Why does the viscosity of mayonnaise increase when it is whipped energetically: a case for studying models linking volume fraction and viscosity of suspensions and emulsions

Why does the viscosity of mayonnaise increase when it is whipped energetically: a case for studying models linking volume fraction and viscosity of suspensions and emulsions

Paul Menut1, Cassandre Leverrier1, Herve This vo Kientza1,2

1. Université Paris-Saclay, INRAE, AgroParisTech, UMR 0782 SayFood, 22 place de l’agronomie, 91120, Palaiseau, France.
2. Inrae-AgroParisTech International Centre for Molecular and Physical Gastronomy, 22 place de l’agronomie, 91120, Palaiseau, France.

*Correspondence: herve.this@agroparistech.fr

Abstract
This supporting document is given in courses of food science and technology, when colloids are discussed. It is an introduction to the various models of viscosity that are often used for suspensions and emulsions such as mayonnaise sauce, focusing on the paradox of the increase in viscosity of the sauce when it is energetically whisked, but no oil is added, so that the volume fraction of emulsions does not change. Exercises are proposed, and references are provided to state-of-the-art articles regarding the various topics covered.

Keywords
colloidal systems, emulsions, models, viscosity, volume fraction.

Edited by: 
Reine Barbar, Institut Agro-Montpellier /UMR IATE.

Reviewers: 
1. Anonymous

2. Patricia O’Hara, Emeritous professor of chemistry, Amherst College.

Received: 
25 August 2025

Accepted : 
25 August 2026

Published: 
10 October 2026

Section:
This article was published in the “Education/supporting Material” section of the International Journal of Molecular and Physical Gastronomy

Citation:
Menut P, Leverrier C, This vo Kientza H. 2026. Why does the viscosity of mayonnaise increase when it is whipped energetically: a case for studying models linking volume fraction and viscosity of suspensions and emulsions, International Journal of Molecular and Physical Gastronomy, 12(1), 9, 1-25. doi: 10.17180/ijmpg-2026-art08.