Variables Influencing Chewing Electromyography Response in Food Texture Evaluation

Food choice is linked to many characteristics, among which texture is one of the most important. As a consequence, texture is a quality parameter that needs to be understood on a global perspective, including physical and psychological aspects. Texture perception is gained from a complex process of chewing, and not from a single action. Thus, there is a need for techniques that consider the whole process of chewing. Among those techniques, electromyography (EMG) seems promising. Different variables influence the chewing response as registered through EMG. Some of those variables are linked to the experimental set-up, where there is a need for standardization as well as data processing procedures. Other variables are linked to subject characteristics, both physical (e.g., facial anatomy, age) and psychological (e.g., personality, cognitive processes). Experimental planning can also constitute a source of variability, the number of products and trials per session being important items. The way the EMG signals are processed (parameters from EMG records) also must be considered in order to extract reliable and consistent conclusions. Because no standard practices have been established for the use of EMG in food texture assessment, it is important to review how this technique has been used, the variables involved, and the meaning or concepts associated with the outputs.