Feed processing and the draw backs of surface tension

30 November 2020

Surface tension is the natural phenomenon created by unified forces between liquid molecules. It is what gives raindrops the ability to create patterns or the dome effect you get when you slightly over fill a glass. Water has the highest surface tension of any liquid bar mercury and it is that exact fact that proves to be counterproductive when adding water during feed manufacturing. Substantially reducing the desired benefits of improved moisture content and hindering feed mill efficiency.

The high surface tension of water creates a small surface area due to their natural cohesion. This decreases the likelihood the droplet will be fully absorbed by the feed particles. However this surface tension can be reduced by using a surfactant such as Selko Fylax which reduces the natural surface tension of water.

There are further benefits of surface tension reduction. Higher surface tension has a negative effect on thermal conductivity which is important during the feed manufacturing process. More effective moisture dispersion and thus improved heart conductivity can create improved starch gelatinization and microbial reduction.

Surface Tension of a 5% dilution in water

A surfactant such as Selko Fylax which is composed of a blend of buffered organic acid also delivers a significant reduction of enterobacteria. Interestingly treating feed with a hydrated solution of organic acids alone shows no significant improvement on enterobacteria reduction in comparison to a non hydrated solution. Findings in the table below show that surfactants have a specific role in increasing the efficacy impact of mould inhibition in finished feed.

Rolling grains particularly benefit from decreased surface tensions. Tempering time used to soften the grain and create flexibility in the outer layers can be positively reduced by adding a surfactant product such as Fylax. Greater surface area needs less time for the liquid to be absorbed. Further to this there is a reduced loss of moisture in the final product after flaking and customers have reported greater flake durability. 


Lauren Judd                Product Manager Feed Additives