Investigation on rice flours and its bio-functionality was carried out. Using various kinds of specialty rice cultivars, diversified processed rice products, such as rice bread, rice noodle and pre-germinated brown rice were developed. High-amylose rice and super-hard rice seemed to be promising for the inhibition of abrupt post-prandial increase of glucose. In order to identify the material rice cultivars by PCR, we developed and improved “enzyme treatment method” for the preparation of template DNA. It became possible to differentiate rice cultivars and to detect the contaminated foreign cereals of the various rice products by PCR.

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In the present study, we investigated how taste stimuli applied to the anterior tongue surface and hypopharyngeal area affected swallowing behaviors in humans. Twenty-nine healthy volunteers were instructed to repeat swallowing as quickly as possible, and swallowing intervals between the fourth and ninth swallow were recorded. During the swallowing test, a taste stimulant was applied to either the oral or hypopharyngeal cavity. For pharyngeal stimulation, distilled water (DW) or 0.3 M NaCl solution was applied at 0.2 mL/min; 0.3 M NaCl solution was used because it is known to completely inhibit water-sensitive responses in the pharyngeal region. For oral stimulation, DW, NaCl solution, or umami solution was applied at the same infusion rate. For NaCl and umami solution, the concentrations of sodium ion used were 6 mM, 40 mM, or 240 mM. The concentration of sodium ion was varied to observe effects on swallowing behaviors. During pharyngeal 0.3 M NaCl or DW stimulation, a wide variation in swallowing intervals was seen among the subjects. The mean swallowing interval was significantly shorter during DW stimulation compared with 0.3 M NaCl stimulation. The longer the swallowing interval with infusion of 0.3 M NaCl solution, the stronger the facilitation of swallowing by DW stimulation. During oral taste stimulation, swallowing interval for umami solution was significantly shorter in a concentration-dependent manner, but this was not the case for NaCl solution. Subjects were then divided into three groups depending on the swallowing interval during 0.3 M NaCl pharyngeal stimulation, high (< 7s), middle (7-11s), or low (> 11s) performance groups. Only middle group exhibited concentration-dependent facilitation by umami stimulation. In addition, the facilitatory effect was different between oral and pharyngeal stimulation, in that there was no significant relationship between the swallowing interval and facilitatory effect with umami solution applied to the oral region. The current results demonstrated facilitatory effects of umami solution applied to the oral region on swallowing behaviors but the effect was not just summative on the swallowing center and the nature of taste inputs on the swallowing network should be discussed.

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The purpose of this study was to determine the effectiveness of a screening test for gustatory function in four basic tastes using a whole-mouth test with one concentration of a taste solution together with the Visual Analogue Scale (VAS) score.
 In experiment 1, 84 healthy subjects were recruited to determine the concentrations used for whole-mouth gustatory tests in this study.
 The subjective intensity of taste was scored by the VAS, to be evaluated as the sensitivity of gestation (hereinafter known as gustatory VAS score).
 In experiment 2, four subjects were randomly pick up from the subjects of experiment 1. The diurnal variation and day-to-day variation of the gustatory threshold value of four basic tastes were investigated.
 In experiment 3, the results from a screening test for gustatory function in four basic tastes using each of the concentration obtained in experiment 1 were investigated.
 The results obtained were as follows:
1. The lowest concentration that could be identified by all subjects was 0.075 M for sucrose, 0.2 M for sodium chloride, 2.0×10^-3 M for citric acid, and 7.5×10^-5 M for quinine hydrochloride.
2. The following observations were made using the screening test for gustatory function developed in this study, Seven of the 25 subjects (28%) were diagnosed as taste decrease. Within the limitation of research design, these results demonstrate that gustatory function in four basic tastes could be assessed using a whole-mouth test with one specific concentration of a taste solution combined with the VAS score. Therefore, this method could be used as a screening test for gustatory function in four basic tastes.

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