The State of Water in Stored Dry Cereal Grains and Legumes

Abstract

Sorption data of products are important in the prediction of the spoilage mechanisms and also find use in the design of storage space, packaging and water removal systems. Adsorption constants were determined for 24 stored dry foods (including cereals and legumes) using the saturated salts technique at a temperature of 300C and a range of water activity aw = 0.11-1.0. An equivalent of monolayers of adsorbed water were circulated for cereals and legumes. The curie equation used for the analysis also categorized the adsorbed water in the foods as (a) the total bound water, (b) the monolayer water that is most stable in foods and (c) the critical water content below which water is riot available for microbial activity. The ranges of the different types of water were 5.57-11.43, 5.43-15.37 and 28.13-114.3% on dry weight basis for monolayer, critical and the total bound water, respectively. Oil seeds were characterized by marked low monolayer and critical moisture.