Energy storage controls crumbly perception in whey proteins/polysaccharide mixed gels

This paper describes the relation between crumbliness of whey proteins/polysaccharide mixed gels and their physical properties. Crumbly sensation relates strongly to the breakdown behaviour of the gels, which is primarily determined by their viscoelastic properties. These properties result from the balance between elastically stored energy and energy dissipation during deformation. The stored energy is determined as the percentage of the recoverable energy in a compression-decompression test. Gels breaking readily via a free-running crack (i.e. high recoverable energy) were perceived as the most crumbly ones. Gels showing slow, yielding-like breakdown (i.e. high energy dissipation) were sensed as the least crumbly by assessors during quantitative descriptive analysis (QDA). Serum release from the gels contributed to a large extent to the energy dissipation and thus decreased crumbliness. Microstructure affects serum release and therefore indirectly microstructure affected the crumbly sensation. The relations between crumbly sensation and physical and structural properties of the gels are, to our knowledge, reported here for the first time and can be applied to control and engineer crumbliness of semi-solid foods. (C) 2007 Elsevier Ltd. All rights reserved.