Saliva-Induced Emulsion Flocculation: Role of Droplet Charge - Food Colloids: Self-Assembly and Material Science - page 463

Chapter 32

Saliva-Induced Emulsion Flocculation: Role
of Droplet Charge

Erika Silletti, 1,2 Monique H. Vingerhoeds, 1,3 Willem Norde 2,4
and George A. van Aken 1,5

1 WAGENINGEN CENTRE FOR FOOD SCIENCE (WCFS), P.O. BOX
557, 6700 AN WAGENINGEN, THE NETHERLANDS
2 LABORATORY OF PHYSICAL CHEMISTRY AND COLLOID
SCIENCE, WAGENINGEN UNIVERSITY, P.O. BOX 8038, 6700 EK
WAGENINGEN, THE NETHERLANDS
3 AGROTECHNOLOGY AND FOOD SCIENCES GROUP B.V., P.O. BOX
17, 6700 AA WAGENINGEN, THE NETHERLANDS
4 UNIVERSITY MEDICAL CENTRE, UNIVERSITY OF GRONINGEN,
P.O. BOX 196, 9700 AD GRONINGEN, THE NETHERLANDS
5 NIZO FOOD RESEARCH, P.O. BOX 20, 6710 BA EDE, THE
NETHERLANDS

32.1 Introduction
Human saliva is a complex heterogeneous biological fluid composed of pro-
teins, electrolytes, small organic compounds and water. 1-3 It is involved in
several functions in the oral cavity and is responsible for maintaining oral
health and for protection of the teeth and mucosal surfaces. 4 Mixing with saliva
plays an important role in facilitating food manipulation and bolus formation
in the oral cavity. 5 For example, the enzymatic activity of salivary a-amylase is
responsible for the initial breakdown of starch-based foods before swallowing.
The human perception of food products is becoming increasingly important
for the food industry in relation to product design and evaluation. Often the
perception of foodstuff - as, for example, an emulsion - cannot be directly
related to the texture of the product before consumption. Moreover, several
authors have reported 6-9 the influence of saliva properties, such as flow,
composition and lubrication, on sensory perception and flavour release. It is
becoming evident that knowledge on the interaction between saliva and food is
of primary importance for understanding the oral processing of food.

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