Measuring cooking experience implicitly and explicitly: Physiology, facial expression and subjective ratings

A current review of U.S. beef flavor I: Measuring beef flavor

Historically, consumer acceptance of beef was determined by tenderness. Developments in genetics and management over the last couple of decades have improved tenderness to the point that it is secondary to other factors in beef's taste. Flavor, however, is an extraordinarily complex taste attribute dependent on biological sensors in the mouth, sinus cavity, and jaws. The culinary industry has recently focused on innovative ways to give consumers new products satisfying their curiosity about different foods, especially proteins. Competition from plant-based, cell-based, and even other animal-based proteins provides diversity in consumers' ability to select a protein that satisfies their desire to include unique products in their diet. Consequently, the beef industry has focused on flavor for the last 10 to 15 years to determine whether it can provide the guardrails for beef consumption in the future. The U.S. beef industry formed a Flavor Working Group in 2012 composed of the authors listed here to investigate new and innovative ways to manage and measure beef flavor. The results of this working group have resulted in dozens of papers, presentations, abstracts, and symposia. The objective of this manuscript is to summarize the research developed by this working group and by others worldwide that have investigated methodologies that measure beef flavor. This paper will describe the strengths of the research in beef flavor measurement and point out future needs that might be identified as technology advances.

New Consumer Research Technology for Food Behaviour: Overview and Validity

BACKGROUND

the last decade has witnessed an explosion of new consumer behaviour research technology, and new methods are published almost monthly. To what extent are these methods applicable in the specific area of food consumer science, and if they are, are they any good?

METHODS

in this paper, we attempt to give an overview of the developments in this area. We distinguish between ('input') methods needed to shape the measurement context a consumer is brought in, e.g., by means of 'immersive' methods, and ('output') methods that perform measurements proper. Concerning the latter, we distinguish between methods focusing on neuro-science, on psychology, and on behaviour. In addition, we suggest a way to assess the validity of the methods, based on psychological theory, concerning biases resulting from consumer awareness of a measurement situation. The methods are evaluated on three summarising validity criteria; conclusions: the conclusion is that behavioural measures generally appear more valid than psychological or neuro-scientific methods. The main conclusion is that validity of a method should never be taken for granted, and it should be always be assessed in the context of the research question.

Development of a direct mapping model between hedonic rating and facial responses by dynamic facial expression representation

Consumer tests are one of the most important activities in product development. More evidence indicates that consumer emotions in real life are mostly driven by unconscious mechanisms, and implicit measurements are regarded as beneficial by an increasing number of sensory and consumer scientists. Nonverbal manner such as facial expression analysis is a supplement to the declarative method and brings very insightful results. Up until now, the facial expression analysis for consumers' acceptance identification is limited to investigate the relationship between hedonic rating and facial expression descriptors, such as facial coding system (FACS or MAX), discrete facial expressions (i.e. happiness, sadness, surprise, fear, anger, and disgust), and affective dimensional model (valence and activation). In this study, we attempt to develop a direct mapping model between the hedonic rating and facial responses evoked by various taste stimuli. Basic taste solutions (sourness, sweetness, bitterness, umami, and saltiness) with six levels, and five types of juice are used as stimuli. Firstly, the hedonic rating categories are defined based on the nine-point hedonic scale, with a coarse-to-fine division of scale levels based on two directions of like and dislike. Secondly, the facial dynamic optical flow method is employed to analyze facial characteristics of the subjects' facial responses evoked by taste stimuli. And the genetic algorithm is conducted to select facial regions that have high contribution to hedonic rating identification. It indicates that the texture changes of eye area, wrinkles at the nasal root, and mouth area can effectively reflect the facial reaction corresponding to hedonic rating. The research shows that it is feasible to establish a direct mapping model between hedonic rating and facial responses. The hedonic rating can be predicted through automatic facial reading technology, without extra transformation from predefined emotional models. In general, this is the first try to discuss the direct prediction of hedonic rating through facial expressions up to now, and it is a complex problem due to various influence factors.

Drivers of Consumer Liking for Beef, Pork, and Lamb: A Review

Tenderness, juiciness, and flavor have been associated with consumer acceptance of beef, lamb, and pork. Drivers of consumer liking are interrelated across these species, but there are differences in consumer preferences. Animal age, animal diet, and subsequent marbling impact consumer liking across species. For beef, consumer research prior to the 1990s showed that tenderness was the main driver of liking. Consumer tenderness and juiciness liking are highly correlated. More recent research has shown that as overall tenderness improved and tenderness variation decreased, flavor has become a more important driver of beef consumer liking. Flavor is affected by consumer preparation methods, familiarity with different flavor presentations, and animal production systems. Animal diet impacts consumer perception of beef tenderness and flavor, especially when comparing forage-fed versus grain-fed beef. Flavor preferences vary across countries more so than preferences for beef based on consumer tenderness preferences and are most likely influenced by the consumption of locally produced beef and the flavor-derived type of beef traditionally consumed. Drivers of pork consumer liking have been shown to be affected by pH, color, water holding capacity, animal diet, and the presence of boar taint compounds. While tenderness and juiciness continue to be drivers of consumer liking for pork, flavor, as impacted by animal diet and the presence of boar taint compounds, continues to be a driver for consumer liking. For lamb, the flavor, as affected by diet, and animal age continue to be the main drivers of consumer liking. Lamb consumers vary across countries based on the level of consumption and preferences for flavor based on cultural effects and production practices.