Preservatives

A preservative is a substance that is added to foods to prevent decomposition by microbial growth or by undesirable chemical changes according to the Food and Agricultural Organization (FAO) and the World Health Organization (WHO) Joint Food Rules Committee. Preservatives are used to increase the shelf-life of a food product while retaining its nutritional value. Artificial preservatives decrease microbial spoilage, reduce the risk of foodborne infections, and keep the food fresh and nutritious.

Figure 1. Antimicrobial mechanisms of natural preservatives. AMPs, antimicrobial peptides; pAMPs, plant antimicrobial peptides.

Depending upon the purpose of their usage in the food products, preservatives can be categorized into three types:

• Anti-microbials: They delay or destroy the growth of bacteria, yeast and molds. This method is the most traditional type of preserving, such as pickling and adding honey to prevent microorganism growth by modifying the pH level. For example, nitrites and nitrates prevent botulism in meat products. Sulfur dioxide prevents further degradation in fruits, wine and beer. Benzoates and sorbates are antifungals used in jams, salads, cheese and pickles.
• Anti-oxidants: They can slow or stop the breakdown of fats and oils. Fats are particularly prone to oxidation and they quickly turn rancid upon coming in contact with oxygen. Oxidation can be prevented by adding antioxidants as preservatives. Examples of anti-oxidants include tertiary butylhydroquinone (TBHQ), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and propyl gallate.
• Anti-enzymatic preservatives: They can block the enzymatic processes, For example, enzyme phenolase can lead to a brown color on the exposed surface of cut potato or fruits and citric acidand erythorbic acid can stop the action of enzyme phenolase.

Preservative must be added to foods in small quantities, and cannot be served as food. The usage of preservative needs to be tightly controlled as excessive usage can be harmful to human health. However, some food producers use preservatives improperly for the pursuit of food appearance and storage, which makes tests on preservative necessary to ensure food safety.

Preservatives Test at Alfa Chemistry

With long-standing experience in food additives test, Alfa Chemistry can offer food preservatives test services to detect and quantify most preservative and banned food additives with high sensitivity and efficiency in accordance with the WHO standard for food additive limits. The test of methods includes but is not limited:
1.Gas Chromatography (GC)
2.Gas Chromatography-Mass Spectrometry (GC-MS/MS)
3.Liquid Chromatography (LC)
4.Liquid Chromatography-Mass Spectrometry (LC-MS/MS)
5.High Performance Liquid Chromatography (HPLC)

The following table shows the type of food preservatives used, the type of food products they are used in. E numbers are codes for substances that are permitted to be used as food additives for use within the European Union and the European Free Trade Association (EFTA).

Table1. The preservatives can be tested at Alfa Chemistry.

At Alfa Chemistry, our laboratory has state-of-the-art instrumentation to analyze preservatives in food products. We also provide consultation on labeling requirements concerning preservatives for packaged food products. Based on professional knowledge and experienced staff, Alfa Chemistry provides a wide range of information about preservatives. Our ordering procedure is as follows. If you have any questions or specific needs, do not hesitate to contact us.

References:
1.Angiolillo, L; et al. Food Additives: Natural Preservatives. Encyclopedia of Food Safety. 2014;2:474 - 476.
2.Lee, N.K.; Paik, H.D. Status, Antimicrobial Mechanism, and Regulation of Natural Preservatives in Livestock Food Systems. Korean Society for Food Science of Animal Resources. 2016, 36 (4): 547-557.