Last updated on April 28, 2023
It is necessary to consider the preservatives of food from two different perspectives. The first is to protect the food from microbial activities; prevent microbial spoilage and prevent the food from becoming microbially unsuitable for health.
The second is that to prevent food loses its freshness over time due to its nature, apart from microorganism activities; it should be considered as delaying or preventing the loss of its structure, appearance, nutritional and flavor characteristics.
Foods that do not add preservatives -especially have a high water content- will, by their very nature, lose their characteristic features after a very short time.
There is a prolongation of the shelf life of sterilized products such as canned and UHT milk without preservatives and these products also become unconsumable after sufficient time. Likewise, drying products only prolongs their shelf life. Whatever it is, it is inevitable for the food to lose its characteristics and deteriorate .
In this context, the fact that consumers demand that the food they buy always be fresh, healthy and have all the characteristics expected from that food, regardless of how far it comes from and how long it stays on the shelf, complicates the situation for producers.
Of course, it is very difficult for a product put on the shelf to still maintain its first day’s freshness and appearance throughout its shelf life (1 month for some food, 12 months for some food).
Ensuring this has made it necessary to use preservatives in the food industry. However, nowadays public health concerns against preservatives cause society to distance itself from preservative food additives. As a result, there has been a paradox between the demanded product (fresh and with all the characteristics of food) and health expectations.
Adding antimicrobial preservatives to food provides the advantage of preventing microbial growth in the product even after the package has been opened. After unpacking, foods are exposed to microorganisms from a wide variety of vectors.
Most simply, after the product is opened, microorganisms in the air fall onto the open food and can develop rapidly in a rich nutrient environment. The addition of antimicrobial preservatives to the food also prevents the problems that may be caused by microorganisms in the process after the packaging of the food is opened.
The most used preservatives are ascorbic acid (vitamin C, E 300), tocopherols (vitamin E; alpha-tocopherol (E 307), gamma-tocopherol (E 308), delta-tocopherol (E 309), citric acid (E 330), sodium benzoate (E 211), calcium propionate (E 282), sodium erythorbate (E 316), sodium nitrite (E 250), sodium nitrate (E 251), potassium sorbate (E 202), BHA (E 320), BHT (E 321), EDTA (E 385), nisin (E 234) and natamycin (E 235).
It has been mentioned before those preservative food additives are used for two different purposes. Additives such as sodium nitrite, sodium nitrate, nisin and natamycin are used to prevent microbial spoilage of food.
Ascorbic acid, tocopherols, BHA, BHT and EDTA are generally used to prevent food from being chemically spoiled due to their nature. These compounds act as antioxidants. Antioxidants can prevent oxidation in food, preventing discoloration and bitter taste.
Nitrate and nitrite are used in industrial meat products to prevent the growth of Clostridium botulinum bacteria. Sulfur dioxide and sulfide are used to inhibit microorganisms that cause spoilage in dried fruits, fruit juices and wines.
Nisin and natamycin are antibiotics produced by microorganisms. While nisin prevents the growth of some bacteria, natamycin has a protective effect against molds and yeasts.
In addition to the protective additives used today, which have been used until recently; However, there are also protective additives that are currently banned. However, while some food preservatives are banned in some countries, they may be free in others.
For example, while the use of BHA (E 320) and BHT (E 321) in food and beverages is prohibited by the United Kingdom, European Union, Japan and other countries, it is free of use in America and Turkey. Calcium sorbate (E 203) can be given as an example of an additive that is banned in Turkey.
Mold etc. on the Food You Bought; Possible Causes
Today, most consumers demand that the product they buy is both fresh, sound and does not contain any preservatives. Naturally, when they observe the growth of microorganisms in a product such as yogurt, cheese, juice, etc. they buy, they naturally complain about the manufacturer.
It is useful to pay attention to the following detail here; Microorganism growth in the product in question can be caused by three different reasons;
1. The pasteurization or commercial sterilization process may not have been applied effectively during the production phase of the product. In this case, a similar problem can be observed in all batch products coming out of that production. The firm is at fault in this scenario.
2. There may be microbial contamination in the product or at any stage of the production process. Depending on the degree of contamination, microbial growth can be observed in a single product or some or all of the products produced. The firm is at fault in also this scenario.
3. Even if the pasteurization or commercial sterilization process is applied effectively and contamination is completely avoided, there may be microorganisms that survive the heat treatment and these surviving microorganisms can grow in the product.
As is known, pasteurization and commercial sterilization do not guarantee the destruction of all microorganisms contained in the food. In these processes, not all microorganisms in the raw material can be killed; however, it is stated that microorganism inhibition is provided at varying rates such as 99.9% or 99.999% depending on the effectiveness of the process (this rate varies according to the norm and efficiency of the process).
The expression “99.999% inhibition achieved” means: “If there are 100,000 microorganisms in the raw material, 99.999 of these bacteria were killed by heat treatment and only 1 living microorganism remained”.
That microorganism will enter one of the products produced in that batch and will develop in that product. In this scenario, the company is not at fault; but the consumer is on his unlucky day that day. He chose the unlucky product from a large batch of solid and trouble-free products.
Through these scenarios, the consumer should know that; A company in which microorganism growth is observed in its products means that it does not use antimicrobial preservative food additives in its products.
The company could have covered this faulty production both by making faulty production and by using protective food additives. In this way, it could both offer low-quality products and disregard consumer health.
Or, it could have ensured the durability of all its products by using antimicrobial preservatives and preventing the deterioration of the products in which the microorganisms that survived the heat treatment will develop. In this way, the company could have maintained its perception at a high level.
As a matter of fact, today, a consumer can affect the perception of millions on the company by bringing up the defective product he has bought on social media. In fact, no company wants to damage the brand perception in the eyes of millions of consumers because of a product.
Companies with microbial growth in their products may or may not be producing faulty products; this situation needs to be investigated, but it is clear that he does not use antimicrobial preservatives. Thus, it is evident that it takes public health concerns into account. However, products with observed microorganism growth should never be consumed and should be returned.
 As an exception, honey can preserve its natural state for quite a long time without spoiling. Theoretically, it can be preserved for up to 500 years without spoiling. It should be protected from sunlight and moisture during storage; It should be protected to prevent any foreign matter or water from entering.
 Researchers state that the microbial load in the air has decreased today compared to the past and that air quality has made great progress in the last 20 years in terms of microbial. This means that food left uncovered may spoil after a longer time than in the past. Although there is an improvement in air quality such as a decrease in the microorganism load, there are still microorganisms in the air and these microorganisms fall into the uncovered food. To protect the food against microorganisms that can be transmitted from the air, it is necessary to keep it covered at all times. On the other hand, landing flying insects like flies into the food or falling into the food is prevented by covering the food.