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Influence of serving temperature on flavour perception and release of Bourbon Caturra Coffee
Abstract
The present study aimed to investigate coffee flavour perception and release as function of serving temperature to support standardisation in the specialty coffee branch. The coffee cultivar Bourbon Caturra was evaluated at six serving temperatures ranging from 31°C to 62 °C. Coffee samples were analysed by dynamic headspace sampling gas chromatography–mass spectrometry and descriptive analyses using sip-and-spit tasting. The release of volatiles followed mostly the van’t Hoff principle and was exuberated at temperatures above 40°C. Aliphatic ketones, alkylpyrazines, some furans and pyridines increased most notably at temperatures at ⩾50 °C. The changes in volatile release profiles could explain some of the sensory differences observed. The flavour notes of ‘sour’, ‘tobacco’ and ‘sweet’ were mostly associated with the coffees served at 31 °C to 44 °C, whereas coffees served between 50 °C and 62 °C exhibited stronger ‘overall intensity’, ‘roasted’ flavour and ‘bitter’ notes.
... Pyrazines are heterocyclic and volatile compounds of thermal origin that contain four carbon and two nitrogen atoms and constitute between 11.8-14% of the volatile compounds identified in roasted and ground coffee [22,41]. in addition to imparting to the coffee's aroma toasted or nuts tones [15,42,43]. They result from the interaction between sugars and nitrogenous compounds (e.g., free amino acids, peptides, and proteins) during the non-enzymatic Maillard reaction [3,14,39,44]. During roasting, the released ammonia interacts with pyrazine precursors giving rise to their formation [45] which are produced more abundantly in Robusta coffees varieties due to their higher concentration of free amino acids [19,38,41,46]. ...
... Pyridines are volatile organic compounds of thermal origin formed by a heterocyclic aromatic ring containing five carbon atoms and one nitrogen [14,16,49] formed by the interaction between sugars and nitrogenous compounds (e.g., free amino acids, peptides, and proteins) during the Maillard reaction [14,43,44,46] or due to trigonelline's thermal degradation [38,46,50,51]. ...
... Pyrroles are heterocyclic volatile compounds of thermal origin with antioxidant capacity [37,44,53] that constitute 11% of the identified compounds in roasted coffee [22]. In addition, they tend to be produced in greater quantities during the roasting of Robusta coffees varieties [38] and they result from the interaction between sugars and nitrogenous compounds (amino acids) during the Maillard reaction [14,39,46] or due to trigonelline's thermal degradation [38]. ...
... Additionally, the thermal lability of some lipids suggests that the roasting degree influences coffee mouthfeel, confirming the high correlation of those properties (Esteban-Díez et al., 2004), which in turn is affected by chlorogenic acids, sugars, and other compounds discussed above, confirming the compounds assigned by ANN weights (Table 1). Regarding coffee intensity, it is related to the overall taste profile, being mainly associated with bitterness, body, roasting level, and aroma (Steen et al., 2017). The combination of different sensory parameters makes intensity an even more subjective sensation. ...
... It could be justified by the lower model accuracies on prediction of test sets for both PLS-DA and ANN (Fig. 2). Moreover, higher-intensity coffees are more related to dark roasts and, consequently, to more bitter and fullbodied beverages (Steen et al., 2017). Most of the compounds found in Table 1 for intensity are also related to properties such as bitterness, body, and roasting level, supporting the findings. ...
... HS-SPME is a conventional method that extracts the headspace of samples onto a fiber coated with various materials, allowing for the adsorption of different compounds based on their polarity and/or molecular weight [23]. This is a fast and sensitive approach for preparing samples prior to GC-MS analysis of VOCs in food samples such as wine, coffee, perfume, spices, and other food products [14,[24][25][26][27]. DHS, which uses a sorbent material coupled with a thermal desorption unit (TDU), has also been reported for food analysis [28][29][30]. While the performance of HS-SPME and SHS is limited by the equilibrium concentration of VOCs in the gas phase, the DHS extraction process can result in a larger amount of adsorbed compounds because more compounds can be accumulated onto the material due to the influence of carrier gas flow, such as N 2 . ...
... VOCs found in green curry paste may originate from individual raw ingredients as cited in Table 1 or derived from paste manufacturing. According to previous work, the key VOCs found in green curry paste may be obtained from the following ingredients: terpinene-4-ol from KL [28], curcuma (CC) [33], and GG [34,35]; limonene from LG [31,37], KL [37], and CC [33]; cumal from CM [36]; α-terpineol from CM [36], KL [37,38], LG [37], CC [33], and GG [34,35]; β-myrcene from LG [31,37], and CM [36]; linalool from CM [36], KL [37,38], CC [33], GG [34,35], and LG [37]; linalyl oxide from KL [38]; γ-terpinene from CM [36], KL [37], and CC [33]; diallyl trisulfide from GL [39]; sabinene from KL [37], CC [33], and GG [34]; trans-linalool oxide from KL [38]; copaene from KL [37,38], and CC [33]; δ-cadinene from LG [31], KL [37,38], CC [33], and GG [35]; ρ-cymene from CM [36], and CC [33]; caryophyllene from KL [37,38], and GG [34,35]. ...
Different automated headspace microextraction techniques were employed prior to analysis with gas chromatography-mass spectrometry (GC-MS) for profiling volatile organic compounds (VOCs) in Thai green curry paste: static headspace (SHS), headspace solid-phase microextraction (HS-SPME), and dynamic headspace (DHS) adsorption of VOCs onto Tenax materials with thermal desorption. By applying these methods, the number of VOCs identified by comparison with the MS and retention index (RI) database was in the order of DHS > SPME > SHS, with 36, 22, and 6 VOCs identified, respectively. This led to a total of 46 identified VOCs. In general, limonene and γ-terpinene were observed with all three extraction techniques. The major VOCs in the green curry were terpinen-4-ol, limonene, cuminaldehyde, and α-terpineol. These findings provide an improved understanding of automated extraction processes for the analysis of VOCs in curry pastes and other food samples in the future.
... Han, Kim and Lee (2017) There was influence of storage temperature, presence of lid and time of analysis in the samples. Medium Steen et al. (2017) The serving temperature of coffee influenced the intensity of flavour. The release of volatiles from the BourbonCaturra coffee was exuberated above 40ºC and coffee below 44 ºC facilitated the translucence of non-'roasted' coffee flavours. ...
... The choice of serving vessel (Van Doorn; Wuillemin; Spence, 2014), the time interval before brewing (Morales, 1989), and the temperature (Adhikari; Chambers; Koppel, 2019; Batali et al., 2022;Chapko;Seo, 2019;Han;Kim;Lee, 2017;Steen et al., 2017;Kerry, 2016) were also identified as significant factors influencing the sensory characteristics of coffee. Notably, temperature was found to have a pronounced impact on coffee's flavor, aroma, and mouthfeel. ...
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.
... [122][123][124] Temperature affects the retention of aroma compounds directly or indirectly. [125] At higher temperatures, the presence of more aroma in the headspace of the food has a direct effect. The changes caused by temperature in tertiary and quaternary structures by affecting the binding sites of proteins are indicated as indirect effects. ...
... [126] Increasing the temperature leads to more evaporation and thus more aroma agents being released. [125] In a study examining the effects of microwave application on aroma compounds, it has been stated that high temperature, and power treatments have a negative effect on aroma compounds and cause the formation of undesirable odor compounds. [127] ...
The tomato processing industry generates a significant amount of a by‐product (pomace), which is a mixture of peels and seeds. The purpose of this study was to compare the effects of conventional oven‐roasting (at 120°C, 150°C, and 180°C for 25 min) and innovative microwave‐roasting (at 240, 388, and 536 W for 3 min) pretreatments on the physicochemical properties, fatty acid profiles, bioactive contents, and aroma profiles of tomato seeds and their hexane‐extracted oils. The total flavonoids contents (TFCs) of the seeds decreased from 258.40 to 141.20 mg quercetin equivalent (QE) per kg after roasting. All roasting treatments improved the extractability of both α‐ and γ‐tocopherols. The amounts of total tocopherols in the seeds increased from 917.61 to 1256.25 mg kg –1 after pretreatment. Luteolin was found to be the most abundant phenolic in seed oils, increasing from 10.68 to 91.72 mg kg –1 , followed by quercetin, ferulic acid, and catechin. Within each roasting technique, the ones treated at 150°C and 338 W yielded the oils with the highest concentrations of aroma compounds, 418 and 92 mg kg –1 , respectively. The detrimental effect of microwave‐roasting on these compounds was more pronounced. In conclusion, microwave‐roasting at shorter times than conventional roasting produced tomato seed oils with well‐preserved bioactive components and few unfavorable changes.
... The top eleven sensory attributes used for assessing overall sensory quality acros reviewed literature. Percentage reported is the number of occurrences of an attribute out of the number of reported attributes[1,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. ...
... The top eleven sensory attributes used for assessing overall sensory quality across the reviewed literature. Percentage reported is the number of occurrences of an attribute out of the total number of reported attributes[1,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. ...
The terroir of coffee is defined as the unique sensory experience derived from a single origin roasted coffee that embodies its source. Environmental conditions such as temperature, altitude, shade cover, rainfall, and agronomy are considered the major parameters that define coffee terroir. However, many other parameters such as post-harvest processing, roasting, grinding, and brewing can combine to influence the perception of terroir. In this review, we discuss the contribution of these parameters and their influence on coffee terroir. Assessment of terroir requires defined sensory descriptors, as provided by the World Coffee Research Lexicon, and standardized roast level, grind size, and brew method. The choice of the post-harvest processing method is often environmentally dependent, suggesting that an inclusion into the coffee terroir definition is warranted. Coffee terroir is often not intentionally created but results from the contributions of the Coffea species and variety planted, environmental and agricultural parameters, and both the harvest and post-harvest method used. The unique combination of these parameters gives the consumer a unique cup of coffee, reminiscent of the place the coffee was produced.
... coffee to water ratio, particle size, extraction time and pressure, water temperatures and composition) have been observed to impact the final beverage's volatile composition (this has been recently reviewed in great depth by Cordoba et al. (2020)). The serving conditions are another lesser-studied but interesting aspect of coffee compositional studiesfor example, the serving temperature has been affirmed to affect coffee volatile and aroma release (Steen et al., 2017). This establishes the need for serving temperature standards for sensory evaluation and analytical studies (Adhikari et al., 2019;Steen et al., 2017), and also promotes further investigations into the dynamics of this aroma release (Chapko & Seo, 2019). ...
... The serving conditions are another lesser-studied but interesting aspect of coffee compositional studiesfor example, the serving temperature has been affirmed to affect coffee volatile and aroma release (Steen et al., 2017). This establishes the need for serving temperature standards for sensory evaluation and analytical studies (Adhikari et al., 2019;Steen et al., 2017), and also promotes further investigations into the dynamics of this aroma release (Chapko & Seo, 2019). Overall, this illustrates the susceptibility of coffee volatile composition and aroma to various steps in the processing pathway. ...
Coffee has attracted significant research interest owing to its complex volatile composition and aroma, which imparts a pleasant sensorial experience that remains challenging to analyse and interpret. This review summarises analytical challenges associated with coffee’s volatile and matrix complexity, and recent developments in instrumental techniques to resolve them. The benefits of state-of-the-art analytical techniques applied to coffee volatile analysis from experimental design to sample preparation, separation, detection, and data analysis are evaluated. Complementary method selection coupled with progressive experimental design and data analysis are vital to unravel the increasing comprehensiveness of coffee volatile datasets. Considering this, analytical workflows for conventional, targeted, and untargeted coffee volatile analyses are thus proposed considering the trends towards sorptive extraction, multidimensional gas chromatography, and high-resolution mass spectrometry. In conclusion, no single analytical method addresses coffee’s complexity in its entirely, and volatile analysis must be tailored to the key objectives and concerns of the analyst.
... The color of the coffee brews differed, particularly in the L* and b* values, where the overdeveloped roasting produced brews with a darker color. Intense roasting reduced the L*, a*, and b* values of the coffee beans due to non-enzymatic browning and pyrolysis reactions such as Maillard browning during roasting [8], [10], [26]. The coffee brew is typically associated with acidity (may be measured as pH as an alternative to total acids, which have more influence on coffee acidity) and the amount of dissolved solids (measured as % Brix). ...
... The pyrazines and alkyl pyrazines identified in the roasted samples include pyrazine, 2,5-dimethyl-; pyrazine, 2,6dimethyl-; pyrazine, ethyl; pyrazine, 2,3-dimethyl-; pyrazine, 2-ethyl-6-methyl-; pyrazine, 2-ethyl-5-methyl-; pyrazine, trimethyl-; pyrazine, 3-ethyl-2,5-dimethyl-; pyrazine, 2,6diethyl-; pyrazine, 2-ethyl-3,5-dimethyl-; pyrazine, 2ethenyl-6-methyl-and pyrazine, (1-methylethenyl)-. Pyrazines are commonly associated with heat processing that involves sugar-amine reaction leading to Maillard reaction and Strecker degradation of amino acids [26]. However, certain pyrazines decreased along with the increase of roasting level, suggesting thermal degradation as the roasting continues [18], [7]. ...
Roasting is an important coffee processing step to generate coffee aroma and flavor. Because roasting is time-temperature dependent, the variation of time and temperature applied may influence the structural properties, visual appearance, and chemistry of coffee. Improper roasting creates roast defects that reduce coffee quality and acceptance. Despite this importance, studies on coffee roast defects, particularly in Robusta coffee is limited. This study aims to characterize two common roast defects, i.e., underdeveloped and overdeveloped, compared with medium roast in Robusta coffee. Sensory evaluation by trained panelists and physicochemical evaluation reveal that the two common roast defect in Robusta coffee can be distinguished clearly through differences in sensory (aroma defect) characteristics as well as physicochemical properties. The overdeveloped roast defect produced darker coffee with the highest pH and total dissolve solids (TDS), and can be characterized by pyridine, furan, phenol and pyrrole derivatives. The carbony and ashy notes of the overdeveloped coffee were potentially contributed by phenol and polyphenol derivatives. In contrast to the overdeveloped coffee, the underdeveloped coffee is markedly characterized by higher concentration of aliphatic acids and higher concentration of pyrazines that contributes to raw nut-like notes. The combination of time and temperature during roasting influences the breakdown of chemical compounds through complex mechanisms involving proteins, carbohydrates and polyphenols degradation. Thus, roasting process variations that determine coffee cup quality and in turn drive consumer acceptance should be controlled. © IJASEIT is licensed under a Creative Commons Attribution-Share Alike 4.0 International License.
... On the other hand, considering the total volatile compounds content, (Amanpour & Selli, 2016;Grosch, 1998;Piccino, Boulanger, Descroix, & Sing, 2014;Steen, Waehrens, Petersen, Munchow, & Bredie, 2017). *Significant odor active values (OAV) > 1; this parameter was calculated by dividing the concentration by the odor threshold. ...
... *Significant odor active values (OAV) > 1; this parameter was calculated by dividing the concentration by the odor threshold. Sensory descriptors are taken from the literature (Amanpour & Selli, 2016;Grosch, 1998;Piccino et al., 2014;Semmelroch & Grosch, 1996;Steen et al., 2017). Different letters indicate significant differences among treatments (P < 0.05). ...
Cold brew coffee is a beverage prepared at low temperatures and over long brewing times resulting in particular physicochemical and sensory characteristics. This type of coffee is usually consumed immediately after preparation or after short storage in refrigerated conditions. However, in recent years many commercial coffee vendors started investing in ready-to-drink cold brew coffees packaged for extended storage. These products present the potential problem of microbial and sensorial alteration. In this study we evaluated five different stabilization techniques with the aim to extend the shelf life of the cold brew coffee while preserving its peculiar organoleptic properties, e.g. HPP (High Pressure Processing), microfiltration, UV irradiation, pasteurization and blast chilling process. The effects were investigated over four months, evaluating the caffeine and the chlorogenic acids contents by HPLC-DAD analysis and carrying out anevaluation of selected volatile compounds by HS-SPME-GC-MS. After four months of storage, the samples treated with pasteurization and HPP maintained a stable content of caffeine and chlorogenic acids, guaranteeing also the microbiological safety of the beverage. At the same shelf-time, the pasteurized samples showed an unaltered flavor profile, while a decrease of about 25% of the total content of volatile compounds was registered for the HPP sample.
... In addition, it is essential to recognize and account for cultural customs, manners, religious beliefs, knowledge, and attitudes toward products [15]. To date, most coffee studies have merely compared differences based on elements such as roasting level [4,16], storage [17,18], brewing methods [2,5,19], serving temperatures [20,21], and geographic origin [22,23] of brewed coffee. Furthermore, there have only been a few crosscultural studies on coffee, where consumers' coffee purchase and consumption behavior were compared between Chinese and Swedish university students [24], and TEP usage was compared between the United States or Canada (US/CA) and Australia or New Zealand (AU/NZ) [13]. ...
The Espresso Protocol (TEP) was used to assess the quality of coffee beans through espresso extraction incorporating a sensory approach. TEP includes overall quality evaluation and attribute evaluation using check-all-that-apply (CATA). This study aims to evaluate the repeatability of TEP when used by experts and to compare cross-cultural assessments to determine its applicability across different countries with diverse coffee cultures. Experts with over three years of experience in the coffee industry from five countries—France (n = 7), India (n = 12), Italy (n = 7), the Republic of Korea (n = 10), and the USA (n = 10)—participated in our study. The experiment was conducted in three replications using eight different single-origin coffee samples over two or three consecutive days. Cluster analysis using CATA data was performed to verify the repeatability of individual participants in the characterization of espresso samples, revealing that most participants were repeatable in their three-time evaluations. Moreover, a significant homogeneity index demonstrated a high degree of similarity in the sensory characteristics used by experts from each country, although cultural differences were observed in the terminology used to describe coffee. In conclusion, the repeatability of individual experts and the reliability of TEP were successfully demonstrated. However, some differences in sensory evaluations were noted across cultures; these were likely influenced by differences in the use of terminology, which emphasizes the need for training in the coffee lexicon.
... We also observed that the coffee brewing method (espresso and cold brew) evoked significant changes in the sensory properties of the examined samples. This is in line with literature data that both different coffee bean grinding degrees and brewing and serving temperatures are important factors influencing the sensory quality of coffee beverages [71]. In our study, cold brew coffees were perceived as sweeter in odour and taste, more fruity in odour and flavour, and rum in odour and flavour compared to espresso coffees. ...
The study investigated the effects of storage temperature, type of coffee, and brewing method on coffee’s volatile compound profile and sensory quality. Three types of coffee were included in the study: Arabica, Robusta, and their 80/20 blend. Samples were stored at 5 °C and 20 °C for one month, after which the changes in the composition of volatile compounds were analysed and the sensory quality of espresso and cold brew coffee was assessed. The results showed that storing coffee at a lower temperature slows the changes in the profile of volatile compounds such as aldehydes, alcohols, pyrazines, and furans, helping preserve the desired aroma and flavour characteristics. Storage at higher temperatures resulted in greater changes in the volatile profile and sensory quality, with higher perceptions of earthy, sharp, and smoky notes and lower chocolatey and sweet notes. The brewing method also had a significant effect on the sensory quality. The espresso coffee had a higher intensity of coffee aroma, chocolate flavour, smoky aroma, and roasted notes. In contrast, cold brew coffee was perceived as sweeter, fruitier, and had more pronounced rum notes. The coffee type also significantly influenced the aroma and flavour profile. Arabica had a more harmonious and mild aromatic profile, while Robusta had a sharper aroma. The blend of Arabica and Robusta combined the characteristics of both coffees and offered a balanced aromatic profile.
... The mimic coffee model consisted of lipids and non-volatile components that might bind aromas, presented in accordance with their actual concentrations in a coffee brew within a 0.2 M phosphate buffer solution at pH 6.0, prepared using disodium phosphate and sodium dihydrogen phosphate. The composition included lipids at a concentration of 0.72% w/w (Ratnayake et al., 1993;Sun et al., 2018), melanoidin (with molecular weight distributions of under 1 kD, 1 kD to 3 kD, and over 3 kD in a ratio of 1:1:1, totaling a concentration of 6 g/L) Coelho et al., 2014;Hofmann & Schieberle, 2002), hydroxyhydroquinone at 0.025 g/L (Lang, Mueller, & Hofmann, 2006;Müller & Hofmann, 2007), and carbohydrates (arabinogalactan at 1.2 g/L and galactomannan at 0.8 g/L) Steen, Waehrens, Petersen, Münchow, & Bredie, 2017). The concentrations of characteristic coffee aromas were determined based on previous reports Piccino, Boulanger, Descroix, & Sing, 2014;Semmelroch & Grosch, 1996). ...
... Kopi yang memiliki kualitas tinggi ditandai dengan nutty, keasaman, kepahitan yang menyenangkan. Kopi jenis robusta yang berasal dari Indonesia, identik dengan aroma nutty (Sepúlveda et al., 2016;Bressanello et al., 2017;Steen et al., 2017). ...
This research studied the effect of the level of black coffee bean defects and roasting temperature on the physicochemical content of coffee powder and the organoleptic content of robusta coffee brewing. This research used a factorial Randomized Complete Block Design (RCBD) with two replications. Parameters in this study, namely moisture content, ash content, pH, caffeine content, color intensity, and sensory. Data analysis in this research used ANOVA at the 5% level and a DMRT follow-up test. The research result show that there is an interaction between the treatment of the type of defective beans and roasting temperature on moisture content, ash, pH, color intensity of robusta coffee powder, and organoleptic brewing of robusta coffee. Different types of defective beans significantly affected the moisture content, ash, pH, caffeine, and color intensity of robusta coffee powder, while differences in roasting temperature significantly affected the water content, ash, pH, caffeine, and color intensity of robusta coffee powder. The best treatment for all physicochemical and organoleptic parameters is partially black beans with a roasting temperature of 180 °C.
... When these expectations are met, there may be less emphasis on texture, yet a discrepancy between the anticipated and actual texture of the food will lead to rejection. Likewise, food temperature can significantly impact our overall perception (Foster et al., 2011;Steen et al., 2017). Additionally, chemesthesis, the perception of chemical or irritant sensations in the mouth, can also influence our preference. ...
While taste and smell perception have been thoroughly investigated, our understanding of oral somatosensory perception remains limited. Further, assessing and measuring indi- vidual differences in oral somatosensory perception pose notable challenges. This review aimed to evaluate the existing methods to assess oral somatosensory perception by examining and comparing the strengths and limitations of each method. The review highlighted the lack of standardized assessment methods and the various procedures within each method. Tactile sensitivity can be assessed using several methods, but each method measures different tactile dimensions. Further investigations are needed to con- firm its correlation with texture sensitivity. In addition, measuring a single textural attri- bute may not provide an overall representation of texture sensitivity. Thermal sensitivity can be evaluated using thermal-change detection or temperature discrimination tests. The chemesthetic sensitivity tests involve either localized or whole-mouth stimulation tests. The choice of an appropriate method for assessing oral somatosensory sensitivity depends on several factors, including the specific research objectives and the target pop- ulation. Each method has its unique intended purpose, strengths, and limitations, so no universally superior approach exists. To overcome some of the limitations associated with certain methods, the review offers alternative or complementary approaches that could be considered. Researchers can enhance the comprehensive assessment of oral somatosensory sensitivity by carefully selecting and potentially combining methods. In addition, a standardized protocol remains necessary for each method.
... For example, studies have demonstrated that the physical temperature of food and drink can profoundly impact their acceptability and people's preferences (see Abraham & Diller, 2019;Brown & Diller, 2008, for reviews). Additionally, temperature has been shown to affect perceived flavour intensity (Steen et al., 2017) and even aftertaste experiences associated with consuming foods (Francis et al., 2005). It is generally appreciated that the temperature at which a food is served plays a crucial role in influencing food tastiness, and previous studies have demonstrated that food temperature significantly stimulates people's appetite (Kokaji & Nakatani, 2021;Sakay, Masuko, & Yamanaka, 2022;Yamin, Mai, & Werle, 2020) and elicits positive evaluations of food (Magee, 2012;Pramudya & Seo, 2018). ...
Nothing beats a comforting image of a bowl of hot soup with whisps of rising steam unless it is the actual soup itself. The current paper investigates the influence of food photography on people’s food expectations. Despite the recognition of the importance of the food temperature depicted in food images, the effectiveness of using visual cues on food photography to indicate temperature and potential managerial outcomes of so doing has barely been researched. This study explored whether the addition of visual temperature cues to food images was effective in activating relevant temperature associations, leading to downstream consequences, including food desirability, freshness perception and willingness to pay (WTP), with a focus on thermal temperature cues. Three online experimental studies were conducted showing that animated traces of steam added to food images not only induced hot temperature perception of the food, but also increased food desirability and freshness perception. Meanwhile, implied animation (i.e., static picture of rising steam) did not produce any such effect. Further, food image appeal was found to be a boundary condition for the effect of hot temperature cues: that is, when the food images is of low appeal, traces of steam which increased hot temperature perception, in turn enhanced freshness perception and food desirability, but not WTP. The effectiveness of animated steam textures crossmodally enhancing thermal temperature perception and food desirability underscores the potential in digital food creation and marketing.
... Another sensory study from Rubico and Mcdaniel (1992) found that the astringency and mouthfeel of the different organic and inorganic acids were more important in the description of the acids than the bitterness and sourness. Additionally, the literature indicates that different roast profiles , and different serving temperatures (Steen et al., 2017;Talavera et al., 2007), of the same coffees, generate different aroma profiles. The perceived acidity is also reported to be influenced by the storage time of the beans after roasting (Kreuml et al., 2013), the method of brewing (Belitz et al., 2009;CRI, 2006;Farah, 2020;Gloess et al., 2013), and pH and titrable acids of the coffee (Brollo et al., 2008;Gloess et al., 2013). ...
... The beer was then purged with nitrogen (100 mL/min) on adsorbent traps (Tenax TA, 200 mg of Tenax with 60/80 mesh, Markes International Limited, Llantrisant, UK) for 20 min, followed by a dry purge for 10 min to remove water. The trapped volatiles were, according to Steen et al. [40], desorbed (Turbo Matrix 350; Perkin Elmer, Shelton, CT, USA) and transferred to a GC-MS (7890A GC system interfaced with a 5975C VL MSD, Agilent Technologies, Palo Alto, CA, USA). Separation of the volatiles was carried out on a DB-Wax capillary column (30 m × 0.25 mm, with 0.50 μm film thickness). ...
The aim of the present study was to investigate the impact of two lager brewing yeasts (KVL001 and KVL018), known to produce different levels of sulfite and thioredoxin, on the flavor stability of beer during storage for 24 weeks at 25 °C and 35 °C. Fermentations with the two yeast strains were carried out in two identical pilot scale brews and provided fresh beers with very similar sensory profiles, only differing significantly in content of sulfite, iron, thioredoxin, and free amino acids. No difference in protein thiols was observed indicating that thioredoxin was not active in the final beer. The yeast strain KVL018 consumed less free amino acids than KVL001 resulting in fresh beers with a higher content of free amino acids. During storage, the beers developed very similarly, but the beers fermented with KVL018 developed more 'fruity aged/vinous' flavor, especially at 35 °C. This suggested that a higher degree of the Maillard reaction took place in these beers due to the higher content of free amino acids. Beers fermented with KVL018 also contained more sulfite and less iron, but scored lower in the general evaluation of the sensory analysis. In conclusion, our results indicate that the yeast strain (KVL001) taking up more free amino acids resulted in more flavor-stable beer due to a lower degree of the Maillard reaction, while no clear effects were observed on oxidation.
... Phytochemicals derived from carbohydrates, sugars, lipids, amino acids and organic acids are an important group of metabolites in coffee, as they contribute significantly to the coffee flavour, mouthfeel, and aroma that emerge during the roasting process within the Maillard reaction (Rocchetti et al., 2020;Steen et al., 2017). A considerable portion of the structural function in green coffee is attributed to carbohydrate and its by-products, which comprise 40-65% of the dry weight (Arya & Rao, 2007;Poisson et al., 2017). ...
Coffee is an export commodity that is prone to fraudulent practices. Therefore, this study presents a novel approach to authenticate coffee origins using targeted metabolomics with gas chromatography-tandem mass spectrometry (GC-MS/MS) and machine learning models. A total of 200 coffee samples from different harvest years and areas from Indonesia were extracted using the derivatisation method and then analysed for their metabolite profiles. Several supervised machine-learning models were tested to classify coffee origins and discover their potential markers. The study found various metabolite features spanning diverse chemical classes, encompassing sugar alcohols, carbohydrates, amino acids, organic acids, fatty acids, and phenols. Random forest (RF) and partial least squares discriminant analysis (PLS-DA) were among the most accurate models in predicting the origin of coffee from several classes in the validation dataset. The accuracy of both models is in the range of 91%–100%. Furthermore, this study proposes a new strategy for determining “intersection features” as the set of features that are important and common to both RF and PLS-DA models, thereby providing a robust selection of coffee origin markers. Overall, the approach and findings of this study have far-reaching implications for coffee authentication.
... The number of acids and phenols identified by G and GG was almost the same. Though acids and phenols were not plentiful in the coffee samples, they could have contributed to the sour smell [29]. In this investigation, GG identified three-fold more hydrocarbons and other compounds than G. ...
The volatiles in coffee play an important part in the overall flavor profile. In this study, GC–TOF/MS and GC×GC–TOF/MS were used to detect the volatile organic compounds (VOCs) in coffee samples of three different brands at three states (bean, powder, and brew). The differences between the two methods in characterizing VOCs were analyzed using the Venn diagram and PCA (principal component analysis). The important aroma-contributing compounds were further compared and analyzed. The results of the venn diagrams of different coffee samples showed that most VOCs existed in 2–3 kinds of coffee. The PCA of VOCs in different coffee samples showed that the VOCs detected by GC–TOF/MS could distinguish the coffee samples in the different states. GC×GC–TOF/MS was suitable for the further identification and differentiation of the different brands of coffee samples. In addition, pyridine, pyrrole, alcohols, and phenols greatly contributed to distinguishing coffee in three states, and alcohols greatly contributed to distinguishing the three brands of coffee.
... Specifically, two distinct varieties of the coffee plant, namely Bourbon and Castillo Tambo, were chosen based on their unique characteristics and growth habits. The Bourbon variety exhibits a tall growth habit and moderate yield, with the potential to produce high-quality coffee at high altitudes [51]. Nonetheless, it is no longer cultivated in the region because of its susceptibility to rust attacks. ...
Background
The microbial biodiversity and the role of microorganisms in the fermentation of washed coffee in Colombia were investigated using the Bourbon and Castillo coffee varieties. DNA sequencing was used to evaluate the soil microbial biota and their contribution to fermentation. The potential benefits of these microorganisms were analyzed, including increased productivity and the need to understand the rhizospheric bacterial species to optimize these benefits.
Methods
This study used coffee beans for DNA extraction and 16 S rRNA sequencing. The beans were pulped, samples were stored at 4ºC, and the fermentation process was at 19.5ºC and 24ºC. The fermented mucilage and root-soil samples were collected in duplicate at 0, 12, and 24 h. DNA was extracted from the samples at a concentration of 20 ng/µl per sample, and the data obtained were analyzed using the Mothur platform.
Results
The study demonstrates that the coffee rhizosphere is a diverse ecosystem composed primarily of microorganisms that cannot be cultured in the laboratory. This suggests that the microbial community may vary depending on the coffee variety and play an essential role in fermentation and overall coffee quality.
Conclusions
The study highlights the importance of understanding and optimizing the microbial diversity in coffee production, which could have implications for the sustainability and success of coffee production. DNA sequencing techniques can help characterize the structure of the soil microbial biota and evaluate its contribution to coffee fermentation. Finally, further research is needed to fully understand the biodiversity of coffee rhizospheric bacteria and their role.
... Another sensory study from Rubico and Mcdaniel (1992) found that the astringency and mouthfeel of the different organic and inorganic acids were more important in the description of the acids than the bitterness and sourness. Additionally, the literature indicates that different roast profiles , and different serving temperatures (Steen et al., 2017;Talavera et al., 2007), of the same coffees, generate different aroma profiles. The perceived acidity is also reported to be influenced by the storage time of the beans after roasting (Kreuml et al., 2013), the method of brewing (Belitz et al., 2009;CRI, 2006;Farah, 2020;Gloess et al., 2013), and pH and titrable acids of the coffee (Brollo et al., 2008;Gloess et al., 2013). ...
Coffee brewed on light, and very light-roast coffee beans have emerged as a recent trend among specialty coffee drinkers. The acidity of such light-roast coffee, and coffee in general, is an important sensory characteristic, as there is demonstrated a clear correlation between the roast level and perceived acidity in brewed coffee. The acidity is believed to be strongly linked to the content and composition of organic acids in coffee. Still, there is limited literature on acid content in brewed coffee and on the relevance of specific acid concentrations to sensory perception. In this study, we determined concentrations of acids and sugars in French-press brewed specialty coffee. We used varying roast degrees in the light to very light range using five coffees from different geographical locations (Brazil, Bolivia, and Kenya) and determined the sensory detection threshold and recognition for selected acids. The concentration of all individual acids except one (formic) either significantly decreased (citric, malic, and chlorogenic acid) or increased (acetic, lactic, phosphoric, quinic, and glycolic acid) systematically with an increasing roast degree, while no systematic trends were found between the different coffee samples. The sugar content decreased with an increasing roast degree. The sensory detection threshold for malic, acetic, and lactic acid was determined to be above the actual concentration of said acids in the coffee and just below for phosphoric acid, indicating that these compounds are unlikely to individually be perceived in coffee. Only citric acid can be clearly detected in the threshold test (not identified by experts in coffee) in concentrations above the measured concentrations, as the detection threshold was below (
... Among the key VACs, alkylpyrazines, 2,3,5,6tetraethylpyrazine, and 2,3-dimethylpyrazine are related to the bitterness of coffee. The former is detected only in hot brew extracts, while the latter is detected in all extracts of roasted coffee beans, except for cold brew extracts (Caporaso et al., 2014;Steen et al., 2017). In addition, pyrrole is a key VAC in coffee and a product of furan degradation during the thermolysis of glucose polymers (Amanpour & Selli., 2016). ...
This study investigated the effects of four brewing methods (cold and hot brew, espresso, and cezve) on the chemical sensory properties of green and roasted coffee beans (cv. Yellow Bourbon) extract. The caffeine and chlorogenic acid contents of the coffee were analyzed using HPLC. The taste and volatile aromatic compounds of coffee were analyzed using an electronic tongue and nose, respectively, and the results were analyzed using principal component analysis. For the taste components analyzed using the electronic tongue, the degree of separation was relatively large depending on the extraction method, and the degree of separation was larger depending on roasting for the volatile compounds analyzed using the electronic nose. Our findings provide basic data for the coffee industry.
Practical Application
The use of an electronic sensor will provide flavor characteristics for four different types of coffee extracted from green beans and roasted beans. In this study, it was confirmed that the extraction method had a greater effect on the taste of coffee, and in the case of the volatile aromatic compounds of coffee, there was a large difference depending on the green beans and roasted beans. Therefore, our findings will provide data based on the sensory properties of coffee.
... 6,7 Coffee is normally consumed hot, and flavor perception will change at lower consumption temperatures. 8,9 Thus, in commercial settings, coffee brewed on a large scale is generally held either in an insulated carafe to maintain the temperature, or in a heated carafe. The method of storing coffee, however, can also impact the quality of coffee. ...
Background
Coffee quality is believed to degrade quickly after brewing, and retail establishments discard unsold brewed coffee after a specified holding time period, sometimes as short as 30 min. We used trained sensory panels to evaluate the flavor profiles of light, medium, and dark roast coffees held in three different carafe types (glass on hot plate, thermal jacket, and vacuum insulated) for times ranging from 15 min to 3 h. Furthermore, a panel of 93 coffee‐industry professionals performed a blind evaluation of fresh (30 min) versus held (180 min) coffee for overall liking and attribute level adequacy.
Results
Sourness increased over time, consistent with acidity increasing over time (i.e., higher titratable acidity, lower pH), but only for the light and medium roasts. Dark roasted coffee became significantly more acidic over 3 h post‐brew but was not perceived as more sour over time by the sensory panel. Variations were observed between the thermal jacket and vacuum carafes for the light and dark roast, but few differences were observed with storage type in the medium roast. Surprisingly, the panel of coffee industry professionals showed no preference for fresh over held.
Conclusions
More sensory attributes decreased than increased over time, suggesting that the primary concern with loss of quality during coffee holding may be the loss of volatile aroma compounds. Hedonic ratings suggest that even if the changes over time are noticeable, they may not negatively impact overall liking. © 2022 Society of Chemical Industry.
... A perhaps surprising result is that the perceived adequacy of flavor intensity, mouthfeel, and acidity all showed little difference with higher temperatures. Much research with calibrated expert panels has indicated that beverage temperature has a large impact on perceived sensory qualities [14][15][16][17] . These studies, however, examined much larger temperature variations than examined here. ...
We recently performed a systematic investigation of consumer preferences for black coffee versus key brewing parameters, including total dissolved solids, extraction yield, and brewing temperature (Cotter et al. in J Food Sci 86(1):194–205, 2021. https://doi.org/10.1111/1750-3841.15561). An experimental goal in that work was for participants to taste the coffee at a beverage temperature of 65 °C, but the large sample size of more than 3000 individual tastings, combined with natural variations in the brewing and cooling processes, meant that coffees were assessed over a normally distributed range of temperatures between 56 and 71 °C. Here we use those data to provide a more detailed analysis of the impact of beverage temperature on consumer acceptance of the coffee, with a key objective of identifying beverage temperatures at which no consumers assess the coffee either as too hot or too cold. Using a 5-point just-about-right (JAR) scale, we find that a majority of consumers (> 50%) assessed the temperature as JAR at all temperatures tested up to 70 °C. A substantial fraction of consumers, approximately 6–12%, assessed the coffee as too cold over the range 56–68 °C. Only above 70 °C did a majority of consumers assess the coffee as too hot and none assessed it as too cold, albeit with 40% still assessing it as JAR. Complementary analyses indicate that beverage temperature over this range had little impact on assessments of the adequacy of flavor intensity, acidity, and mouthfeel, but did correlate slightly with overall liking and purchase intent. Overall, the results suggest that temperatures over the range of 58–66 °C maximize consumer acceptance, and that 68–70 °C is the minimum temperature range at which no consumers will assess black coffee as too cold.
... Es de hacer notar que la temperatura recomendada por el Centro de Elaboración del Café (USA) y el Centro Nórdico del Café (Noruega) para servir la bebida de café oscila entre los 80-85 °C (176-185 °F) [122][123][124][125][126] ; Por otro lado, la Asociación Nacional del Café de los Estados Unidos de América recomienda servir el café con una temperatura oscilante entre los 82.2-85 °C (179.96-185 °F) 127 . ...
El café es una de las bebidas más consumidas en el mundo y su popularidad no está basada en su valor nutricional o sus potenciales beneficios a la salud, si no en su sabor placentero y las propiedades estimulantes de la cafeína. Esto es respaldado por las últimas estadísticas publicadas por la Organización Internacional del Café (ICO, por sus siglas en inglés) según la cual aproximadamente 1.4 billones de tazas de café son consumidas diariamente además del hecho de que la taza de consumo global se ha duplicado en los últimos 50 años por causa de la apertura de nuevos mercados. La amplia aceptación del café está ligada a sus propiedades sensoriales las cuales a su vez están fuertemente influenciadas por una cadena de eventos que inician desde la cosecha y las practicas postcosecha (i.e., fermentación, lavado, secado, tamizado, eliminación de granos defectuosos y almacenamiento), seguidas por el tueste, molido y empacado del producto para su posterior comercialización. No obstante, existen otros factores que también afectan las propiedades organolépticas de la bebida tales como, pero no limitado a: el pH y temperatura del agua, las mezclas realizadas antes o después del tueste, la especie y/o variedad de café, las adulteraciones, la incorporación de aditivos, el método de preparación de la bebida, el tipo de recipiente en el que se sirve la infusión, entre otros. El presente artículo presenta una breve descripción de los factores que afectan la calidad de la taza relacionados con el procesamiento del grano oro del café. Sin embargo, aunque los factores ya mencionados son tomados en consideración por los catadores, para fines comerciales, la calidad del café está y siempre estará en manos del consumidor. Después de todo la mejor prueba es cuando la persona lo prueba. Palabras clave: organoléptica, perfil de tueste, endotérmica, exotérmico, ma-croscópica, microscópica, reacción Maillard, caramelización.
... Moreover, the vanilla aroma used in this study did not elicit a taste in the stock solution, however perceiving this compound in real-food matrices might still produce an associated 'taste' perception (without necessarily activating gustatory receptors). In addition, the serving temperature of the test meals was low, which could potentially affect volatile release profiles and thus the retronasal olfactory perception (Bartoshuk et al., 1982;Steen et al., 2017;Talavera et al., 2006). More pronounced sensory-specific effects can, therefore, be expected at higher serving temperature(s) for aroma compounds. ...
Obesity has become a critical health issue in many developed countries, including New Zealand. While the aetiology of obesity is likely to be multifactorial, overconsumption is deemed as a key behavioural contributor to the growing obesity rate. Emerging sensory nutritional research has proposed that obesity is linked to altered olfactory and gustatory sensitivities, which can in turn influence consumption, particularly of foods rich in sugar, salt, and fats. Despite being promising, empirical studies to test for this hypothesis have returned highly controversial results. The present doctoral thesis aims to ‘systematically evaluate the role of olfaction and gustation in regulating an individual’s adiposity and eating behaviour’, using well-validated psychophysical, nutritional, and food-psychological approach.
The present thesis firstly aimed to develop and test for new approaches to quantify individual chemosensory sensitivities to food-related stimuli, based on assessments of individual performance to decremental (d′(d)) and incremental (d′(i)) stimulus range. Subsequently, these sensitivity measures were analysed against inter-individual differences in adiposity measures and eating behaviour. Additional exploratory research was performed to further analyse possible factors driving chemosensory links to food-related behaviour. Two separate datasets were collected in this thesis, with Data Collection 1 involving N=70 (age range = 21-39 years, BMI range = 20.5-48.1 kg·m-2) and Data Collection 2 involving N=61 (age range = 21-39 years, BMI range = 19.7-41.5 kg·m-2) participants.
The results from the first analysis show that individuals’ sensitivities to decremental stimulus range (d′(d)) and to incremental stimulus range (d′(i)) represent distinct measures. Furthermore, the measure of d′(d) is positively associated with adiposity measures, whereas d′(i) exhibits a negative relationship. Furthermore, these two separate sensitivity measures had significant, but contradictory, relationships with snack intake and total habitual energy intake. Specifically, individuals with poor olfactory and gustatory sensitivities (high d′(d) and low d′(i)) appeared to consume more sweet versus savoury snacks, than their counterparts, pointing to an important differentiating role of snack consumption.
In the context of the aforementioned findings, the last study of the thesis tested whether exposure to olfactory and gustatory cues in a meal influences subsequent snack choice and intake. With a repeated-subject design over one control and four testing sessions, the participants had breakfasts with manipulated olfactory and gustatory characteristics and recorded their snack intake throughout the day. Results from this study revealed that high-intensity olfactory and gustatory characteristics of a meal reduce sweet snack intake and increase the non-sweet snack intake, while total snack intake is maintained across the sessions. Specifically, individuals with high gustatory sensitivity showed more sensory-specific effects compared to the low-sensitivity group. Moreover, the high-BMI group showed sensory-specific effects for low- and high-intensity sweet taste cues, in contrast, the low-BMI group showed sensory-specific effects only for the high-intensity taste cues. Overall, the findings of this specific study highlight that the olfactory and gustatory cues of a meal may have a day-long effect on snack choice, providing novel insights into the observed association between sensory sensitivity and adiposity.
Overall, this doctoral thesis systematically assessed the role of individual olfactory and gustatory sensitivities in influencing adiposity and eating behaviour. With multifactorial data ranging across sensory science, nutrition and food psychology, this thesis provides new insights into inter and intra-individual differences in olfactory and gustatory sensitivities, and their important links to eating behaviour.
... Coffee, like wine and beer, has a wide range of unique aroma profiles that describes and define each cup of coffee. Multiple factors such as species, cultivar, origin, post-harvest processing, roast profiles Munchow et al., 2020), brewing methods (Stanek et al., 2021), and serving temperature (Steen et al., 2017;Talavera et al., 2007) influence the aroma profile of a cup of coffee. Coffee is also a global commodity commonly paired with foods. ...
Coffee has, like wine and beer, a wide aroma spectrum, yet coffee-food pairings have not found their way into the menu of fine restaurants and the scientific literature. It is still unknown why certain beverage-food pairings are a match. The aim of this study is twofold: first, we characterize four coffees by sensory descriptive analysis (DA) where assessors evaluated samples before and after tasting aqueous solutions representing five basic tastes (BT); secondly, we investigate consumers’ liking of the same four coffees, both in isolation and when paired with a sweet or savory food.
The DA results showed that exposure to all BT influenced the subsequent perceived attribute intensity of coffee; however, the direction of the effect was dependent on the BT, the coffee, and the specific sensory attribute. Most sensory attribute intensities decreased after exposure to the BT, only exposure to the BT bitter increased the intensity of more attributes than it decreased.
The consumer test showed that preference for the coffee were mostly related to intrinsic characteristics of the samples as over half of the data variance in consumer liking (56%) related to the difference between samples described by fruity, floral and berry attributes, and samples described by chocolate, nutty and sweet attributes. Pairing coffee with either sweet or savory food accounted for an additional 20% of the variance in liking. Drivers of liking were sample-specific, with one common denominator: when consumers perceive the coffee as sour, they liked it significantly less. Overall, with respect to coffee-food pairing, coffee characterized as having chocolate, nutty, sweet notes are more suitable to be paired with food than coffees characterized as fruity, floral, berry.
... A perhaps surprising result is that the perceived adequacy of flavor intensity, mouthfeel, and acidity all showed little difference with higher temperatures. Much research with calibrated expert panels has indicated that beverage temperature has a large impact on perceived sensory qualities (Stokes et al. 2016;Steen et al. 2017;Adhiraki et al. 2019;Chapko and Seo 2019). These studies, however, examined much larger temperature variations than examined here. ...
We recently performed a systematic investigation of consumer preferences for black coffee versus key brewing parameters, including total dissolved solids, extraction yield, and brewing temperature (Cotter et al., Journal of Food Science, 2021). An experimental goal in that work was for participants to taste the coffee at a beverage temperature of 65°C, but the large sample size of more than 3,000 individual tastings, combined with natural variations in the brewing and cooling processes, meant that coffees were assessed over a normally distributed range of temperatures between 56 and 71°C. Here we use those data to provide a more detailed analysis of the impact of beverage temperature on consumer acceptance of the coffee. Using a 5-point just-about-right (JAR) scale, we find that a majority of consumers (>50%) assessed the temperature as JAR at all temperatures tested up to 70°C. A substantial fraction of consumers, approximately 6 to 12%, assessed the coffee as too cold over the range 56 to 68°C. Only above 70°C did a majority of consumers assess the coffee as too hot and none assessed it as too cold, albeit with 40% still assessing it as JAR. Complementary analyses indicate that beverage temperature over this range had little impact on assessments of the adequacy of flavor intensity, acidity, and mouthfeel, but did correlate slightly with overall liking and purchase intent. Overall, the results suggest that temperatures over the range of 58 to 66°C maximize consumer acceptance, and that 68 to 70°C is the minimum temperature range at which no consumers will assess black coffee as too cold.
... 3-Hexanone was the only volatile compound from ketone class which was detected in coffee samples. It exhibits sweet, fruity odour in coffee (Steen et al., 2017) and the area percentage of 3-hexanone increased with coffee roasting (P>0.05). In the previous Turkish coffee studies 3-hexanone was not detected in any Turkish coffee brew (Kıvaçlı and Elmacı, 2016;Amanpour and Selli, 2016;Ayseli et al., 2021), Propanoic acid and hexanoic acid from acid class, benzene ethanol from alcohol class, dihydro-2-methyl-3(2H)-furanone, 3,5-dimethyl-2(5H)-furanone, 2(5H)furanone from furanone class were found in roasted and ground coffee samples. ...
Roasting is the most important coffee processing stage that affects coffee flavour. Coffee brew is prepared by various methods and Turkish coffee brewing technique is one of the oldest methods among other coffee preparation techniques. In this study, volatile compounds of light, medium, dark roasted ground coffee and Turkish coffee brews prepared from light, medium, dark roasted coffees were evaluated and the effect of roasting process was determined. The volatile compounds from acid (2), alcohol (1), aldehyde (2), furan (8), furanone (3), ketone (1), lactone (1), phenol (3), pyrazine (19), pyridine (1), pyrrole (6), and thiophene (1) chemical group was detected in all roasted ground coffee samples. However, volatiles compounds from acid, alcohol and furanone group were not detected in any Turkish coffee brew. Pyrazines were main volatile compounds of light roasted ground coffee and Turkish coffee brew of light roasted coffee. On the other hand, furans were main volatile compounds of medium, dark roasted ground coffee and Turkish coffee brew prepared from medium, dark roasted coffees followed by pyrazines.
... Possible confounding effects due to associative 'taste' perception should be considered when interpreting the current results. In addition, the serving temperature of the test meals was low, which could potentially affect volatile release profiles and thus the sensory perception (Bartoshuk et al., 1982;Steen et al., 2017;Talavera et al., 2006). More pronounced sensory-specific effects may be expected at a higher serving temperature. ...
Exposure to sensory cues has been shown to profoundly affect sensory-specific appetite and satiety in empirical settings. The present study aims to understand whether taste and aroma, presented in a real food matrix, can elicit sensory-specific effects on subsequent snack consumption in real life. A total of 61 male participants (final N=40; 21-39 years; 19.7-41.5 kg·m⁻²) undertook five breakfast sessions. In each session, participants were served oat puddings of customised, pre-determined portions, which was either plain (used as the control), or with added low or high intensity of vanilla aroma or non-caloric sweetness. Participants were asked to report pre- and post-meal satiety and meal pleasantness using a Satiety Labelled Intensity Magnitude (SLIM) and a hedonic Visual Analogue scale (VAS), respectively. Participants then recorded all-day food intake using standard Food Records, which enabled estimates of individual total, sweet, and non-sweet snack intake. Our results showed that breakfasts with high-intensity aroma or taste led to more significant reductions in hedonic VAS post-breakfast, as opposed to the control or low-intensity conditions (p<0.05). The total snack intake was maintained at a similar level across the conditions (p>0.05). Compared to the control or low-intensity conditions, breakfasts with high-intensity vanilla aroma or sweet taste were associated with increased sensory-incongruent (i.e., non-sweet) and decreased sensory-congruent (i.e., sweet) snack intake (non-sweet intake: aroma (F(2, 108)=59.65, p<0.001), taste (F(2, 108)=43.74, p<0.001); sweet intake: aroma (F(2, 108)=6.93, p=0.001), taste (F(2, 108)=13.94, p<0.001)). Overall, this study is the first to compare sensory-specific effects of retronasally-introduced aroma and taste on snack intake throughout the day, highlighting the important functional roles of sensory exposures in orientating food choices.
... Standard methods were used to assess the proteinogenic amino acids profile ( Volatile compound profile analysis. The volatile compound profile was determined by Gloess et al. (2013) and Steen et al. (2017) methods with midifications. Compounds were extracted by solid phase microextraction (SPME) using carboxen/ polydimethylsiloxane (CAR/PDMS) fibre (Supelco, USA). ...
During the roasting process, a cascade of chemical reactions occur, from which non-volatile compounds degrade and form new compounds with potential aroma attributes. Considering that the roasting process significantly influences the biologically active compound concentration and some unwanted compound formation, such as acrylamide, it is crucial to understand the roasting process from both positive and negative aspects. The aim of this study was to evaluate the chemical composition changes in different roast level coffee samples from Colombia. The moisture, pH, acrylamide, total phenolic, and flavonoid content, and the volatile compound profile were analysed for coffee samples roasted at three different roast levels (light, medium, dark). The results showed a decrease of total phenolic and flavonoid concentration with increased roast level. Acrylamide concentration reached the highest peak in the medium roasted and the lowest in dark roasted coffee. With increasing roast level, the volatile organic acid concentration decreased, while furan and phenol compound concentration increased in the dark roasted coffee. Dark roasted coffee had the lowest acrylamide and organic acid concentration, and the highest pH in brew, which would be more suitable for coffee consumers with a sensitive stomach.
... This may be supported by identifying key aroma-active compounds associated with liking. The aroma composition of coffee is influenced by numerous factors, such as processing (roasting temperature, fermentation, grinding, brewing techniques), additives (milk, fat, creamer-liquid or granular substances instead of milk), coffee species, geographical origin, ripening stage, storage condition, and so on (Caporaso et al., 2018;Parat-Wilhelms et al., 2005;Pérez-Martínez et al., 2008;Ross et al., 2006;Schenker et al., 2002;Steen et al., 2017). ...
Coffee aroma is a complex mixture of volatile compounds. This study characterized the important aroma‐active compounds associated with consumer liking in formulated coffee‐flavored dairy beverages. Nine coffee‐flavored dairy beverages were formulated: low fat–low coffee; medium fat–low coffee; high fat–low coffee; low fat–medium coffee; medium fat–medium coffee; high fat–medium coffee; low fat–high coffee; medium fat–high coffee; and high fat–high coffee. Regular coffee consumers, (n = 231) used a nine‐point hedonic scale to rate acceptance of aroma. Volatile compounds were extracted by head space‐solid phase micro‐extraction (HS‐SPME) and analyzed by gas chromatography‐mass spectrometry‐olfactometry (GC‐MS‐O) using a modified frequency (MF) approach. Fifty‐two aroma‐active compounds were detected. Thirty‐one aroma‐active compounds were considered important compounds with MF‐value ≥ 50%. The total number of aroma‐active compounds and their intensity were affected because of fat and coffee concentration. Partial least squares regression (PLSR) was performed to determine the relationship between aroma‐active compounds and liking. PLSR analysis identified three groups of compounds regarding liking. Twenty‐five compounds were associated with positive liking, for example, 2‐(methylsulfanylmethyl) furan (coffee like). Sixteen compounds were negatively associated with liking, for example, 2‐methoxyphenol (bacon, medicine like). Eleven detected compounds had no association with liking, for example, butane‐2,3‐dione (butter, fruit like).
Practical Application: The result of this study may be applied to formulate coffee‐flavored dairy beverages to maximize consumer acceptance and aroma‐liking. This study suggested too low coffee concentration is not desirable. Too much fat affects aroma release and/or alters the characteristic coffee flavor which negatively affects consumer acceptance.
... That is, the majority of people can discriminate the sound of hot from cold water when poured at a level that is significantly above chance. Given that the temperature at which beverage, such as coffee, is served, influences the release of aromatic flavor volatiles from the surface of the drink (Steen et al., 2017), the sound of temperature likely helps to subtly set people's aromatic flavor expectations too. The various informative sounds associated with the preparation of coffee can help to set people's (often unconscious) expectations, just like the "sizzle that sells the steak." ...
Eating and drinking are undoubtedly amongst life’s most multisensory experiences. Take, for instance, the enjoyment of flavor, which is one of the most important elements of such experiences, resulting from the integration of gustatory, (retronasal) olfactory, and possibly also trigeminal/oral-somatosensory cues. Nevertheless, researchers have suggested that all our senses can influence the way in which we perceive flavor, not to mention our eating and drinking experiences. For instance, the color and shape of the food, the background sonic/noise cues in our eating environments, and/or the sounds associated with mastication can all influence our perception and enjoyment of our eating and drinking experiences. Human-Food Interaction (HFI) research has been growing steadily in recent years. Research into multisensory interactions designed to create, modify, and/or enhance our food-related experiences is one of the core areas of HFI (Multisensory HFI or MHFI). The aim being to further our understanding of the principles that govern the systematic connections between the senses in the context of HFI.
In this Research Topic, we called for investigations and applications of systems that create new, or enhance already existing, multisensory eating and drinking experiences (what can be considered the “hacking” of food experiences) in the context of HFI. Moreover, we were also interested in those works that focus on or are based on the principles governing the systematic connections that exist between the senses. HFI also involves the experiencing of food interactions digitally in remote locations. Therefore, we were also interested in sensing and actuation interfaces, new communication mediums, and persisting and retrieving technologies for human food interactions. Enhancing social interactions to augment the eating experience is another issue we wanted to see addressed here, what has been referred to as “digital commensality”.
... Good quality is not only the main factor that determines the price of coffee, but is also an important factor influencing the income of coffee farmers. The content of lipids, protein and sucrose directly determines coffee quality [5,6] . Flavor and taste (FT) are also important evaluation factors determining coffee quality. ...
Coffea arabica (Arabica) and C. canephora(Robusta) are the most popular coffee species in the world, accounting for 99% of overall consumption of coffee beans. Arabica generally possesses better coffee quality than Robusta partly due its higher sucrose content. The flavor and taste (FT) of coffee, as important aspects of coffee quality, are mainly affected by the content of caffeine, phenolic acid and terpenoid compounds, which use sucrose as an important precursor. However, how sucrose affects the coffee FT remains unclear. In this study, coffee beans at different developmental stages from Arabica #161 (A161, high-sucrose variety) and Robusta #6 (R6, low-sucrose variety) were sampled to perform transcriptomic analysis. Most differentially expressed genes (DEGs) between them were enriched in sucrose-related metabolisms and the FT-related metabolism processes: caffeine biosynthesis, phenylpropanoid and flavonoid pathway, terpenoid metabolism. Thirty-four candidate DEGs probably contributed to the higher content of sucrose, anthocyanin and linalool in A161, and higher content of caffeine and carotenoid in R6. Generally, sucrose-related metabolisms were strongly associated with FT-related substance accumulation. The content of sucrose and its influence on the downstream secondary metabolism probably play important roles in the FT quality of coffee beans. Our results provide efficient targets for investigation regarding the influence of sucrose on FT quality of coffee beans.
... About 40-46, 42-45, 43-48, and 44-51 volatile compounds were identified in nuts under T20-LH, T20-HH, T30-LH, and T30-HH treatments, respectively, during the ripening stage (Table 1 and Table S1). It had been previously reported that the volatile compounds in coffee beans increased significantly as the temperature increased, ranging from 31 ℃ to 62 ℃ (Steen et al., 2017). Possibly, the higher volatile compounds emission under higher temperature treatments were influenced by their greater evaporation. ...
The postharvest ripening stage is necessary for Torreya grandis (T. grandis) nuts to complete aromatic synthesis, which requires appropriate temperature and relative humidity (RH). Currently, scarce information is available regarding the changes in aroma profiles in T. grandis nuts and the relationship with their response to different environmental conditions. Therefore, the interaction of temperature (20 °C or 30 °C) and relative humidity (70% RH or 90% RH) was investigated on aromatic substances after harvest. The results showed that 56 aromatic components were detected by a gas chromatography-mass spectrometer (GC-MS) and mainly divided into five categories, among which terpenes were the most abundant (56.2–86.7%). Principal component analysis (PCA) showed that both temperature and humidity can affect the aroma composition, and terpenes were mainly influenced by humidity. Specifically, D-limonene occupied the largest proportion of terpenes (63.0–90.8%) and was significantly upregulated by high humidity.
... Body Taste resulting from the area is supported by the quality of the produced coffee beans. Another defected value that results in a brew coffee flavor is the spread of dust or soil (1,3,5,8,11,13,16,(18)(19). The Aroma of coffee produced will differ in each coffee producing region. ...
The purpose of this research is to get information on the value of defectives, water content, taste, and the overall acceptance of Arabica coffee derived from 20 coffee producers in West Sumatera. Taste testing involves trained q grader. The Data of research results analyzed descriptively. The results showed that the quality defectives of coffee is at a quality level from 3 to 5 and 70% quality of coffee in accordance with SNI (Indonesian National Standards) 01-2907-2008. The type of defective in coffee beans is the rupture seeds, brown seeds, black seeds then followed by perforated seeds. Taste of coffee Brew are Excellent Aroma and complex coffee flavor, good acidity and thickness of seeds. Vanilla flavor and taste of fruits and spices. The color of the Arabica coffee powder varies from brown, black and color like cinnamon, As well as overall acceptance kinda like. This indicates the need to implement standard operational procedures to improve the quality of coffee in West Sumatera Framework
... The use of DHS was reported for the extraction of volatile compounds from EC samples through a Purge-and-Trap (PT) sampling [117]. In PT application, an inert gas, especially nitrogen (N2), is purged to the sample at a specific flow rate to extract VOCs, which are collected into an adsorbent trap. ...
Espresso coffee (EC) is a common coffee preparation technique that nowadays is broadly widespread all over the globe. Its popularity is in part attributed to the intense aroma and pleasant flavor. Many researchers have studied and reviewed the aroma of the coffee, but there is a lack of specific review focused on EC aroma profile even if it is intensively investigated. Thus, the objective of the current review was to summarize the aroma profile of EC and how different preparation variables can affect EC flavor. Moreover, a collection of diverse analytical procedures for volatile analysis was also reported. The findings of this survey showed that the volatile fraction of EC is extremely complex, but just some compounds are responsible for the characteristic aroma of the coffee, such as some aldehyde, ketones, furanones, furans, sulfur compounds, pyrazines, etc. In addition, during preparation, some variables, e.g., temperature and pressure of water, granulometry of the coffee particle, and brew ratio, can also modify the aroma profile of this beverage, and therefore its quality. A better understanding of the aroma fraction of EC and how the preparation variables should be adjusted according to desired EC would assist coffee workers in obtaining a higher quality product.
... That is, the majority of people can discriminate the sound of hot from cold water when poured at a level that is significantly above chance. Given that the temperature at which beverage, such as coffee, is served, influences the release of aromatic flavor volatiles from the surface of the drink (Steen et al., 2017), the sound of temperature likely helps to subtly set people's aromatic flavor expectations too. The various informative sounds associated with the preparation of coffee can help to set people's (often unconscious) expectations, just like the "sizzle that sells the steak." ...
The coffee drinking experience undoubtedly depends greatly on the quality of the coffee bean and the method of preparation. However, beyond the product-intrinsic qualities of the beverage itself, there are also a host of other product-extrinsic factors that have been shown to influence the coffee-drinking experience. This review summarizes the influence of everything from the multisensory atmosphere through to the sound of coffee preparation, and from the typeface on the coffee packaging through the drinking vessel. Furthermore, the emerging science around sonic seasoning, whereby specific pieces of music or soundscapes, either pre-composed or bespoke, are used to bring out specific aspects in the taste (e.g., sweetness or bitterness) or aroma/flavor (nutty, dark chocolate, dried fruit notes, etc.) of a coffee beverage is also discussed in depth. Relevant related research with other complex drinks such as beer and wine are also mentioned where relevant.
... 5-Methylfurfural has a sweet, spicy, coffee, and caramel flavor (Fors, 1983). 2-Acetyl-5-methylfuran has a sweet, moldy, nutty, and caramel-like aroma note (Steen et al., 2017). 5-Hydroxymethyl furfural has a sweet, coffee, and caramel flavor characteristic. ...
Sugar-smoking contributes to improving flavor attributes of meat products. However, there is rather limited information concerning the relationship between sugar-smoking process parameters and volatile compound (VC) fingerprinting as well as related quality attributes of sugar-smoked chicken. In this work, the changes in VC across the whole sugar-smoking process were determined and analyzed and physicochemical properties, free fatty acid, thiobarbituric acid reactive substances values, and E-nose were also performed to characterize the quality properties of sugar-smoked chicken breast (CB) and chicken skin (CS). Results suggested that a higher amount (P < 0.05) of total VC was observed in CS compared with CB during the whole processing, which may be correlated with higher thiobarbituric acid reactive substances values, and higher polyunsaturated fatty acid/saturated fatty acid ratio. According to E-nose analysis, the volatile flavor is clearly separated in the sugar-smoking stage. Volatile fingerprinting results revealed that heterocycles were the characteristic flavor formed during sugar-smoking process and hexanal, nonanal, furfural, 5-methyl-2-furancarboxaldehyde, and 2-acetyl-5-methylfuran were the major volatiles of the CS, which was closely related to lipid oxidation and caramelization reaction. Above all, the flavor of sugar-smoked chicken was mainly derived from CS and sugar-smoked process improved the flavor of CS. This study could provide theoretical guidance for regulation of the color and flavor of sugar-smoked chicken and further promote the development of the industry.
... The evaluation was initiated when the coffee had cooled to 55 • C, despite consumer preferences favouring higher consumption temperatures of more than 60 • C [19,20]. Starting at a lower temperature reduces the risk of scalding and has furthermore been shown to provide better balance between subtle flavour notes and the highly impactful roasted notes found at higher temperatures [21]. ...
The specialty coffee industry is growing and, as a result, there is an accelerated interest in modulating roast profiles to present customers with new and diverse sensory experiences. The present study investigates the chemical and sensory effects of subtle variations in the ‘development time’ phase of the coffee roasting process. Four roast profiles were studied through sensory descriptive analysis (DA), gas chromatography–mass spectrometry (GC–MS), and nuclear magnetic resonance (NMR). Multivariate analysis showed clear separation of DA, GC–MS, and NMR data. A prolonged development time facilitated a statistically significant shift in the chemical and sensory profile of the coffee. The findings suggest that a short development time increases the fruity, sweet and acidic characteristics of the coffee, whereas a longer development time shifts the balance towards a more roasty, nutty, and bitter profile. The results provide evidence that supports the effect of subtle roast profile modulations. This lays a strong foundation for the inclusion of development time as a critical control parameter in the certification system of the Specialty Coffee Association, quality control, and product development strategies.
The purpose of this study was to determine the retronasal threshold values of capsaicin and dihydrocapsaicin according to the change in serving temperatures. Threshold tests were performed using five series of three alternative forced choice method in aqueous‐based matrices at varying temperature levels. The retronasal threshold values of capsaicin at 4°C, 25°C, and 60°C were 1.83, 1.57, and 1.57 mg/kg, respectively; no significant differences were observed. Similarly, the retronasal threshold of dihydrocapsaicin at 4°C, 25°C, and 60°C reached 2.14, 1.71, and 1.78 mg/kg, respectively; no differences based on serving temperature were observed ( p > .05). These values were slightly higher than best estimate thresholds reported in different countries.
Practical Applications
Capsaicin and dihydrocapsaicin are two of the major compounds responsible for how we perceive spiciness in food. This study found no differences in best estimate thresholds (BETs) according to the temperature at which the food was served, suggesting that the serving temperature does not impact the recognition threshold of capsaicin and dihydrocapsaicin. This means that the serving temperature does not alter the human perceived spiciness in foods having capsaicin and dihydrocapsaicin above BET levels.
Fermentation is critical for developing coffee physicochemical properties. This study 14 aimed to assess the differences in quality traits between fermented and unfermented coffee with 15 four grinding sizes of coffee powder using multiple digital technologies. A total of N = 2 coffee 16 treatments (i) dry processing, (ii) wet fermentation with grinding levels (250, 350, 550, and 750 µm) 17 were analysed using near-infrared spectrometry (NIR), electronic nose (e-nose), and headspace/gas 18 chromatography-mass spectrometry (HS-SPME-GC-MS) coupled with machine learning (ML) mod-19 eling. Most overtones detected by NIR were within 1700 – 2000 nm and 2200 – 2396 nm ranges while 20 enhanced peak responses of fermented coffee were lower. The overall voltage of nine e-nose sensors 21 obtained from fermented coffee (250 µm) was significantly higher. Two ML classification models to 22 classify processing and brewing method using NIR (Model 1) and e-nose (Model 2) values as inputs 23 were highly accurate (93.9% and 91.2%, respectively). Highly precise ML regression Model 3 and 24 Model 4 based on the same inputs for NIR (R=0.96) and e-nose (R=0.99) were developed respectively 25 to assess 14 volatile aromatic compounds obtained by GC-MS. Fermented coffee showed higher 2-26 methylpyrazine (2.20 ng/mL) and furfuryl acetate (2.36 ng/mL) content, which induces a stronger 27 fruity aroma. This proposed rapid, reliable, and low-cost method showed to be effective in distin-28 guishing coffee postharvest processing method and evaluating tehir volatile compounds, which has 29 the potential to be applied for coffee differentiation and quality assurance and control.
Although the roles of coffee origin, roasting degree, and consumption methods on the sensory properties of coffee have been actively discussed, the type of water used in brewing plays as important a role as coffee beans, roasting degree, and brewing skills in deciding coffee quality. As water is an essential ingredient in coffee brewing, we must consider its role in the process. This study analyzed the impact of three types of water (depending on total dissolved solids [TDS]) on consumer liking (appearance, flavor, taste, aftertaste, and overall) and coffee emotion lexicons at three roasting degrees (three water types × three roasting points). A total of 167 consumers evaluated their liking for nine coffee samples and conveyed their emotion lexicons utilizing the check-all-that-apply method. For coffee extraction, purified water, tap water, and bottled water from Australia were used for the evaluation and they had TDS content of approximately 0, 100, and 200 ppm, respectively. An analysis of variance demonstrated that all sensory attributes had significant differences, except for aftertaste. Consumer liking decreased in relation to increasing TDS at the medium and dark roasting points. Coffee brewed using purified water was preferred by coffee consumers at medium and dark roasting points. Additionally, when they had their highly preferred coffee samples, they experienced positive emotions, such as feeling energetic, nostalgic, independent, adventurous, and focused.
This narrative review examines the complex relationship that exists between the presence of specific configurations of volatile organic compounds (VOCs) in food and drink products and multisensory flavour perception. Advances in gas chromatography technology and mass spectrometry data analysis mean that it is easier than ever before to identify the unique chemical profile of a particular food or beverage item. Importantly, however, there is simply no one-to-one mapping between the presence of specific VOCs and the flavours that are perceived by the consumer. While the profile of VOCs in a particular product undoubtedly does tightly constrain the space of possible flavour experiences that a taster is likely to have, the gustatory and trigeminal components (i.e., sapid elements) in foods and beverages can also play a significant role in determining the actual flavour experience. Genetic differences add further variation to the range of multisensory flavour experiences that may be elicited by a given configuration of VOCs, while an individual’s prior tasting history has been shown to determine congruency relations (between olfaction and gustation) that, in turn, modulate the degree of oral referral, and ultimately flavour pleasantness, in the case of familiar foods and beverages.
The effect of coffee bean quality (specialty and regular) and brewing method (cold and hot) on the sensory profile and physicochemical characteristics of coffee beverages was studied. Cold brew was prepared by immersion and hot brew coffee by French Press. Total dissolved solids (TDS), titratable acidity (TA), caffeine, trigonelline, 4 and 5- caffeoylquinic acids were quantified by instrumental methods, volatile compounds by GC–MS, and the coffee flavor was through quantitative sensory evaluation. Coffee beverages were more differentiated by brewing method than by the coffee bean quality used in the preparation. Cold brew coffees were mainly associated with volatile 2-methyl-butanal, 5-methyl furfural, and dihydro-2-methyl- 3 (2H) -furanone. Hot brew coffee beverages were identified with some specific furans and 2-methoxy-4-vinylphenol. No significant differences were found in TDS, caffeine, trigonelline, 4 and 5 caffeoylquinic acids. A higher TA was observed in hot coffee beverages than in cold brew coffees. Regular bean quality promoted undesirable sensory attributes in both cold and hot brew beverages. However, these attributes were perceived in higher intensity in hot brew coffee beverages. Thus, differences in brewing methods affect the extraction of the chemical compounds present in different coffee bean quality, translating into variations in the sensory profile.
Three hundred consumers were required to mix a hot and a cooler coffee together until it was at a desired temperature for drinking. They added creamer and sweetener to taste. In a 2nd experiment, 108 consumers performed the same experiment with black coffee only, but repeated it using different coffee strengths. In all experiments, the chosen mean preferred temperature for drinking was around 60 °C (140 °F). Black coffee drinkers chose a slightly higher mean temperature than drinkers with added creamer, and they also chose a slightly lower mean temperature when the flavor was stronger. In all cases, consumers tended to choose, on average, temperatures for drinking coffee that were above the oral pain threshold and the burn damage threshold.
For the consumer, flavor is arguably the most important aspect of a good coffee. Coffee flavor is extremely complex and arises from numerous chemical, biological and physical influences of cultivar, coffee cherry maturity, geographical growing location, production, processing, roasting and cup preparation. Not surprisingly there is a large volume of research published detailing the volatile and non-volatile compounds in coffee and that are likely to be playing a role in coffee flavor. Further, there is much published on the sensory properties of coffee. Nevertheless, the link between flavor components and the sensory properties expressed in the complex matrix of coffee is yet to be fully understood. This paper provides an overview of the chemical components that are thought to be involved in the flavor and sensory quality of Arabica coffee.
Numerous types of sulfur‐containing flavor compounds are associated with foods. However, thiazoles represent an extremely potent sensory source. In this review the foods in which thiazoles have been identified are discussed. In addition, isolation and identification techniques specific to thiazoles are evaluated. Other important areas covered include the synthesis of thiazoles and the sensory properties of both naturally occurring and synthesized derivatives.
The effects of salt (0% or 0.5% of NaCl) and umami compounds (0% or 0.3% of monosodium glutamate (MSG)+0.15% of disodium salts of ribonucleotides) on odour and flavour attributes of beef broth model systems (BG) were studied at two serving temperatures (25 and 50°C). Flavoured BG samples were prepared using 1-octen-3-ol (35mgl−1) and 2,6-dimethylpyrazine (100mgl−1) alone (BGO and BGD) or in combination (BGOD). A noticeable odour and flavour potentiator effect of NaCl on flavour intensities (overall, broth-like and saltiness in all samples; mushroom flavour in BGO and BGOD samples; nutty and cocoa flavour in BGD and BGOD samples), partly related to a “salting out” phenomenon, was found. Compared to 2,6-dimethylpyrazine, 1-octen-3-ol provided a less congruent flavour, which could explain the absence of a potentiator effect of umami compounds on mushroom flavour intensity. Cocoa and nutty flavour intensities increased with serving temperature in both BGD and BGOD model systems. However, mushroom odour and flavour increased in BGOD model systems but not in BGO samples, as a result of the likely enhancement effect displayed by the presence of 2,6-dimethylpyrazine. Salting-out phenomenon on particular aroma-active volatile compounds was established using sensory analysis. The potentiator flavour effect of MSG and NaCl was dependent on the characteristics of the model systems.
The aim of this study was to determine experimentally the vapour pressures of aroma compounds at various temperatures, especially at negative ones. The aroma compounds were: acetone, 2-butanone, 2-hexanone, 2-octanone, ethyl acetate, ethyl butanoate, ethyl hexanoate, n-hexanal, n-hexanol and γ-hexalactone. The technique used was a static device where vapour pressure was measured at equilibrium. The temperatures of analysis varied from −40 to 25 °C. Volatility of a pure compound depends on characteristics such as length of the aliphatic chain, the functional group and temperature. Among an homologous series, volatility increases when the aliphatic chain decreases and when temperature increases. For aroma compounds which have the same number of carbon atoms in their structure, volatility depends not only on either temperature or molecular weight, but also on the functional group of the molecule. At a given temperature volatility of compounds which have the same number of carbon atoms in their structure, decreases as follows: ester> ketone> aldehyde> alcohol> lactone.
The threshold values of taste substances are influenced by several factors. To learn about the effect of the temperature on stimulus, recognition and terminal thresholds, these threshold values were determined for sucrose, sodium chloride, caffeine, quinine hydrochloride, citric and tartaric acid at tempertures of 10, 20, 40 and 60°C in a panel of 19 tasters. The individual values were found to vary over a wide range, resulting in a relatively large standard deviation of the mean threshold values. A temperature-dependence was found for the stimulus and recognition thresholds which was different for the different taste substances. The stimulus and recognition thresholds are lowest in the temperature range of 20 to 40°C. The threshold values increase with increasing temperature, and except for citric acid, significant and highly significant differences existed particularly between 20 and 60°C, whereas statistically verifiable results could not be obtained between 10 and 20°C. There was no verifiable temperature dependence either for the terminal thresholds. The terminal thresholds were found to lie rather in a relatively narrow concentration range and to be largely independent of the temperature. The results suggest that in warm dishes and beverage more taste substances are required to produce the same taste intensity. A dependence of the individual thresholds upon age, sex and smoking habits could not be found.
Volatile components in maize flour, extruded under different conditions obtained by varying product temperature (120, 150, or 180 °C), moisture level (14, 18, or 22%), and residence time (35 or 60 s), were identified and evaluated by gas chromatography/mass spectrometry (GC/MS) and GC olfactometry (GCO). Eighty compounds were identified in the headspace collections of the extrudates. Increasing the product temperature, reducing the moisture level, or prolonging the residence times generally increased the numbers and quantities of Maillard-derived compounds, such as pyrazines, pyrroles, furans, and sulfur-containing heterocycles. In low-temperature (120 °C) and high-moisture (22%) extrusions, the main volatiles were compounds associated with lipid degradation, with few compounds derived from the Maillard reaction. Increasing the temperature and reducing the moisture level to 18% gave rise to the formation of some pyrazines and thiophenones. A marked increase in quantities of 2-furfural, 2-furanmethanol, and alkylpyrazines occurred in the extrusions at 180 °C and 14% moisture level. Under these conditions, other nitrogen- and sulfur-containing heterocyclic compounds were also generated. GCO assessments identified 2-acetyl-1-pyrroline and 2-acetylthiazole as compounds that contributed to cereal-like odors of the extrudates. Some other sulfur-containing compounds were also believed to be involved in the aroma of extrudates processed at 180 °C and 14% moisture level. Keywords: Cereal; maize; extrusion processing; aroma; volatiles; Maillard reaction
ABSTRACTR-index measures were obtained from judges who ranked black coffees for preferred drinking temperature. Preferred temperatures were above thermal pain and thermal damage thresholds. The least preferred temperature was below the oral thermal pain threshold. Similar results were obtained with a ranking for temperatures that judges felt were most likely to be served in a coffee shop. Observations of customers in coffee shops indicated that they began sipping coffee at similar high temperatures.
The hospitality and food science literatures specify brewing and holding temperatures for hot beverages such as coffee, while the medical literature states that those very beverage temperatures will cause scalds and harm. These two specifications are at odds with one another, and recommend different approaches to serving and handling hot beverages. Considering the disparate standards it is interesting to note that no one has reported asking consumers of hot beverages at which temperature they prefer to consume their hot beverages. This pilot study is a first step in determining the consumer preferred hot beverage temperature. The research intent is to see if a temperature, or temperature range, can be established at which consumers drink a hot beverage, in this case coffee. The research is particularly relevant given recent litigation relative to spills and burns at foodservice operations, and subsequent changes in holding temperatures at some quick service restaurant chains. The findings suggest that the standard brewing and holding temperatures are too high for consumption, while the temperature identified as the medical literature threshold for burns is too low for consumption. ©
Two experiments demonstrate that the sensitivity to heat pain varies significantly within the oral-facial region. Although
the chin, the vermilion border of the lip, and the tonguetip are about equally sensitive, the mucosal lip and the dorsum of
the tongue produce thresholds approximately 1.5°C higher. The spatial heterogeneity of heat-pain thresholds is discussed in
relation both to local variations in perceived warmth in the same areas and to the neural and physical variables that might
underlie them.
The aim of this study was the investigation of the influence of milk proteins (casein and whey proteins) and milk fat on the release of flavour compounds from white coffee beverages in the oral cavity. For this reason a retronasal headspace technique for measurement of the after-flavour was adapted. A ‘Gas Sampler’ equipped with a mouthpiece was used as an ‘Oral Breath Sampler (OBS)’. Analyses were performed by gas chromatography with mass spectrometric detection. It was noticed that the sampling at different hours resulted in different standard deviations. The flavour release is more constant in the morning (Variation coefficient from 3% to 28%; median: 10%) than in the afternoon (7–52%; median: 23%). The relationships between flavour release and some salivary parameters like salivation rate, buffer capability and protein content were also studied. The ‘Oral Breath Sampling’ was considered to be a valuable sampling method for the analysis of the retronasal aroma release from coffee beverages.
Flavour perception is characterised by complex interactions between physicochemical processes (textural properties, aroma release, etc.) and (bio)chemical, physiological and behavioural phenomena. The complexity of ‘peripheral’ processes and their interaction and reciprocal feedback mechanisms is enormous and hitherto not fully understood. In this overview, diverse peripheral factors are discussed with a focus on behavioural responses to sensory stimulation during food consumption and the resulting feedback effects. This review thereby aims at deepening the understanding of a key issue: not only do the chemical structures and concentrations/compositions of food stimuli determine our sensory perception and appreciation of foods, e.g. in terms of flavour acceptance and preference, but specific behavioural and physiological parameters provide additional clues to understand how individuals perceive and respond to stimulations, e.g. acceptance or rejection.
The influence of matrix composition and mastication on the temporal release of seven aroma compounds was studied in a model mouth system. 2-Butanone, diacetyl, ethyl acetate, 3-methyl-1-butanol, hexanal, 2-heptanone and ethyl butyrate were released from water and sunflower oil, with and without mastication, for 15, 30, 60, 120, 240, 480 and 720 s. Aroma compounds were quantified by gas chromatography/mass spectrometry. Volatile compounds were released at significantly different rates. The release of hydrophobic compounds from the oil was decreased, whereas the release of the hydrophilic compound diacetyl was increased in comparison with the water matrix. Interactions were observed between volatile compounds and matrix, as well as between volatile compounds and mastication. Linear release rate constants were related to physico-chemical characteristics, such as molecular weight, boiling points, vapour pressures, octanol–water, gas–water and gas–oil partition coefficients. The octanol–water partition coefficients correlated reasonably well with linear release rate constants for the release from water and oil without mastication, and from water with mastication. The other physico-chemical characteristics correlated poorly with linear release rate constants.
The study compares standard addition (SA), stable isotope dilution assay (SIDA) and multiple headspace extraction (MHE) as methods to quantify furan and 2-methyl-furan in roasted coffee with HS-SPME-GC-MS, using CAR-PDMS as fibre coating, d(4)-furan as internal standard and in-fibre internal standardization with n-undecane to check the fibre reliability. The results on about 150 samples calculated with the three quantitation approaches were all very satisfactory, with coefficient of variation (CV) versus the U.S. Food and Drug Administration (FDA) method, taken as reference, almost always below the arbitrarily-fixed limit of 15%. Furan was detected in the 1-5 ppm range, 2-methyl-furan in the 4-20 ppm range. Moreover, experimental exponential slopes (Q) and linearity (r) of both furan and 2-methyl-furan MHE regression equation on 50 samples were very similar thus making possible to use the same average Q value for all samples of the investigated set and their quantitation with a single determination. This makes this approach very rapid and competitive in-time with SA and SIDA. A non-separative method (HS-SPME-MS) was also developed in view of possible application on-line monitoring of furan and 2-methyl-furan in a pilot-plant with the aim of optimizing the roasting process to reduce these compounds to a minimum. Sampling times of 20 and 5 min were tested, the latter enabling total analysis time to be reduced to about 9 min. The results on 105 samples with both SIDA and MHE approaches were again highly satisfactory most of the samples giving a CV% versus the conventional methods below 20%. In this case too average Q values for both furan and 2-methyl-furan were used for MHE. The separative method presented very good repeatability (RSD% always below 10%) and intermediate precision over three months (RSD% always below 15%); performance were similar for the non-separative method, with repeatability (RSD%) always below 12% and intermediate precision over three months (RSD%) always below 15%. The sensitivity of both separative and non-separative methods was also very good, LOD and LOQ being in the ppb range for both furan and 2-methyl-furan, i.e. well below the amounts present in the roasted coffee samples.
Volatile compounds in fifty-eight Arabica roasted coffee samples from Brazil were analyzed by SPME-GC-FID and SPME-GC-MS, and the results were compared with those from sensory evaluation. The main purpose was to investigate the relationships between the volatile compounds from roasted coffees and certain sensory attributes, including body, flavor, cleanliness and overall quality. Calibration models for each sensory attribute based on chromatographic profiles were developed by using partial least squares (PLS) regression. Discrimination of samples with different overall qualities was done by using partial least squares-discriminant analysis (PLS-DA). The alignment of chromatograms was performed by the correlation optimized warping (COW) algorithm. Selection of peaks for each regression model was performed by applying the ordered predictors selection (OPS) algorithm in order to take into account only significant compounds. The results provided by the calibration models are promising and demonstrate the feasibility of using this methodology in on-line or routine applications to predict the sensory quality of unknown Brazilian Arabica coffee samples. According to the PLS-DA on chromatographic profiles of different quality samples, compounds 3-methypropanal, 2-methylfuran, furfural, furfuryl formate, 5-methyl-2-furancarboxyaldehyde, 4-ethylguaiacol, 3-methylthiophene, 2-furanmethanol acetate, 2-ethyl-3,6-dimethylpyrazine, 1-(2-furanyl)-2-butanone and three others not identified compounds can be considered as possible markers for the coffee beverage overall quality.
Equilibration time and temperature were the factors studied to choose the best conditions for analyzing volatiles in roasted ground Arabica coffee by a static headspace sampling extraction method. Three temperatures of equilibration were studied: 60, 80, and 90 degrees C. A larger quantity of volatile compounds was extracted at 90 degrees C than at 80 or 60 degrees C, although the same qualitative profile was found for each. The extraction of the volatile compounds was studied at seven different equilibration times: 30, 45, 60, 80, 100, 120, and 150 min. The best time of equilibration for headspace analysis of roasted ground Arabica coffee should be selected depending on the chemical class or compound studied. One hundred and twenty-two volatile compounds were identified, including 26 furans, 20 ketones, 20 pyrazines, 9 alcohols, 9 aldehydes, 8 esters, 6 pyrroles, 6 thiophenes, 4 sulfur compounds, 3 benzenic compounds, 2 phenolic compounds, 2 pyridines, 2 thiazoles, 1 oxazole, 1 lactone, 1 alkane, 1 alkene, and 1 acid.
Extrusion temperature (120, 135, and 150 degrees C) and quantity of added sodium hydroxide (0, 3, and 6 g/kg feedstock) were used as variables to study flavor generation in extrusion cooking of wheat flour. In total, 127 volatile components were identified in the extrudates, of which 51 contained sulfur. The levels of pyrroles, thiophenes, thiophenones, thiapyrans, and thiazolines increased at higher extrusion temperatures, whereas furans and aldehydes decreased. The addition of sodium hydroxide also affected the formation of volatile compounds. However, thiophenes, thiophenones, polythiacycloalkanes, thiazoles, thiazolines, pyrroles, and some pyrazines tended to increase with the more alkaline extrusion conditions. Some compounds from lipid-Maillard interactions were identified in the extrudates. Analysis of the volatile components by gas chromatography-olfactometry showed sulfur- and nitrogen-sulfur-containing heterocycles as possible contributors to the sulfury and rubbery odors observed in extrudates produced at the higher temperature and more alkaline conditions.
Previous investigations of coffee flavor have been confined to the analysis of the aroma substances. These investigations showed that about 30 volatile compounds were substantially responsible for the coffee flavor. The aim of this study was to investigate the influence of different milk additives and one coffee whitener on the release of flavor impact compounds from coffee beverages. For the investigation of these effects an external static headspace technique was developed. With this technique the most potent odorants of the coffee beverage were determined. Analyses were performed by gas chromatography/olfactometry, flame ionization detection, and mass spectrometric detection. In addition, sensory studies of the odor profiles were performed. Milk and vegetable products as additives for coffee beverages affected the release of aroma substances in the brew through their lipid, protein, and carbohydrate components. All beverages with an additive showed reduced, but typical, odor profiles for each additive.
The influence of human whole saliva on odor-active esters and thiols was investigated. Special emphasis was placed on food-relevant concentrations of the odorants. It was found that the amounts of the esters were reduced during incubation with saliva to different extents according to their chemical structures. Considerable degradations were also observed for 2-furfurylthiol, 2-phenylethanethiol, and 3-mercapto-3-methyl-1-butanol, being reduced from approximately 70 to 20% of their initial concentrations within a period of 10 min. Decrease of the odorants did not occur after thermal treatment of the saliva. Generally, the enzymic processes were found to be dependent on the salivary activity of each individual panelist as well as on the odorant's concentrations applied. These investigations were aimed at finding an explanation for the persistence of aftertaste in humans, as it is induced by some odor-active compounds after the consumption of food materials.
Using thin-walled aluminum thermodes individually fitted to the roof of the mouth, the pain threshold of the hard palate was measured in four subjects. By rapidly circulating hot water and water at 37 C alternately, the temperature of the thermode could be raised and lowered between a neutral and a test level. Temperature within the thermode was measured in every observation by a fine wire thermocouple in the circulating water. Temperature between the thermode and the hard palate was also measured over the entire range of temperatures studied, and a correction for the gradient across the thermode wall was determined and applied to the water temperature. Stimuli between 40 C and 49 C were administered. Each subject was exposed to 288 stimuli in six experimental periods. The range of stimuli reported as painful was from 44.5 C for the first reports of pain to 47.7 C which always evoked pain. A preliminary study was made of the buccal temperature changes occurring during drinking hot beverages, and evidence indicates the sipping of air with small amounts of the hot liquid maintains the tissue temperatures within tolerable limits.
Submitted on November 22, 1961
This study examined the effect of oral and product temperature on the perception of texture and flavor attributes. A trained panel assessed 21 texture and flavor attributes in one high-fat and one low-fat product of two semi-solids: custard dessert and mayonnaise. The products were evaluated at 10, 22 or 35 degrees C in combination with oral temperatures of 27, 35 and 43 degrees C. Results showed that modulation of product and oral temperature had significant effects on a number of attributes. Flavor intensities, melting mouth feel, and fat after feel increased, while subjective thickness decreased with increasing product temperature. Neither product- nor oral temperature had an effect on over-all creaminess. Oral temperature affected a number of mouth feel attributes: melting, heterogeneous and smooth. Furthermore, large differences existed in ratings between the high- and low-fat products of custard and mayonnaise, and they were more prominent in mayonnaise. We conclude that the effect of oral temperature on the perception of sensory attributes in semi-solids was small, but present, while the product temperatures influenced the ratings greatly.
Hot beverages such as tea, hot chocolate, and coffee are frequently served at temperatures between 160 degrees F (71.1 degrees C) and 185 degrees F (85 degrees C). Brief exposures to liquids in this temperature range can cause significant scald burns. However, hot beverages must be served at a temperature that is high enough to provide a satisfactory sensation to the consumer. This paper presents an analysis to quantify hot beverage temperatures that balance limiting the potential scald burn hazard and maintaining an acceptable perception of adequate product warmth. A figure of merit that can be optimized is defined that quantifies and combines both the above effects as a function of the beverage temperature. An established mathematical model for simulating burns as a function of applied surface temperature and time of exposure is used to quantify the extent of thermal injury. Recent data from the literature defines the consumer preferred drinking temperature of coffee. A metric accommodates the thermal effects of both scald hazard and product taste to identify an optimal recommended serving temperature. The burn model shows the standard exponential dependence of injury level on temperature. The preferred drinking temperature of coffee is specified in the literature as 140+/-15 degrees F (60+/-8.3 degrees C) for a population of 300 subjects. A linear (with respect to temperature) figure of merit merged the two effects to identify an optimal drinking temperature of approximately 136 degrees F (57.8 degrees C). The analysis points to a reduction in the presently recommended serving temperature of coffee to achieve the combined result of reducing the scald burn hazard and improving customer satisfaction.