Adding fish oil to food
Discover how food technologists at the Riddet Institute are adding large amounts of fish oil to foods without affecting their taste or shelf life.
Fish oil and protein mixture
The fish oil and protein mixture form 2 separate layers before homogenisation.
Fish oil has a characteristic taste and smell that’s difficult to hide. Fish oil also contains polyunsaturated fatty acids, which spoil quickly once exposed to air, light and heat. Spoilage produces volatile compounds – a stronger fishy taste and smell – so adding fish oil to foods is challenging.
Reducing the fishy taste
There are three approaches to adding fish oil to foods to reduce the fishy taste and smell:
Use high-quality fish oil.
Stabilise the fish oil with antioxidants.
Encapsulate the fish oil droplets with a coating that will prevent oxidation – this is called microencapsulation.
Testing microencapsulated fish oil
The microencapsulated fish oil is tested for quality.
Often, all three approaches are needed to overcome the problem.
Microencapsulation: a protective barrier
Microencapsulation creates a barrier around tiny oil droplets. This barrier stops air from entering and volatile compounds from escaping. When fish oil is added to foods, this barrier protects it from oxidation during processing. The food doesn’t taste or smell fishy and keeps its normal shelf life.
Making microencapsulated fish oil
Microencapsulation protects fish oil from oxidation
Fish oil oxidises easily, causing a fishy taste and smell. Scientists at Riddet Institute have created a way of coating tiny droplets of fish oil to prevent oxidation, so the oil can be added to food. This process, called microencapsulation, is described here.
To microencapsulate the oil, food technologists at the Riddet Institute first mix fish oil with a formulation containing proteins and surfactants and then homogenise to create fish oil emulsion. The proteins and surfactants form a barrier around the oil droplets protecting them from spoilage.
Homogenisation makes the oil droplets smaller and spreads them evenly throughout the liquid emulsion. This stops the oil from separating out and makes it easier for the protein mixture to encapsulate the oil droplets. The encapsulated oil droplets are very tiny – 300–400 nm. This is 50 to 100 times smaller than the diameter of an average human hair.
The unique formulation of the microencapsulation emulsion is the intellectual property (IP) of the Riddet Institute. To stop other people from copying their technology, they hold a patent.
How much fish oil can you add to foods?
The amount of microencapsulated fish oil you can add depends on the type of food and how it is processed and stored. Generally, you can add higher amounts of fish oil to solid foods like bread and muffins than to liquid foods. It is harder to add high amounts to acid foods like juice than to milk.
It is possible to add the recommended daily allowance (RDA) to one serving of the food, but it does add to the cost. In the end, the amount added will be determined by the food industry and how much consumers are prepared to pay.
