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WATER SORPTION ISOTHERM REFERENCE MATERIAL

Objective



The Water Sorption Isotherm represents the equilibrium relationship between the water content of a food and its water activity (aw). At equilibrium, water activity is, in effect, equivalent to the relative humidity of the atmosphere surrounding the food.

Accurate definition of the water sorption isotherm is of considerable importance to processors of food and agricultural products.

Particular applications include drying of foods to ensure the required stability, mixing of foods and prediction of the sorption isotherm of the products and, packaging where the freshness of a product such as cheese depends upon the ability of the container to maintain the specified degree of humidity.
The water activity subgroup of COST 90 (physical properties of foods) has developed a method for determining sorption isotherms and showed that micro crystalline cellulose (MCC) could serve as a stable and homogeneous reference material. The reference material based on MCC is designed to ensure correct application of the method.

RESULTS

The original COST 90 method has been further refined in order to improve definition of the MCC oven drying conditions. The water content of the reference material (RM 302) has been certified at 10 water activities and allows the application of the COST 90 method to be checked over the normal range of interest.
The project is terminated: EUR report 12 429 (1989).

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

BBSRC Institute of Food Research
Address

BS Bristol
United Kingdom

Participants (10)

Federal Research Centre for Nutrition
Germany
Address
Haid-und-neustr.9
76131 Karlsruhe
Institut National de la Recherche Agronomique (INRA)
France
Address
Rue De La Géraudière
44026 Nantes
LUDWIG-MAXIMILIANS UNIVERSITY OF MUNICH
Germany
Address
Geschwister-scholl-platz 1
80539 Muenchen
Ministry of Agriculture, Fisheries and Food (MAFF)
United Kingdom
Address
135 Abbey Road
AB9 8DG Aberdeen
South Bank University
United Kingdom
Address
Borough Road
SE1 0AA London
Stazione Sperimentale per l'Industria delle Conserve Alimentari
Italy
Address

Parma
Universidad Politecnica ETSIA
Spain
Address

Valencia
Universität Hohenheim
Germany
Address

70593 Stuttgart
Université de Bourgogne
France
Address

21000 Dijon
Wageningen Agricultural University
Netherlands
Address

Wageningen