What is lactic acid? It is an organic compound produced when glucose is broken down and oxidized; and a colorless liquid with the formula of C3H6O3, soluble in water, ethanol, and glycerol.
Applications of Lactic Acid in Food Industry
1) It is used for preservation. It can be used as antibacterial and seasoning, and also can be used to adjust PH value, extend shelf life, keep food color, improve product quality and so on.
2) It can be used as seasoning. Lactic acid can maintain the stability of microorganisms and taste more moderate by adding the right amount in salad, soy sauce, vinegar and other condiments.
3) Lactic acid can be used as sour agent in soft drinks and juices.
4) For beer brewing, lactic acid can not only adjust the pH value to promote saccharification which is conducive to yeast fermentation and beer quality improvement but also increase the flavor of beer and extend the shelf life.
5) Lactic acid is a natural ingredient in dairy products. It has a dairy taste and good anti-microbial effects which has been widely used in the production of yogurt cheese, ice cream and other dairy food as the sour agent.
6) Lactic acid powder can be used as the sour taste regulator for the buckwheat. It is a natural fermented acid which can bring a unique taste to the bread, and also a natural sour conditioning agent to cakes, biscuits and other baked goods with seasoning and antibacterial effects which improve the quality of food and extend shelf life.
Applications of Lactic Acid in Pharmaceutical Industry
1) Lactic acid vapor disinfection can be used in wards, operating rooms and laboratories to effectively kill bacteria in the air.
2) It can be used as preservatives, carrier agents, complex solubilizer, pharmaceutical preparations, pH adjusters and the like.
3) Lactic acid can be polymerized into polylactic acid. And then it can be processed and used as surgical suture which does not need removing and can be automatically degraded into lactic acid and then absorbed by the body. This polymer compound can also be used as an adhesive in organ transplantation and bone joiner.
4) Lactic acid can be formulated directly into drugs or daily health care products.
5) Lactic acid can regulate muscle activity and have anti-fatigue effects.
Applications of Lactic Acid in Industry
1) Lactic acid in the fermentation industry can be used to control PH value and improve the purity of the fermentation.
2) Lactic acid can maintain tobacco humidity in the cigarette industry. Lactic acid can also neutralize nicotine, reduce harmful ingredients on the human body and improve the quality of tobacco.
3) In the textile industry, lactic acid can be used to deal with fiber to make the fiber easy to color and increase the gloss and soft touch.
4) Lactic acid can be used as a pH adjusting agent and a synthetic agent in the paint and ink industry. In the plastic fiber industry, it is the first choice for biodegradable new materials, polylactic acid (PLA).
5) Lactic acid can also be used as the starting material of polylactic acid, producing a new generation of biodegradable plastics.
6) In the tannery industry, lactic acid can used to remove the lime and calcium from the leather to get soft, delicate, and high quality leather.
7) Because lactic acid has a unique complexing constant for nickel, it can be used for nickel plating processes. It can also be used as acid buffer and stabilizer in the plating tank. In the microelectronics industry, lactic acid is a safe organic dissolving agent with high purity and low metal content which can meet the semiconductor industry with higher quality requirements, such as cleaning the photosensitive material.
8) Lactic acid as a pH regulator and synthesis agent can be applied to a variety of water-based coating. Lactic acid products have low boiling points and are well used as safe dissolution systems for high solid coatings. Lactic acid provides an opportunity to coatings containing high solids with good fluid properties.
9) Lactic acid has detergency effects with better performance than traditional organic detergents. Lactic acid has antimicrobial properties that, when used in conjunction with other antimicrobial agents such as ethanol, it can produce synergistic effects.
Application of Lactic Acid in Cosmetics Industry
1) L-lactic acid is part of the skin's inherent natural moisturizing factor. It is widely used as a moisturizer for many skin care products. L-lactic acid is the most effective AHA.
2) L-lactic acid naturally exists in the hair, and can keep the hair surface gloss bright. So lactic acid is often used as a conditioning agent for various hair care products.
3) Lactic acid can be used as a humectant in a variety of bath products, such as private bath liquid, strip soap and moisturizing honey and can also be used as PH regulator in liquid soap, soap and shampoo. In addition, the addition of lactic acid in the strip of soap can reduce the loss of moisture during storage, thus preventing the drying of the soap.
Applications of Lactic Acid in Agriculture and Animal Husbandry Industry
1) Lactic acid with an optical purity of up to 99% or more can be used to produce slow release pesticides such as herbicides with no harm to crops and soils.
2) Lactic acid polymer can be used in the production of agricultural film, which can be used to replace plastic film, and can be absorbed by the soil after decomposition which is conducive to environmental protection.
3) Lactic acid is also used for green fodder storage and pasture ripening agent.
4) As a growth promotion in pig and poultry feed, lactic acid can reduce the PH value in the stomach, activate digestive enzyme, and improve the ability of amino acid digestion, which is good for the intestinal epithelial growth. The piglets fed a diet containing an acidifying agent for several weeks after weaning can increase the body weight by 15%
5) lactic acid inhibits the growth of microorganisms. Lactated piglets may be infected with the diseases caused by E. coli and Salmonella. Lactic acid can prevent pathogens growth in the gastrointestinal tract of piglets .
6) Lactic acid can be used as preservatives and microbial stabilizers for feed, cereal and meat processed products.
7) In the poultry and pig drinking water, the lactic acid can effectively inhibit the growth of pathogens, and increase animal weight gain rate.
What is lactic acid in the body
For the human body, lactic acid is one of the fatigue substances. When people keep body temperature and body movement to produce calories, the body will produce lactic acid. Most of the energy we need for living comes from sugar. Blood sends glucose to various organs which will consume and produce heat. This process produces water, carbon dioxide and pyruvic acid. Pyruvate and hydrogen combine to form lactic acid. If the body's energy metabolism is normal, there will be no accumulation of lactic acid which will be sent to the liver, and further broken down into water and carbon dioxide and so that the fatigue can be eliminated.
If the movement is too intense or lasting, or the body lacks of necessary vitamins and minerals to decompose the lactic acid, then it may be too late to be treated which may cause lactic acid accumulation. Too much lactic acid will make the weak alkaline body fluids become acidic, which will affect the smooth absorption of nutrients and oxygen, and weaken the normal function of cells. Accumulation of lactic acid may also cause muscle contraction, which will squeeze blood vessels,and thus lead to poor blood flow, muscle soreness, chills, and headaches. In the early stage, it may cause soreness and fatigues, and may result in physical acidification and serious illness in the long term.
Some people sleep to eliminate fatigue, which is ineffective. Chemical drugs may have a temporary relief, but they also have side effects. The correct way is to exercise slightly. Stretching exercise can relax muscles and promote blood circulation. It will get the best results to combine light food especially those rich in vitamin B family, and high quality sleep.
Molecular formula: C3H6O3
Molecular weight: 90.08
Relative density: 1.200
Melting point: 18℃
Boiling point: 122℃ (15 mmHg)
Dissociation constant: pKa = 4.14 (22.5℃)
Flash point:> 110℃
Burning heat: 15.13kj / kg
Isotonicity: 2.3% (W / V) solution isotonic with plasma
Solubility: with ethanol (95%), ether, water immiscible, insoluble in chloroform
Specific heat: 2.11 KJ / g