Boric acid and borax are not legal food additives, but there are still unscrupulous businesses who use them illegally to increase the elasticity and toughness of food, extend the shelf life, or maintain beautiful color. Even in addition to alkali rice dumplings, other products such as rice cakes and oil noodles are used. Foods that pursue “taste”, such as hamburgers, meatballs, fish slabs and shrimps, also often suffer.
What effects do borax and boric acid have on the human body? Let us first briefly understand the structure and characteristics of borax, and its relationship with “boric acid”.
The difference and conversion between boric acid and borax The difference and conversion between borax and boric acid
Borax, also known as sodium tetraborate, has the chemical formula Na2B4O7 and is a Common boron-containing salts appear as colorless crystals or white powder. It can inhibit the growth of yeast and mold. It was once used as a preservative. It can also inhibit the action of tyrosinase and prevent tyrosine from oxidizing into melanin. In recent years, it has been often abused to prevent shrimp food from blackening. change, keeping its color and luster beautiful.
Borax is easily soluble in water, and the B4O72- anion can combine with water molecules to form the protagonist of this article, boric acid (H3BO3), and hydroxide ions (OH–), so it is alkaline. The boric acid molecules in the aqueous solution will further combine with hydroxide ions to produce borate ions (B(OH)4–). The “-OH groups” on both sides of them can interact with the -OH groups in long chain molecules in food. The group reaction forms bonds and acts as a bridge between long chains, allowing the long chain molecules to form a 3D network structure. This is the key to borax making food more elastic.
Similarly, borax will be acidified into boric acid in an acidic solution, such as sulfuric acid or hydrochloric acid, but due to the low concentration of hydroxide ions, borate ions will not be generated. In short, boric acid is a product of borax dissolved in water or combined with acid. Therefore, when food reacts with borax solution, both borax and boric acid will often remain in it. After eating, the gastric juice is acidic. , borax will be converted into boric acid in the body.
The difference between boric acid and borax and the conversion of boric acid commonly found in nature
Boric acid is an inorganic weak acid containing boron. It appears as white powder or transparent crystals and feels greasy. It is slightly soluble in cold water, but its solubility increases with increasing temperature. At 20°C, 1 liter of Water dissolves approximately 47.2 grams of boric acid. Boric acid is actually quite common in nature: seawater itself contains boric acid and other salts; in some particularly volcanic areas, such as Tuscany and Lipari Islands in Italy and Nevada in the United States (Nevada), traces of it can also be found. Sometimes, boric acid also coexists with boron-containing minerals (such as borax ore) and is interspersed in the mineral structure.
In addition, boron is also indispensable for the growth of plants. It can promote lignin production and the growth of rhizomes; If there is a lack of boron, the plant will turn yellow or black, and the leaf shape may even be stunted. These boron elements are often stored in plants in the form of “boric acid”, especially fruit trees and fruits. Therefore, ingesting trace amounts of boric acid is not earth-shattering. The human body can metabolize it naturally and will not cause any harm to health.
The difference between boric acid and borax and other applications of converted boric acid: disinfection, nitropyridine removal, buffer solutions
In addition to naturally helping plants grow, boric acid It is also used in medicine. It has a disinfecting effect and can treat minor cuts and burns. It can also inhibit fungal infections (such as Candida or tinea pedis). It is often used as a dressing or ointment. The diluted boric acid aqueous solution (the maximum allowable concentration is 3%) can be used as eye drops or eyewash to relieve eye discomfort. It is also the only acid currently known to be beneficial to the eyes.
In addition, boric acid has the function of killing common pests (borax has the same effect). The main mechanism is to corrode the exoskeleton of insects and affect their metabolism through food intake. In 1948, the United States Environmental Protection Agency (USEPA) used boric acid to control the number of cockroaches, termites, fire ants, silverfish and fleas; it had both disinfecting and insecticidal properties , also allowing it to be used as a wood preservative. Other uses of boric acid include: controlling the speed of nuclear fission reactions in nuclear power plants, making sodium perborate tetrahydrate to make heat-resistant glass (borosilicate), and aqueous solutions of boric acid and its borate roots can be used as acid-base buffers in swimming pools, etc. .
Attention! Boric acid cannot be added to food
After reading this, you may think: Boric acid is not bad! In addition to existing in nature, it is also a good helper in human life. However, then we will also explain something that needs to be paid attention to when using it – the toxicity of boric acid.
Although boric acid itself is not very toxic, it has a “cumulative effect” in the body. Even if the amount taken each time is not large, if it accumulates in the body after continuous ingestion, it may still damage the central and digestive systems and hinder the function of digestive enzymes. , causing symptoms such as loss of appetite, inhibiting nutrient absorption and promoting fat decomposition, leading to weight loss. In addition, in boric acid feeding studies in rats, mice and dogs, it has also been observed that long-term or short-term intake of large amounts of boric acid or borax can affect the male reproductive system, such as testicular atrophy. However, boric acid is nowNo obvious carcinogenic or genetic mutations have been observed in this segment, and the International Center for Research on Cancer (IARC) has not classified it as a carcinogen.
In terms of dosage, if an adult ingests 1 to 3 grams of boric acid, symptoms of “boric acid poisoning” will occur, including vomiting, diarrhea, erythema on the skin, and even risk of shock or coma; oral administration can be fatal. The dosages are 15 to 20 grams for adults, 5 to 6 grams for young children, and 2 to 3 grams for infants.
Therefore, the Expert Committee on Food Additives of the Food and Agriculture Organization and the World Health Organization (FAO, WHO JECFA) believes that borax and boric acid are potentially harmful to human health and should not be used as food additives. The World Health Organization (WHO) recommends that the “Tolerable Daily Intake (TDI)” of boric acid is 0.16 mg/kg bw/day, that is, the allowable intake of 0.16 mg per kilogram of body weight per day. At present, most countries around the world have banned the use of borax or boric acid as food additives (however, the European Union allows borax or boric acid to be used as preservatives in caviar), and Taiwan has also banned it. Our food additives are listed on the front, and borax is not included. It’s on the permission list.
In addition to relying on inspections and spot checks by relevant units, the next time we buy related foods, we can also try to choose products with complete packaging and labeled food ingredient information. The more care you take, the less you will need. Share the risks.
Source: Pan Science
