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Impact of crema on expected and actual espresso coffee experience
Abstract
The formation and stabilization of crema on espresso coffee are areas that have been well studied during the last 2 decades. In contrast, the contribution of the sensory perception of crema in the coffee consumption experience has not received a lot of attention. Crema being a key visual differentiator between espresso coffees, it may influence the overall sensory and hedonic experiences through the process of assimilation or contrast of visually induced expectations. The objective of this research was therefore to investigate the role of the expectation generated by crema visual cues on actual sensory and hedonic espresso coffee consumption experience. The study was designed to measure the impact of absence, presence and amount of crema on expectation for espresso coffee in liking, quality, overall taste intensity, bitterness and smoothness. Four espresso coffees with different amounts of crema were rated on each attribute by espresso coffee consumers in three evaluation conditions: visual condition (expectation induced by crema visual cues), in-mouth condition (espresso coffee tasting while participants were blindfolded), full condition (standard tasting). The aim of this procedure was to quantify the respective contribution of crema visual cues and in-mouth espresso coffee tasting to the overall espresso coffee experience. Results showed that espresso coffee without crema was expected to be moderately liked, low in quality and weakly smooth as compared to espresso coffee with crema. Such expectations negatively impacted hedonic and sensory in-mouth experience through assimilation effect. Change in crema amount also impacted consumers' expectation which in turn modulated hedonic and sensory experience for espresso coffee. For the first time, this study highlighted the key role of crema visual cues on espresso coffee consumption experience.
... High (2016) Instant coffee had less acceptance and lacks the desirable aromas and flavors associated with fresh filter coffee as determined from the descriptive analysis. Medium Labbe et al. (2016) Crema is an important component of the coffee espresso experience since its absence induced low expectations in coffee espresso quality, overall taste, bitterness and smoothness Medium Pereira et al. (2016) The inoculated process resulted in a complex coffee beverage, with noticeable hints of fresh fruit like banana, orange and pineapple, and full bodied with very smooth sensation due to the lactic acid. ...
... Studies in this realm have revealed that some consumers favored pure coffee, while others lean towards coffee with additives (Geel;Kinnear;De Kock, 2005). Furthermore, the presence of crema in espresso is favored by some (Labbe et al., 2016), and the inclusion of aromas such as vanilla and nutty notes can enhance overall liking (Bhumiratana et al., 2019;Roman-Maldonado et al., 2022). Conversely, undesirable qualities such as rancid oil and greasy notes tend to lead to disliking among consumers (Chung et al., 2022). ...
Coffee is a beverage whose price is closely related to the characteristics of its flavor, necessitating reliable sensory tests. To quantify their sensory attributes , classic sensorial methods such as Quantitative Descriptive Analysis (QDA) can be useful. However, uncertainties persist due to protocol variations, which made uncertain the quality of these protocols in evaluating coffee. This study aimed to conduct a systematic review to assess the quality of QDA protocols used for assessing Coffea arabica's sensory attributes. The review encompassed various critical protocols control points, including pre-test procedures, coffee processing and preparation techniques, test application and data collection procedures. It was also summarized key attributes, highlighting factors impacting coffee's sensory traits and bias risk of the studies. As the main results, it was saw that the studies have many limitations, such as not citing or controlling critical points in the tests procedures and application, which made most studies having a medium-high bias rating. The primary sensory results findings of the studies included topics such as the impact of brewing time, chemical compounds associated with sensory attributes and the effect of various roasting techniques on the sensory qualities of coffee. In conclusion, standardizing sensory evaluations in future research could enhance consistency and accuracy, yielding less biased results.
... Each glass was marked with a number established before the test (three-digit random number). Each coffee was prepared and served at 75 • C, individually, as proposed by Labbe et al. (2016) [10], in order to ensure a constant temperature across coffee. The assessors had to wait 5 min between one sample and another and were required to eat unsalted crackers and rinse their mouths with water. ...
... Each glass was marked with a number established before the test (three-digit random number). Each coffee was prepared and served at 75 • C, individually, as proposed by Labbe et al. (2016) [10], in order to ensure a constant temperature across coffee. The assessors had to wait 5 min between one sample and another and were required to eat unsalted crackers and rinse their mouths with water. ...
The coffee extraction methods modify the structure of the foam (when it is present) and the sensory profile of the beverage. In this research, three ways of extracting and two varieties of 100% Arabica were compared. Nineteen bars and fifteen bars were applied to the coffee thanks to the use of compatible capsules and machines. The method with the moka was considered, which acts at low pressures and does not allow the formation of foam (crema). In addition, the Brazil and Guatemala Arabica varieties were considered to understand the extent to which Arabica coffee can respond in structural and sensorial terms to the extraction techniques applied. The results show that 19-bar espresso coffees have a very stable crema with very small bubbles, which give a uniform and fine structure to the coffee crema. On the contrary, the pressure at 15 bars generates more unstable foams and bubbles that tend to be disproportionate, with more marked effects in the Brazil variety. The sensory profiles of the coffees respond to the extraction techniques applied. While the coffee extracted with the moka has sensory descriptors with rather low values, those obtained at 19 and 15 bars have much wider profiles. In conclusion, different pressure intensities to the coffee extraction affect the quality of crema and the solubilization of organoleptically active compounds.
... In the non-blind test, the taste score of Starbucks was much higher than that of 7-11, this may imply that the scores reported were markedly influenced by the assimilation effects of coffee brand. Female participants could not distinguish the coffee tastes between two brands in blind test (Starbucks, 51.2;(7)(8)(9)(10)(11) 50.7; p>0.05), whereas they distinguished the tastes in non-blind test (59.4: 46.5; p<0.001). ...
... According to this theory, the initial judgment raised from expectations acts as an anchor to a more informed perception, which drives the final judgment or attitude in one of two possible ways: if the informed perception falls in the person's latitude of discrepancy acceptance, the initial judgment is assimilated; if the discrepancy is higher than the person's latitude of acceptance, it produces a contrast effect, meaning that the final judgment changes in the opposite direction in a greater magnitude than the actual discrepancy. Labbe et al. (2016) found that espresso coffee without crema was expected to be moderately liked, low in quality and weakly smooth as compared to espresso coffee with crema. Such expectations negatively impacted hedonic and sensory in-mouth experience through assimilation effect. ...
In recent years, coffee drinking has become a hot issue, especially many coffee brands have joined the market, thus enlarging the consumer population. According to surveys, approximately two-thirds of Taiwanese have the habit of coffee drinking. This study attempted to examine the effects of coffee brand and testing method on the participants’ subjectively perceived coffee taste. A total of 45 male and 29 female university students were recruited as participants in the test. Participants were requested to drink these two brands of Americano (Starbucks and 7-11, with 50 mL for each trial) and then reported their perceived taste scores (scale, 1-100) under two testing methods (blind and non-blind). Results of 3-way ANOVA showed that gender (p<0.01) and brand (p<0.01) had the significant influence on the taste score, whereas the interaction effect of brand x method was also significant (p<0.05). The 2-way ANOVA results revealed that gender (p<0.01) and brand (p<0.001) changed the participants’ taste scores under the blind and non-blind conditions, respectively. In the blind test, the overall taste score of men was significantly higher than that of women, however, there was no difference between two brands. In the non-blind test, the taste score of Starbucks was much higher than that of 7-11, this may imply that the scores reported were markedly influenced by the assimilation effects of coffee brand. Female participants could not distinguish the coffee tastes between two brands in blind test (Starbucks, 51.2; 7-11, 50.7; p>0.05), whereas they distinguished the tastes in non-blind test (59.4: 46.5; p<0.001). However, the phenomenon was not found in males. Findings of this study showed that, for Americano, the assimilation effect of coffee brand for women was significantly higher than that of men, although somewhat assimilation effect was also observed for men and the effect was non-significant. Since the Americano taste scores of two brands did not differ significantly during the blind test, this study indirectly confirmed the brand value of Starbucks based on the pricing strategy.
... Pozos-Brewer (2015) found that every coffee and coffee shop movement address different demographic characteristics and different lifestyles. It has been further stated that coffee drinking habits, and their hedonic and pragmatic consumption motivations, are different from consumer to consumer (Labbe et al., 2016), and that the participation of consumers in the coffee drinking culture varies considerably from person to person (Kim et al., 2016). ...
... The coffee shop experience is a hedonic and pragmatic source of motivation for consumers. The coffee drinking motivations of consumers in coffee shops differ from person to person (Labbe et al., 2016). In the Bourdieu's study Distinction, he argues that, when it comes to eatingdrinking style, music taste, and clothing, taste patterns bring together consumers with similar preferences and behaviours, while those with different tastes differ or separate from each other (Arun, 2013;Bourdieu, 1984). ...
The rise in the coffee consumption, as one of the most popular beverages in the world, has opened the door to “coffee shops” in their modern form. The present study analyses the type of Turkish consumers who prefer national and international coffee shops based on their demographic characteristics and motivations. A total of 448 visitors to coffee shops during the Istanbul Coffee Festival filled out the developed survey form. 411 of these were used for data analysis. The data obtained in the research were divided into four groups through a Chi-squared Automatic Interaction Detection (CHAID) Analysis and Correspondence Analysis, depending on the demographic and motivational characteristics of the consumers with experience of national and international coffee shops. Consumers attribute importance to the atmosphere, image, coffee quality and location of coffees shops, while the target market of coffee shops is generally well-educated, consisting of mostly female consumers over the age of 30. The first and the second group preferred the coffee experience of international coffee shops, while the third group preferred only national coffee shops. The respondents in the fourth group preferred the national coffee shops, but also stated a desire to experience coffee in international coffee shops.
... There are many studies related to different methods of preparation and the chemical and sensorial impact in the brew. [1,17,18] Labbe et al., [19] mentioned that the cream is formed in the espresso method, which is a typical characteristic and one of the greater sensorial impacts of this preparation, whereas the French press method did not present much cream. Because of the above, there was a significant difference between samples where the 'persistence of cream' attribute was compared. ...
... [21][22][23] In Figure 1, it can also be observed that there are two attributes of taste/flavor that separate espresso samples from French press samples regardless of their origin (Colima or Hidalgo): 'acidity', and 'body'. The judges described the samples obtained by the espresso method homogeneously, which could be due to sensory and hedonic expectations that influence the real perception of food as mentioned by Labbe et al., [19] , when the judges observe the presence of cream in the samples, they expect more acidity and body. ...
A sensory evaluation was performed for coffee samples using the Check-All-That-Apply (CATA) method. The samples included Mexican coffee from Hidalgo and Colima states. The brews were prepared by the espresso and French press methods. The data obtained were analyzed using Cochran´s Q test in order to determine any significant differences between samples. There were significant differences (P < .05) only in visual attributes, due to intrinsic characteristics of the preparation methods of the samples. Additionally, the results were analyzed using Multiple Correspondence Analysis (MCA), where from a two-dimensional graphic, differences and similarities between samples and attributes were observed. In the same way, it was observed that visual attributes had greater influence for the description of the samples.
... It is observed that, in all genotypes, the Espresso method remained in groups with higher values for aroma, and lower for flavor and overall impression. This can be explained by the fact that this kind of method, demands a very fine grind, having the capacity to potentiate the characteristics of aroma, due to crema formation (Labbe et al., 2016), and also more intense extraction, which can cause confusion in the beverage profile with the bitter taste, being negatively related to consumer acceptance, especially those used to consuming filtered coffee. Corroborating these data, the term bitterness can be observed in Figures 1A, 1B, and 1C, being decisive in the characterization of the samples of the Espresso preparation method, by CATA test. ...
Coffee is one of the most consumed beverages in the world, with unique organoleptic characteristics of aroma and flavor, also varying according to the several extraction methods. Therefore, the objective of this study was to investigate whether the different Arabic coffee genotypes prepared by various extraction methods would influence amateur consumers’ perception of sensory and hedonic judgments of specialty coffee. A large-sample experiment (n = 270) was conducted in a coffee shop at the Universidade Federal de Lavras and participants were divided into three groups according to the evaluated genotypes (Bourbon Amarelo, Pacamara and Híbrido de Timor), who tasted four samples, varying to the extraction methods (‘Conventional Brewed’, Hario V60, French Press and Espresso). From the results obtained, it is possible to conclude that there is a change in the sensory perception of aromas and flavors of coffees in all genotypes studied in the four extraction methods, as well as in the acceptance and purchase intention by consumers.
... The intrinsic sensory properties of foods (ISPF) refer to their color, aroma, taste, and texture [22,23], which are determined by their chemical composition and physical structure [24]. Sensory characteristics of food products are traditionally measured using discriminant, descriptive, and affective methods [2]. ...
The application of sensory and consumer science (SCS) in developing novel food products that meet consumer demands has become increasingly important in recent years. In this context, this review article explores the significance of SCS in developing novel food products.
It highlights the instrumental of SCS in developing healthier food options by reducing sodium, sucrose, and fat while maintaining sensory appeal. It also outlines the transition from traditional sensory methods using trained panels to consumer-based methods that better capture consumer preferences and expectations.
The paper proposes a sequence for developing novel food products based on SCS, focusing on both intrinsic (sensory properties) and extrinsic (packaging, labeling, etc.) factors. Conjoint analysis is the most representative method used to understand the impact of extrinsic factors on consumer preferences and predict purchase behavior. Lastly, the final product should be optimized based on consumer feedback and compared to competitors before the market launch. Overall, the paper emphasizes the importance of SCS in creating successful food products that align with consumer preferences and health trends.
... We examined the aesthetic judgment of food in terms of visual perception and gustatory and olfactory dimensions. Since the experimental materials were visual in nature, the gustatory and olfactory ratings would indicate the effects of the visual stimuli on the imagined aesthetic experience of consuming the food, not the actual experience of the food (Labbe et al., 2016). People are known to establish expectations regarding gustatory and olfactory responses to food according to visual cues such as color (Piqueras-Fiszman & Spence, 2015; Spence & Piqueras, 2013). ...
Generally, people prefer to dine in beautiful environments. Previous studies have reported that environmental factors affect an individual's perception of food; however, little is known about the effect of environmental aesthetics on food perception. In Experiment 1, we used photographs of restaurant (1a) or non-restaurant (1b) environments with high or low aesthetic value, paired with images of foods, and participants were asked to rate the visual, olfactory, and gustatory aesthetic value of the food. Results showed significantly higher ratings for food perception in all three sensory modalities in the high aesthetic value environment, together with positive emotion and the desire to eat, compared with the low aesthetic environment. Experiment 2 extended the study to two real-world environments (one high and one low aesthetic value) and actual food consumption. The results also found higher aesthetic ratings in the olfactory and gustatory systems and greater desire to eat again in an environment with high aesthetic value than in an environment with low aesthetic value. This research also explored the mediating role of emotion in the relationship between environmental aesthetics and food perception and found a significant mediating relationship. In conclusion, environmental aesthetics play an important role in food perception, and these findings provide insights into increasing positive food perception in daily life.
... EC brewing has been studied in various scientific experiments using different devices (e.g., espresso and capsule machines, etc.) and methodologies to optimize the beverage preparation process [4][5][6][7][8][9]. Indeed, coffee is a popular beverage with a unique sensory profile and also a complex source of hundreds of bioactive compounds, starting from green beans up to the final cup of coffee. ...
This study aims to assess for the first time the content of phytosterols (PS) in espresso coffee (EC) to deepen the knowledge about the phytochemicals and health potentials of coffee brews. PS were extracted by hot saponification from 14 EC samples produced with coffee originating from 13 coffee-producing countries. PS were identified and quantified by high-performance liquid chromatography (HPLC) after derivatization. Among the detected PS, β-sitosterol (4.1–18.2 mg/L) was the most abundant followed by stigmasterol (1.1–4.9 mg/L), campesterol (0.9–4.7 mg/L), and cycloartenol (0.3–2.0 mg/L). Total PS fraction ranged from 6.5 mg/L to 30.0 mg/L with an average level of 15.7 ± 5.8 mg/L. Therefore, a standard cup of EC (25 mL) could provide 0.4 ± 0.1 mg of PS.
... Whereas many recent studies have investigated mainly the roasting (Bustos-Vanegas et al., 2018;Gloess et al., 2018) and brewing steps of coffee production (Parenti et al., 2014;Labbe et al., 2016), the impacts of the post-harvest processing of the coffee cherries and beans, besides genetic attributes of coffee varieties and farming practices, on the coffee quality still remain an open field of research (Lee et al., 2015;Vaughan et al., 2015;De Bruyn et al., 2017;Waters et al., 2017;Pereira et al., 2019;Zhang et al., 2019). Among numerous post-harvest processing practices, wet processing is commonly applied for Coffea arabica to generate high-quality Arabica coffee. ...
Post-harvest wet coffee processing is a commonly applied method to transform coffee cherries into green coffee beans through depulping or demucilaging, fermentation, washing, soaking, drying, and dehulling. Multiple processing parameters can be modified and thus influence the coffee quality (green coffee beans and cup quality). The present study aimed to explore the impacts of these parameters, including processing type (depulping or demucilaging), fermentation duration, and application of soaking, on the microbial community dynamics, metabolite compositions of processing waters (fermentation and soaking) and coffee beans, and resulting cup quality through a multiphasic approach. A large-scale wet coffee processing experiment was conducted with Coffea arabica var. Catimor in Yunnan (China) in duplicate. The fermentation steps presented a dynamic interaction between constant nutrient release (mainly from the cherry mucilage) into the surrounding water and active microbial activities led by lactic acid bacteria, especially Leuconostoc and Lactococcus. The microbial communities were affected by both the processing type and fermentation duration. At the same time, the endogenous coffee bean metabolism remained active at different stages along the processing, as could be seen through changes in the concentrations of carbohydrates, organic acids, and free amino acids. Among all the processing variants tested, the fermentation duration had the greatest impact on the green coffee bean compositions and the cup quality. A long fermentation duration resulted in a fruitier and more acidic cup. As an ecological alternative for the depulped processing, the demucilaged processing produced a beverage quality comparable to the depulped one. The application of soaking, however, tempered the positive fermentation effects and standardized the green coffee bean quality, regardless of the preceding processing practices applied. Lastly, the impact strength of each processing parameter would also depend on the coffee variety used and the local geographical conditions. All these findings provide a considerable margin of opportunities for future coffee research.
... The degree of roasting of the beans used to brew the coffee is then reflected in the colour of the beverage, going from caramel to black, which is associated to rather distinct flavour profiles (Bhumiratana, Adhikari, & Chambers, 2011;Dmowski & Dąbrowska, 2014) and preference niches (Bhumiratana, Adhikari, & Chambers, 2014;Kanjanakorn & Lee, 2017). In addition, great emphasis is also placed on the appearance of the crema (see Illy & Navarini, 2011;Labbe, Sudre, Dugas, & Folmer, 2016) when companies advertise their espresso coffees (e.g., see Kuehlwein, 2017;Spence & Carvahlo, 2019). It is noticeable here also how Nespresso's recent Vertuo coffee machines highlight on the website how 'a generous coffee crema' is a signature feature of the range (see https://www.nespresso.com/de/en/nespressovertuo-kapselmaschinen-system-entdecken). ...
Coffee is one of the world’s most popular beverages, with an estimated four hundred billion cups being consumed each and every year. In this review, we investigate just what effect the multisensory atmosphere/context has on people’s perception of, not to mention their choices concerning, coffee. We demonstrate how many different aspects of the environment influence people’s choice of what beverage to drink as well as what they think about the experience. Specifically, the visual, auditory, olfactory, and tactile aspects of the environment have all been shown to impact the experience of tasting and drinking coffee. This extensive body of empirical research complements the emerging findings demonstrating the influence of the receptacle in which coffee is consumed. Looking to the future, and acknowledging the profound influence of multisensory atmospherics on the experience of beverages, it would seem likely that there will be growing interest in optimizing and/or personalizing the environment for the kind of multisensory tasting experience that the coffee consumer wishes to have.
... According to Illy (2002, p. 90), writing in Scientific American, cell wall fragments (solid materials) make their way into the crema, along with less desirable aroma notes, thus potentially reducing the pleasantness of the tasting/ drinking experience. In addition to the sensory perception of espresso, crema also exerts a major impact on the consumers' hedonic experience (Labbe, Sudre, Dugas, & Folmer, 2016). Thus, transparency may be good for the drinking vessels used to serve espresso as it will presumably help to draw the taster's attention to the quality of the crema. ...
This review summarizes the latest evidence concerning the impact of the colour, shape, texture, weight, and other material properties of the drinking receptacle on the perception of coffee. The colour of the cup, for instance, has been shown to prime notions of sweetness (e.g., pink cup) or acidity (e.g., yellow or green cup) that may carry over to influence the tasting experience. Meanwhile, the shape and surface feel of the drinking vessel have also been shown to exert a profound influence over the perceived aroma/taste of coffee. Given that the various sensory attributes of the drinking vessel can exert such a striking influence over the drinking experience, the challenge, moving forward, is to optimize the design of the receptacle in order to enhance the multisensory tasting experience for the consumer. Given that different styles/varieties of specialty coffee have different dominant/desirable qualities (e.g., acidity/sweetness), in the future, the design of coffee cups may need to be customized for different coffee drinking experiences (e.g., origin or roast), much as seen in the world of fine wine (with different glasses for different grape varieties).
... In a variety of applications the physics are dominated by fluid flow through a porous medium, which is bounded by a plate having holes. Examples of such applications are: a) the flow through packages containing agricultural produce having vent holes [1,2,3,4,5], b) the flow through a cake layer deposited on top of a microfiltration membrane [6,7,8], c) the flow through biological tissues having orifices controlling transport of water and solutes [9,10,11], and d) the liquid flow through an espresso coffee capsule [12,13,14,15]. A sketch of the above flow problem is shown in figure 1. ...
In this paper we perform direct numerical simulation (DNS) on the problem of fluid flow through a filter plate backed by a packed bed of spheres, resembling a cake layer on top of a membrane. For both the complete problem, and its single components (the filter plate and a bed of spheres of finite height) we have observed three flow regimes, depending on the Reynolds number. In each regime the flow resistance is showing a different scaling with the Reynolds number. In the Stokes flow regime the total flow resistance can be decomposed in linear independent components. The interior flows inside the filter holes and inside the packed bed follow the same correlations as hold for the single component. However, at the transition zone between filter plate and packed bed, there is a diverging flow in the first row of the packed bed, whose contribution in the flow resistance scales with the fractional hole to the power −1.5. Similar scaling exponent has been found earlier for the viscous-inertial regime with Reynolds numbers larger than 10, which has been modelled using the porous medium approach. Our findings suggest that also in the Stokes flow and the weakly flow regime the problem can also be solved with the same porous medium approach using the Navier-Stokes equation having Darcy-Brinkman terms incorporated. This investigation provides a good basis for developing more accurate analytical models for the flow resistance of membrane filters with a cake layer on top.
This market research proposal for Nespresso was part of my second-year final project. The research focuses on understanding consumer behavior and identifying market opportunities for Nespresso's products. It explores key factors like consumer familiarity with Nespresso products, their perceptions of crema, and the maintenance costs of coffee machines. The study uses statistical techniques such as multiple linear regression, two-way ANOVA, and cluster analysis to provide insights into consumer preferences and to help Nespresso achieve its business objectives, including increasing awareness and promoting sustainability.
From its legendary discovery in Abyssinia (today Ethiopia) to becoming one of the most consumed beverages in the world, coffee has captivated the enthusiasts for centuries due to its unique aroma and taste, as well as its effects as a stimulant in enhancing mental performance (e.g., alertness, concentration, attention). This article provides a brief overview on the production and processing of coffee, focusing on the Coffea arabica and Coffea canephora var. Robusta, also known as Arabica and Robusta, respectively. Differences in chemical compositions (e.g., lipid, sucrose, trigonelline, diterpenes, caffeine, chlorogenic acids) of bean variety contribute to desirable/undesirable sensory attributes, as well as the health implications of the final brew products. Roasting of green beans, which is typically carried out at 170–230 °C for 10–15 min, causes the degradations of polysaccharides, sugars, amino acids, chlorogenic acids, and so on. Concomitantly, a myriad of aroma volatiles and complex condensed products are formed, mainly due to Maillard reaction, Strecker degradation and pyrolytic reactions. The effects of roast time–temperature profiles on a number of key physicochemical phenomena are discussed, including changes in microstructural, formation of aroma species, development of color, and generation of CO2 during roasting. Optimal storage conditions and packaging are important in delaying product staling and to mitigate CO2 degassing issues. These aspects, along with other factors that affect the shelf-life of coffee, are discussed. Finally, a brief literature review on the health implications of coffee consumption is presented, highlighting the importance of several bioactive components (e.g., caffeine, chlorogenic acids, melanoidins, trigonelline, acrylamide, and diterpenes).
Coffee foam is the frothy layer that forms above the liquid phase of espresso and instant coffee beverages. While the carbon dioxide formed during roasting is responsible for crema formation in espresso, gasification is the established foaming approach in instant coffee. The protein-like fractions and polysaccharides extracted from roasted coffee promote foamability and foam stability, respectively. Crema of consolidated texture retains the volatile aromatic substances and prevents the espresso from cooling too rapidly. Further, an inverse relationship has been observed between foam persistence and volatility of aroma molecules above the cup. Gasified spray-dried instant coffee exhibited an accelerated delivery rate of hydrophobic aroma compounds. Thus, foam is the signature of a high-quality cup of coffee. Despite its various functionalities, coffee foam is scarcely investigated owing to its metastable nature. Only recently, the chemical, structural, and interfacial rheology properties of the coffee foam have been looked at. The current study intends to review the scientific knowledge acquired on coffee foam, thus far. The initial sections describe the general attributes and functions of espresso and instant coffee foam. Further, the mechanisms of formation and stabilization of coffee foam are detailed, followed by the factors influencing the same. The following discussions focus on the role of coffee foam in determining the sensory and aroma release characteristics of the beverages. The scope for future research in this field of study is highlighted in the concluding section.
Espresso coffee (EC) is a complex and much appreciated beverage among coffee consumers. The extraction phase of EC, a combination of physical and chemical variables in a very short time, has a direct effect on the flavour of the beverage. This research aims to optimize the extraction process of EC by decreasing the amount of ground coffee from 14g to 12g (double cup), while keeping constant the particle size of ground coffee and the physical parameters of the espresso machine, making use of the following accessories: two different filter baskets, and four different heights of perforated discs (4-7mm). Quantitative analyses on several organic acids (acetic, citric, caffeic, malic, tartaric) and caffeine, trigonelline, nicotinic and 5-caffeoylquinic acid are carried out with HPLC-VWD through a newly developed method. This combines the quantification of organic acids, obtained through HPLC-VWD, with the results of a sensory panel evaluation on the descriptive notes of EC. The outcomes will trigger and support further studies on different extraction processes, to develop more sustainable and economically affordable coffee of high quality.
Objetivo: O objetivo deste estudo foi avaliar os efeitos moderadores do hedonismo nos fatores determinantes que influenciam na deciso de consumo de caf no Brasil.Mtodo: Foram avaliados 505 consumidores de 25 Estados brasileiros. Ao abrigo da anlise multivariada Regresso Linear Mltipla.Originalidade/Relevncia: As motivaes para o consumo de caf diferem entre os consumidores. Algumas motivaes hednicas so apresentadas na literatura, e exercem o papel de moderadoras nas relaes entre fatores ambientais fsicos onde h o consumo de caf, e fenmenos cognitivos durante o seu consumo. No entanto, ainda permanecem desconhecidas como as motivaes hednicas podem exercer impacto de moderao nas relaes do ambiente fsico e evocaes cognitivas versus o consumo do caf.Resultados: Os resultados fornecem evidncias empricas de que os fatores motivacionais do ambiente fsico e das evocaes cognitivas no so suficientes para compreender o consumo de caf.Contribuies Tericas/Metodolgicas: Este estudo apresenta um avano na literatura ao estudar o efeito de moderao hednicas nas relaes testadas, revela que o consumo de caf no ocorre por questes utilitrias, mas sim pela importncia e satisfao, no atendimento de diferentes sentidos multissensoriais como: prazer, excitao, diverso entre outros fenmenos hednicos.
Espresso machines maintain constant the extraction process of espresso coffee (EC), however, it is difficult to grind roasted coffee in homogeneous way. This research aims to investigate grinded beans at specific particle sizes in three variously designed filter baskets and to compare the concentration of bioactive compounds while decreasing the amount of ground coffee. Analyses on caffeine, trigonelline and chlorogenic acids are carried out with HPLC-VWD, while volatiles with HS-SPME/GC-MS. Extracting with smaller particles escalates the quantity of bioactive compounds. The amount of caffeine/cup increased moving from 500-1000 µm to 200-300 µm particle size, both in Arabica and Robusta for all filter baskets. Keeping constant the volume of EC at various heights of perforated disc, the amount of bioactive compounds at 12 g were only around 9% lower than at 14 g. The outcomes will support further studies on different extraction processes, to develop more sustainable and economically affordable coffee.
Nespresso is one of the most successful and innovative ventures in the consumer product industry in recent decades. Yet, it remains relatively understudied. The purpose of this paper is to provide an integrative insight into the ‘Nespresso model’. We focus on a firm-centric research strategy that is anchored in a systematic review of the academic literature.We find that Nespresso’s model is highly integrated and is configured towards delivering superior value at every step, including logistics. Implications for academics are that firm-centric research may bring unique industrially relevant insights. Managers will find novel ways of leveraging their firm’s strategic advantages.
http://www.sciencedirect.com/science/article/pii/S095032931730023X
The study of the human response to food is a complex and rapidly evolving field. It encompasses a wide range of scientific disciplines, ranging from food science and technology to nutrition, biochemistry, physiology, psychology, marketing and catering. As may be expected in such an interdisciplinary area, numerous scientific concepts have evolved to describe various aspects of the phenomenon under investigation. However, the terminology used to describe these concepts, as well as the methods for measuring them, differ from one discipline to another. Food ‘acceptance’ is one such concept. Since the focus of this chapter concerns factors that influence food acceptance, I would first like to describe and define food acceptance and then to detail the operational approach that we have used to measure it in the laboratory.
Expectations are generated by a variety of factors. We indicate a flow chart for the role of expectations at the point of choice and in influencing sensory perception at the time of consumption. We review the sparse literature on how advertising, packaging and information generate sensory expectations. The application of various theories to explain the observed effects of sensory expectations are reviewed. There is overwhelming evidence for assimilation-contrast effect, although no studies have been specifically designed to detect it. Finally we review the reasons why individuals might differ in the way that expectations influence sensory perception. These reasons include ideas from persuasion literature and private body consciousness. A number of behavioral hypothesis that follow from these theories are developed.
A set of six espresso coffees with different foam characteristics and similar above cup and in-mouth flavour sensory profiles was produced by combination of two varying parameters, the extraction pressure and the filtration of the coffee beverage. The coffees were subsequently evaluated in a comparative manner by a set of analytical (headspace, nose-space) and sensory (Temporal Dominance of Sensations) techniques. The presence of espresso crema in its standard quantity was demonstrated to be associated with the optimum release of pleasant high volatiles, both in the above cup headspace and in-mouth. On the other hand, the TDS study demonstrated that increasing amount of crema was associated with increasing roasted dominance along coffee consumption. Furthermore, a parallel was established between the roasted sensory dominance and the dominant release of 2-methylfuran in the nose-space. This was, however, an indirect link as 2-methylfuran was indeed a chemical marker of roasting but does not contribute to the roasted aroma. Lowering the standard amount of crema by filtration clearly decreased the release of pleasant high volatiles and the in-mouth roasted sensory dominance. On the other hand, increasing the usual crema volume by increasing the extraction pressure did not bring any added value concerning the above cup and in-mouth release of pleasant high volatiles.
This study was carried out in order to compare two mechanisms designed to reveal consumers' preferences: a Vickrey auction which measures willingness to pay, and a common hedonic test. Via these two methods, the objective was to assess the respective effects of sensory characteristics and external information on the overall evaluation of five brut non-vintage Champagnes. One hundred and twenty three consumers were randomly assigned to two groups and took part in one of the methods. Whichever the method, they evaluated the Champagnes in a blind condition, then on the basis of bottle presentation and, finally, after observing the bottle while tasting. Results revealed that the two methods performed equally in revealing the effect of external information on the overall evaluation of Champagnes. Participants are unable to discriminate Champagnes after blind tasting, while significant differences in preferences for the products appeared when labels were made known, and the preferences observed respected the hierarchy of the market. Nevertheless, some differences between the two methods were observed suggesting that these methods could be used differently according to the specific objectives of the study.
Coffee beverage known as espresso, must be topped by a velvety thick, reddish-brown foam called crema, to be considered properly prepared and to be appreciated by connoisseurs. In spite of the relevant role played by crema as a quality marker, espresso coffee foam has not yet been the subject of detailed investigations. Only recently, some aspects of the Physics and Chemistry behind the espresso coffee foam have attracted the attention of scientists. In addition to sharing several characteristics with other food foams like beer foam, for instance, the espresso coffee foam may contain solid particles (minute coffee cell-wall fragments), it is subjected to a remarkable temperature gradient and its continuous phase is an oil in water emulsion rendering it a very complex system to be studied. Moreover, in the typical regular espresso coffee cup volume (serving) of 25-30 mL, crema represents at least 10% of the total volume, and this is a limitation in obtaining experimental data by conventional instruments. The present work is aimed at reviewing the literature on espresso coffee foam. The traditional espresso brewing method will be briefly described with emphasis on the steps particularly relevant to foam formation and stabilization. In addition to present up-dated experimental data on surface properties at solid/beverage and air/beverage interface, recent advances on the espresso foam formation mechanism, as well as on foam stability, will be critically examined. The key role played by carbon dioxide generated by roasting and the effects of low and high-molecular-weight coffee compounds in promoting/inhibiting the espresso coffee foam will be discussed and emphasized.
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.
In this work the thermal profiles of five coffee pods (pure Arabica, pure Robusta, and Arabica Robusta blends: A20R80, A80R20, and A40R60) at 90, 100 and 110 °C are reported. Moreover the chemical–physical and sensorial properties of espresso coffee (EC) obtained from five different coffee pods were investigated. The analysis of the thermal profiles highlighted that the extraction process can be considered as an isothermal process because, after a starting phase, the recorded temperatures stayed around a mean temperature (Tm). In addition the Tm recorded for each extraction temperature was significantly lower than those set up by the controller. The chemical–physical parameters of EC samples increased proportionally with extraction temperature highlighting that the effectiveness of extraction process scales up with percolation temperature. The solid and caffeine contents of the EC samples extracted at 110 °C are related to an over extraction process. Principal Component Analysis (PCA) was applied to identify relationships and differences among EC samples. Pure Arabica and A80R20 EC samples at 100 and 110 °C have shown sensorial attributes typical for a fine espresso coffee.
We report a study designed to assess whether there is any ‘weight’ to the claim that better (or, at the very least, more expensive) wines come in heavier bottles. A field study was conducted in an independent wine retailer in which we looked for correlations between weight, price, and a range of other explanatory variables. The data concerning 275 wine bottles from five countries were analyzed. An internet-based questionnaire was also conducted in order to assess the belief that 150 Spanish consumers held concerning the relationship between the weight of the bottle and the quality (and price) of the wine. The results revealed that the weight of the wine bottles correlated positively and significantly with the price of the wines; the significance level of this correlation varied by country. In addition, the weight of the bottle was also correlated with a number of other properties of the wine, including its vintage, color, and alcohol content. These findings suggest that consumers can extract potentially useful information by simply ‘feeling’ the price of the wine (i.e., by holding the bottle in their hands). The results of the questionnaire revealed a consumer trend toward associating the weight of the bottle, the price of the wine, and its quality.
The current study presents the results of a survey performed to investigate whether different patterns of foam and lacing affect consumer beer preference and the perception of beer characteristics. The impact of three different levels of foam (huge, medium and little) at pouring, and two lacing patterns (very laced to not laced) during consumption, was evaluated on a set of 26 attributes by a panel of Italian beer consumers. Overall, beers which delivered a medium level of foam at pouring were considered by Italian consumers as the best dispensed, the most liked for their visual appearance, the most attractive to consume and the most likely to be purchased. Cluster analysis determined four groups of consumers with different preference patterns for beer foam and expectations for sensory characteristics of the beer. It was found that 80% of consumers preferred a medium level of foam and no lacing, whereas 20% of consumers preferred a high level of foam and lacing. Furthermore, for nearly 40% of consumers, foam and lacing patterns generated expectations regarding beer sweetness, bitterness, fruitiness, perceived level of alcohol, effervescence and the thirst quenching character of the beer.
Assimilation and contrast effects in the placement of opinion items in a series and in the evaluation of the acceptability of such items are explained by principles derived from psychophysical studies of stimulus placement and the development of scales of judgment. The book contains a systematic survey of relevant psychophysical studies plus an analysis of several of the authors' recent experiments on the judgment of weights, opinion topics, and political parties. In addition to the argument that assimilation and contrast effects depend on the location of anchors employed by the judge in evaluating the stimulus items, the authors introduce the concepts of latitude of acceptance and latitude of rejection and discuss the implications of these concepts for attitude change and communication. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Two coffees of different botanical and geographical origins were used: Brazil coffee (dry-processed Arabica) and Uganda coffee (dry-processed robusta). The samples were roasted, and the foamability and foam stability of the espresso coffee were determined as a function of the degree of roast. Espresso coffees were characterized with regard to the amount of total solids, pH, fat, protein, and carbohydrate. The polymeric carbohydrates were precipitated with ethanol solutions (55 and 75% ethanol fractions), and the component monosaccharides were quantified by gas−liquid chromatography. A principal component analysis was applied to the chemical variables. This study showed that foamability of the espresso coffee increases with degree of roast and depends on the amount of protein in the infusion. Foamability as a function of the degree of roast does not differ significantly for the two coffees. Foam stability of espresso coffee as a function of degree of roast is related to the amount of galactomannan and arabinogalactan present and seems to be independent of the origin of the coffee despite the coffees having shown a different degree of roast for maximum foam stability. The degree of roast as a technological parameter does not allow an espresso coffee with maximum foamability and foam stability to be obtained at the same time. Keywords: Espresso coffee; degree of roast; foamability; foam stability; galactomannan; arabinogalactan; multivariate analysis; principal component analysis
The present study reports on the classification of terms used to describe texture and/or mouthfeel characteristics of coffee, particularly espresso coffee, resorting to the classical food texture approach and putting in evidence how consumption habits (i.e., the brewing method) affect the terms used to describe it. Trained panelists have been interviewed in order to generate spontaneously a large number of descriptive texture terms. The terms collection was processed according to methodology previously adopted for liquid foods and beverages to classify the terms into well known mouthfeel categories. This classification identified a reduced number of texture terms categories to set up a list of terms submitted to the same trained panelists and to 93 Italian and 143 non-Italian consumers in the form of a questionnaire with forced choice. Results show that the term “body” alone cannot be used to describe the mouthfeel of coffee beverages, prepared with different brewing methods. The obtained responses may constitute the basis for the development of an appropriate terminology for communicating the mouthfeel characteristics of espresso coffee, and may assist in addressing the finding of correlations between perceived texture and objective measurements of physical properties of the beverage.
In this study, the effect of partial alcohol reduction in wine on consumer expectation and overall liking was investigated in real-life settings (by a Home-Use-Test). By varying the wine in the bottle and by manipulating the information on the label, it was possible to assess the relative impact of sensory properties and information cues on overall liking.Standard Chardonnay and Syrah wines were partially dealcoholized from about 13.5% to about 9.5%. After bottling, these dealcoholized wines were presented once with information about real alcohol content (9.5%) and once with false information about alcohol content (13.5%). A third bottle with standard wine inside was also presented with real information about alcohol content (13.5%). A group of 194 French wine consumers rated the three wines at home for liking before and after tasting on continuous hedonic scales. Another group of 90 French wine consumers evaluated the wines at the laboratory.The same order of preference was obtained in both laboratory and home conditions but wines generally attained significantly higher hedonic scores in Home-Use-Tests. A strong segmentation of consumers highlighted specific consumer behaviors regarding expectation and overall liking of wines. Results emphasized the importance of both sensory and information cues in the development of overall liking by consumers.
Espresso coffee is a polyphasic beverage in which the physico-chemical and sensory characteristics obviously depend on both the selection of ground roasted coffee and the technical conditions of the percolation process. The aim of this work was to evaluate the influence of the coffee/water ratio on the physico-chemical and sensory quality of espresso coffee. Furthermore, the influence of botanical varieties (Arabica and Robusta) and the type of roast (conventional and torrefacto) on the selection of coffee/water ratio was studied. The relationship between pH and the perception of acidity intensity is discussed in relation to the influence of the coffee/water ratio, type of coffee and roast. The optimisation of other technical parameters in previous studies seemed to minimise the influence of an increase in the coffee/water ratio on the extraction of soluble and solid compounds. In fact, only some sensory attributes, such as bitterness, astringency and burnt, acrid and earthy/musty flavours were proposed as relevant to the selection of 6.5 g 40 mL−1 or 7.5 g 40 mL−1 in conventional roasted coffees (Arabica 100% and Robusta blend), and 6.5 g 40 mL−1 in torrefacto roasted coffees. On the other hand, the addition of sugar during the roasting process in torrefacto roast coffees seemed to contribute to a higher generation of acids, melanoidins and other compounds by the Maillard reaction or caramelisation, which led us to select the lowest coffee/water ratio. Copyright © 2006 Society of Chemical Industry
Espresso coffee extraction is the most common brewing method in Italy and it is becoming very popular in many other countries around the world. Water (including its ionic content) is an essential ingredient and its role in Espresso brewing must be taken into due consideration. It is well known that water treatment is necessary to remove possible off-flavours deriving from the disinfection performed at municipal waterworks as well as to prevent expensive professional Espresso coffee machine from scaling problems. However, there is little awareness of the direct effect of water composition on the quality of coffee beverages, particularly for Espresso coffee.In this paper, the state of the art is reviewed with emphasis of water/coffee components interaction during the brewing process. The role played by alkalinity and selected cations on sensory properties of Espresso coffee is discussed.
Espresso, cappuccino and latte are new coffee products entering the daily lives of many consumers. There is increasing consumption of such speciality coffees but no sensory basis for new product development. This study was designed to meet this need. Preference in 100 consumers was studied using six espresso blends of coffee beans. Blends were specifically developed to match key European and North American styles. Products prepared were both espresso and espresso-milk coffees. It was observed that females and males had different preferences for espresso coffee but that this effect was reduced on addition of milk. Gender of target consumer, and end use of espresso, should be thus considered in developing coffee blends. In this way acceptability in specific or target groups of consumers can be maximised. In addition individuals may experience a development of appreciation of coffee character reflected in a change in preference.
The relationship between the physical structure of espresso coffee foam, called crema, and the above-the-cup aroma release was studied. Espresso coffee samples were produced using the Nespresso extraction system. The samples were extracted with water with different levels of mineral content, which resulted in liquid phases with similar volatile profiles but foams with different structure properties. The structure parameters foam volume, foam drainage, and lamella film thickness at the foam surface were quantified using computer-assisted microscopic image analysis and a digital caliper. The above-the-cup volatile concentration was measured online by using PTR-MS and headspace sampling. A correlation study was done between crema structure parameters and above-the-cup volatile concentration. In the first 2.5 min after the start of the coffee extraction, the presence of foam induced an increase of concentration of selected volatile markers, independently if the crema was of high or low stability. At times longer than 2.5 min, the aroma marker concentration depends on both the stability of the crema and the volatility of the specific aroma compounds. Mechanisms of above-the-cup volatile release involved gas bubble stability, evaporation, and diffusion. It was concluded that after the initial aroma burst (during the first 2-3 min after the beginning of extraction), for the present sample space a crema of high stability provides a stronger aroma barrier over several minutes.
Information about a product may shape consumers' taste experience. In a wine tasting experiment, participants received (positive or negative) information about the wine prior to or after the tasting. When the information was given prior to the tasting, negative information about the wine resulted in lower ratings compared to the group that received positive information. No such effect was observed when participants received the information after the tasting but before they evaluated the wine. Results suggest that the information about the wine affected the experience itself and not only participants' overall assessment of the wine after the tasting.
Perceptual discrimination is fundamental to rational choice in many product categories yet rarely examined in consumer research. The present research investigates discrimination as it pertains to consumers' ability to identify differences-or the lack thereof-among gustatory stimuli. Three experiments reveal systematic bias resulting from the presence of common visual and verbal product cues. Particularly noteworthy is the finding that the amount of bias induced by a subtle, nonevaluative cue can far exceed the bias induced by overt and well-established evaluative cues. In addition, the effects these cues have on perceptual discrimination diverge from the effects they have on preference. (c) 2007 by JOURNAL OF CONSUMER RESEARCH, Inc..
Three espresso coffee (EC) samples of different botanical varieties and types of roast were prepared in standard conditions using an experimental EC prototype: Arabica coffee, Robusta Natural blend, and Robusta Torrefacto blend (a special roast by adding sugar). The ECs were characterized with regard to the physical parameters, amount of total solids, total solids on filtrate, lipids, caffeine, trigonelline, and chlorogenic acids by HPLC, and sensory descriptive analysis related to foam appearance, taste, and mouthfeel. Principal component analysis (PCA) was applied to differentiate the EC samples. Arabica and Robusta samples were separated successfully by principal component 1 (55.3% of variance) including physicochemical and sensory parameters related to foam and taste of ECs. Torrefacto and Robusta Natural EC samples were separated by principal component 2 (20.7% of total variance) including mouthfeel and other attributes of color foam. Some interesting correlations among sensory and physicochemical variables were found. A very simple discriminate function was obtained by discriminate analysis allowing the classification of each EC sample into its respective group with a success rate of 100%.
Eighty-eight consumers participated in a blind pre-test in which they rated their baseline preference for chocolate pudding, their liking of three tasted brands of chocolate pudding, and their level of concern for 20 different food processing and preservation technologies. All returned one month later and tasted the same puddings, but this time they were informed that they had been processed by one of several different novel or traditional food processing techniques. Different sub-groups were informed of the name of the process, the name plus a factual description of the process, or the name, the factual description, plus a benefit statement. Ratings of expected liking were obtained before and after viewing the samples, but before tasting them. Finally, subjects tasted and rated the products for actual liking and a sub-group rated their concern levels for the same 20 technologies rated in the pre-test. Pre-test results showed females to have significantly higher concern levels for all technologies. Individuals who had demonstrated a willingness to consume foods processed by one novel technology (irradiation) had lower concern ratings for all technologies. Ratings of concern were negatively correlated with expected liking for products believed to be processed by the technologies. Expected liking ratings were positively influenced by visual exposure to the product and by a safety and benefit statement. Linear regression of the change in product liking as a function of whether products were better or worse than expected supported an assimilation model of the effect of disconfirmed expectations on liking/disliking. Lastly, post-test concern levels for many of the technologies were reduced by participation in the study.
Carrot texture preference of 7-to-11-year-old children
- D Morizet
- L Depezay
- P Combris
- P Masse
- S Nicklaus
- A Giboreau
Morizet, D., Depezay, L., Combris, P., Masse, P., Nicklaus, S., & Giboreau, A. (2011). Carrot texture
preference of 7-to-11-year-old children. Culinary Arts and Sciences VII, 119.