[Required Knowledge] Of Common Preservatives
Jun 30, 2020
NO.1 Sorbic acid and its potassium salt
Sorbic acid is a colorless needle-like crystal or white crystal powder, odorless or slightly pungent odor, good light and heat resistance, but it is easy to be oxidized and discolored when exposed to the air for a long time, and it is difficult to dissolve in water, so it is generally easy to use Potassium salt soluble in water. Sorbic acid and its potassium salt have a broad antibacterial spectrum, and can be used in almost all foods with a pH value below 6.0. It is the most widely used acidic preservative. Sorbic acid and its potassium salt can effectively inhibit mold, yeast and aerobic bacteria, but it is almost ineffective against aerobic bacteria. Its toxicity is far lower than other preservatives, and its antiseptic effect is stronger than sodium benzoate and calcium propionate. However, sorbic acid and its potassium salt may become a source of nutrients for microorganisms in heavily polluted products, which will promote pollution. Limitation for use: The content of sorbic acid in bread, pastry and bakery fillings and surface slurry products shall not exceed 1g/kg.
Antiseptic mechanism: Sorbic acid combines with the sulfhydryl group in the microbial mold system to destroy many important enzymes of the microorganisms, thereby inhibiting the function of the growth of microorganisms. In addition, it can also interfere with transmission skills, such as the transmission of cytochrome C to oxygen and the transmission of energy on the surface of cell membranes, thereby inhibiting the proliferation of microorganisms and achieving the purpose of preservation.
NO.2 Propionic acid and its sodium and calcium salts
Propionic acid is a colorless, oily, clear liquid with a peculiar smell and a slightly spicy pungent oily rancidity. Propionate sodium salt and calcium salt are white powders with good water solubility, stable to light and heat, and smell similar to propionic acid. Both propionic acid and propionate are easily absorbed by the human body and participate in the normal metabolic process of the human body. There is no harmful effect, but the antibacterial effect is not as strong as sorbic acid and benzoic acid. Propionic acid and salts have a good anti-mold effect, have little inhibitory effect on bacteria, and have no inhibitory effect on yeast, so they are often used in cakes, bread and cheese. Calcium salt cannot be used together with the leavening agent sodium bicarbonate to generate insoluble salts to reduce the production of CO2. The alkalinity of the sodium salt will delay the fermentation of the dough, so sodium propionate is commonly used in pastry, and calcium propionate is commonly used in bread. Use limit: the content of propionic acid in bread and pastry products shall not exceed 2.5g/kg.
Antiseptic mechanism: Propionic acid and its sodium salt and calcium salt are acid-type preservatives, and the main antiseptic effect is undissociated propionic acid. Propionic acid is a monocarboxylic acid, which inhibits the synthesis of β-alanine by microorganisms and plays an antibacterial effect.
The use of food additives should meet the following basic requirements:
(1) Should not cause any health hazards to the human body;
(2) The spoilage and deterioration of food should not be covered up;
(3) Food additives should not be used to conceal the quality defects in the food itself or in the process of processing, or use food additives for the purpose of adulteration, adulteration, or forgery;
(4) The nutritional value of the food itself should not be reduced;
(5) On the premise of achieving the expected results, reduce the amount of food used as much as possible.
Important hint:
The above preservatives belong to the food additives in the table A.1, and the food additives with the same function (the same color and coloring agent, preservatives, antioxidants) listed in the table A.1 are used in combination, and their respective dosages account for their maximum usage The sum of the ratios should not exceed 1.
While using preservatives, the amount of yeast also needs to be increased.
