Sorbic acid has sorbic acid, potassium sorbate and calcium sorbate three varieties. Sorbic acid is insoluble in water. It must be dissolved in ethanol or potassium hydrogen sulfate before use. It is inconvenient and irritating when used, so it is generally not used. Calcium sorbate FAO/WHO stipulates that its use range is small, so it is also not often used; potassium sorbate has no disadvantages, is easy to dissolve in water, and has a wide range of uses. We can often see it in some beverages, preserved fruits, canned foods, etc. Here I will focus on potassium sorbate: It is unsaturated hexacarbonic acid; the potassium sorbate sold in the market is white or light yellow granules, the content is 98%–102%; no odor, or slightly odor, easy to absorb moisture, easy to oxidize and turn brown It is stable to light and heat, the relative density is 1.363, the melting point is decomposed at 270 °C, and the pH of its 1% solution is 7-8. Potassium sorbate is an acidic preservative, which has high antibacterial property and inhibits the growth and reproduction of mold; it mainly inhibits the growth and antiseptic effect of microorganisms by inhibiting the dehydrogenase system in microorganisms, against bacteria, mold, Yeast has inhibitory effect; its effect is weakened with the increase of PH. When the pH reaches 3, the bacteriostatic peak reaches the peak. When the pH reaches 6, the antibacterial ability remains, but the minimum concentration (MIC) can not be lower than 0.2%. It is proved that PH: 3.2 is impregnated with potassium sorbate solution of pH 2.4, and the storage period of non-sterilized food is 2-4 times shorter.
The three mechanisms of action of sorbic acid, potassium sorbate and calcium sorbate are the same, the toxicity is smaller than that of benzoic acid and paraben, the daily allowance is 25mg/Kg, the benzoic acid is 5 times, and the paraben is 2.5. It is a relatively safe food preservative; it can be used in soy sauce, vinegar, noodle sauce, jam, pickles, canned foods and some alcoholic beverages.