Holistic and consumer-centric assessment of beer: A multi-measurement approach.

Despite occupying a cornerstone position in consumer research and innovation, product liking/disliking provides only partial insight into consumer behaviour. By adopting a consumer-centric perspective and drawing on additional factors that underpin food-related consumer behaviour, a more complete product understanding is gained. The present research showcases this approach in a study with New Zealand beer (incl. pilsner, lager and ale categories). Implementation of a multi-variate approach with 128 regular beer drinkers provided assessments pertaining to liking and sensory novelty/complexity, situational appropriateness of consumption, as well as attitudes/perceptions and emotional associations. The 9 samples grouped into two clusters, where 4 of the beers were similar in being perceived as having less complex flavours, being appropriate for many uses and evoking stronger emotional associations of "relaxed/calm." The 4 beers were perceived as "easy to drink", and were, on average, most liked. One of the samples in this cluster was lighter in alcohol (2.5% ABV), but not inferior to beers with 4-5% ABV. The 5 beers in the second cluster were, on average, less liked and were associated with more negative emotions, e.g. "unhappy, "jittery", and "tense". Additional insights were gained from segmentation which identified two groups of consumers, named 'Lager Lovers' and 'Ale Aficionados'. Beers 1-4 were positively perceived by 'Lager Lovers' but less so by 'Ale Aficionados', and vice versa. The study was conducted under central location test conditions compatible with testing protocols often used in product research. The study protocol can be amended to include few/many consumer-centric measures and extended to product testing where packaging, brand, and other extrinsic information is available to consumers.

A Mendelian trait for olfactory sensitivity affects odor experience and food selection.

Humans vary in acuity to many odors [1-4], with variation within olfactory receptor (OR) genes contributing to these differences [5-9]. How such variation also affects odor experience and food selection remains uncertain [10], given that such effects occur for taste [11-15]. Here we investigate ß-ionone, which shows extreme sensitivity differences [4, 16, 17]. ß-ionone is a key aroma in foods and beverages [18-21] and is added to products in order to give a pleasant floral note [22, 23]. Genome-wide and in vitro assays demonstrate rs6591536 as the causal variant for ß-ionone odor sensitivity. rs6591536 encodes a N183D substitution in the second extracellular loop of OR5A1 and explains >96% of the observed phenotypic variation, resembling a monogenic Mendelian trait. Individuals carrying genotypes for ß-ionone sensitivity can more easily differentiate between food and beverage stimuli with and without added ß-ionone. Sensitive individuals typically describe ß-ionone in foods and beverages as "fragrant" and "floral," whereas less-sensitive individuals describe these stimuli differently. rs6591536 genotype also influences emotional associations and explains differences in food and product choices. These studies demonstrate that an OR variant that influences olfactory sensitivity can affect how people experience and respond to foods, beverages, and other products.

Identification of regions associated with variation in sensitivity to food-related odors in the human genome.

Humans vary in their ability to smell numerous odors [1-3], including those associated with food [4-6]. Odor sensitivity is heritable [7-11], with examples linking genetic variation for sensitivity to specific odors typically located near olfactory receptor (OR) genes [12-16]. However, with thousands of aromas and few deorphaned ORs [17, 18], there has been little progress toward linking variation at OR loci to odor sensitivity [19, 20]. We hypothesized that OR genes contain the variation that explains much of the differences in sensitivity for odors, paralleling the genetics of taste [21, 22], which affect the flavor experience of foods [23-25]. We employed a genome-wide association approach for ten food-related odors and identified genetic associations to sensitivity for 2-heptanone (p = 5.1 × 10(-8)), isobutyraldehyde (p = 6.4 × 10(-10)), ß-damascenone (p = 1.6 × 10(-7)), and ß-ionone (p = 1.4 × 10(-31)). Each locus is located in/near distinct clusters of OR genes. These findings increase the number of olfactory sensitivity loci to nine and demonstrate the importance of OR-associated variation in sensory acuity for food-related odors. Analysis of genotype frequencies across human populations implies that variation in sensitivity for these odors is widespread. Furthermore, each participant possessed one of many possible combinations of sensitivities for these odors, supporting the notion that everyone experiences their own unique "flavor world."

Examples of perceptive interactions involved in specific "red-" and "black-berry" aromas in red wines.

A preparative HPLC method, which preserves wine aromas and isolates fruity characteristics in specific fractions, was applied to red wine aroma extracts. Various odor-active zones were detected in typical fractions by GC-O analysis of their extracts. Through further GC-MS analyses, the aromatic compounds responsible for 15 of these odoriferous zones were identified as various ethyl esters and alkyl acetates. In view of their olfactory thresholds, the concentrations of these compounds had no direct impact on the fruity aroma of red wines. Nevertheless, an overall sensory effect of "red-" or "black-berry" nuances was clearly established. Higher than average levels of ethyl propanoate, ethyl 2-methylpropanoate, and ethyl 2-methylbutanoate were involved in black-berry aromas, whereas ethyl butanoate, ethyl hexanoate, ethyl octanoate, and ethyl 3-hydroxybutanoate conferred red-berry aromas.

Instrumental and sensory approaches for the characterization of compounds responsible for wine aroma.

More than 800 aromatic compounds have been identified in wine, some of them at the ng/l level. Wine, therefore, constitutes a very complex matrix, from which it is difficult to isolate a specific aroma character. Gas chromatography-olfactometry (GC-O) applied to wine extracts is used to characterize odor-active zones that are often treated in a hierarchical way by Aroma Extract Dilution Analysis (AEDA). The aromatic impact of the volatiles is evaluated, generally by determining perception thresholds. This methodology has provided convincing results concerning wine flavors, but it does have its limitations. For instance, data on beta-damascenone have demonstrated that these methods could reach their limits for this volatile, in particular, because of the non-quantitative representation of aroma extracts of wines, and because of the difficulty to accurately determine the perception threshold in wines for a compound already present. For beta-damascenone, we have shown that its very low detection threshold with GC-O, its wide range, and its dependence on the composition of the medium resulted in overestimating its direct impact on the aroma of wine. Another way to facilitate the characterization of aromatic compounds was, therefore, investigated. High-Performance Liquid Chromatography (HPLC) methods were developed for the analysis of wine extracts. From an aromatic extract, 25 fractions with various flavors were thus obtained, and reverse-phase methodology was used for the selection and characterization of red- and black-fruit aromas in red wines.

Which impact for beta-damascenone on red wines aroma?

beta-Damascenone, a C-13 norisoprenoid compound, is usually presented as an impact odorant in red wines. Its direct contribution to their aroma was investigated. Both free beta-damascenone and beta-damascenone precursors were isolated from various French red wines and then analyzed by gas chromatography-mass spectrometry, revealing concentrations in the vicinity of 1 and 2 microg/L for free compounds and both forms, respectively. Gas chromatography-olfactometry analyses were also performed on dilutions of both red wine extracts and pure beta-damascenone. The very low detection threshold in olfactometry for this compound explains why it is found at the highest dilution factor in aroma extract dilution analysis methods. Moreover, determination of beta-damascenone's odor thresholds confirmed the huge importance of the matrix: beta-Damascenone is characterized by a very low perception threshold in hydroalcoholic solution as compared to red wine, where it is over 1000-fold higher. In hydroalcoholic solution, beta-damascenone enhanced fruity notes of ethyl cinnamate and caproate and masked the herbaceous aroma of IBMP. Globally, these results suggested that beta-damascenone has more an indirect than a direct impact on red wine aroma.