2019 Volume 23 Issue 3 Pages 171-179
The present study assessed the difference in physical properties between α-amylase-added bread, which is bread prepared with the addition of α-amylase (a starch-degrading enzyme used for promoting the gelatinization of wheat starch and inhibiting the ageing of the gelatinized starch), and additive-free bread to which α-amylase has not been added. The study also examined the difference in masticability of the two bread samples by means of electromyography of masseter muscles during mastication and by observing the changes in properties of the bread sample boluses during mastication. The results indicated that the addition of α-amylase to bread promotes the gelatinization of wheat starch and enables the preparation of bread that is soft. Furthermore, electromyography of masseter muscles during mastication showed that, compared with the bread to which α-amylase had not been added, the more softly prepared α-amylase-added bread was easier to masticate. As to the relation between the number of times of mastication and the properties of the bread sample boluses, the hardness of the α-amylase-added bread sample at five times of mastication was found to be softer than that of the bread sample prepared without the addition of α-amylase. However, no significant difference between the two bread samples was found at mastication of ten times or more. The moisture content ratio of the bread boluses increased with the number of times of mastication. This trend is presumably due to the effects of saliva secreted during mastication. These results suggest that, by adding α-amylase to bread, it is possible to prepare bread that is easy for elderly people to masticate.
