Dynamics of food breakdown during eating in relation to perceptions of texture and preference: a study on biscuits

Combined recording of masticatory muscle activity and jaw movement patterns during eating was used to examine the process of food breakdown in the mouth for a series of "Rich Tea"-type biscuits in 19 ordinary consumers. These data indicated an initial increase in chewing work from the masticatory muscles over the first 5-10 chews followed by a decline over the remainder of the chewing sequence. The work was concentrated in vertical closing of the jaw during the early chews but as this declined over the later chews there was an increase in the amount of work occurring with the teeth in near occlusion. The relative amount of work input into the chewing sequence, the duration of the sequence, and the degree of work undertaken at occlusion, differed among groups of the consumers who were classified according to their chewing efficiency (CE). Subjects from different CE groups appeared to have different understandings of the textural characteristics of the samples which they assessed as "hardness'', "crunchiness" and "crumbliness". Differences in the oral breakdown patterns for different CE groups may provide an understanding of differences in consumer preferences for the samples. (C) 2000 Elsevier Science Ltd. All rights reserved.