More and more people like to buy food with "preservative-free" marked on the food packaging. Among various types of food additives, food preservatives can be said to be the category that consumers have the most misunderstandings about. Due to lack of knowledge and certain misunderstandings, some consumers equate food preservatives with "poisonous and harmful" and regard preservatives in food as a major safety hazard in food. But are foods labeled “preservative-free” necessarily safe? Are foods labeled as containing preservatives necessarily harmful to health? Let us have a comprehensive understanding of food preservatives, and everyone will know the correct answer.
1. Why are food preservatives used in food?
In the general natural environment, food will lose its original nutritional value, tissue properties, color, aroma and taste due to the action of microorganisms, and become food that does not meet hygienic requirements. Food preservatives refer to chemically synthesized substances or natural substances added to food for the needs of food preservation, food processing, storage and transportation. It can prevent food from spoilage caused by microorganisms and ensure that food has a certain shelf life in a normal natural environment.
In modern food processing, only with considerable food preservation capabilities can it be possible to meet the needs of consumers. Therefore, appropriate preservative techniques must be used for food. The purpose of food preservatives, broadly speaking, is to reduce and avoid food poisoning in humans. In a narrow sense, it is one of the effective measures to prevent food spoilage by preventing the action of microorganisms.
2. Why can food preservatives prevent corrosion?
Traditional research believes that the mechanism of action of food preservatives is mainly manifested in the following three aspects:
1. Acts on the cell wall and cell membrane system;
2. Act on genetic material or genetic particle structure;
3. Act on enzymes or functional proteins.
In recent years, further research has found that preservatives mainly inhibit the respiration of microorganisms, and the antibacterial efficacy of different antibacterial agents also varies. At present, the preservative mechanism of food preservatives is still under study.
3. What are food preservatives?
Food preservatives are classified as Category 17 in my country, with 28 varieties. Preservatives are divided into two categories according to their sources: chemical preservatives and natural preservatives. Chemical preservatives are further divided into organic preservatives and inorganic preservatives. The former mainly includes benzoic acid and sorbic acidetc., the latter mainly includes sulfites and nitrites. Natural preservatives are usually extracted from metabolites of animals, plants and microorganisms. For example, nisin is a polypeptide substance extracted from the metabolite of nisin. The peptide can be degraded into various amino acids in the body. Countries around the world have different regulations on this preservative. Our country has different regulations on nisin. Bacteriocins have regulations on their scope of use and maximum allowable dosage.
IV. What issues should be paid attention to when using food preservatives?
Like all kinds of food additives, preservatives must be added in strict accordance with my country's "Hygienic Standards for the Use of Food Additives" and cannot be used beyond the standard. There are many problems in the practical application of preservatives, such as failing to achieve the preservative effect and affecting the flavor and quality of food. For example, when tea polyphenols are used as preservatives, too high a concentration will make people feel bitter and astringent, and will also cause oxidation. And cause food to change color.
Since most of the preservatives currently used are synthetic chemical preservatives, excessive use will cause certain damage to the human body. Therefore, our country has strict regulations on the use of preservatives, and it is clear that their use should meet the following standards:
1. Reasonable use is not harmful to human health;
2. Does not affect the digestive tract flora;
3. Can be degraded into normal components of food in the digestive tract;
4. Does not affect the use of drugs, especially antibiotics;
5. No harmful components are produced during heat treatment of food.
Currently, many foods on the market only promote “preservative-free” as a selling point. This misleads consumers to a certain extent and causes consumers to fear food preservatives.
Consumers can see many foods labeled "preservative-free" on the market, including juice drinks, tea drinks, canned products, condiments, candied dried fruit products, instant noodles, etc. Most brands are marked with "preservative-free" on the outer packaging. This product does not contain preservatives", "This product does not add any food preservatives" and other words. Most consumers also believe that foods labeled “preservative-free” are safer and should give priority to purchasing “preservative-free” foods.
However, statistics show that many food safety problems are caused by food spoilage, which to a certain extent can be said to be caused by the failure to add preservatives as required. At the same time, according to relevant personnel from the State Administration of Quality and Technical Supervision, many foods currently on the market labeled "preservative-free" still contain a certain amount of preservatives.
According to countryThe use of preservatives according to national standards is a guarantee for food safety. For preservatives listed in the "Catalogue of Food Raw Materials and Additives", as long as they are added according to national standards, they will not be harmful to the body. Therefore, everyone should not be overly superstitious about "contains-free" preservative". As long as you understand science and are not blind, you will definitely be able to eat healthily and eat beautifully!