Mastication efforts on block and finely cut foods studied by electromyography

To quantify the mastication effort for finely cut foods, mastication patterns were analyzed by electromyography (EMG) while normal subjects ate a mouthful size (7 g block, the same weight cut, and the same volume cut) of raw carrot, cucumber, roast pork, and surimi gels. Instrumental compression test revealed that raw carrot and cucumber exhibited high fracture stress and small relative deformation for fracture, while roast pork and surimi gels fracture at low stress and large deformation. For raw carrot and cucumber, the number of chews, masticatory time, total duration of mastication, and total muscle activities evaluated by EMGs were greater for cut samples than for same weight block samples. For roast pork and surimi gel, these factors were the same for equal-weight cut and block samples. Cut samples with the same volume, but of smaller weight, were often eaten with less total mastication effort until swallowing than a block sample. These results revealed that cutting food does not help reduce mastication effort for the same weight as a mouthful size block, although it may make easier mastication by decreasing the weight of one mouthful. (C) 2006 Elsevier Ltd. All rights reserved.