Views: 0 Author: Site Editor Publish Time: 2021-04-09 Origin: Site
The history of food preservation by natural means even predates the cultivation of crops. As early as 12,000 years ago, air-dried and sun-dried meat, fruits and vegetables began to appear in the Middle East. Salt has been used as a natural preservative for almost the same length of time. More and more food processors are choosing natural technologies and ingredients to extend shelf life-natural preservatives such as herbs and spices are beginning to be widely used-they can also provide food with color and flavor.
Food preservatives can be divided into two categories: natural preservatives and synthetic preservatives according to different sources. For a long time, due to the high cost of natural preservatives, they have not been widely used in food processing. However, synthetic preservatives represented by potassium sorbate and sodium benzoate are obtained in food processing because of their low price and good antiseptic effect. It is widely used. However, studies have found that some synthetic preservatives are carcinogenic, teratogenic and easy to cause food poisoning. For example, benzoate may cause food poisoning, and nitrite and nitrate may generate carcinogenic sub Nitramine. In addition, the current chemical preservatives have limited antibacterial ability, and poisoning events that lead to food deterioration due to antibacterial failure often occur. Natural preservatives have the incomparable advantages of synthetic preservatives, such as strong antibacterial, safe and non-toxic, good water solubility, good thermal stability, and wide range of action. Therefore, the development of efficient, safe and stable natural preservatives has become food science research One of the hot spots is that natural preservatives are not only harmless to human health, but also have certain nutritional value. With the deepening of research, more and more natural antibacterial substances have been revealed. According to the source of natural preservatives, they are divided into three categories: natural preservatives extracted from natural plants, natural preservatives derived from animals, and natural preservatives derived from microorganisms.
Briefly introduce the classification and mechanism of food preservatives and the types and research progress of natural food preservatives.
Food preservatives are food additives that can prevent spoilage caused by microorganisms and extend the shelf life of food. China's "Sanitary Standards for the Use of Food Additives" (GB2760-211) strictly stipulates the types of preservatives that can be used in food , Quality standards and additive dosage. Food preservatives are divided into fungicides and antibacterial agents according to their functions, and chemical preservatives and natural preservatives according to their sources.
It is generally believed that food preservatives can denature the protein of microorganisms and cause damage to substructures such as cell membranes and cell walls. Since these substructures are all necessary for bacteria, food preservatives can achieve the purpose of sterilization or antibacterial as long as they act on one of the substructures.
At present, the natural food preservatives used in food generally fall into three categories: direct extracts obtained from natural plants, engineered products obtained from microorganisms, and substances obtained from animal bodies. A large number of facts and literature reports prove that these extracts can effectively prevent the growth of pathogenic microorganisms and are ideal natural antibacterial and antiseptic materials.
Food preservatives are divided into natural preservatives and chemical synthetic preservatives. Because the cost of artificial chemical synthetic preservatives is much lower than that of natural food preservatives, and natural preservatives have the disadvantages of low potency, large dosage and short antibacterial effectiveness, the use of synthetic preservatives in food production has long been dominant. However, synthetic preservatives have certain toxicity, which is harmful to the human body and even have the risk of causing cancer. Natural preservatives have the advantages of strong antibacterial, safe and non-toxic, good water solubility, and wide range of action.
Related to natural preservatives are also acidic flavoring agents, food coating agents and stabilizers
