Fish Silage Preservation

Fish Silage Preservation

By-products from farmed species and wild fish are raw materials for fish silage production. Borregaard LignoTech has developed a combination of formic acid and lignosulphonic acid, which controls the pH and reduces corrosion.

SoftAcid Aqua M - Fish silage preservation

Lignosulphonic acid is also a natural antioxidant and gives an extra protection against degradation of the fish silage. Hence, SoftAcid Aqua M+ improves the quality of the fish silage by preserving the fish by-products from oxidation.


  • SoftAcid Aqua M / SoftAcid Aqua M+


  • Stronger antioxidant effect
  • Reduced corrosion rate

Figure 1: Degradation rate of ethoxyquin with and without lignosulphonic acid (LS) in formic acid.

SoftAcid Aqua M+ graph

Large scale trial: 1000 litre containers stored outside exposed to all kinds of weather conditions. Sampling started in October 2010. The results are measured by HPLC. Note: Slow degradation of ethoxyquin during winter period due to very cold weather. Laboratory trials have also been performed (at 20-25°C), supporting the results presented above. The stability trials all show that lignosulphonic acid has a stabilising effect upon ethoxyquin.

Figure 2: Significantly less corrosion with SoftAcid Aqua M on carbon steel

Corrosion SoftAcid Aqua M