Ethoxyquin ban in the EU: Are there viable alternatives?

by Kristin Hals and Sofia Helena Lindahl, Research and Development Department, Borregaard AS

Ethoxyquin has, for decades, been widely used as an antioxidant in the feed sector, primarily in the marine industry.

This antioxidant inhibits the oxidation of highly unsaturated fatty acids in fishmeal and fish silage. Ethoxyquin has the unique property of being able to dissolve in both aqueous- and oil phases, depending on pH. However, there are concerns related to the use of this antioxidant (See Figure 1). In June 2017, the EU commission suspended the authorisation of ethoxyquin for all animal species and categories. Hence, there is a need to find an alternative solution.
 

A new alternative product containing the antioxidant propyl gallate has been developed by Borregaard. This product is optimised to ensure high quality, as well as stable product performance. The new combination of propyl gallate, lignosulphonic acid and formic acid provides a viable alternative for the market.

In June 2017, the EU commission suspended the authorisation of ethoxyquin (See Figure 1) for all animal species and categories [1]. Ethoxyquin has been the antioxidant of choice for decades, especially in the fish industry, in order to prevent rancidification of fats and oils during processing and storage.

Borregaard has many years of experience evaluating the efficiency of antioxidants. There are several different methods available on the market for testing antioxidant capacity [2-5] and the DPPH-assay [6] is one commonly used method. At Borregaard, an inhouse developed DPPH (2,2-diphenyl-1-picrylhydrazyl) based method – the BAU* method - is used, which will be described later in this text.

*Borregaard Antioxidant Unit

Fish silage
Fish silage contains fish, or parts of fish, combined with an additive for stabilising the silage during storage. Organic acids of different types are typically used as silage additives. Under the right conditions, temperature between 5 and 40 °C and at pH between 3.5 and 4.5, the fish mass will begin to decompose.

In this process, called autolysis, enzymes break down the muscles, and a liquid mass is formed, which is desirable given its ease of handling through pumps, piping, etc. (See Figure 2). Marine lipids contain high levels of long chained polyunsaturated fatty acids (PUFA). The PUFAs are readily oxidised by oxygen, which results in rancidification of fats and oils and consequently a decrease in product quality. Fishmeal and fish oil contain relatively high concentrations of PUFAs and are therefore especially prone to oxidation.

To prevent the oxidation of PUFAs in fishmeal and fish oil, the industry currently uses synthetic antioxidants like: ethoxyquin (E324), BHA (butylated hydroxy-anisole, E-320) and BHT (butylated hydroxy toluene, E321). In addition, natural antioxidants like tocopherols are also used.

Read the full article, HERE.

The Aquaculturists

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