Sorbic Acid as a Preservative
L ‘ Sorbic acid (E200) is a natural organic compound, widely used as a preservative in the food industry for the absolute harmlessness. Particularly interesting are its antifungal properties, which make it commonly used in food products such as cheeses (to control the growth of mold and yeast on the rind), yogurt , lemonades, lemon juice , fruit juices , sauces , tomato sauce. , ketchup , dressings for salads , bread of rye, alcoholic and non-alcoholic flavored drinks, gnocchi , polenta , cakes, bakery products, wine and cider. In fact, sorbic acid is much more effective in slightly acidic foods than in neutral ones; its antifungal power is equal to that of benzoates , and even higher at pH between 4.0 and 6.0 (the undissociated form is therefore more active than the dissociated one). This feature enhances its antifungal properties, since molds, unlike bacteria , grow in an acidic environment and hardly grow on alkaline foods. Sorbic acid, very active on molds and yeasts, therefore manifests a synergistic action with thebenzoic acid , more active on bacteria. To maximize its effectiveness, it is important that the sorbic acid is added to hygienically flawless products, to prevent residual microorganisms from metabolizing it inactivating it.
Despite the moderate antibacterial properties of sorbic acid, especially at pH values below 4.5, lactic bacteria are resistant to its action; as we have seen, therefore, this additive is successfully used in yoghurt and in all products that undergo lactic fermentation. Another important advantage of sorbic acid is the absence of significant influences on the taste of food, even if in some sweet white wines it can react to give geraniol, with a not very inviting taste. In wine, sorbic acid is used as an anti-fermentative in partial replacement of sulfur dioxide , which has a strong antibacterial effect, but can reveal unpleasant odors and flavors on the palate .
At room temperature, sorbic acid appears as a white solid with a faint and characteristic odor; as shown in the figure, its chemical formula is C 6 H 8 O 2 .
In foods, sorbic acid is generally added as a salt of calcium , sodium and potassium ; we generally speak of “sorbates”, respectively indicated with the initials E201 ( Sodium sorbate ), E202 ( Potassium Sorbate ) and E203 ( Calcium Sorbate ). Sorbic acid is only slightly soluble in water (the solubility improves in the hot one) but completely soluble in alcohol; potassium sorbate, on the other hand, is very soluble in water, but slightly soluble in alcohol ; calcium sorbate is mainly used in dairy products .
In nature, sorbic acid is found in apples , plums and the fruits of the mountain ash ( Sorbus aucuparia ), from which another interesting additive with a sweetening and anti-aging power is obtained, sorbitol . Sorbic acid and sorbates are however industrially synthesized through various and different chemical processes; given the synthetic origin there are no dietary restrictions, therefore sorbic acid and its salts can be consumed by all religious groups, vegans and vegetarians .
In the body, sorbic acid is metabolized to carbon dioxide (CO 2 ) and water (H 2 O) with the same mechanism as fatty acids normally present in food. As a rule, therefore, there are no side effects at the concentrations used; only in a small percentage of individuals sorbic acid can trigger allergic reactions , while its contact with the skin produces urticaria supported by non-immunological mechanisms, due to a non-specific mast cell degranulation with histamine release (the same induced by the bites of nettle ).
Sorbic acid against Candida
Finally, the presence of sorbic acid and / or sorbates also in herbal products and in those intended for personal hygiene, in order to prolong their shelf-life , should be noted . In some forums it is recommended to use sorbic acid against candida ; in reality these are basically wrong advice, considering the slightly alkaline pH of the intestinal contents , but above all the body’s ability to absorb and metabolize this substance with extreme ease, preventing it from reaching the colon where its antifungal action is required; theoretically, the use of highly concentrated sorbic acid in capsules could be helpfulor controlled-release tablets. Another solution could be to take sorbic acid together with fiber supplements , such as psyllium seeds ; in this way the substance could be trapped inside the water and fiber gel, bypassing the absorption in the small intestine ; moreover, the soluble fiber tends to acidify the stool , amplifying the antifungal effect of sorbic acid and / or its salts. In this sense, therefore, the same discourse made for caprylic acid and its effectiveness against candida is valid .