Use of sensory and physico-chemical parameters to understand consumer perception of attiéké, a fermented cassava product

Background: Cassava breeding research programs focused initially on agronomic performance but in recent years they have con-sidered the processability and the organoleptic properties of the final product, to increase the adoption of new varieties. One important cassava foodstuff is attiéké, a fermented and granular product, so it is necessary to determine criteria used by attiéké processors to select raw cassava and the characteristics leading consumers to like this product. This study assessed the attiéké pro-duction process, the criteria associated with the quality of attiéké, the sensory drivers of consumer acceptance, and their thresholds. Results: The total processing yield of attiéké varied according to the cassava variety and depended primarily on the fermentation-pressing yield. However, it was not correlated either with the peeling yield or with morphological characteristics of cassava roots. The production of a ton of attiéké required about 150 h. Dry matter, organic acids, soluble sugars, total pectin, and the pH of raw material and attiéké varied depending on the cassava variety. Ten discriminating sensory attributes of attiéké were identified. Consumer testing showed that overall liking for attiéké was associated with sourness, texture, and brightness. Acceptable sensory score thresholds were 1.67–2.18 for sour odor, 4.75 to 6.3 for cohesiveness, and 5.4 to 6.3 for ‘mouth feel sensation’. Attiéké dry matter correlated positively with cohesiveness and moldability. Conclusions: Several potential solutions are discussed to improve the adoption of cassava varieties for attiéké production. How-ever, further studies need to be carried out to translate the sensory thresholds of texture attributes into robust instrumental methods because texture is an important attribute of attiéké in addition to sourness

Key Aroma Compounds of Dark Chocolates Differing in Organoleptic Properties: A GC-O Comparative Study

International audienceDark chocolate samples were previously classified into four sensory categories. The classification was modelled based on volatile compounds analyzed by direct introduction mass spectrometry of the chocolates’ headspace. The purpose of the study was to identify the most discriminant odor-active compounds that should characterize the four sensory categories. To address the problem, a gas chromatography-olfactometry (GC-O) study was conducted by 12 assessors using a comparative detection frequency analysis (cDFA) approach on 12 exemplary samples. A nasal impact frequency (NIF) difference threshold combined with a statistical approach (Khi² test on k proportions) revealed 38 discriminative key odorants able to differentiate the samples and to characterize the sensory categories. A heatmap emphasized the 19 most discriminant key odorants, among which heterocyclic molecules (furanones, pyranones, lactones, one pyrrole, and one pyrazine) played a prominent role with secondary alcohols, acids, and esters. The initial sensory classes were retrieved using the discriminant key volatiles in a correspondence analysis (CA) and a hierarchical cluster analysis (HCA). Among the 38 discriminant key odorants, although previously identified in cocoa products, 21 were formally described for the first time as key aroma compounds of dark chocolate. Moreover, 13 key odorants were described for the first time in a cocoa product

Organoleptic properties of dark chocolates investigated by direct-injection mass spectrometry (PTR-ToF-MS) and GC-Olfactometry

International audienc

Nose-space of dark chocolates using PTR-ToF-MS and link to flavour perception through simultaneous Temporal Dominance of Sensations (TDS)

International audienceIntroduction: Aroma of dark chocolate depends on process and cocoa origin and variety. A sensory analysis of 206 standardized chocolates produced from various cocoa beans classified them in four sensory categories. These categories were confirmed in a PTR-MS analysis of the chocolates volatilome [1]. The objective here was to study the nosespace of a subset of chocolates simultaneously with their temporal profile to better explain the sensory categorization at a perception level. Methods: A Temporal Dominance of Sensations (TDS) evaluation of 8 chocolates (2 selected per category) was done in triplicate by 12 subjects while the aroma released in their nose were simultaneously collected and injected into a PTR-ToF-MS. The two sets of data were analyzed conjointly by defining an index of abundance of each detected aroma compound while a given attribute was dominant: the Abundance While Dominance (AWD) index [2]. Results TDS is able to dynamically capture multidimensionality of perception. The obtained TDS curves clearly differentiated the chocolates that were regrouped by sensory category as revealed by a principal component analysis (PCA). The dynamics of perception have been considered only scarcely in comparison to simultaneous in vivo aroma release over time measured by on-line mass spectrometry (nosespace). Computation of the AWD indices at individual level allowed to statistically assess the differences between the products over subjects and replicates and assessed statistically the relationships between the two sets of data. Through correspondence analyses (CA) some relationships between certain aroma compounds and the sensory attributes expected to be related to them were found. Although in previous studies pairing nosespace and TDS various temporal links could be proposed [3], no clear relationships could be safely established due to the fact that the conclusions: were mainly based on a descriptive analysis of the data conducted at panel level. Conclusions Pairing nosespace with Temporal Dominance of Sensations evaluation of dark chocolates categorized in four sensory groups provides meaningful data that can be analyzed at individual level thanks to the AWD indices. Descriptive multivariate analyses of these AWD indices gave interesting clues on the relationships between the aroma compounds released in mouth and their expected perceived sensory attributes. Novel Aspect Pairing nosespace PTR-ToF-MS with Temporal Dominance of Sensations allows assessing the relationships between aroma compounds released in vivo and their perception.References: 1. Deuscher Z., Andriot I., Sémon E, …, Le Quéré J.L., SMMAP2017, Dineyland Paris, October 2-5 (2017). 2. Schlich P., Thomas A., Visalli M., Labarre D., Sémon E., Le Quéré J.L., in Flavour Science: Proceedings of the XIV Weurman Flavour Research Symposium, (Taylor A.J., Mottram D.S., Eds.), Context Products Ltd., Leicestershire (UK), 327-332 (2015). 3. Déléris I., Saint-Eve A., Dakowski F., Sémon E., Le Quéré J.L., Guillemin H., Souchon I., Food Chem., 127(4), 1615-1624 (2011)

Nosespace of dark chocolates differing in sensory characteristics using PTR-TOF-MS and link to flavour perception through simultaneous Temporal Dominance of Sensations (TDS)

International audienceAroma of dark chocolate depends on process and cocoa origin and variety. Repeated sensory analyses of standardized chocolates produced from various cocoa beans using a standard fabrication process allowed classifying them in four sensory categories. These categories were confirmed in a PTR-MS analysis of the volatilome of 206 chocolate samples [1]. The objective here was to study the nosespace of a subset of chocolates simultaneously with their temporal profile to better explain the sensory categorization at a perception level. A Temporal Dominance of Sensations (TDS) evaluation of 8 chocolates (2 selected per category) was done in triplicate by 12 subjects while the aroma released in their nose were simultaneously collected and injected into a PTR-ToF-MS. The two sets of data were analyzed conjointly by defining an index of abundance of each detected aroma compound while a given attribute was dominant: the Abundance While Dominance (AWD) index [2]. The dynamics of perception have been considered only scarcely in comparison to simultaneous in vivo aroma release over time measured by on-line mass spectrometry (nosespace). TDS is able to dynamically capture multidimensionality of perception. The obtained TDS curves clearly differentiated the chocolates that were regrouped by sensory categories as revealed by a principal component analysis (PCA). Although in previous studies pairing nosespace and TDS various temporal links could be proposed [3], no clear relationships could be safely established due to the fact that the conclusions were mainly based on a descriptive analysis of the data conducted at panel level. Computation of the AWD indices at individual level allowed to statistically assess the differences between the products over subjects and replicates and assessed statistically the relationships between the two sets of data. Through correspondence analyses (CA) some relationships between certain aroma compounds and the sensory attributes expected to be related to them were found. Pairing nosespace with Temporal Dominance of Sensations evaluation of dark chocolates categorized in four sensory groups provided meaningful data that could be analysed at individual level thanks to the AWD indices. Descriptive multivariate analyses of these AWD indices gave interesting clues on the relationships between the aroma compounds released in mouth and their expected perceived sensory attributes. 1. Deuscher Z., Le Quéré J.L. et al., J. Mass Spectrom., submitted (2018). 2. Schlich P., Le Quéré J.L. et al., in Flavour Science (Taylor A.J., Mottram D.S.,Eds.), Context Products Ltd., Leicestershire (UK), 327-332 (2015). 3 Déléris I., Saint-Eve A., Dakowski F., Sémon E., Le Quéré J.L., Guillemin H., Souchon I., Food Chem., 127(4), 1615-1624 (2011)

Chocolates classification according to their volatile compounds fingerprints measured by PTR-ToF-MS

International audienc

Organoleptic properties of dark chocolates investigated by direct-injection mass spectrometry (PTR-ToF-MS) and GC-MS-Olfactometry

National audienc

Does aroma composition allow to discriminate groups of dark chocolates categorized on the basis of their organoleptic properties? Inputs of direct-injection mass spectrometry (PTR-ToF-MS) and GC-Olfactometry

International audienc

Organoleptic propoerties of dark chocolates investigated by direct-injection mass spectrometry (PTR-To-MS) and GC-olfactometry

15. Weurman Flavour Research Symposium ; Graz (Autriche) - (2017-09-18 - 2017-09-22)International audienceA preliminary sensory study conducted on a set of 187 dark chocolates varying in terms of cocoa origin and variety allowed their classification into four distinct sensory categories. Fingerprints in volatile organic compounds (VOCs) of these chocolates wereobtained by a direct-injection mass spectrometry headspace method using Proton Transfer Reaction Mass Spectrometry (PTR-MS). This chemical analysis allowed discriminating the four sensory poles, so the sensory discrimination seemed to be mainly based on volatile compounds. Then, the key odorants responsible for chocolates differentiation were determined through identification of targeted aroma compounds by GC-MS after GC-O analyses of extracts representative of each subset of chocolates. Twelve dark chocolates were studied using the detection frequency method. The odour eventsgenerated by a panel of 12 assessors were grouped into 124 odorant areas (OAs).Correspondence analyses allowed distinguishing the samples while identifying 34 OAs that appear relevant to discriminate the chocolates sensory poles. Among these characteristic OAs, five were identified unambiguously with GC-MS and the remainingneed to be resolved from numerous coeluted peaks