Food Colloids

Course content

Foods are complex materials that consist of multiple dispersed and continuous phases. Foods consist for example of simple solutions, crystals of sugars and fats, droplets of oil, dispersed fibers, polymers and proteins. Foods can be characterized as thin and viscous solutions, gels and pastes as well as solids. Food colloids are found in all kinds of food from dairy products to beer. Food colloids has internal surfaces that can be charged and adsorb surface active molecules. The particles in foods interact, particles can grow or shrink in size, particles can coalesce and aggregate and food are dynamic systems where liquids can become solid and vice versa.

The course is a fully theoretical course about the fundamental forces stabilizing and destabilizing colloidal systems and the experimental methods to study properties such as structure, functionality and changes in such properties of colloidal foods.

Course content:

Introductions to dispersed systems: gels, emulsions, micro and nano- emulsions, sols and foams.

Forces between particles in foods. Free energy, phases and phase diagrams. Hydrophobicity and hydrofilicity

Surfaces in foods: surface tension, Gibbs adsorption isotherm. Contact angles and wetting. Ionic strength and charged surface, surface and zeta potential.

Phase behavior of lipids and other amphifilic molecules.

Emulsions and emulsifiers. Emulsification and Emulsions breakdown.

Foams and foaming agents. Whippable emulsions.

Solids dispersions and dispersant. Sedimentation, haze and turbidity.

Experimental methods: Rheology Differential scanning calorimetry, light, x-ray and neutron scattering, Microscopy and other imaging techniques.

Stability of foods and colloidal stability. Flavor distribution and flavor release from colloidal systems.

 

Education

MSc Programme in Food Science and Technology

Learning outcome

Knowledge:

  • Knowledge of the fundamental of dispersions colloidal systems.
  • Knowledge of the interactions and forces that stabilized and destabilizes colloidal systems.
  • Knowledge of phase diagrams and the theory behind phase diagram. Knowledge of surface chemistry and theory of surface tension.

 

Skills:

  • Skills in presenting and explaining complex relations and theory.
  • Skills in applying theoretical concepts and making calculations.

 

Competences:

  • Competences in describing and understanding complex food systems using colloidal chemical concepts.
  • Competences in understanding and preventing colloidal floors in food
  • Competences in based on colloidal chemical knowledge choosing experimental techniques to study properties of foods.

Lectures, group work, theoretical exercises, poster presentations, open discussion.

See Absalon for specific course literature.

Qualifications corresponding to basic chemistry, basic physical chemistry, and basic food chemistry on bachelor level.

ECTS
7,5 ECTS
Type of assessment
Oral examination, 20 min
Oral examination without preparation time. The examination takes its starting point in posters produced by the student.
The student draws a poster and present it. The presentation soon develops into a scientific conversation with the examiners. The examiners possess questions in the full curriculum and might include supplementary materials (graphs, table, pictures and drawings).
Aid
Without aids
Marking scale
7-point grading scale
Censorship form
No external censorship
More than one internal examiner
Criteria for exam assessment

Cf. Learning Outcome.

Single subject courses (day)

  • Category
  • Hours
  • Lectures
  • 60
  • Preparation
  • 95
  • Theory exercises
  • 30
  • Class Seminar
  • 10
  • Project work
  • 10
  • Exam
  • 1
  • English
  • 206