Water & Wastewater Treatment In The Food Industry: Foaming – The Perennial Problem?
Foam In Food Processing – What Is The Problem?
When any foodstuff, food-processing ingredient or food waste comes in contact with water and some form of agitation there is the potential to create a foam.
A foam is defined as a mass of small bubbles formed on or in liquid, typically by agitation or fermentation.
The generation of large amounts of foam can cause severe operational problems in both food processing and wastewater treatment. These include:
- equipment failures,
- product loss,
- product contamination.
Any food processing operator who has stood up to his or her knees in foam will understand the problems foaming can cause.
All types of food industry applications including meat processing e.g. in blood tanks , brewing, wine making, dairy , corn oil, juice processing , potato and vegetable processing, soft drink manufacture, rice processing and sugar refining can be subject to foaming issues.
Reducing Food Process Foaming: What Options Are Available To The Food Industry?
There are only two options available to reduce foaming issues in the food industry.
- Change the process to reduce agitation. Use of mechanical foam breaking blades or water sprays This may involve considerable capital cost and may be inappropriate i.e. an effective alternate process is not available.
- Chemical antifoams or defoamers. This a potential cost-effective option, which is finding increasing application in the food industry.
What Are Chemical Antifoams /Defoamers?
These chemical agents both collapse foam and inhibit its formation by disrupting the surface of the bubble membrane. These prevents foam recurring later in the process or during discharge. A common problem with mechanical methods.
Antifoams are derived from three main groups:
- Silica or silicon oil
- A variety of waxes
- Higher alcohols or fatty acid derivatives.
All types of antifoams are available as a food grade concentrate or ready to use dilution
Application Of Antifoams Or Defoamers In Food Processing
As a general rule the best place to apply a defoamer is right at the surface of the water by e.g. spray, before the foam becomes troublesome. Although defoamers will collapse foam, they may be more effective when fed before it develops, as a preventative measure.
Spraying units are normally supplied by the chemical antifoam supplier to allow their product to be applied. These units are available in multiple configurations and can be adapted to suit all plant sizes.