Preservatives are a class of food additives that can inhibit microbial activity and prevent food spoilage. To make food have a certain storage period, certain measures must be taken to prevent microbial infection and reproduction. Practice has proved that the use of preservatives is one of the most economical, effective and easiest ways to achieve the above goals. The prescribed preservatives include 25 kinds of benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, and calcium propionate.
The article contains the following three points:
1. What is the antiseptic principle of preservatives?
2. What are the commonly used preservatives?
3. The development trend of preservatives
What is the antiseptic principle of preservatives?
1. Interfering with the enzyme system of microorganisms, destroying their normal metabolism and inhibiting the activity of enzymes.
2. Coagulate and denature the protein of microorganisms, interfering with their survival and reproduction.
3. Change the permeability of the cell plasma membrane, inhibit the elimination of enzymes and metabolites in the body, and lead to their inactivation.
What are the commonly used preservatives?
1. Benzoic acid and its salts
White granule or crystalline powder, odorless or slightly benzoin smell. The optimum pH for anti-corrosion is 2.5-4.0. In products above PH5.0, the bactericidal effect is not very ideal. Because its safety is only equivalent to 1/40 of potassium sorbate, Japan has completely banned its application in food.
2. Sorbic acid and its salts
White crystalline powder or light yellow crystalline powder or scaly. Potassium sorbate is an acid preservative with high antibacterial performance and inhibits the growth and reproduction of mold. It mainly inhibits the dehydrogenase system in microorganisms, so as to inhibit microorganisms and play a role in antisepsis. It has inhibitory effect on bacteria, mold and yeast. The antiseptic effect is significantly higher than that of benzoic acid, which is 5-10 times that of benzoate.
It is mainly divided into three types: sorbic acid, potassium sorbate and calcium sorbate. Sorbic acid is insoluble in water, it must be dissolved in ethanol or potassium bisulfate before use. It is inconvenient and irritating to use, so it is generally not commonly used. Calcium sorbate FAO/WHO stipulates that its scope of use is small, so it is not often used. Potassium sorbate does not have their disadvantages. It is easily soluble in water and has a wide range of applications. It can often be seen in some beverages, preserved fruits, canned foods and other foods.
3. Dehydroacetic acid and sodium salts
Dehydroacetic acid and its sodium salt are white or light yellow crystalline powder, stable to light and heat, degraded into acetic acid in aqueous solution, and non-toxic to human body. It is a broad-spectrum preservative, which has a strong inhibitory effect on bacteria, molds and yeasts in food. Widely used in antiseptic preservation of meat, fish, vegetables, fruits, beverages, pastries, etc.
4. Calcium propionate
White crystalline granules or powder, odorless or slightly smelling of propionic acid, stable to light and heat, easily soluble in water. Propionic acid is a product of the oxidation of amino acids and fatty acids in the human body, so calcium propionate is a very safe preservative. It has inhibitory effect on mold, has little inhibitory effect on bacteria, and has no effect on yeast. It is often used in the fermentation of noodle products and the prevention of mildew in cheese products.
5. Sodium Lactate
Colorless or yellowish transparent liquid, no peculiar smell, slightly salty and bitter taste, miscible in water, ethanol, glycerin. The general concentration is 60%-80%, and the maximum use limit of 60% concentration is 30g/KG. Sodium lactate is a new type of antiseptic and preservative, which is mainly used in meat and poultry products, and has a strong inhibitory effect on meat food bacteria. Such as Escherichia coli, Clostridium botulinum, Listeria and so on. Through the inhibition of food pathogenic bacteria, thereby enhancing food safety. Enhance and improve the flavor of meat and extend the shelf life. Sodium lactate has good dispersibility in raw meat, and has good adsorption to water, so as to effectively prevent dehydration of raw meat and achieve freshness and moisture retention. It is mainly suitable for barbecue, ham, sausage, chicken, duck and poultry products, and sauce and marinated products, etc.
The development trend of preservatives
At present, although natural preservatives cannot completely replace chemical preservatives due to reasons such as antibacterial effect, stability, and price. The composite preservative based on this is still under development. However, natural preservatives are developing rapidly in the fields of food and medicine due to their incomparable unique advantages such as strong antibacterial properties, safety and non-toxicity, good thermal stability, and wide range of action. It can be predicted that natural preservatives and compound preservatives will be the main development direction of preservatives in the future, and will replace chemical preservatives into our lives.