1 Introduction
Generic hexadiene – ( 2,4 ) – potassium ; 2,4 – potassium sorbate
Formula C6H7KO2
Simple structure CH3CH = CHCH = CHCOOK
Quality standard: National People’s Republic of China GB13736-2008
Commonly known as: Preservatives
ChI = 1/C6H8O2.K/c1-2-3-4-5-6 (7) 8 ;/ h2-5H, 1H3, (H, 7,8) ;/ q; +1 / p-1/b3 -2 +,5 -4 + ;
2 production methods
1 and mainly uses the method. Sorbic acid as raw materials, potassium hydroxide or potassium carbonate for neutralization reaction.
2 sorbic acid was added to the reaction kettle , sorbic acid was then added to 66% by mass of water, was added dropwise a solution of 49% potassium hydroxide at 45 ℃, Ph = 8 until the reaction solution until the reaction is about 45min. Adding a certain amount of carbon, vacuum filtration , at 40 ~ 45 ℃ and the filtrate was evaporated under reduced pressure reaches 3 ~ 4h after heating to 70 ℃ discharge requirements . By centrifugal dehydration crystallization liquor recovery ; finally dried to obtain the product under 105 ℃. [ 1 ]
3 Uses
The main use
Preservatives for food preservatives are acidic reaction with organic acids using antiseptic effect increased . Potassium carbonate or potassium hydroxide and sorbic acid as raw materials. [ 2 ]
Sorbic acid ( potassium ) can effectively inhibit mold , yeast and the activity of aerobic bacteria , so as to effectively extend the storage time of the food and keep the original flavor of the food .
We buy the packaging ( or canned ) food , the ingredients often see one of the words ” sorbic acid ” or ” potassium sorbate ” , people often mistakenly thought to be components of the fruit , ” pear” is . In fact, they are commonly used in food additives ! Whether they have no harm to human body , plain consumption is indeed necessary , the following is the relevant information about the sorbic acid , potassium sorbate for reference only:
Sorbic acid ( chemical name : 2,4 – sorbic acid Formula : C6H8O2 ]
Potassium sorbate ( chemical name : 2,4 – potassium sorbate ] Formula : C6H7KO2)
Sorbic acid, potassium sorbate properties, uses similar : Sorbic acid is recommended by the FAO and WHO efficient and safe preservative widely used in food , beverages, tobacco , pesticides, cosmetics and other industries , as the unsaturated acid, also can be used in resins, spices and rubber industry.
4 Nature
Physical Properties
Potassium sorbate is a white to pale yellow crystalline flake , crystalline granule or crystalline powder , odorless or slight odor, hygroscopic long-term exposure to air, oxidation and decomposition and discoloration. Soluble in water , potassium sorbate , 67.6g/100ml (20 ℃); 5% brine , 47.5g/100ml ( room temperature ) ; 25% sugar , 51g/100ml ( room temperature ) . Dissolved in propylene glycol , 5.8g/100ml; ethanol , 0.3g/100ml. 1% aqueous solution of potassium sorbate PH7 ~ 8.
Spectral characteristics
Using FLS 920 fluorescence spectrometer to study the three-dimensional fluorescence spectra of potassium sorbate solution was found when moved from 320 nm excitation light red 500 nm, fluorescence has two peaks : 485 nm and 565 nm, the former strength significantly greater than the latter , the corresponding the excitation peak was 380 nm and 470 nm.
Fluorescence analysis of these two peaks is potassium sorbate molecule conjugated π bond and non-bonding electron stimulated transitions caused by n , in accordance with its peak at 485 nm the fluorescence intensity with the concentration of (0.05 ~ 12 g / L ) non-linear variation of the concentration of potassium sorbate can be detected . further to fresh apple juice , for example, based on fluorescence spectroscopy to study the feasibility of potassium sorbate was detected in fresh apple juice mass concentration . [ 3 ]
Chemical properties
Combustible , fire exhaust fumes containing potassium spicy . Has a strong inhibitory effect of spoilage bacteria and fungi , and because of the low toxicity than other preservatives , it has become the world ‘s leading preservatives. Under acidic conditions, corrosion can give full play the role of a neutral role when low.
Cosmetic preservatives. An organic acid preservatives. Average amount of 0.5 %. May be mixed with sorbic acid . Although potassium sorbate soluble in water, easy to use, but its pH 1% solution is 7-8 , so there is a tendency to increase the pH of cosmetics , should be taken when using .
Content analysis:
After taking pre- dried sample 0.25g 105 ℃ 3h after ( accurate to 0.1mg). Add 250ml flask with a glass stopper , add 36ml of glacial acetic acid and acetic anhydride 4m1, warm make into a solution . Cooled to room temperature , add crystal violet test solution (TS-74) 2 drops of 0.1mol / L acetic acid solution through the blue-green endpoint titration to acid and to maintain 30s does not disappear. Meanwhile blank test , and make the necessary corrections. Each Ml0.1mol / L perchloric acid is equivalent potassium sorbate (C6H7KO2) 15.02mg.
Toxicity: Continue reading →