Magnesium Silicate?

Magnesium silicate is a general term for compounds comprising magnesium oxide, silicic acid, and water, existing in various compositions. Natural minerals that contain magnesium silicate include talc, olivine, and pyroxene.

Olivine, also known as bitter earth, is primarily composed of magnesium orthosilicate, whereas magnesium pyroxene consists of magnesium metasilicate. These compounds differ in crystal forms and properties.

Both magnesium orthosilicate and magnesium metasilicate can be synthetically produced by heating and fusing silicic acid with magnesium oxide.

Uses of Magnesium Silicate

Magnesium orthosilicate is utilized as a raw material in the production of blast furnace slag. On the other hand, the production of magnesium disilicate, which naturally occurs as serpentine, is prohibited due to its carcinogenic properties.

Dimagnesium trisilicate, occurring naturally as seafoam stone, is also synthesized artificially using magnesium sulfate and sodium silicate.

What Is Sodium Silicate?

Sodium Silicate is the generic name for the sodium salts of silicic acid. There are various compositions such as Na4SiO4, Na2Si2O5, and Na2Si4O9, but in general, sodium silicate is often referred to as sodium metasilicate, which is Na2SiO3.

Sodium Silicate is a colorless crystalline solid at room temperature and soluble in water. Its concentrated aqueous solution is irritating and is called aqueous glass. When hydrochloric acid is added to aqueous glass, silicic acid is obtained.

Uses of Sodium Silicate

Sodium Silicate is used in a variety of applications, including adhesives and ceramics. It is used as an adhesive in the manufacturing process of various paper products, such as toilet paper cores and cardboard, because of its high safety and low environmental impact.

In ceramics, coating cup handles and other parts with sodium silicate before attaching them to cups can prevent damage due to foaming.

Sodium Silicate is also used as a rust inhibitor for metals. It reacts with metal to produce a layer of silicic acid and metal oxides on the surface of the metal, preventing further erosion.

Other uses include additives in soaps and detergents, building materials, and foundries.

Derivatives of sodium silicate include silica gel, zeolite, and silicic anhydride.

Properties of Sodium Silicate

Aqueous solutions of sodium silicate are weakly alkaline, and are stable at pH 10.2 or higher. Adding acid lowers the pH and increases the viscosity due to siloxane bond formation.

Aqueous solutions of sodium silicate react with heavy metals and other substances to form precipitates. This property is widely used in sewage treatment and water treatment.

When alcohol, phenol, or aldehyde is added to sodium silicate, it dehydrates and releases silica gel.

Types of Sodium Silicate

Sodium Silicate is a silicate of sodium, generally expressed as Na2O, nSiO2, and mH2O. Depending on the ratio of the three components, there are various types of sodium silicate with different physical and chemical properties in glassy, crystalline, and aqueous solution forms. Industrially, it is manufactured with SiO2/Na2O ranging from 0.5 to 4.

Crystalline sodium silicates include sodium orthosilicate (2Na2O-SiO2.xH2O), sodium sesquisilicate (3Na2O-2SiO2.xH2O), and sodium metasilicate (Na2O-SiO2.xH2O).

Aqueous solutions are also available with different ratios of Na2O and SiO2, such as No. 1 and No. 2.

Structure of Sodium Silicate

The structure of sodium silicate varies depending on its type, but in general, it consists of silicate tetrahedra bonded via covalent oxygen atoms to form a three-dimensional network of silicon and oxygen atoms. Sodium cations are incorporated into the network, filling the spaces between the sodium silicate tetrahedra and balancing the negative charge of the oxygen atoms.

In aqueous solution, they exist as chained metasilicate ions rather than orthosilicate ions. As the concentration of sodium ions decreases, branching and cross-linking of the silicate ions occurs, giving rise to a network structure.

Other Information on Sodium Silicate

1. Production Process of Sodium Silicate

Sodium Silicate can be produced by either the dry process or the wet process.

In the dry process, silica sand is mixed with sodium hydroxide or sodium carbonate and melted. The resulting cullet and water are dissolved in an autoclave, filtered through a filter press, and the molar ratio is adjusted to obtain sodium silicate.

In the wet process, sodium hydroxide and silica sand are reacted in an autoclave with pressurized steam. Sodium silicate is then filtered and concentrated.

2. History of Sodium Silicate

Sodium Silicate was first scientifically recognized and studied in earnest around the 1820s. After 1920, industrial production began in the U.S. and Europe, and the use of sodium silicate began to expand.

What Is Potassium Silicate?

Potassium Silicate is a silicate of potassium with the chemical formula K2SiO3.

It is either a white solid at room temperature or a highly viscous, fizzy liquid, similar to water glass.

It is synthesized by the reaction of potassium silicate with potassium hydroxide in a wet or dry process.

It often exists in a hydrated water state and is known to have various compositions such as K2O, SiO2, and H2O, but most of these are obtained at temperatures above 200°C and their presence has not been confirmed at room temperature.

Uses of Potassium Silicate

Potassium Silicate is used for a variety of purposes, but is most often used as a fertilizer for plants. Potassium, along with calcium and magnesium, is necessary for plant growth, so these minerals are blended with compounds of silicate and sold as potassium silicate fertilizers.

Many are industrially manufactured with a SiO2 to K2O ratio (molar ratio) of 2~3, and are used as a coating material for welding rods, a hardener for paints, and a raw material for detergents, among others, with compositions to suit their applications.

Properties of Potassium Silicate

Potassium Silicate is often handled in aqueous solution. It is similar to sodium silicate in characteristics, being a viscous liquid, colorless, odorless, and strongly alkaline. Contact with skin and eyes causes irritation. It mixes freely with water and is insoluble in ethanol. It is stable under normal conditions, but reacts with acids to form silica gel.

Hydrous crystals of sodium silicate are well known, such as sodium metasilicate 9-hydrochloride, sodium metasilicate 5-hydrochloride, and sodium sesquisilicate 5-hydrochloride.

In contrast, the conditions for the presence of hydrous crystals of potassium silicate are very limited.

Structure of Potassium Silicate

Silicate tetrahedra are bonded via shared oxygen atoms to form a three-dimensional network of silicon and oxygen atoms. Potassium silicate cations are incorporated into the network, filling the spaces between the silicate tetrahedra and balancing the negative charge of the oxygen atoms.

In aqueous solution, they exist as chained metasilicate ions rather than orthosilicate ions. As the concentration of potassium silicate ions decreases, the silicate ions become branched and cross-linked, resulting in a network structure.

Other Information about Potassium Silicate

1. Use of Potassium Silicate as a Fertilizer

Potassium Silicate is often used as a fertilizer because it provides plants with both potassium and silicon, nutrients essential for plant growth and development. It is produced as a fertilizer by mixing it with fly ash or magnesium hydroxide and calcining it.

Potassium is one of the essential nutrients for plants and is required for a variety of physiological processes, including photosynthesis, water regulation, and protein synthesis.

Although silicon is not considered an essential nutrient for plants, it has been shown to have many beneficial effects on plant growth and health, including increased resistance to pests and diseases and tolerance to non-living stresses such as drought and heat.

2. Environmental Safety of Potassium Silicate Fertilizers

Potassium Silicate fertilizers are considered environmentally safe. They have a pH of about 10, but because they are a physiologically neutral fertilizer, changes in soil pH are small. In addition, they do not run off with rainwater, etc., allowing nutrients to be retained in the soil and slowly released to plants. 

3. Use of Potassium Silicate as a Surface Modifier

When potassium silicate is used as a concrete surface modifier, even if cracks occur after construction, water causes the modifier to react with the calcium hydroxide inside the concrete to form a gel with a composition similar to cement hydrate.

It forms a waterproof and deterioration-preventive protective layer and can repair cracks on its own. The waterproofing and deterioration-preventing effect can be demonstrated over a long period of time, resulting in highly durable concrete structures and reduced life-cycle costs.

It is often used mixed with sodium silicate.

What Is Aluminum Silicate?

Aluminum Silicate is the general term for a mixture of aluminum oxide, silicon dioxide, and water. It is found in a variety of compositions and is abundant in nature.

Aluminum silicate is sometimes used to refer to the calcite alone. Calcite is a white orthorhombic crystal at room temperature and insoluble in water. It is resistant to acids and bases and is not eroded.

There are natural aluminum silicates and artificially synthesized aluminum silicates of various compositions.

Uses of Aluminum Silicate

In addition to its use as a raw material for ceramics and paints, synthetic aluminum silicate is also used in medicine.

In its pharmaceutical form, synthetic aluminum silicate is often used as a medicine to reduce inflammation of the stomach and intestines. It tends to be avoided in patients with kidney problems because of the possibility of developing side effects such as kidney stones when administered over a long period of time.

Aluminum silicate fiber is also attracting attention for its low thermal conductivity and excellent thermal and chemical stability.

Properties of Aluminum Silicate

Aluminum silicate is generally an odorless white solid. In its natural mineral form, it is considered safe and non-toxic.

However, prolonged exposure to aluminum silicate dust can cause respiratory problems such as silicosis. Silicosis is a lung disease that causes scarring of lung tissue and reduced lung function and may also increase the risk of lung cancer.

Some forms of aluminum silicate, such as synthetic forms like zeolite, can be chemically altered and pose a significant risk to human health.

When handling aluminum silicate, it is important to use appropriate personal protective equipment such as masks to prevent exposure.

Types of Aluminum Silicate

Aluminum Silicate is available in many minerals and compounds that vary in composition and structure.

Common types of aluminum silicate include:

1. Kaolinite

A clay mineral commonly found in soils and used in the manufacture of pottery, paper, and other materials.

2. Andalusite

This mineral crystallizes at lower pressures than kyanite and lower temperatures than sillimanite. The crystalline system is orthorhombic.

3. Kyanite

Similar in composition to andalusite, kyanite is sometimes used in decorative objects. The crystalline system is triclinic.

4. Sillimanite

Sillimanite is orthorhombic in crystal system. It has the same composition as kyanite and andalusite, but a different crystal structure.

5. Zeolite

A highly porous, synthetic aluminum silicate used as a catalyst, adsorbent, and ion exchanger.

6. Mica

A group of minerals with excellent heat resistance and insulating properties often used in cosmetics, insulation, and electronics.

7. Feldspar

This mineral group is commonly used in the manufacture of ceramics and glass due to its low melting point and ability to reduce thermal expansion.

There are many other types of aluminum silicate minerals and compounds, each with its own unique properties and uses.

Structure of Aluminum Silicate

Aluminum Silicate compounds are generally composed of a three-dimensional network consisting of an octahedron composed of one aluminum atom and six oxygen atoms and a tetrahedron composed of one silicon atom and four oxygen atoms. Depending on the chemical composition and the morphology of the network structure, it yields a variety of properties.

The network structure depends on the type of aluminum silicate. For example, in the mineral kaolinite, silicon tetrahedra are arranged in layers, with aluminum octahedra between the layers. In contrast, zeolites have an infinite series of SiO4 or AlO4 tetrahedral structures.

What Is Glutamic Acid?

Glutamic Acid is a non-essential amino acid that can be synthesized by the body. It serves as a neurotransmitter between synapses.

In the brain, glutamic acid binds to its receptors and activates them to transmit information for learning. It is also useful as a flavor component.

There are several methods of producing glutamic acid, including hydrolysis, extraction, and chemical synthesis. Currently, the amino acid fermentation method, in which glutamic acid is obtained by fermenting sugarcane molasses with fermentation bacteria, is the most common method.

Uses of Glutamic Acid

The main uses of glutamic acid are in seasonings and supplements.

1. Seasonings

Glutamic Acid is one of the components of umami, so monosodium glutamate, a glutamate salt, is commercialized and sold as an umami seasoning.

In the case of chemical seasonings, glutamic acid is sold in the form of glutamic acid trim combined with sodium, which is easily dissolved in water.

Glutamic acid is abundantly contained in seaweeds such as kelp and plant foods such as Chinese cabbage, green tea, and tomatoes.

2. Supplements

In addition to its function as one of the brain’s neurotransmitters, glutamic acid plays an important function in the body, detoxifying ammonia and becoming a component of proteins that strengthen muscles and immunity.

Therefore, glutamic acid deficiency can lead to impaired brain function and inhibited urination. Glutamic acid has been commercialized as a dietary supplement with the goal of compensating for glutamic acid deficiency.

Glutamic acid also produces GABA, which calms brain excitation; GABA is a type of amino acid that has been used in supplements and foods in recent years for its stress-reducing and relaxing effects.

Properties of Glutamic Acid

Glutamic Acid is a non-essential amino acid that is necessary for the production of alanine, aspartic acid, and serine, and is found in nature as L-glutamic acid.

1. Physical Properties

Glutamic Acid is a white, odorless, crystalline powder with molecular formula C5H9NO4 and molecular weight 147.13. It has a boiling point of 249°C and no melting point, flash point, or decomposition temperature. It is not flammable and can be handled relatively safely.

2. Chemical Properties

The product is insoluble in water, and is largely insoluble in ethanol and diethyl ether. It is hazardous in contact with strong oxidizing agents.

During thermal decomposition, there is a high possibility of releasing irritating and toxic gases and vapors. Work should be done in areas with local exhaust ventilation and use is to be avoided at high temperatures.

Other Information on Glutamic Acid

1. History of Glutamic Acid

Glutamic Acid was discovered in 1866 by the German chemist Ritthausen as a hydrolysis product of gluten, a protein of wheat. Later, in 1908, Kikunae Ikeda, a professor at Tokyo Imperial University (now the University of Tokyo), discovered that glutamic acid has a delicious taste. He also announced that in addition to the four basic tastes of sweet, salty, sour, and bitter, glutamic acid has a fifth basic taste, umami.

It was also clarified that the fifth basic taste, umami, is more easily soluble in water when it is combined with sodium. Sabrosuke Suzuki, the founder of Ajinomoto, worked to commercialize monosodium glutamic acid, and the world’s first chemical seasoning was launched in 1909.

2. Safety of Glutamic Acid

Excessive intake of natural glutamic acid can cause sleeping disorders neurosis, hallucinations, and other risks. In addition, excessive intake of the chemical seasoning monosodium glutamic acid is said to cause headaches, burning, and numbness in the hands and feet.

On the other hand, research has reported that proper intake of glutamate is beneficial to the human body in terms of activating brain function, detoxifying ammonia, and having a diuretic effect, as well as reducing the accumulation of fat, beautifying the skin, and lowering blood pressure.

As with water and salt, excessive intake of these substances can be poisonous even if they are necessary for the human body.

What Is Glutathione?

Glutathione (GSH) is a tripeptide consisting of glutamic acid, cysteine, and glycine. The amino group of cysteine and the carboxy group of glutamic acid’s side chain form an amide bond. Oxidized glutathione (GSSG) is formed when two molecules of glutathione form a disulfide bond. However, typically, ‘glutathione’ refers to the reduced form (GSH). Its chemical formula is C10H17N3O6S, and the CAS number is 70-18-8. It appears as a white powdery solid at room temperature, with a melting point of 195°C, soluble in water, and practically insoluble in ethanol and diethyl ether.

Uses of Glutathione

Glutathione is used as a reducing agent in synthetic organic chemistry and biochemistry. For example, it is used in elution buffers to elute GST (glutathione S-transferase) fusion proteins from glutathione-agarose beads. In living organisms, it serves as an antioxidant, protecting cells from reactive oxygen species such as free radicals and peroxides. Medications containing glutathione are available in both oral and injectable forms and are used for various conditions, including drug toxicity, acetonemic emesis, metal poisoning, hyperemesis gravidarum, and gestational hypertension.

Principle of Glutathione

1. Structure of Glutathione

Glutathione is a tripeptide formed from glutamic acid, cysteine, and glycine, denoted as L-γ-glutamyl-L-cysteinyl-glycine. It is characterized by a γ-glutamyl bond between the γ-carboxy group of glutamate and the α-amino group of cysteine.

2. Redox Reaction of Glutathione

Glutathione contains a thiol group on the cysteine residue’s side chain. When oxidized, two molecules of reduced glutathione (GSH) form a disulfide bond, converting to the oxidized form (GSSG). In animal cells, it reduces disulfide bonds in cytosolic proteins to cysteines. It also reduces peroxides and reactive oxygen species, playing a key role in removing oxidative stress.

3. Detoxification Action of Glutathione in Vivo

Glutathione acts nucleophilically through the sulfur moiety of the cysteine residue’s thiol group. In vivo, it is catalyzed by glutathione-S-transferases (GSTs) to bind to various substances, including poisons, antibiotics, leukotrienes, and prostaglandins, forming conjugates. These conjugates are then expelled from cells, aiding in detoxification.

Types of Glutathione

Glutathione is available as a chemical reagent for research and development as well as a pharmaceutical product in forms like tablets and injections. It is used to replenish glutathione in the human body and detoxify toxins. It is indicated for various conditions, including drug intoxication, acetonemic emesis, and impaired liver function in chronic liver diseases. Available in various quantities for research, such as 10mg to 500g, glutathione requires refrigerated storage to prevent oxidation. Both reduced and oxidized forms of glutathione are available, and it is essential to distinguish between them.

What Is Gluconic Acid?

Gluconic acid is an organic compound with the chemical formula C6H12O7. It is an optically active compound, and only the D form occurs naturally.

It is also a type of aldonic acid (a derivative obtained by oxidizing monosaccharides, in which the formyl group at the 1-position of aldose is replaced by a carboxyl group).

The CAS registration numbers are 526-95-4 for the D form and 133-42-6 for the racemic form.

Uses of Gluconic Acid

1. Food Industry

Gluconic Acid is used as a food additive because of its non-volatility and low acidity. Its main uses are as a pH adjuster for processed rice products, and as a seasoning and pH enhancer for various beverages, pickles, dressings, and sauces.

When used in foods, it is labeled as an acidifier, an hydrogen ion concentration adjuster, a pH adjuster, or gluconic acid.

Potassium gluconic acid and sodium gluconic acid, which are salts of gluconic acid, are also used as food additives.

For example, they are used to replace the processing function of salt in the manufacture of bread, soy sauce, etc. It is also used as a taste improver for the sweetener sodium saccharin.

• Calcium salts: Stabilizer
• Calcium Lactate Gluconic Acid: Calcium agent
• Iron Gluconic Acid: Black olive flavor

2. Medical Field

In the medical field, it is mainly used as a medicine for iron deficiency. The incorporated gluconic acid ions effectively facilitate the absorption of metal ions in the body.

Calcium gluconic acid ointment is also effective in the treatment of chemical wounds caused by hydrogen fluoride. Calcium ions taken up as gluconic acid salts have the ability to combine with soluble fluoride ions to form insoluble calcium fluoride, making it non-toxic.

Salts with quinine are used as a malaria treatment in the form of intramuscular injections, and zinc salts are substances used to castrate male dogs.

3. Industry

In industry, gluconic acid is sometimes used as a weak acid to remove precipitation of metal salts and to clean metals.

Properties of Gluconic Acid

Gluconic Acid is a substance that readily dehydrates to the cyclic ester glucono-delta-lactone (D-(+)-gluconic acid-δ-lactone) when dissolved in an acidic solution. Dehydration also readily occurs when attempting to isolate free acids from solution.

In aqueous solution, it exists as an equilibrium mixture with this compound, so the pure form can only be obtained in salt form.

It is also a strong chelating agent and works particularly well in alkaline solutions. Specifically, it is known to chelate calcium, iron, aluminum, copper and other heavy metal ions.

In nature, gluconic acid is particularly abundant in honey and royal jelly. Other sources include soybeans, rice, shiitake mushrooms, and fermented foods such as wine, soy sauce, and vinegar.

It is the only organic acid known to increase bifidobacteria. It has a soft sour taste and is corrosive and irritating.

Structure of Gluconic Acid

Gluconic Acid has a molecular weight of 196.155, a melting point of 131 °C, and is a colorless crystal at room temperature. It has a density of 1.23 g/mL and an acid dissociation constant pKa of 3.86. It is readily soluble in water. Its solubility in water is 316 g/L.

Gluconic Acid has a carboxyl group at the end of its six-carbon chain and five hydroxy groups, one on each of the second through sixth carbon atoms.

Types of Gluconic Acid

Gluconic Acid is sold mainly as a reagent for research and development and as an industrial raw material. Both are usually aqueous solutions of about 50%.

R&D reagent products are available in 25g, 500g, and other capacities. They are offered in capacities that are easy to handle in the laboratory.

When the term gluconic acid is used without any declaration, it usually refers to D-gluconic acid.

When sold as an industrial raw material, it is usually supplied as a raw material for food additives such as acidifiers and pH adjusters, etc. It is sold in large volumes such as 20 kg or 250 kg to meet demand at factories. This also usually refers to D-gluconic acid.

Other Information on Gluconic Acid

Biosynthesis of Gluconic Acid

Gluconic Acid is produced in the phosphogluconic acid pathway, one of the metabolic pathways of glucose in vivo. The reduced form of glucose is the sugar alcohol sorbitol, whereas the oxidized form of glucose is the sugar acid gluconic acid.

What Is Glucono-Delta-Lactone?

Glucono-delta-lactone, a natural organic compound, has the chemical formula C₆H₁₀O₆. Known also as honeydew acid, it is found abundantly in honey. This compound, differing from glucose by having a hydroxy group replaced with a ketone, offers a mild sweet and sour taste. It finds use as an additive in both food and cosmetics.

Uses of Glucono-Delta-Lactone

As a safe, natural lactone, glucono-delta-lactone serves various purposes in the food industry due to its harmless nature. It functions as an expander, coagulant, pH adjuster, and acidifier, contributing a gentle sweet and sour flavor, making it an ideal food additive.

1. Expanding Agent for Foods

Primarily used alongside baking soda as an expanding agent, glucono-delta-lactone is a component of certain baking powders. It reacts slowly with baking soda in the dough of cakes, doughnuts, and bread, generating uniform air bubbles for dough expansion, offering a safer and taste-neutral alternative to traditional alum-based leavening agents.

2. Food Coagulant

Its ability to gradually convert to gluconic acid upon dissolving in water, lowering pH, makes Glucono-Delta-Lactone an effective coagulant. This property is especially useful in tofu and cheese production, where it ensures even coagulation and supports mass production processes.

3. pH Adjuster

Utilized to adjust the pH of various foods, including noodles, processed meats, and fish products like fish cakes, glucono-delta-lactone’s mild pH-adjusting capability is essential for maintaining the desired taste and stability of food products.

4. Acidifiers

Adding a sour note to juices, jams, and sorbets, glucono-delta-lactone acts as an acidifier, enhancing flavors without overpowering them.

5. Cosmetic Additive

In cosmetics, glucono-delta-lactone’s chelating properties help trap metal ions, stabilizing products like shampoos and facial cleansers. It also enables gel formation in facial packs when mixed with polysaccharides.

Properties of Glucono-Delta-Lactone

Chemical Formula	C6H10O6
Common Names	Gluconolactone, GDL, Honey Acid
CAS No.	90-80-2
Molecular Weight	178.14 g/mol

Water and alcohol-soluble, glucono-delta-kactone transforms into gluconic acid when dissolved in water, a process that accelerates with heat.

Other Information About Glucono-Delta-Lactone

Synthesis

Naturally produced by honey bees, glucono-delta-lactone is synthesized from glucose. Commercially, it is mass-produced through enzymatic fermentation, offering an efficient synthesis route from glucose.

What Is Glycerin?

Glycerin, also known as glycerol, is a trivalent alcohol with the chemical formula C3H8O3 and a CAS number of 56-81-5. It has a molecular weight of 92.09, a melting point of 17.8°C, and a boiling point of 290°C. Glycerin is a clear, colorless, odorless liquid at room temperature, highly viscous with a sweet taste. Its density is 1.261 g/cm3, and it is soluble in water and ethanol, but extremely difficult to mix with diethyl ether.

Glycerin is used in various industries, including pharmaceuticals. It is also present in living organisms as the backbone of triglycerides, phospholipids, glycolipids, and other substances.

Uses of Glycerin

Glycerin has diverse applications, including as a food additive, in pharmaceuticals, and cosmetics. As a food additive, it serves as a sweetener, preservative, humectant, and thickening stabilizer, and does not cause tooth decay. In pharmaceuticals and cosmetics, it is used as a moisturizer and lubricant, and in the preparation of enema solutions, cough syrups, gargles, toothpaste, soaps, and lotions.

In the machinery industry, glycerin is sometimes used in antifreeze solutions. It also serves as a raw material in synthetic chemistry for products like nitroglycerin and allyl iodide as well as in the manufacture of surfactants and polyurethane resins.

Properties of Glycerin

1. Synthesis of Glycerin

Glycerin can be obtained from natural sources like soybean oil and tallow through hydrolysis of triacylglycerols (triglycerides), or synthetically from propylene. In chemical synthesis, it is produced by hydrolysis under basic conditions via epichlorohydrin. Glycerin is also a byproduct in the synthesis of fatty acid methyl esters for biodiesel fuel, often incinerated due to impurities.

2. Physical Properties of Glycerin

Glycerin is soluble in water and exhibits strong hygroscopicity. Its aqueous solution has a freezing point depression, making it useful as an antifreeze. It has a melting point of 17.8°C but can supercool to a glassy state at around -100°C. Crystals can be obtained by further cooling and slow reheating.

3. Chemical Reactions of Glycerin

Glycerin, a trivalent alcohol, reacts with various substances. It yields allyl alcohol when heated with formic acid, and acrolein when heated with potassium hydrogen sulfate. Glycerin can undergo dehydration with acetone to yield a protected derivative. One of its notable reactions is the Skraup quinoline synthesis, where acrolein reacts with aniline derivatives under oxidative conditions to form quinoline.

Types of Glycerin

Glycerin is available in various forms, including pharmaceuticals, food additives, industrial chemicals, cosmetic raw materials, and research reagents. In pharmaceuticals, it is commonly used in enemas, as well as in ointments and lubricating agents. For industrial use, it is sold in large quantities like 22 kg cans and 250 kg drums, while smaller capacities are available for research and development purposes.