The influence of aging on the use of the TDS technique for the perception of food texture

TDS (Temporal Dominance of Sensations) is a modern technique for monitoring sensory perception that has become widely used in many areas of food research. TDS allows subjects to report dominant sensory sensations throughout the chewing sequence, including the perception of odours, tastes, and textures. It is unknown however whether the TDS methodology can be used in older subjects, which is limiting for those wanting to gain insights in the sensory perceptions of such demographics.

The dynamic perception of food texture by older adults in one aspect of sensory perception which has interest from food manufacturers. As people age there is a natural decline in many biological processes which are important for the dynamic perception of food texture. Cognitive speed, muscular strength, oral coordination, the number of natural teeth, and saliva flow will tent to decline with age, and the number of chews and time required to prepare foods for safe swallowing increases.

Consequently, a study was undertaken to compare the ability of subjects aged 18-30 years with subjects aged 55-70 years to undertake the TDS technique involving the perception of food texture. Each subject took part in a training session, followed by 2 separate TDS sessions. The first TDS session involved reporting dominant textural sensations of similar nuts (peanuts, almonds, macadamia nuts, and cashew nuts), and the second session involved reporting dominant sensations of distinctly different manufactured foods (cheese, shortbread, chocolate, and gelatine gels).

Results show that older subjects successfully undertook the sensory task required, generating typical TDS curves for both sessions. However, some differences in curves were observed between age groups, as were differences in general behaviour in the use of the TDS program, which will be discussed.