title: Effect of the bitterness of food on muscular activity and masticatory movement.
abstract: OBJECTIVE
  The purpose of this study was to clarify the effect of the bitterness of food on muscular activity and masticatory movement.
  
  
  METHODS
  Twenty healthy subjects were asked to chew a non-bitter gummy jelly and a bitter gummy jelly on their habitual chewing side. The masseter muscular activity and the movement of mandibular incisal point were recorded simultaneously. For all cycles excluding the first cycle, parameters representing the muscular activity (total integral value and integral value per cycle) and masticatory movement (path, rhythm, and stability) were calculated and compared between the two types of gummy jellies.
  
  
  RESULTS
  The total integral value of masseter muscular activity during the chewing of bitter gummy jelly was significantly smaller than during the chewing of non-bitter gummy jelly, however, no definite trends in the integral value per cycle and the stability of movement were observed. The parameters representing the movement path tended to be small during the chewing of bitter gummy jelly than during the chewing of non-bitter gummy jelly. The masticatory width was significantly smaller during the chewing of bitter gummy jelly. The parameters representing the rhythm of movement were significantly longer during the chewing of bitter gummy jelly than during the chewing of non-bitter gummy jelly.
  
  
  CONCLUSIONS
  From these results it was suggested that the bitterness of food does not affect the integral value per cycle or the stability of the masticatory movement, but it does affect the movement path and rhythm, with narrowing of the path and slowing of the rhythm.
authors.affiliation: Department of Partial and Complete Denture, School of Life Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan.
authors.forename: Yamato
authors.initials: Y
authors.lastname: Okada
authors.affiliation: Department of Partial and Complete Denture, School of Life Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan. Electronic address: h-shiga@tky.ndu.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shiga
mesh_terms: D000328:Adult; D005260:Female; D005502:Food; D006801:Humans; D007180:Incisor / Q000502:physiology; D008297:Male; D008334:Mandible / Q000502:physiology; D008406:Masseter Muscle / Q000502:physiology*; D008409:Mastication / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D013649:Taste / Q000502:physiology*; D055815:Young Adult
keywords: Food bitterness; Gummy jelly; Masseter muscular activity; Masticatory movement