Sodium diacetate
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| General | ||||||||||||||||
| Surname | Sodium diacetate | |||||||||||||||
| other names |
E 262b |
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| Molecular formula | (NaC 2 H 3 O 2 ) x + (C 2 H 4 O 2 ) y | |||||||||||||||
| Brief description |
colorless crystalline solid with an acetic acid odor |
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| properties | ||||||||||||||||
| Molar mass | 142.09 g mol −1 (for the molar composition (NaC 2 H 3 O 2 ) 1 + (C 2 H 4 O 2 ) 1 ) | |||||||||||||||
| Physical state |
firmly |
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| density |
1.4 g cm −3 (20 ° C) |
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| solubility |
very light in water (1040 g l −1 at 20 ° C) |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||||||||
Sodium diacetate is a white mixture of acetic acid and sodium acetate .
As a food additive , it should contain 39–41% acetic acid and 59–61% sodium acetate.
properties
In aqueous solution, sodium diacetate forms a buffer solution as a 1: 1 mixture of the medium-strength acid acetic acid and the weak base acetate . The resulting pH is 4.75. The buffer range of the solution is in the pH range between 3.75 and 5.75. The use of sodium diacetate as an acidity regulator in the food industry is based on this effect . A preservative effect is claimed.
Confusion as substance / molecular formula
Because sodium diacetate is a mixture of substances and not a pure substance, its “ sum formula ” varies depending on its composition. Correctly, no empirical formula should be given. Its name as a substance comes from the decades of use of the term "sodium diacetate" in the sense of an additive in the food industry. The similarity of the name with the (real chemical) substance " sodium bicarbonate " suggested that sodium diacetate would also be a substance, although it is a mixture. In the nomenclature of food additives, it was therefore initially listed indiscriminately under E 262 “Sodium Acetate”. Only recently have the E numbers E 262a for sodium acetate and E 262b for sodium diacetate been differentiated.
use
Sodium diacetate is the food additive E 262b or E 262 (ii). It is used as an acidity regulator and preservative for bread , among other things (see list of food additives - E 262b).
Manufacturing
It is produced by combining 40% acetic acid with 60% sodium acetate.
Individual evidence
- ↑ a b c d e Entry on sodium hydrogen diacetate in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
- ↑ Spiegel Online : Why Nobody Knows What We Really Eat , August 15, 2008.
- ↑ DIRECTIVE 96/77 / EC OF THE COMMISSION of December 2, 1996 laying down specific purity criteria for food additives other than colors and sweeteners (PDF; 373 kB)