Cohesiveness and flowability of particulated solid and semi-solid food systems

Abstract

Cohesiveness and flowability of particulated food systems is of particular interest in the oral processing and swallowing of food products, especially for people suffering from dysphagia. Although cohesiveness of a bolus is an essential parameter in swallowing, a robust technique for objective measurement of cohesiveness of particulated semi- or soft-solids is still lacking. In our approach the ring shear tester is used to measure the cohesiveness and flowability of a model particulated food system based on fresh green pea powders and pastes with controlled moisture content. The focus is on how the cohesiveness and flowability of dry pea particles change as they absorb moisture, swell and soften, while continuously agglomerating until a paste like bolus is achieved. Differently hydrated pea powders start to granulate with increasing moisture content resulting in decreasing flowability and increasing cohesiveness until a critical moisture content of approximately 73 wt% is reached. Above the critical moisture content, cohesiveness starts to decrease and flowability increases, i.e. indicating the transition into the rheological domain of concentrated suspension flow. Besides moisture content we also show that water adsorption capacity i.e. hydration properties and resulting degree of particle softness tremendously influences the flowability factor and cohesiveness of powder systems. Thus ring shear tester can be used to provide guidelines for food paste formulation with controlled cohesiveness.

Bolus rheology and ease of swallowing of particulated semi-solid foods as evaluated by an elderly panel

“…Cohesiveness of the different broccoli samples was determined with a Powder Flow Tester (PFT Powder Flow Tester, Brookfield Engineering Laboratories -Ametek Inc., USA) using the experimental methods described by Tobin et al 14…”

“…In this research cohesiveness refers to the internal strength of compacted material and is linked to flowability by the degree of deformation and destruction of the material when mechanical load is applied. 6,14 Subsequently a highly cohesive material would be more difficult to flow. Cohesiveness was measured objectively using a ring shear tester, a method commonly used for powders which has been previously shown to be able to measure flowability of particulated foods at different moisture contents.…”

Optimizing Texture Modified Foods for Oro-pharyngeal Dysphagia: A Difficult but Possible Target?

“…In the oral phase, chewing and mixing with saliva as a binding agent is useful to produce a bolus that is both lubricated and cohesive ( 62 ). Nowadays, there is not a robust and standardized methodology, acknowledged by the scientific community as a valid way of evaluating cohesiveness ( 63 , 64 ).…”

“…Unfortunately, to date, a robust technique for measuring cohesiveness is still lacking. Even if the TPA test using double compression is often used, there is a reduced correlation between measurement and sensory perception ( 64 ). It could be useful to carry out new studies of viscoelasticity and cohesiveness of products for dysphagia and thickened food especially in non LVR using LAOS technique.…”

Human oral processing and texture profile analysis parameters: Bridging the gap between the sensory evaluation and the instrumental measurements

“…This method first proposed in powder evaluation by Jenike (1964) was developed by Ashton, Cheng, Farley, & Valentin, 1965) and Schulze (2008), and used widely for granular materials. Recently, ring shear test based on this method has been applied to food samples such as pea powders with different moisture contents (Tobin et al, 2017) and cooked rice (Yu et al, 2019). These papers show great potential for the ring shear test for wider range of food samples.…”