In today's era of emphasizing food safety and quality, preservatives play a crucial role in the food industry, ensuring food freshness and extending shelf life. Among them, benzoic acid (CAS No. 65-85-0, molecular formula C7H6O2) holds a significant position in the field of food preservation due to its exceptional preservative properties. This article delves into the preservative mechanism of benzoic acid, revealing the mysteries of this food preservation technology.

ITEMS OF ANALYSIS	SPECIFICATION	RESULTS	testing method
APPEARANCE:	WHITE FLAKES	PASSED	IN HOUSE #PSB01
MELTING POINT:	121-123℃	122.3	GB/T 617
ASSAY (%):	99.50MIN	99.56	GC IN HOUSE #PSB02
LOSS ON DRYING (%):	0.1MAX	0.03	GB1901-2005
COLOR (HAZEN):	20MAX	18	GB/T 3143
HEAVY METAL (AS Pb) (PPM):	10MAX	2	IN HOUSE # PSB 04
CHLORIDE(AS Cl) (PPM):	200MAX	50	IN HOUSE # PSB 05
ARSENIC (AS AS) (PPM):	2MAX	2	IN HOUSE # PSB 06
HALOGEN, HALOGENIDE(PPM)	300MAX	200PPM	EN14582：2007
PHTHALIC ACID	PASSED	PASSED	EN14372：2004
RESUDUE ON IGNITION(%):	0.05MAX	0.03	GB 1901-2005

Benzoic acid, a common organic compound, is widely used in the field of food preservation. It not only effectively inhibits the growth and reproduction of microorganisms, thereby extending the shelf life of food, but also becomes the preferred preservative for many food manufacturers due to its harmlessness to humans. So, how does benzoic acid achieve its preservative function?
The preservative mechanism of benzoic acid primarily relies on its unique chemical properties. When benzoic acid is added to food, it can quickly penetrate the food tissue and form a dense protective film on the food surface. This protective film effectively blocks the invasion of external microorganisms, reducing the risk of food contamination. Additionally, benzoic acid can interfere with the permeability of microbial cell membranes, disrupting the metabolic balance within microbial cells, and thus inhibiting the growth and reproduction of microorganisms.
Apart from its exceptional preservative properties, benzoic acid boasts a wide range of applications. As a food preservative, it is widely used in the preservation and shelf life extension of various foods, such as pastries, beverages, and condiments. Furthermore, benzoic acid is an important raw material for the production of pesticides, dyes, pharmaceuticals, fragrances, mordants, and plasticizers, and it serves as a modifier for polyamide resins and alkyd resins, as well as an anti-rust inhibitor for steel equipment, demonstrating its diversified application value.
It is worth mentioning that the preservative effect of benzoic acid has not only been widely recognized, but its safety has also been thoroughly verified. Benzoic acid can be rapidly metabolized into harmless substances in the human body, posing no adverse effects on human health. Therefore, the use of benzoic acid as a food preservative is safe and reliable.
In summary, benzoic acid, with its unique preservative mechanism and wide range of applications, has become one of the indispensable preservatives in the food industry. It not only effectively extends the shelf life of food, ensuring food freshness and safety, but also wins the trust and praise of consumers due to its harmlessness to humans. In the future, with the continuous development of the food industry, benzoic acid is expected to play its unique preservative role in more fields, bringing more convenience and beauty to people's lives.