Preservative is known as an antiseptic. It is a kind of food additives to maintain the original characteristics and nutritional value. Preservative is a additives which means to inhibit microbial activity, prevent food spoilage to extend the shelf life. Depending on its different role, it can be broken down as preservatives, disinfectants, fungicides, preservation agent. According to sources from the antiseptic effect of substances, preservatives are generally divided into acid preservative, preservative ester, inorganic and biological preservatives four categories.

Agents commonly used preservatives are parabens, benzoic acid, sodium benzoate, ethanol, sorbic acid, anti-corrosion agent for oral administration. Topical antiseptic agent include chlorobutanol, phenol and cresol. The preservative effectiveness relationship with pH value greatly. Parabens and preservatives benzoic acid in acidic preservative efficacy under strong alkaline fall. Various preservatives which are effective inhibitory concentration cannot be lower than this concentration when used. The amount of preservative also cannot be too large to prevent harmful.

Preservatives in our food additives health standards set forth in benzoic acid and its salts, sorbic acid and its salts, parabens, propionic acid salts, dehydroacetic acid, and also in the food industry with other uses of sulfur dioxide and coke sulfites. In addition, some both as a preservative and as a condiment traditionally use, harmless to human body, such as salt, sugar, vinegar, wine or spices are not included in the statutory preservatives, food additives standard in the country have not been controlled. It said preservative can only control low levels of pollution, insufficient to control high levels of pollution, therefore, we must reduce moisture in foods, pay attention to production hygiene and good packaging.