David Labbe

When machine tastes coffee: instrumental approach to predict the sensory profile of espresso coffee.

A robust and reproducible model was developed to predict the sensory profile of espresso coffee from instrumental headspace data. The model is derived from 11 different espresso coffees and validated using 8 additional espressos. The input of the model consists of (i) sensory profiles from a trained panel and (ii) on-line proton-transfer reaction mass spectrometry (PTR-MS) data. The experimental PTR-MS conditions were designed to simulate those for the sensory evaluation. Sixteen characteristic ion traces in the headspace were quantified by PTR-MS, requiring only 2 min of headspace measurement per espresso. The correlation is based on a knowledge-based standardization and normalization of both datasets that selectively extracts differences in the quality of samples, while reducing the impact of variations on the overall intensity of coffees. This work represents a significant progress in terms of correlation of sensory with instrumental results exemplified on coffee.

Training is a critical step to obtain reliable product profiles in a real food industry context

In the recent past, many authors have evaluated the benefit of training in the case of descriptive profiling. Conflicting results were presented, sometimes even concluding that untrained panels performed as well as trained ones. In this study, a panel of ten assessors evaluated eight soluble coffees from a benchmarking with repetition before and after a training of 21 h using a pre-defined glossary of 17 attributes. The benefits of training are multiple in this typical example from the food industry, where complex products are described within a relatively narrow sensory range. Two other means are proposed to shorten the duration of the study without altering the relevance of the data. First, monitoring panel performance during training helps to keep the training duration as short as possible. Second, a single evaluation of products is enough to provide reliable data for products as homogeneous as soluble coffee. In other more heterogeneous products, such as meat, cheese, etc., replicates are essential in order to determine the variability within products with the same treatment or even with the same product.

Sensory basis of refreshing perception: Role of psychophysiological factors and food experience

Refreshing is a term often used to characterize certain types of foods and beverages. This review first explores what is known from sensory and consumer studies on refreshing perception in relation to food and beverage consumption. It then presents and discusses the similarities between sensory characteristics perceived as refreshing with those perceived during and after drinking water. In general, refreshing drinks and beverages seem to help alleviate symptoms experienced during water deprivation, including thirst, mouth dryness and mental fatigue. The role that learning may have in the construction of refreshing perception during each food experience is also discussed. The review showed that a refreshing value (perceived or expected) tends to be associated with foods sharing some characteristics with water in terms of their sensory profile (clear, cold, liquid); and that food experiences may induce associative learning about perceptions of existing or new products marketed as refreshing.

Impact of novel olfactory stimuli at supra and subthreshold concentrations on the perceived sweetness of sucrose after associative learning.

The impact of coexposure to a novel olfactory stimulation in combination with sweet taste on the construction of perceptual interaction was studied. The first objective was to explore whether a new flavoring perceived retronasally at a subthreshold concentration could enhance the perceived sweetness after a coexposure with sucrose using an approach encouraging associative learning. After validating the associative learning by showing an increase of the perceived sweetness by the flavoring at a suprathreshold concentration, we showed that the flavoring stimulation did not impact the perceived sweetness when presented at a subthreshold concentration. The second objective was to validate the absence of associative learning when subjects were exposed to the sucrose flavored solution in a context of coexposure akin to sensory profiling training. As expected, we confirmed that coexposure following sensory profiling training did not promote associative learning, probably because this approach encouraged subjects to consider the olfactory and sweet taste combination as a set of distinct qualities. The potential role of neural integration processes in these results was discussed.

Is portion size selection associated with expected satiation, perceived healthfulness or expected tastiness? A case study on pizza using a photograph-based computer task

Increasing portion sizes over the last 30 years are considered to be one of the factors underlying overconsumption. Past research on the drivers of portion selection for foods showed that larger portions are selected for foods delivering low expected satiation. However, the respective contribution of expected satiation vs. two other potential drivers of portion size selection, i.e. perceived healthfulness and expected tastiness, has never been explored. In this study, we conjointly explored the role of expected satiation, perceived healthfulness and expected tastiness when selecting portions within a range of six commercial pizzas varying in their toppings and brands. For each product, 63 pizza consumers selected a portion size that would satisfy them for lunch and scored their expected satiation, perceived healthfulness and expected tastiness. As six participants selected an entire pizza as ideal portion independently of topping or brand, their data sets were not considered in the data analyses completed on responses from 57 participants. Hierarchical multiple regression analyses showed that portion size variance was predicted by perceived healthiness and expected tastiness variables. Two sub-groups of participants with different portion size patterns across pizzas were identified through post-hoc exploratory analysis. The explanatory power of the regression model was significantly improved by adding interaction terms between sub-group and expected satiation variables and between sub-group and perceived healthfulness variables to the model. Analysis at a sub-group level showed either positive or negative association between portion size and expected satiation depending on sub-groups. For one group, portion size selection was more health-driven and for the other, more hedonic-driven. These results showed that even when considering a well-liked product category, perceived healthfulness can be an important factor influencing portion size decision.

Right Sizing: Sensory-Based Product Design Is a Promising Strategy to Nudge Consumers toward Healthier Portions

Research has shown that people consume more food when offered larger portions, and that reducing exposure to large food portions and packages could decrease the average daily energy consumed. In this context, our aim is to develop strategies to promote healthier eating behaviors by reducing portion selection and intake. The present research investigates the impact of different visual attributes of foods on quantity perception and portion selection. In the first study, we tested whether modifying the shape of a familiar food influenced the ideal portion size in adults. In the second study, we assessed the impact of shape, number of units, size, and color variety on a perceived quantity for a familiar multiunit product in children. Participants (N1 = 70 adults, N2 = 62 children) completed different picture-based computer tasks. As hypothesized: (1) adults selected a smaller ideal portion size for an elongated product than for wider and thicker shapes, and (2) children’s perception of food quantity was primarily driven by number of pieces, with smaller effects of size and elongation. Perceived quantity was not influenced by color variety. These findings suggest that it may be possible to reduce the size of food portions without negatively impacting perceived quantity, and to provide opportunities to nudge consumers towards smaller portions while maintaining satisfaction.

Prediction of the overall sensory profile of espresso coffe by on-line headspace measurement using proton transfer reaction-mass spectrometry

Abstract Analytical and sensory profiling were performed on different commercially available espresso coffees. Chemical information about differences in composition of the coffee headspace characterising different coffee blends was obtained by on-line analysis using PTR-MS. In addition, an expert panel trained for coffee tasting described each sample by scoring key flavour attributes on an 11-point intensity scale. The overall sensory description of each sample was correlated with the analytically obtained differences in chemical composition to develop a tool predicting the sensory profile based on analytical data. This novel and efficient approach of characterising the coffee aroma by on-line analysis may shorten the time required for the development of new products and improve quality control in a more automated and objective manner.

Bites‘n’Bits: Inferring Eating Behavior from Contextual Mobile Data

We collect and analyze mobile data about everyday eating occasions to study eating behavior in relation to its context (time, location, social context, related activities and physical activity). Our contributions are three-fold. First, we deployed a data collection campaign with 122 Swiss university students, resulting in 1208 days of food data, 3414 meal occasions, 1034 snacking occasions, 5097 photos, and 998 days of physical activity. Second, we analyzed the collected data and report findings associated to the compliance, snacks vs. meals patterns, physical activity, and contextual differences between snacks and meals. Third, we addressed a novel ubicomp task, namely the classification of eating occasions (meals vs. snacks) in everyday life. We show that a machine learning method using time of day, time since last intake, and location is able to discriminate eating occasions with 84% accuracy, which significantly outperforms a baseline method based only on time.

Fairness-Based Tasks for Assessing Children’s Perceptions of Food Quantities and Associations with Portion Selection

It is critical to develop ecologically valid experimental methods to assess consumers’ food-related behaviors. Ad libitum approaches are often used but may not be appropriate for studies with children or with products that are not typically consumed until the individual feels full. The current study presents novel methods to assess children’s size perception and portion preference for gummy candies. In the first study, 62 children (30 boys, 32 girls) aged 6 to 9 years completed two matching tasks: one using pictures on a computer screen, and a similar task where the products were physically manipulated. Results of the two matching tasks were correlated, demonstrating that a computer-based approach could be used to predict the factors influencing children’s perception of food amount: the number, size, and shape of pieces. In the second study, a portioning measure was developed to investigate whether the factors identified in the matching tasks were confirmed in a task that more closely represented portion selection in the real world. The effects observed in the matching tasks could not be replicated in the portioning task. The size of each item had no significant impact on the portion selection, suggesting that it may be possible to reduce the size of pieces in snacks where multiple pieces are typically consumed without negatively impacting perceived quantity in children, thus offering a promising strategy to nudge children toward choosing smaller portions.

Consumer Understanding, Perception and Interpretation of Serving Size Information on Food Labels: A Scoping Review

The increase in packaged food and beverage portion sizes has been identified as a potential factor implicated in the rise of the prevalence of obesity. In this context, the objective of this systematic scoping review was to investigate how healthy adults perceive and interpret serving size information on food packages and how this influences product perception and consumption. Such knowledge is needed to improve food labelling understanding and guide consumers toward healthier portion size choices. A search of seven databases (2010 to April 2019) provided the records for title and abstract screening, with relevant articles assessed for eligibility in the full-text. Fourteen articles met the inclusion criteria, with relevant data extracted by one reviewer and checked for consistency by a second reviewer. Twelve studies were conducted in North America, where the government regulates serving size information. Several studies reported a poor understanding of serving size labelling. Indeed, consumers interpreted the labelled serving size as a recommended serving for dietary guidelines for healthy eating rather than a typical consumption unit, which is set by the manufacturer or regulated in some countries such as in the U.S. and Canada. Not all studies assessed consumption; however, larger labelled serving sizes resulted in larger self-selected portion sizes in three studies. However, another study performed on confectionary reported the opposite effect, with larger labelled serving sizes leading to reduced consumption. The limited number of included studies showed that labelled serving size affects portion size selection and consumption, and that any labelled serving size format changes may result in increased portion size selection, energy intake and thus contribute to the rise of the prevalence of overweight and obesity. Research to test cross-continentally labelled serving size format changes within experimental and natural settings (e.g., at home) are needed. In addition, tailored, comprehensive and serving-size-specific food literacy initiatives need to be evaluated to provide recommendations for effective serving size labelling. This is required to ensure the correct understanding of nutritional content, as well as informing food choices and consumption, for both core foods and discretionary foods.