Objective characterization of food firmness and cohesiveness during chewing using the electronic sensing system

The Electronic Sensing System (ESS) uses electromyography to study the chewing sequence. An insightful study of the ESS revealed that chewing on the right side, and using the right masseter muscle was the most reliable and easiest method for using this system. Reference foods also were used to study the effects of electrodes placement on ESS signals. Standard procedures for using the ESS were developed. The ESS program provided rapid analysis of EMG parameters: total energy (TE), peak energy (PE), Fourier power (FP), ascending (AE) and descending energy (DE). Model food systems made of gels and leavened cakes were created to study the effect of hardness and cohesiveness, respectively. The hardness parameter was well predicted by the ESS parameter ∑(TE x PE x FP) for the model gel system and obtained a high correlation (r > 0.8) to sensory firmness.{09}Using the ESS parameter, firmness in six commercial breads was differentiated (P < 0.05), with a high correlation to bread firmness (r > 0.82). This parameter was further studied with 17 commercially obtained food products. ESS parameters of panelists correlated highly with sensory hardness measurements of the food samples (r > 0.65). The cohesiveness of mass of a cake model food system was determined and studied. A discussion of descending energy (DE) explained how it contributed to the cohesiveness of mass measurement. When the ESS hardness parameter was included, the ESS parameter, ∑DE/∑(TE x PE x FP), indicated the cohesiveness of mass for the cake model system for all ESS panelists (r > 0.77). This parameter also was able to differentiate the cohesiveness of mass of commercial bread with r values >0.62. The correlation was lower than that for bread samples because of a large range of textures. This was explained by the confounding nature of ESS curves when foods with different hardness values were tested, resulting in discrepancies to sensory data and low correlation values. This indicates that the ESS can determine differences of food groups with similar textures.