Petit four

Project

TIFN: Air bubbles in food

Consumers like the taste and mouthfeel of foamy foods. Foam and small air bubbles (microbubbles) could be used to produce tasty food that contains less fat and more protein and fibre. Too little is currently known about this subject.

Aim

The project gathers information in order to produce popular foods containing less fat and more protein and fibre. The aims of the project are:

  • To gain an understanding of the mechanisms responsible for forming and stabilising (or destabilising) microbubbles.
  • To gain an understanding of the physical, chemical and sensory behaviour of microbubbles.
  • To gain an understanding of the links between the physical and chemical properties of the ingredients and the formation, stability and properties of multi-component aerated systems. 

Foams are not easy to stabilise, although techniques for forming and stabilising foam in food are improving all the time. However, there is still only limited knowledge of what are referred to as microbubbles, tiny bubbles that can be used as a structure element in foods to replace fat, for example, or as surface-active particles to stabilise larger air bubbles.

Method

The study features various research lines. The main focus is on: finding ways of stabilising air bubbles with the help of particles, applying small stable bubbles in food systems, determining the main parameters that govern foam stability in conventional multi-component foams, and devising a good method for determining the dispersion of different sizes of air bubbles in foams. Various experiments using differing techniques have been conducted to generate stable bubbles, revealing this is only possible for certain particles and proteins. The reason for this difference is as yet unclear. Stock has been taken of various techniques to measure the dispersion of different sizes of air bubbles in aerated systems.

Results

X-ray Tomography may be a good method for measuring the structure of foam. After consulting with CAT-Agrofood (which provided funding), one of these devices was purchased and taken into operation in early 2013. A macroscopic model is being developed to relate the properties of a foam (dispersion of different bubble sizes, time scale, coalescence, drainage, disproportioning) to physical parameters such as concentration of the surfactant, properties of the surfactant (size, charge, hydrophobicity), etc.

The results of this research will enable the food industry to produce healthier and tastier products.

Publications