The Association Between Quinine Hydrochloride Sensitivity and Disgust Proneness in Children and Adults

One of the major challenges of masking the bitter taste in medications: an overview of quantitative methods for bitterness

Objective

The aim of the present study was to carry out a systematic research on bitterness quantification to provide a reference for scholars and pharmaceutical developers to carry out drug taste masking research. Significance: The bitterness of medications poses a significant concern for clinicians and patients. Scientifically measuring the intensity of drug bitterness is pivotal for enhancing drug palatability and broadening their clinical utility.

Methods

The current study was carried out by conducting a systematic literature review that identified relevant papers from indexed databases. Numerous studies and research are cited and quoted in this article to summarize the features, strengths, and applicability of quantitative bitterness assessment methods.

Results

In our research, we systematically outlined the classification and key advancements in quantitative research methods for assessing drug bitterness, including in vivo quantification techniques such as traditional human taste panel methods, as well as in vitro quantification methods such as electronic tongue analysis. It focused on the quantitative methods and difficulties of bitterness of natural drugs with complex system characteristics and their difficulties in quantification, and proposes possible future research directions.

Conclusion

The quantitative methods of bitterness were summarized, which laid an important foundation for the construction of a comprehensive bitterness quantification standard system and the formulation of accurate, efficient and rich taste masking strategies.

Taste assessment for paediatric drug Development: A comparison of bitterness taste aversion in children versus Naïve and expert young adult assessors

Medicines for children often taste bitter, presenting a significant challenge to treatment compliance. However, most studies on paediatric drug development rely on adult volunteers for sensory research, and the level of expertise required from these assessors is unclear. This study aimed to address this gap by investigating perceived bitterness aversion to taste strips impregnated with different concentrations of quinine hydrochloride in 439 school-aged children. Expert (n = 26) and naïve (n = 65) young adult assessors evaluated quinine solutions as well as taste strips, for methodological bridging purposes. All assessors differentiated the aversiveness of the taste strips in a dose dependent manner. Younger children aged 4-8 years had difficulty discriminating higher bitter concentrations, whereas pre-adolescents 9-11 years and naive adults showed better discrimination at the top of the scale. Naive assessors showed similar bitter perception as children. However, the results were slightly different between strips and solution in adults. These findings highlight the key role that adult panels can play in paediatric formulation development. Taste strips show promise as a safe and pragmatic tool for sensory pharmaceutical evaluations, though further studies are warranted to establish the relationship between age and hedonic taste perception using compounds with diverse physicochemical and sensory qualities.

Exploring the role of disgust sensitivity and propensity in selective eating

While disgust is a clinically and theoretically relevant construct for selective eating, limited research has examined how different aspects of disgust relate to selective eating severity in adults. Thus, the present study sought to 1) compare disgust propensity (how easily people are disgusted) and disgust sensitivity (how unpleasant disgust is) across a spectrum of selective eaters, 2) explore the specificity of the associations between disgust sensitivity/propensity and selective eating across selective eating and related phenotypes, and 3) explore whether the relationship between selective eating and disgust is food-specific. Participants were 554 adults recruited on Amazon's Mechanical Turk who completed cross-sectional surveys on study constructs. The sample was recruited to over-represent individuals with high levels of selective eating. Results support that disgust propensity, but not sensitivity, was elevated in the impaired selective eating group compared to non-impaired selective eaters and non-selective eaters. Only the selective eating phenotype was independently associated with both disgust sensitivity and propensity. Correlation results supported that the associations between selective eating and disgust were specific to the disgust elicited by food (i.e., animal protein, fruits, vegetables). Overall, results support that disgust propensity and disgust sensitivity play a role in selective eating. Results imply that disgust sensitivity associated with selective eating appears limited to the food domain and may be more specific to disgust eliciting food itself, rather than signs of food contamination or spoilage.

The processing of visual food cues during bitter aftertaste perception in females with high vs. low disgust propensity: an fMRI study

An extremely bitter taste can signal food spoilage, and therefore typically elicits disgust. The present cross-modal functional magnetic resonance imaging experiment investigated whether the personality trait ‘disgust propensity’ (DP; temporally stable tendency to experience disgust across different situations) has an influence on the processing of visual food cues during bitter aftertaste perception. Thirty females with high DP and 30 females with low DP viewed images depicting sweet food (e.g., cakes, ice cream) and vegetables, once in combination with an extremely bitter aftertaste (concentrated wormwood tea), and once with a neutral taste (water). Females highly prone to disgust (compared to low disgust-prone females) showed increased activity in the anterior cingulate cortex (ACC) and increased mPFC-insula connectivity when presented with the mismatch of a bitter aftertaste and visual cues of sweet food. The ACC is involved in conflict monitoring and is strongly interconnected with insular areas. This connection plays a critical role in awareness of changes in homeostatic states. Our findings indicate that the personality trait DP is associated with cross-modal integration processes of disgust-relevant information. Females high in DP were more alert to food-related sensory mismatch (pleasant visual features, aversive taste) than females low in DP.

Disgust Propensity and the Bitter Aftertaste Response

Introduction

A high level of disgust propensity (the general tendency to respond with the emotion of disgust to any given situation) is associated with an increased sensitivity to bitter taste. The present study examined the relationship between disgust propensity and the sensitivity to bitter aftertaste.

Methods

A total of 200 women rinsed their mouth with concentrated wormwood tea (Artemisia absinthium). The resulting aftertaste was evaluated (intensity of bitterness and disgust) every 15 s for 10 min. A multiple linear regression analysis was calculated to capture the association between aftertaste ratings and affective variables (e.g., disgust propensity, depression symptoms).

Results

Higher disgust propensity was associated with higher initial disgust ratings and faster reduction of disgust over time. Higher depression scores were associated with a slower disgust reduction.

Conclusion

We demonstrated that affective variables predict the temporal course of the wormwood aftertaste response. Having a higher disgust propensity was associated with a shortened disgust recovery.

Implications

A shortened disgust recovery may be adaptive because it enables faster processing of new disgust stimuli.