Howard R. Moskowitz

Psychophysics of sweet and fat perception in obesity: problems, solutions and new perspectives

Psychophysical comparisons seem to show that obese individuals experience normal sweet and fat sensations, they like sweetness the same or less, but like fat more than the non-obese do. These psychophysical comparisons have been made using scales (visual analogue or category) that assume intensity labels (e.g. extremely) which denote the same absolute perceived intensity to all. In reality, the perceived intensities denoted by labels vary because they depend on experiences with the substances to be judged. This variation makes comparisons invalid. Valid comparisons can be made by asking the subjects to rate their sensory/hedonic experiences in contexts that are not related to the specific experiences of interest. Using this methodology, we present the evidence that the sensory and hedonic properties of sweet and fat vary with body mass index. The obese live in different orosensory and orohedonic worlds than do the non-obese; the obese experience reduced sweetness, which probably intensifies fat sensations, and the obese like both sweet and fat more than the non-obese do. Genetic variation as well as taste pathology contribute to these results. These psychophysical advances will impact experimental as well as clinical studies of obesity and other eating disorders.

The chemical interactions underlying tomato flavor preferences.

Although human perception of food flavors involves integration of multiple sensory inputs, the most salient sensations are taste and olfaction. Ortho- and retronasal olfaction are particularly crucial to flavor because they provide the qualitative diversity so important to identify safe versus dangerous foods. Historically, flavor research has prioritized aroma volatiles present at levels exceeding the orthonasally measured odor threshold, ignoring the variation in the rate at which odor intensities grow above threshold. Furthermore, the chemical composition of a food in itself tells us very little about whether or not that food will be liked. Clearly, alternative approaches are needed to elucidate flavor chemistry. Here we use targeted metabolomics and natural variation in flavor-associated sugars, acids, and aroma volatiles to evaluate the chemistry of tomato fruits, creating a predictive and testable model of liking. This nontraditional approach provides novel insights into flavor chemistry, the interactions between taste and retronasal olfaction, and a paradigm for enhancing liking of natural products. Some of the most abundant volatiles do not contribute to consumer liking, whereas other less abundant ones do. Aroma volatiles make contributions to perceived sweetness independent of sugar concentration, suggesting a novel way to increase perception of sweetness without adding sugar.

Relationship between obesity, weight loss, and taste responsiveness

Abstract Obese, mildly overweight and normal weight females rated glucose solutions of increasing concentrations for perceived intensity and pleasantness. Obese and mildly overweight subjects found increasingly sweet solutions more pleasant than did normals. Weight loss by dieting did not affect this relationship. Weight loss due to intestinal bypass surgery altered ratings of the pleasantness of glucose solutions, making them appear more similar to ratings given by normal weight individuals. Finally, after weight loss by dieting, all weight groups found the sweet taste of milkshake pleasant even after a preload and consumed large amounts of the milkshake. Prior to weight loss, ingestion of a preload had produced lowered pleasantness ratings and reduced consumption.

Strawberry Flavor: Diverse Chemical Compositions, a Seasonal Influence, and Effects on Sensory Perception

Fresh strawberries (Fragaria x ananassa) are valued for their characteristic red color, juicy texture, distinct aroma, and sweet fruity flavor. In this study, genetic and environmentally induced variation is exploited to capture biochemically diverse strawberry fruit for metabolite profiling and consumer rating. Analyses identify fruit attributes influencing hedonics and sensory perception of strawberry fruit using a psychophysics approach. Sweetness intensity, flavor intensity, and texture liking are dependent on sugar concentrations, specific volatile compounds, and fruit firmness, respectively. Overall liking is most greatly influenced by sweetness and strawberry flavor intensity, which are undermined by environmental pressures that reduce sucrose and total volatile content. The volatile profiles among commercial strawberry varieties are complex and distinct, but a list of perceptually impactful compounds from the larger mixture is better defined. Particular esters, terpenes, and furans have the most significant fits to strawberry flavor intensity. In total, thirty-one volatile compounds are found to be significantly correlated to strawberry flavor intensity, only one of them negatively. Further analysis identifies individual volatile compounds that have an enhancing effect on perceived sweetness intensity of fruit independent of sugar content. These findings allow for consumer influence in the breeding of more desirable fruits and vegetables. Also, this approach garners insights into fruit metabolomics, flavor chemistry, and a paradigm for enhancing liking of natural or processed products.

Human taste perception

The recent literature in human taste research is critically reviewed. Special emphasis is placed on the qualities of taste and on taste intensity measurements. The underlying theme throughout the review is taste research methods. Phenomena receiving special attention are taste adaptation and taste mixtures.

Sweet taste induced by miracle fruit (Synsepalum dulcificum)

Abstract Topical application of miracle fruit (Synsepalum dulcificum) caused subsequently tasted hydrochloric and citric acids to taste less sour than normal and as if they had been sweetened. Gymnema sylvestre abolished this sweetness and returned the sourness of both acids to approximately their normal intensities although Gymnema sylvestre alone did not significantly affect the taste of the acids. This suggests that miracle fruit adds sweetness to acids without directly blocking sour receptor sites. When sugar was added to citric acid to make it about as sweet as it was after miracle fruit, then the sourness was suppressed in the mixture just as sourness was suppressed by miracle fruit. This suggests that the reduction in sourness after miracle fruit resulted from mixture suppression, i.e., the mutual suppression usually observed between different qualities in a mixture. When several acids were matched in sourness they did not become equally sweet after miracle fruit.

Psychophysical and psychometric approaches to sensory evaluation

Sensory evaluation has recently utilized the methods developed by psychophysicists and psychometricians, who seek to represent data in terms of various scales and mathematical formulations. This review covers the development of ratio scaling to develop relations between sensory and instrumental measures of food, the use of multivariate psychophysical procedures which relate a variety of physical variables to a single sensory response, and the use of multidimensional scaling to relate different sensory percepts to each other. Each of these approaches is nascent in applications to sensory evaluation, although the mathematics and formulations are very developed. Each approach gives the experimenter insights into subjective and objective correlations and the manner in which the panelist perceives relations among stimuli. The treatment of the reported literature for each approach follows the same course: necessary conditions for its application to sensory evaluation, experiences with model systems and real foo...Sensory evaluation has recently utilized the methods developed by psychophysicists and psychometricians, who week to represent data in terms of various scales and mathematical formulations. This review covers the development of ratio scaling to develop relations between sensory and instrumental measures of food, the use of multivariate psychophysical procedures which relate a variety of physical variables to a single sensory response, and the use of multidimensional scaling to relate different sensory percepts to each other. Each of these approaches is nascent in applications to sensory evaluation, although the mathematics and formulations are very developed. Each approach gives the experimenter insights into subjective and objective correlations and the manner in which the panelist perceives relations among stimuli. The treatment of the reported literature for each approach follows the same course: necessary conditions for its application to sensory evaluation, experiences with model systems and real foods, and potential uses and limitations in sensory evaluation.

Reinventing the role of consumer research in today's open innovation ecosystem.

Consumer research (CR) has played a key role in the food and beverage industry. Emerging from laboratory product-tests, it has evolved into a corporate testing service that measures the consumer reactions to products/concepts using a wide range of analyses/metrics. We propose that CR transform itself in light of accelerated knowledge expansion, mounting global, and local economic pressure on corporations and changing consumer needs. The transformation moves from its traditional testing into creating profoundly new knowledge of the product and understanding of the corporations current and future customers. CRs tasks will involve: contributing/expanding science, applying open innovation principles, and driving consumer-centric innovation. We identify seven paradigm shifts that will change CR, namely: a different way of working—from testing to open sourcing; from good corporate citizen to change leader; open new product development (NPD) process; new management roles/cultures; universities and industry, new education curricula, and cooperation; from battle over control to sustainable sharing is winning model (SiW); and the central role of design. This integrative, innovative CR requires the implementation of three recommendations: start the change process now, fine-tune along the way; create a new marketing/CR department; and educate and professionalize. These recommendations provide the blueprint for jump-starting the process and call for immediate actions to deal with the severity of the crises facing the CR profession.

Drivers of Vaginal Drug Delivery System Acceptability from Internet-Based Conjoint Analysis

Vaginal microbicides potentially empower women to protect themselves from HIV and other sexually transmitted infections (STIs), especially when culture, religion, or social status may prevent them from negotiating condom use. The open literature contains minimal information on factors that drive user acceptability of women’s health products or vaginal drug delivery systems. By understanding what women find to be most important with regard to sensory properties and product functionality, developers can iteratively formulate a more desirable product. Conjoint analysis is a technique widely used in market research to determine what combination of elements influence a consumer’s willingness to try or use a product. We applied conjoint analysis here to better understand what sexually-active woman want in a microbicide, toward our goal of formulating a product that is highly acceptable to women. Both sensory and non-sensory attributes were tested, including shape, color, wait time, partner awareness, messiness/leakage, duration of protection, and functionality. Heterosexually active women between 18 and 35 years of age in the United States (n = 302) completed an anonymous online conjoint survey using IdeaMap software. Attributes (product elements) were systematically presented in various combinations; women rated these combinations of a 9-point willingness-to-try scale. By coupling systematic combinations and regression modeling, we can estimate the unique appeal of each element. In this population, a multifunctional product (i.e., broad spectrum STI protection, coupled with conception) is far more desirable than a microbicide targeted solely for HIV protection; we also found partner awareness and leakage are potentially strong barriers to use.