The effect of sweeteners on bitter taste in young and elderly subjects

The purpose of this study was to quantify the degree of reduction in perceived bitterness by sweeteners at both threshold and suprathreshold concentrations of bitter compounds. Detection and recognition thresholds were determined for six bitter compounds (caffeine, denatonium benzoate, magnesium chloride, quinine hydrochloride, sucrose octaacetate, and urea) in the absence and presence of several suprathreshold concentrations of five sweeteners. The sweeteners were: sucrose, aspartame, sodium saccharin, mannitol, and sorbitol. Polycose was also tested along with the sweeteners. The degree to which bitter thresholds were affected by the addition of sweeteners was dependent on the chemical classification of the sweeteners and their concentrations. In general, the natural sweeteners, sucrose, mannitol, and sorbitol, were more effective than the noncaloric sweeteners, aspartame and sodium saccharin, in elevating the detection and recognition thresholds of the bitter compounds. A sweetness intensity approximating that of 6% sucrose (0.175 M sucrose) or greater was required to elevate thresholds. For elderly subjects, sweeteners did not significantly elevate thresholds for denatonium benzoate and sucrose octaacetate. The degree to which sorbitol and sucrose can decrease the perceived bitterness intensity of suprathreshold concentrations of the six bitter compounds was also determined. The concentrations of sweeteners and bitter compounds were selected to be of moderate to high subjective intensity. The levels of sweeteners used in the mixtures were: sucrose (none, 0.946 M, and 2.13 M) and sorbitol (none, 2.1 M, and 3.68 M). Both sweeteners significantly reduced the bitterness ratings of almost every concentration of the six bitter compounds. The greatest reductions in bitterness were 87.0% for 0.192 μM denatonium benzoate mixed with 2.13 M sucrose and 84.7% for 1.8 M urea mixed with 3.68 M sorbitol.     

Artificial rearing alters development of the nucleus of the solitary tract

Previous studies have shown that damage induced to fungiform papillae of the anterior tongue at postnatal day 2 (P2) alters both pre- and postsynaptic development of gustatory recipient zones within the rostral nucleus of the solitary tract (NST). The present study was conducted to determine whether or not artificial rearing (AR) manipulations, which reduce normal orochemical stimulation during early postnatal development, would be sufficient to produce alterations in anatomical development of the rostral gustatory NST. Two groups of Long-Evans hooded rats were examined. One group received normal rearing with a lactating dam from birth to weaning (mother reared; MR). A second group of animals received artificial rearing via intragastric cannulae between the ages of P4 and P14, and were thereafter returned to lactating dams until the age of weaning (P21). Following weaning and maturation to adulthood (P49), the organization of gustatory afferent terminal fields in the NST was examined using fluorescent tracing procedures which permit the simultaneous visualization of gustatory afferent terminal fields arising from the seventh and ninth cranial nerves. Results show that AR manipulations between the ages of P4 and P14 produce alterations in development of gustatory afferent terminal fields in the NST that are essentially similar to those observed following early postnatal receptor damage. These results confirm previous suggestions that orochemical stimulation during a limited portion of rats' postnatal life is essential in inducing normal presynaptic development in the gustatory NST.     

Combining repeated taste exposure and escape prevention: an intervention for the treatment of extreme food selectivity

Repeated taste exposure has been used to introduce novel foods in several settings, but none of these efforts have targeted clinical populations. This study describes an intervention that combines repeated taste exposure and escape prevention in the treatment of extreme food selectivity in two children with autism. Future applications of repeated taste exposure are discussed.     

Association of tongue brushing with the number of fungiform taste buds and taste perception: A preliminary study using confocal laser scanning microscopy in combination with a filter-paper disc method

ObjectiveThe aim of this study was to investigate the association of tongue brushing with the number of fungiform taste buds and taste perception using a confocal laser scanning microscopy in combination with a filter-paper disc method (FPDM).MethodsTwenty-four subjects with or without a habit of tongue brushing (11 males and 13 females, 20–46 years old) participated in this study. Nine of the 24 subjects had no habit of tongue brushing (Group 1, n = 9). Fifteen subjects had a habit of tongue brushing, and the brushing regions of the tongue were as follows: central region (Group 2, n = 7), or entire region (Group 3, n = 8) of the tongue dorsum. Using confocal laser scanning microscopy, the average number of taste buds per fungiform papilla (FP) was counted. Taste perception was evaluated using an FPDM. These observations were performed in the midlateral region of the tongue since the distribution of fungiform papillae is large in the midlateral region compared to that in the central region.ResultsThe subjects in Group 3 showed a significantly decreased number of fungiform taste buds compared to Group 1 and Group 2. Group 3 also showed significantly higher FPDM scores than the other two groups.ConclusionsExcessive tongue brushing of the entire tongue dorsum, including the midlateral region, may have an association with the decreased number of FP and taste buds and decreased taste sensation. To avoid these conditions, instituting proper tongue brushing methods, such as limiting it to the central region of the tongue and using a light touch, is suggested and is important for the subjects who are eager to participate in tongue brushing.     

二甲双胍对2型糖尿病大鼠肠道L细胞及味觉受体的影响

目的观察二甲双胍对于2型糖尿病大鼠肠道L细胞功能及味觉受体相关蛋白的影响。方法将18只健康的8~10周龄雄性Wistar大鼠经高糖高脂饮食4周后予链脲佐菌素(STZ)成模。随机分为三组:模型组+二甲双胍、模型组+普食;对照组。分别于成模干预前和干预第6周时行口服糖耐量实验(OGTT),并测血脂及胰高血糖素样肽-1(GLP-1)表达量。第6周时处死大鼠,并留取肠道组织标本运用real-time RT-PCR法检测胰高血糖素原(PG)基因,Western blot检测葡萄糖转运蛋白-2(GLUT-2)、味觉受体T1R2、T1R3及Gαgust蛋白的表达。结果干预后二甲双胍组和正常组的随机血糖均较干预前明显下降,差异有统计学意义(P0.01),且二甲双胍组下降更明显(P0.05)。干预后二甲双胍组血清总胆固醇(CHOL)较干预前明显改善(P0.05),低密度脂蛋白胆固醇(LDL-C)、甘油三酯(TG)均较干预前也有所下降,但差异无统计学意义(P0.05),且与正常组、对照组干预后相比,二甲双胍组CHOL明显下降(P0.01),LDL-C及TG也有所下降,但差异无统计学意义(P0.05)。干预6周后,二甲双胍组空腹血清GLP-1的表达量较干预前增加,且比正常组和对照组高,差异有统计学意义(P0.05);高糖负荷后,二甲双胍组血清GLP-1表达水平明显增加,且与正常组及对照组相比差异有统计学意义(P0.05)。结论二甲双胍具有良好的降糖降脂的作用;二甲双胍可能具有通过上调肠道L细胞内PG基因的表达,从而促进肠道L细胞GLP-1的产生,同时影响GLUT-2、味觉受体及其下游的信号因子Gαgust表达,进而间接起到降糖的作用。     

Influence of habitual mouth breathing on taste sensation

Purpose

Although habitual mouth breathing is recognized to cause various disorders of orofacial growth and function, including taste sensation, the relationship between habitual mouth breathing and taste disorders has not been investigated sufficiently. This study aimed to examine the influence of habitual mouth breathing on taste sensitivity and relevant factors such as salivation, oral moisture, and olfactory function.

Consumption of Sweet, Salty, Sour, and Bitter Solutions by Selectively Bred Alcohol-Preferring and Alcohol-Nonpreferring Lines of Rats

To determine whether selective breeding for high or low oral ethanol consumption is associated with different preferences for nonpharmacological solutions with various flavors, the oral intake of a range of concentrations of sucrose (0.5–64.0 g/100 ml), NaCl(0.025–3.2 g/100 ml), citric acid (0.008–2.048 g/liter), and sucrose octaacetate (0.002–0.512 g/liter) was studied in alcohol-preferring (P) and alcohol-nonpreferring (NP) rats. Separate groups of 7–8 rats from each line were tested for consumption of each of the four flavors. The flavored solutions were presented continuously with water and food always available, and the concentrations were doubled every 48 hr. Although rats from both lines showed a strong preference for the sucrose solutions, P rats consumed greater amounts than NP rats [F(7,98) = 5.57, p < 0.001], Rats of the P line drank less of the NaCl solutions than NP rats [F(7,98) = 3.88, p < 0.0011], but the effect was not as robust as the line differences seen with sucrose. The P and NP rats did not differ in citric acid or sucrose octaacetate intake at any of the concentrations tested. Selective breeding for high oral ethanol preference appears to be positively associated with consumption of sweet solutions and negatively associated with intake of salty solutions.     

胸锁乳突肌瓣联合人工生物膜修复腮腺切除术后缺损的临床观察

目的 评价腮腺切除术后应用胸锁乳突肌瓣联合人工生物膜改善面部凹陷畸形、预防味觉出汗综合征的效果. 方法 68例患者随机分为2组,修复组36例,采用胸锁乳突肌瓣联合人工生物膜修复腮腺切除术后创面;对照组32例,术后创面不做修复. 随访6~24 个月,比较2组患者术后面部凹陷畸形及味觉出汗综合征的发生率. 结果 修复组和对照组面部凹陷畸形发生率分别为8. 33%(3/36)和81. 25%(26/32),修复组低于对照组,差异具有统计学意义(χ2 =36. 83,P<0. 05);修复组和对照组味觉出汗综合征的发生率分别为5. 56%(2/36)和62. 50%(20/32),修复组低于对照组,差异有统计学意义(χ2 =25. 10,P<0. 05);2组均无颈部运动障碍发生.结论 胸锁乳突肌瓣联合人工生物膜修复腮腺切除术后缺损对改善术后面部凹陷畸形及预防味觉出汗综合征有显著效果.     

Taste and olfactory disturbances after treatment for acne with isotretinoin,a 13-cis-isomer of retinoic acid

Summary We report an olfactory disturbance after acne treatment with isotretinoin. A disturbance in taste was also reported by the patient. Examination of the nose showed no pathological findings. A CT scan was done to exclude a tumor or a lesion at the lamina cribrosa. Taste and smell examinations were performed and verified the lost qualities.