This study aimed to investigate “melt-in-mouth” sensory attributes in bread using four samples: freshly baked and after 1, 3 and 7 days of refrigerated storage (5 ℃). The “melt-in-mouth” sensory attributes were evaluated as the intensities of “ease of dissolving in saliva” and “ease of swallowing”, which both decreased during storage. The crumb firmness as measured by its elastic properties increased and the water dissolution and water swelling rates of baked bread powder and starch powder decreased significantly during storage. X-ray diffractograms of the baked bread powder showed that as refrigerated storage time increased starch retrogradation increased. During storage, starch retrogradation caused the crumb water absorption to decrease and the crumb firmness to increase, resulting in greater difficulty in dissolving in saliva and in swallowing, respectively.

View full abstract

[in Japanese]

View full abstract

Konjac starches were isolated by immersing konjac “Tobiko” (fly powder) in an alkaline solution, washing with water, allowing the material to stand and centrifuging the material at different rotational speeds. The resulting material contained approximately 95%(w/w) starch by dry weight . The precise shape and particle size of the starches were determined by optical or electron microscopy; sizes ranged from 1-4µm. The polarization cross was observed for all starches, regardless of particle size, using polarized light microscopy. The pasting properties of the starches were measured using a Rapid Visco-Analyzer and were compared with those of four other kinds of starch. It was determined that the pasting temperature and temperature at peak viscosity of konjac starches were higher than those of sweet potato and potato starches, and that peak viscosity and set- back were high next to those of sweet potato and wheat starches, respectively.

View full abstract