Relationship of electromyography (EMG) masticatory variables with sensory texture and instrumental texture parameters of different textured foods

Electromyography (EMG) is an upcoming technique for food texture evaluation which has the potential to come up as a successful comprehensive texture evaluation method. EMG texture evaluation is in its development phase and its relations with conventional texture measurement techniques need to be established and evaluated. The objective of this study was to investigate the relationship of EMG masticatory variables with sensory texture and instrumental texture parameters as measured for different textured foods. Five food samples were purchased from the local market namely, dhokla, paneer, rasgulla, cake and jelly. Food samples were subjected to proximate analysis, sensory textural evaluation and two-bite tests using texture profile analyzer. Nutritional compositions of all the selected food materials were significantly (p ≤ 0.01) different values. Textural parameters like hardness, cohesiveness and gumminess showed highly significant (p ≤ 0.01) variations among different selected foods. The study was conducted on eight human subjects. Eighteen EMG mastication variables were obtained during chewing of these five different foods. Fifteen mastication variables were found to be significantly (p ≤ 0.05) effective in explaining the variation in texture of the selected food samples. Mastication parameters were reduced from eighteen to five in number using cluster analysis. Correlation coefficients between EMG mastication parameters at different stages (early, middle and late), and sensory and instrumental texture parameters were found significant. Principal component analysis was conducted on various mastication parameters which resulted in two meaningful principal components, comprising of mastication time, total muscle activity, cycle time, early burst duration and early muscle activity, could explain a cumulative variance of up to 82%. The first principal component (PC1) scores correlated significantly with sensory texture parameters and instrumental texture parameters namely hardness, cohesiveness, chewiness gumminess and adhesiveness. PC1 showed correlation with sensory cohesiveness, chewiness and adhesiveness at (p ≤ 0.05) while with hardness at (p ≤ 0.10) and with gumminess at (p ≤ 0.20). For the instrumental texture parameters significant correlations were found with cohesiveness and gumminess at (p ≤ 0.05). The study revealed that EMG is capable of comprehensively quantifying the dynamic changes occurring in the mouth during chewing of different textured foods. So the information generated through EMG investigations can complement the sensory and instrumental textural analysis for designing new foods.