How to use food preservatives?

Food preservative is an additive that can prevent corruption and deterioration caused by microorganisms and prolong the shelf life of food. because it also has the effect of preventing food poisoning caused by microbial reproduction, it is also called anti-microbial agent. the main function is to inhibit the reproduction of microorganisms in food. common are benzoic acid, sodium benzoate, potassium sorbate and so on. Let's take a look at how to use food preservatives.

Action mechanism of food preservatives

1. Food preservatives can coagulate or denature the protein of microorganisms, thus interfering with their growth and reproduction.

2. Food preservatives have an effect on microbial cell wall and cell membrane, which can destroy or damage cell wall or interfere with the mechanism of cell wall synthesis, resulting in the leakage of intracellular substances or affecting the respiratory chain electron transport system related to the membrane. thus it has the effect of antimicrobial.

3. Food preservatives act on genetic material or genetic particle structure, which in turn affects the replication, transcription and protein translation of genetic material.

4. Food preservatives act on the enzyme system of microorganisms, inhibit the activity of enzymes and interfere with their normal metabolism.

How to use food preservatives?

1. Ph value and water activity: in water, some preservatives are in ionization equilibrium, such as acid preservatives, whose antiseptic particles mainly rely on unionized acids. This kind of preservatives have a good effect when the pH value is low. The activity of water is high, which is beneficial to the growth of bacteria and mold. Generally, the activity of water for bacteria is more than 0.9, and that of mold is less than 0.7. Reducing the activity of water is beneficial to the antiseptic effect of preservatives.

2. combined use of preservatives: all kinds of preservatives have a certain range of effects, no preservatives can inhibit all corrupt microorganisms, and many microorganisms may also produce drug resistance, so preservatives with different ranges of action should be used together. The combined use of preservatives may have three effects, one is synergistic or synergistic effect, the other is increasing or additive effect, and the other is antagonistic effect.

3. Preservative use time: the effect of the same preservative may be different due to different occasion and time. We must first ensure that the food itself is in good sanitary conditions, and put the time of addition of preservatives in the induction period of bacteria. If the proliferation of bacteria enters the logarithmic phase, the effect of preservatives is not good. Preservatives are generally added early, with good effect and low dosage. The more serious the infection of food is, the worse the effect of preservatives is. If the food has gone bad, any preservatives are irreversible.

4. the influence of food composition: the function of preservatives is affected by the raw materials and ingredients of food, such as flavor agents, flavors and emulsifiers in food, salt, sugar and ethanol can reduce the activity of water. Some ingredients in food react with preservatives, which may invalidate some or all of the preservatives and be decomposed by microorganisms in the food. Sorbic acid can be reduced to sorbitol by lactic acid bacteria. It can be used as its carbon source.

Matters needing attention in the use of food preservatives

1. Before adding preservatives, we should ensure that the food is sterilized completely and there should not be a large number of organisms, otherwise the addition of preservatives will not have an ideal effect. Such as potassium sorbate, not only will not play the role of anticorrosion, but will become a nutritional source of microbial reproduction.

2. The toxicity and scope of use of all kinds of preservatives should be understood and added according to the safe dosage and scope of use. For example, sodium benzoate, because of its strong toxicity, has been banned in some countries, while China has strictly determined that it can only be used in sauces, jams, pickles, canned foods and some alcoholic drinks.

3. We should understand the effective use environment of all kinds of preservatives. Acidic preservatives can only be used in acidic environment, but not in neutral or alkaline environment, such as potassium sorbate, sodium benzoate and so on. Nipagin esters in ester preservatives can also be used between pH4~8, and the effect is good.

4. We should understand the types of microorganisms that can be inhibited by all kinds of preservatives. Some preservatives have an effect on mold and some have an effect on yeast. Only by mastering this characteristic of preservatives, we can prescribe the right medicine to the case. Generally, there are many products that have been compounded to carry out comprehensive preservation and preservation, such as King of Anti-decay and Anti-mildew preservative.

5. According to the difference of all kinds of food processing technology, we should consider the price and solubility of preservatives, as well as the influence on food flavor and other factors, synthesize their advantages and disadvantages, and then add them flexibly.