Hélène Labouré

In-Mouth Mechanisms Leading to Flavor Release and Perception

During eating, foods are submitted to two main oral processes—chewing, including biting and crushing with teeth, and progressive impregnation by saliva resulting in the formation of a cohesive bolus and swallowing of the bolus. Texture influences the chewing behavior, including mastication and salivation, and in turn, these parameters influence texture perception and bolus formation. During this complex mouth process, flavor compounds are progressively released from the food matrix. This phenomenon is mainly dependent on the food texture, the composition and in-mouth breakdown, and on saliva impregnation and activity, but an individuals anatomical and physiological aspects characteristics should also be taken into account. This article reviews the knowledge and progresses on in-mouth processes leading to food breakdown and flavor release and affecting perception. Relationships between food texture and composition, food breakdown, oral physiology, and flavor release are developed and discussed. This review includes not only the mechanical aspects of oral physiology but also the biological aspects such as the influence of saliva composition, activity, and regulation on flavor perception. In vitro and in silico approaches are also described.

In vivo aroma release of milk gels of different hardnesses: inter-individual differences and their consequences on aroma perception.

The effect of textural modifications of solid milk gels on in vivo aroma release and aroma perception was investigated with a panel of 14 subjects. Great inter-individual differences were observed on aroma-release data, and the consequences of these differences on aroma perception were studied. From a hierarchical cluster analysis performed with several parameters extracted from release curves, the subjects were gathered into two groups, and a specific aroma-release profile was identified for each one. Then, by using a sensory profile, we showed that the intensity of the aroma perception was dependent on the release profile presented by the panelist. Second, we observed that, during the chewing phase, the aroma was perceived as more intense for the firmer gel and for panelists for whom the aroma release begins during the chewing of the product.

Solid cheese consumption: Quantification of oral coating

Mouth coating, defined as the residual food that sticks to the oral surface after food ingestion, plays an important role in both the delivery of food components and mouth feel and after-feel perceptions. The aim of this work was to adapt a rapid and simple instrumental method to the quantification of food remaining after the in vivo ingestion of a solid food. This method was investigated in 12 non-trained subjects who consumed four melted cheeses differing in terms of their fat and water contents. Mouth coating was determined by fluorescence measurements using curcumin, an oil-soluble dye that had been added to the cheeses during their preparation. The results obtained showed that this method was reproducible, reliable and discriminating and could be used for solid cheeses covering a broad range of textures.

The structure of a food product assortment modulates the effect of providing choice on food intake

Several authors showed that providing choice may increase food liking and food intake. However, the impact of choice may be modulated by assortments characteristics, such as the number of alternatives or their dissimilarity. The present study compared the impact of choice on food liking and intake under the two following conditions: (1) when choosing a product to consume from among similar products versus dissimilar products; and (2) when choosing a product to consume from among pleasant products versus unpleasant products. Two experiments were carried out using the same design: the apple puree experiment (nxa0=xa080), where the volunteers choose from among similar products (apple purees varying in texture) and the dessert experiment (nxa0=xa080), where the volunteers choose from among dissimilar products (fruit dessert, dairy dessert, custard, pudding). During the first session, participants rated their liking for 12 products (apples purees or desserts). Then the participants were divided into a pleasant group (nxa0=xa040) in which volunteers were assigned three pleasant products, and an unpleasant group (nxa0=xa040) in which volunteers were assigned three unpleasant products. Finally, all of the volunteers participated in a choice session - volunteers were presented with their three assigned products and asked to choose one of the products, and a no-choice session - volunteers were served with one product that was randomly selected from among their three assigned products. Providing choice led to an increase in food liking in both experiments and an increase in food intake only for the desserts, namely only when the volunteers chose the product to consume from among not too similar alternatives. No effect of assortments pleasantness was observed.

Using food comfortability to compare food's sensory characteristics expectations of elderly people with or without oral health problems

Food consumption is by far the most important point where foods organoleptic properties can be perceived and can elicit sensory pleasure. Ageing is often accompanied by oral impairments. Those impairments may impact food perception by changing texture perception and the release of flavor components, which have a significant impact on food acceptability. The present study aimed at evaluating the impact of oral health on the perception of food comfortability in an elderly population. This was achieved by asking elderly people with a good oral health and elderly people with poor oral health to rate six cereal products and six meat products using a food comfortability questionnaire. Thirty-seven and 35 elderly people (65-87 years old) underwent either a cereal or meat session, respectively. The present study showed very few effects of dental and saliva status on food perception. For the cereal products, a significant effect of dental status was observed for one texture descriptor and one flavor descriptor, and a significant effect of salivary status was observed for two texture descriptors and one flavor descriptor. For the meat products, a significant effect of dental status and a significant effect of salivary status were observed on one flavor descriptor. For both products, no significant impact of dental or salivary status was observed on the general perception of food oral comfort nor on food bolus formation. Future studies exploring the impact of a broader set of oral parameters and potential adapting factors are needed to further explore the results of the present study.nnnPRACTICAL APPLICATIONSnDuring oral food consumption, mastication, salivation, and swallowing play a key role in the acceptance of food and beverages by modulating the perception of texture, taste, and aroma, as well as providing eating comfort by assisting the food breakdown process into a bolus that can be safely swallowed. The age-related oral impairments such as loss of teeth, decrease in salivary flow or dysphagia are known to have an impact on food consumption. However, very few products are developed to skirt those impairments. Therefore, in the context of an ageing population, there is a need to develop functional foods that meet the specific nutritional needs of the elderly population, as well as a well-balanced flavor and texture framework. Considering the large interindividual variability observed on the elderly people, developing adapted functional foods is a major challenge for the food industry and society.

The Potential Use of Raw and Deodorized Non-Conventional Protein Powder in Human Food

This study aimed to evaluate the potential use of a non-conventional protein source, a powder made from earthworms, as human food. Sensory analyses were done in order to assess the acceptability of cookies that were fortified with Eisenia foetida (Ef) protein powder. Cocoa and cinnamon were used as taste-masking agents. The acceptability of cookies fortified with deodorized Ef protein powder (off-flavor reduced) was also evaluated. We demonstrated that cocoa cookies can be fortified with 3.9% of raw Ef proteins and that cocoa/cinnamon cookies can be fortified with 5.2% of raw Ef proteins without any loss in their acceptability. Cookies fortified either with a raw protein powder or with a deodorized protein powder are significantly different up to a protein substitution level of 5%. Unflavored cookies can be fortified with 5.6% of deodorized Ef proteins and remain acceptable.