What Is an Anti-Microbial?

Food preservatives are additives that can prevent spoilage and deterioration caused by microorganisms and extend the shelf life of food. Because it has the function of preventing food poisoning caused by microbial reproduction, it is also called antimicrobial. Its main role is to inhibit the reproduction of microorganisms in food ^[1] .
Antiseptics generally refer to food preservatives

Chinese name: Food preservative
Foreign name: antimicrobial
Alias: Antimicrobial

Belongs to: additive
Often seen: Benzoic acid, sodium benzoate, potassium sorbate
Features: Strong antibacterial effect at low concentration

Food Preservatives Overview

Food preservatives have a continuous inhibitory effect on the growth of microorganisms whose metabolic substrate is putrefactive. The important thing is that it can inhibit the occurrence of the most prone to corruption in different situations, especially when the general sterilization is insufficient. Mineral oil, coal tar, and tannin for fiber and wood preservation, and formaldehyde, mercury, toluene, butyl p-hydroxybenzoate, nitrofuran derivative, or balsam resin for biological specimens. The use of preservatives in food is limited, so it often depends on physical methods such as drying and curing. Special preservatives include organic acids such as acetic acid, vegetable oils based on oleate, and essential oils such as mustard. For parts of the organism (such as the surface of the human body or the digestive tract), various preservatives (such as iodoform, phenyl salicylate, aniline dyes, or acridine-based pigments) can be used according to specific conditions.

Food preservatives are agents that inhibit material spoilage. That is, it has a continuous inhibitory effect on the growth of microorganisms using putrefactive substances as metabolic substrates. The important thing is that it can inhibit the most prone to corruption in different situations, especially when the general sterilization is insufficient.

There are different types of applications in various countries in the world, there are 50 kinds in the United States, and about 40 kinds in Japan. ^[2] Different bactericides have basically no bactericidal effect and only have the effect of inhibiting the growth of microorganisms. The toxicity is low and the flavor of food is basically not damaged. The method is relatively easy to grasp ^[2] .

There are 30 kinds of preservatives stipulated in China, such as benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, and calcium propionate.

Requirements for food preservatives

1) Stable in nature: it is effective for a certain period of time after being added to food, and has good stability in food;

2) Strong antibacterial effect at low concentration;

3) It should not have a pungent odor itself;

4) The role of digestive enzymes should not be hindered, and the role of beneficial bacteria in the intestine should not be affected;

5) Reasonable price and easy to use.

Mechanism of food preservatives

It can make the protein of microorganisms coagulate or denature, thus disturbing its growth and reproduction.

Preservatives have an effect on microbial cell walls and cell membranes. Due to the mechanism that can damage or damage the cell wall, or interfere with the synthesis of the cell wall, the intracellular material is leaked out, or the respiratory chain electron transfer system related to the membrane is affected, thereby having an antimicrobial effect.

It acts on the genetic material or genetic particle structure, and then affects the replication, transcription, and protein translation of genetic material.

Acts on the enzyme system of the microorganism, inhibits the activity of the enzyme, and interferes with its normal metabolism.

Food preservatives

Food preservatives are divided into fungicides and bacteriostatic agents according to their functions. The two are often difficult to distinguish due to differences in concentration, duration of action, and microbial properties. It can also be divided into organic chemical preservatives and inorganic chemical preservatives according to their properties. There is also nisin, a peptide antibiotic containing 34 amino acids produced by Streptococcus lactis. There are 28 varieties. Preservatives are divided into two categories: chemical preservatives and natural preservatives. Chemical preservatives are divided into organic preservatives and inorganic preservatives. The former mainly includes benzoic acid and sorbic acid, and the latter mainly includes sulfite and nitrite. Natural preservatives are usually extracted from metabolites of animals, plants and microorganisms. ^{[3] For} example, nisin is a peptide substance extracted from the metabolites of nisin. Peptides can be degraded into various amino acids in the body. The regulations on this kind of preservatives are different in different countries around the world. China There are regulations on the scope of use and the maximum permitted amount of nisin.

Types of food preservatives

Benzoic acid and salt: carbonated drinks, low-salt pickles, preserves, wine, fruit wine, fudge, soy sauce, vinegar, jams, fruit drinks, barreled thick fruit and vegetable juices for the food industry.

Potassium sorbate: In addition to the same as above, there are also fish, meat, eggs, poultry products, fresh fruits and vegetables, collagen casings, jelly, lactic acid bacteria drinks, cakes, fillings, bread, moon cakes, etc.

Sodium dehydroacetate: yuba, pickles, orange juice.

Propyl paraben: fruit and vegetable preservation, fruit drinks, jams, pastry traps, egg yolk traps, carbonated drinks, vinegar, soy sauce

Calcium propionate: raw and wet noodle products (cut noodles, crusts), bread, vinegar, soy sauce, pastries, soy products.

Sodium diacetate: in various pickles, flours and doughs.

Sodium lactate: grilled meat, ham, sausage, chicken and duck products and sauce products.

Streptococcus lactis: canned food, vegetable protein drinks, dairy products, meat products, etc.

Natamycin: cheese, meat, wine, fruit juice, tea, etc.

Hydrogen peroxide: raw milk preservation, dried tofu in bags

Food Preservatives Organic Chemical Preservatives

It mainly includes benzoic acid and its salts, sorbic acid and its salts, and esters of p-hydroxybenzoic acid. Benzoic acid and its salts, sorbic acid and its salts all have antibacterial effects through undissociated molecules. They all need to be converted into corresponding acids before they are effective, so they are called acid preservatives. They have certain bacteriostatic ability against molds, yeasts and bacteria under acidic conditions. They are often used for the preservation of foods such as fruit juices, beverages, canned food, soy sauce and vinegar. In addition, propionic acid and its salts are particularly effective in inhibiting bacteria that cause the production of filamentous goo, and have high safety.

Food preservatives, inorganic chemical preservatives

It mainly includes sulfur dioxide, sulfite and nitrite. Nitrite can inhibit Clostridium botulinum and prevent botulism, but it is mainly used as a colorant. Sulfite can inhibit the enzymes required for certain microbial activities, and has the characteristics of acid preservatives, but it is mainly used as a bleaching agent. Fungicides are rarely added directly to food.

Food Preservatives Precautions

The effect of preservatives is not absolute. It only has the effect of extending the storage period of certain foods within a certain limit, and its preservative effect is different according to the change of environmental pH. In addition, preservatives must be used according to the addition standard. Arbitrary abuse ^[4] .

As with all types of food additives, preservatives must be added strictly in accordance with China's "Sanitary Standards for the Use of Food Additives" and must not be used beyond standards. There are many problems in preservatives in practical applications, for example: the preservative effect is not achieved and the flavor of food is affected

Food preservative And quality, such as when tea polyphenols are used as preservatives, excessive concentrations can make people feel bitter and astringent, and they can also cause food to change color due to oxidation.

In the production and processing of food, due to the different types, properties, scope of use, price and toxicity of preservatives, the following points should be noted before reasonable use.

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

2. To understand the toxicity and range of use of various preservatives, and add it in accordance with the safe amount and range of use. For example, sodium benzoate, because of its strong toxicity, has been banned in some countries, and China has also strictly determined that it can only be used in sauces, jams, pickles, canned foods and some wines.

3. You should understand the effective use of various types of preservatives. Acidic preservatives can only be used in acidic environments and have a strong and effective preservative effect, but they have little effect in neutral or alkaline environments, such as sorbic acid. Potassium, sodium benzoate, etc., but the paraben esters in the ester preservative can also be used at pH 4-8, and the effect is also good.

4. You should understand the types of microorganisms that can be inhibited by various preservatives. Some preservatives have effects on molds and some have effects on yeasts. Only by mastering this characteristic of preservatives, you can prescribe the right medicine, and generally have a mixed form. Many comprehensive antiseptic and fresh preservation products, such as Jianying Anticorrosive King and antifungal preservatives and other products.

5. According to the different types of food processing technology, factors such as the price and solubility of preservatives, and whether they affect the flavor of the food should be considered, and the advantages and disadvantages should be combined, and then added and used flexibly.

Food preservatives

In fact, the food additives allowed by national laws are subject to strict safety evaluation. Ordinary people can eat it reasonably within the correct range and amount of use, and its safety can be completely guaranteed. As for the large-scale food safety issues that have caused public concern in the past, it is because the hygiene standards in the food production process have not been effectively implemented, or the use of food additives in accordance with regulations has not been a "crime" of the preservatives themselves.

Food Preservatives Taboo

Finally, a special point must be mentioned: children, pregnant women and other sensitive people who are in a special period of physical development should not eat foods that use excessive preservatives.

Misunderstanding of food preservatives

Don't deliberately pursue preservative-free products

Consumers can see a lot of foods marked "preservative-free" in the market, including fruit juice drinks, tea drinks, canned products, condiments, candied dried fruit products, instant noodles, etc. Most brands have marked " "This product does not contain preservatives", "This product does not add any food preservatives" and other words. Most consumers also consider foods labeled "preservative-free" to be safer, and prefer to buy "preservative-free" foods.

However, statistics show that many food safety problems can be said to be caused to some extent by the lack of preservatives. At the same time, according to relevant personnel of the State Bureau of Quality and Technical Supervision.

The use of preservatives in accordance with national standards is a guarantee of food safety. As long as the preservatives listed in the "Food Ingredients and Additives Catalogue" are added in accordance with national standards, it is not harmful to the body. Consumers should not be too superstitious "No Contains preservatives. " ^[3]

The first is to move from higher toxicity to lower toxicity and safety. The core of human progress is health and harmony. As people's health requirements increase, food safety standards are becoming more stringent. While governments are rapidly revising food safety standards to improve food safety and national health, they also protect their food industries through "green barriers" and reduce the impact of foreign food on their food industries.

Food Preservatives Trend 2

The second is the development from chemically synthesized food preservatives to natural food preservatives. In view of the safety and other deficiencies of chemically synthesized food preservatives, humans are exploring safer and more convenient natural food preservatives. Such as microbial streptococci, natamycin, monascus, etc .; animal-derived lysozyme, chitosan, protamine, propolis, etc .; plant-derived agar oligosaccharides, eucomtin, and spices , Clove, ume extract, etc .; R-polysaccharides of microbial, animal and plant composite sources.

Food Preservative Trend Three

The third is to develop from a single antiseptic to a broad-spectrum antiseptic. Their bacteriostatic range is relatively narrow. Some have an inhibitory effect on fungi and have no effect on bacteria; some have inhibitory effects on only a few microorganisms. Therefore, most food manufacturers add a variety of preservatives to achieve the purpose of preservation. People are eager to use a single food preservative in a broad sense that can both kill bacteria and inhibit bacteria. Broad-spectrum preservatives will become one of the research directions in the industry.

Food Preservative Trend 4

The fourth is to develop from the harsh use environment to the convenience of use. Some are sensitive to food pH, heating temperature, etc .; some have poor water solubility; some have a bad smell; some cause food to fade, etc. The development trend should be food preservatives that do not have strict requirements on the food production environment.

Food Preservatives Trend Five

Fifth, the higher price of natural food preservatives is developing towards lower prices. Natural food preservatives are non-toxic and harmless and expensive. Most food manufacturers are unbearable, such as lysozyme, nisin, natamycin, protamine and so on. Significantly reducing the cost of natural food preservatives is one of the prerequisites for widespread application of natural food preservatives.