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Impact of wet and dry process on green coffee composition and sensory characteristics

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... The roasted coffees were assessed by experienced cuppers who testified that no undesired off-note had spoiled the coffees—and still, the dry process coffee revealed its own specific sensorial characteristics, as did the wet process coffee (Selmar et al. 2002). Similar experiments undertaken later with Robusta confirmed these results (Leloup et al. 2005). This means that process-immanent factors should be responsible for the specific flavor expressions of differentially processed coffees. ...
... Whereas these authors did not find significant differences with regard to caffeine, Guyot and coworkers reported small losses of caffeine (3%) during the soaking phase of the wet process as compared to the dry process (Guyot et al. 1995). However, other workers confirmed the first observation that caffeine remained unchanged (Leloup et al. 2005; Duarte et al. 2010; Joët et al. 2010). In contrast, chlorogenic acids were proved to be affected by processing—not only with reference to total chlorogenic acids but also to chlorogenic acid subgroups or individual chlorogenic acids (Balyaya and Clifford 1995a,b; Guyot et al. 1995; Leloup et al. 2005; Duarte et al. 2009, Joët et al. 2010). ...
... However, other workers confirmed the first observation that caffeine remained unchanged (Leloup et al. 2005; Duarte et al. 2010; Joët et al. 2010). In contrast, chlorogenic acids were proved to be affected by processing—not only with reference to total chlorogenic acids but also to chlorogenic acid subgroups or individual chlorogenic acids (Balyaya and Clifford 1995a,b; Guyot et al. 1995; Leloup et al. 2005; Duarte et al. 2009, Joët et al. 2010). A strong influence by the maturation stage of the coffee fruits was reported (Clifford et al. 1986; Clifford and Kazi 1987; De Menezes and Clifford 1988; de Menezes 1994). ...
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This paper represents a brief overview on coffee processing with special emphasis on the physiology and biochemistry of the coffee beans. Green coffee is obtained by submitting the harvested coffee cherries to either wet or dry processing. It is well accepted that wet processed coffees evolve much better quality. The decisive quality criterion of coffee as a beverage is its aroma, being composed of more than 800 compounds. Surprisingly, only about 30 of these contribute significantly to the specific coffee aroma. These aroma impact compounds are suitable indicators to estimate objectively the aroma differences resulting from different processing. Up to now, the reasons for the quality differences of technologically distinctively produced coffees are unknown. In this context, the biochemical and physiological processes which occur in the living coffee bean during post harvest processing, and which are related to quality, must be taken into consideration. The coffee plant reveals some particularities which are relevant for the generation of aroma components but which, so far, hardly any attention has been paid to: the coffee bean stands intermediately between recalcitrant and orthodox seeds. It does not undergo a resting period induced by maturation drying, and seed germination is initiated while the fruit is still in the final stages of development. In consequence, coffee beans that are submitted to processing do not represent resting seeds but rather developing seedlings. Substantial features of a seed in state of germination are an increasing rate of respiration and the mobilization of storage compounds. These physiological processes must have an impact on the concentration of aroma precursors in green coffee beans and thus on coffee quality. Accordingly, the reported discrepancies between differently processed coffees appear to be the consequence of distinct developmental stages in the course of the coffee seed germination, since the different processing procedures (dry or wet) are suitable to favour germination to an unequal extent.
... The roasted coffees were assessed by experienced cuppers who testified that no undesired off-note had spoiled the coffees-and still, the dry process coffee revealed its own specific sensorial characteristics, as did the wet process coffee (Selmar et al. 2002). Similar experiments undertaken later with Robusta confirmed these results (Leloup et al. 2005). This means that process-immanent factors should be responsible for the specific flavor expressions of differentially processed coffees. ...
... Whereas these authors did not find significant differences with regard to caffeine, Guyot and coworkers reported small losses of caffeine (3%) during the soaking phase of the wet process as compared to the dry process (Guyot et al. 1995). However, other workers confirmed the first observation that caffeine remained unchanged (Leloup et al. 2005;Duarte et al. 2010;Joët et al. 2010). In contrast, chlorogenic acids were proved to be affected by processing-not only with reference to total chlorogenic acids but also to chlorogenic acid subgroups or individual chlorogenic acids (Balyaya and Clifford 1995a,b;Guyot et al. 1995;Leloup et al. 2005;Duarte et al. 2009, Joët et al. 2010. ...
... However, other workers confirmed the first observation that caffeine remained unchanged (Leloup et al. 2005;Duarte et al. 2010;Joët et al. 2010). In contrast, chlorogenic acids were proved to be affected by processing-not only with reference to total chlorogenic acids but also to chlorogenic acid subgroups or individual chlorogenic acids (Balyaya and Clifford 1995a,b;Guyot et al. 1995;Leloup et al. 2005;Duarte et al. 2009, Joët et al. 2010. A strong influence by the maturation stage of the coffee fruits was reported (Clifford et al. 1986;Clifford and Kazi 1987;De Menezes and Clifford 1988;de Menezes 1994). ...
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The mode of coffee processing strongly influences the quality of green coffee and thereby establishes the characteristic differences in the flavor of wet and dry processed coffees. These variations are due to differences in the metabolic processes occurring within the vital coffee seeds during the course of processing. Biochemical and molecular biological studies revealed that germination is initiated during postharvest treatment, and stress metabolism is induced in the coffee beans, especially while drying. The detected differences in the time courses and amplitudes of metabolic processes are responsible for the distinct substantial composition characteristic of differently processed green coffees, and the peculiarities of wet and dry process coffees are established. Accordingly, it should be possible to modify the substantial composition of green coffee by deliberately changing the processing conditions, thereby improving its quality and health promoting effects.
... This is carried out by chemical products or by natural fermentation for varying lengths of time, which will depend on climatic conditions and fruit ripeness (Teixeira et al., 1995). At the end of fermentation, the wet processed seeds are washed and dried (Leloup, Cancel, Liardon, Rytz, & Pithon, 2004). The final product is a ''washed" or ''parchment" coffee (Smith, 1985). ...
... It is well known that post-harvest processing has pronounced effects on the chemical composition of coffee seeds, specially in water-soluble components like sugars, caffeine, trigonelline and chlorogenic acids (Smith, 1985). Despite the considerable availability of studies comparing coffees processed by dry and wet methods in the literature (Balylaya & Clifford, 1995;Clifford & Ramirez-Martinez, 1991;Guyot, Guele, Assemar, Tchana, & Pomathios, 1995;Knopp, Bytof, & Selmar, 2006;Leloup et al., 2004;Mazzafera & Padilha-Purcino, 2004), data on the chemical composition of coffees processed by semi-dry methods are still scarce. ...
... Considering the similarity of dry and semi-dry methods, the present results are in agreement with results from Balylaya and Clifford (1995), using three dry and wet-processed C. canephora cv. Robusta samples and Leloup et al. (2004) for six Robusta samples. On the other hand, in Balylaya and Clifford (1995), wet-processed Arabica seeds (n = 3) showed lower levels of total chlorogenic acids compared to dry processed seeds. ...
Article
The levels of nine chlorogenic acids, caffeine, trigonelline and sucrose were determined by HPLC-UV and HPLC-RI systems in wet and semi-dry post-harvested coffee seeds from 17 Brazilian Arabica cultivars and progenies. Coffees processed by wet method showed higher contents of chlorogenic acids (p = 0.02) and trigonelline (p < 0.01), and lower content of sucrose (p = 0.02) compared to those produced by a semi-dry method. Regarding caffeine, no difference was observed between both methods. The implications of the differences observed in the chemical composition of coffee seeds treated by wet and semi-dry methods on cup quality deserve investigation.
... Table 2 gives an overview of analytical data. The data are averages from literature reviews, 80 and from investigations executed in other analytical contexts, 82 where the components of constituent groups had been individually determined and summarized. 79 The in-bean localization of distinct components during the development stages of growing and ripening of the coffee fruit had been observed with electron microscopy supported by tissue coloring. ...
... The cherries can be processed by either the dry method -sun drying on patios for 3-9 days followed by mechanical removal of the dried outer parts, resulting in 'natural coffee' or by the wet method -pulping, controlled fermentation of the mucilage in an 18-36 h process, then rinsing the residuals and drying to produce the 'washed coffee.' 106 The metabolism occurring in the beans during the processes differ in their time windows, 107,108 and variations in the composition of aroma precursor can result. 82 This may well explain the observed sensory differentiation of the coffees originating from dry and wet processed beans. 109 Roasting Roasting the coffee beans is an essential transformation, performed at about 200 C. 110 The coffee beans become dry, expand in volume, become brown and brittle, and develop a characteristic flavor and aroma profile. ...
... Table 2 gives an overview of analytical data. The data are averages from literature reviews, 80 and from investigations executed in other analytical contexts, 82 where the components of constituent groups had been individually determined and summarized. 79 The in-bean localization of distinct components during the development stages of growing and ripening of the coffee fruit had been observed with electron microscopy supported by tissue coloring. ...
... The cherries can be processed by either the dry method -sun drying on patios for 3-9 days followed by mechanical removal of the dried outer parts, resulting in 'natural coffee' or by the wet method -pulping, controlled fermentation of the mucilage in an 18-36 h process, then rinsing the residuals and drying to produce the 'washed coffee.' 106 The metabolism occurring in the beans during the processes differ in their time windows, 107,108 and variations in the composition of aroma precursor can result. 82 This may well explain the observed sensory differentiation of the coffees originating from dry and wet processed beans. 109 Roasting Roasting the coffee beans is an essential transformation, performed at about 200 C. 110 The coffee beans become dry, expand in volume, become brown and brittle, and develop a characteristic flavor and aroma profile. ...
Article
Chemistry of coffee, under the heading of biodiversity, covers both general and new aspects of interest: the challenge of an expanding cultivation of coffee; the rise and threat of species; coffee components developing in the fruit, at postharvest treatment, via the roasting process, in the preparation of the beverage; and, finally, the beverage's effects on humans.
... Moura et al. (2007) studied the influence of roasting on coffee sensory characteristics and cited the words: characteristic aroma and flavor, caramel flavor, chocolate, citric fruits, sweetness, acidity, aftertaste and body. Similarly, other authors assessing coffee quality reported frequently used terms such as fruity, citric, caramel, chocolate, floral, malt, sweet (Jong et al., 1998;Narain et al., 2003;Leloup et al., 2004;Nebesny and Budryn, 2006;Scholz et al., 2013). Sensory negative terms including green, earthy, bitter and burnt are also reported. ...
... Moura et al. (2007) studied the influence of roasting on coffee sensory characteristics and cited the words: characteristic aroma and flavor, caramel flavor, chocolate, citric fruits, sweetness, acidity, aftertaste and body. Similarly, other authors assessing coffee quality reported frequently used terms such as fruity, citric, caramel, chocolate, floral, malt, sweet (Jong et al., 1998;Narain et al., 2003;Leloup et al., 2004;Nebesny and Budryn, 2006;Scholz et al., 2013). Sensory negative terms including green, earthy, bitter and burnt are also reported. ...
Article
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This work evaluated the sensory quality of coffee genotype groups, discriminated by their genealogical origin, based on current methodology of the specialty coffee market and use of the "Sensogram" and content analysis as complementary methodologies. We assessed forty-one Coffea arabica genotypes, comprising six groups: Bourbon, Caturra, Híbrido de Timor (HT), Catimor, Traditional Cultivars (Mundo Novo and Catuaí), and HT Derived Cultivars (Pau-Brasil MG 1, Paraíso MG H419-1, Catiguá MG 2 and Obatã IAC 1669-20) in the randomized block design with two replications. Higher intragroup genetic variability was verified for sweetness, flavor and aftertaste on the standard grading scale. The results showed that the HT derived cultivars group was superior to the others with regards to the Final Score of coffee quality. It presented a confidence interval (85 to 89 points) for classification as an excellent specialty coffee. The Sensogram illustrated the relationship among scores for the groups and sensory attributes, expressing the higher score for flavor in the groups Híbrido de Timor and HT derived cultivars. In the content analysis, six categories and ten subcategories of quality attributes were identified. The studied genealogic groups have genetic potential to produce differentiated coffees. The Sensogram and content analysis are methodologies that complement the current specialty coffee scoring scale, subject to use in the sensory characterization of specialty coffee with respect to quality and intensity of nuances.
... Para obter-se um café de boa qualidade e um produto de bebida suave, devese manter a temperatura de secagem ao redor de 40ºC na massa do café ( Sfredo et al., 2005;Borém et al., 2008). No processamento e secagem do café, podem ocorrer transformações físicas, químicas, bioquímicas e fisiológicas (Leloup et al., 2004;Santos et al., 2009). Acredita-se, que as transformações poderão provocar a desorganização das membranas celulares em condições inadequadas de secagem. ...
... Alterações na membrana celular após a secagem podem ser identificadas pela (Borém et al., 2006) lixiviação de várias soluções citoplasmáticas e (Neya et al., 2004) em análises ultra-estruturais de tecidos após a embebição. A retirada da água induz a parede celular à contração e, consequentemente, à redução do volume celular, provocando uma aglomeração dos componentes citoplasmáticos, tornando o conteúdo da célula incrivelmente viscoso (Hoekstra et al., 2001). Os trabalhos encontrados não relacionam, no entanto, a interferência desse fenômeno à preservação das membranas celulares e à qualidade física do café destinado para o consumo. ...
Article
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The maintenance of the integrity of cellular membranes, among other events, is a strong indicator that the quality of the coffee was preserved in the post-harvesting process. Therefore, this work aimed to analyze the effect of different drying methods on the maintenance of the integrity of cell walls and plasma membrane of natural and de-pulped coffee in order to determine the conditions and the moment that microscopic ruptures take place. The coffee was submitted to a pre-drying period on a concrete patio. After this, a sample of each type of coffee was dehydrated outdoors and another, with heated air at 40ºC and 60ºC in fixed-layer dryers, controlling the grain temperature and the moisture content to 11% (bu). During the drying process the coffee grains were randomly sampled and fragments of the endosperm were prepared for scanning electron microscopy and eletromicrographs were taken. Measurements of the cells were taken for evaluating changes in the plasma membrane of the endosperm cells in relation to the moisture content and drying period. The cell cytoplasm of the coffee grains with 11% moisture content was not affected when dried under sun light and at the temperature of 40°C. When dried at 60°C, changes in the cellular structures of the cytoplasm were observed for coffees with moisture content of 20%.
... One of the benefits of chlorogenic acid for humans is an antioxidant [3]. Some studies reported various methods to process coffee beans [4,5]; one method is fermentation. Some factors affect the fermentation such as type and amount of substrate, type and amount of starter, temperature, pH, and fermentation duration [6]. ...
Article
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A green coffee bean contains phenolic compounds with strong antioxidant activity, such as chlorogenic acid. Fermentation is one of the ways to increase the antioxidant activity of coffee beans by using microorganisms. This review aims to study the antioxidant activity of fermented green coffee beans and the factors involved in the fermentation process. We selected original research articles providing data on the antioxidant activity of fermented green coffee beans published from 2015 to 2021. Fermented green coffee beans shows stronger antioxidant activity compared to the controls. The amount of substrate, yeast (as a starter), and fermentation duration influence the antioxidant activity of the fermented green coffee beans. The fermented green coffee beans with yeast had significantly higher antioxidant activity than those in unfermented coffee.
... But among the available methods for sensory analysis of coffee, those of the "Specialty Coffee Association" (SCA) classification are considered the most suitable for high-quality coffees due to their recommended use of a specific protocol to carry out sensory analysis. These protocols are based on objective assessment methods, such as the presence or absence of sweetness and defects, thus minimizing subjectivity in comparison with other methodologies (Leloup et al. 2004). ...
Article
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Cup tasting is the most important tool to access the quality of coffee beans. However, the use of sensory evaluation alone can present some problems, since bias from the previous knowledge of a particular sample and health conditions of the taster can influence the results. Given the well-established potential of spectroscopic methods in coffee quality evaluation, in the present study, we sought to evaluate the potential of FTIR spectroscopy for quantitative evaluation of specialty coffee quality. Samples of specialty coffee were provided by the Federação dos Cafeicultores do Cerrado Mineiro and Fazenda Barinas. They were roasted in IKAWA coffee roaster, analyzed by a group of Q-graders, and submitted to FTIR analysis. Physicochemical analyses (pH, titratable acidity, brix, total solids, and browning compounds) were also employed to show potential differences. Only pH showed significant difference between the beverages. PLS results showed consistent models for predicting the quality previously given by the cuppers, with low values of RMSEC and RMSEP (0.23 both). Also, the models showed high values of Rc (0.99) and Rv (0.97). The whole spectra were considered as important to classify the coffees by their quality, showing the complexity of the beverage.
... ese characteristics are linked to the areas where the co ees are grown and their cultivated genotypes [2]. Some researchers report signi cant di erences among beverages from co ee that is processed using di erent methods [3,4]. It is currently believed that di erent processing methods induce di erent metabolic reactions in co ee fruits, which can a ect the chemical compositions of the co ee beans and thereby their cupping quality [5,6]. ...
Article
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Coffee is one of the most important and widely used commercial crops in the world. After ripe coffee cherries are harvested, coffee must pass through several steps to become (green) raw coffee beans. Commonly, there are three different processing methods used to obtain green coffee beans from coffee cherries, namely, the wet, dry, and semidry methods. Microorganisms (yeasts and bacteria) play a major role in coffee fermentation process by degrading mucilage by producing different enzymes (pectinase), acids, and alcohols. Starter culture development is crucial and is done by selecting microorganisms that have certain characteristics, such as mucilage degradation ability, tolerance to stress during fermentation, the ability to suppress the growth of pathogenic fungi, and a positive impact on the sensory quality of the coffee. Currently, green coffee beans obtained from farms that use any of the above processing methods are fermented with selected microorganisms to improve the favour and aroma of the coffee. This is the result of a new insight into the development of unique favoured coffee and into engaging with the coffee market to better benefit. ‚is review gives a comprehensive overview of the fermentation process, microorganisms and starter cultures, and fermentation’s impact on coffee quality. Future prospects are also discussed through the incorporation of recent research.
... The CN coffee beverage has a strong coffee aroma, moderate acidity, intense body and pleasant sweetness. On the other hand, in the CD coffee beverage are present a weak coffee aroma and body of medium intensity, and the acidity and sweetness are lower than in the CN coffee beverage [21]. ...
Article
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Post-harvest processes (PHP) interfere with the quality of the coffee beverage. Recently, biochemical phenomena and critical points concerning coffee quality in PHP were identified. The objective was to evaluate the chemical composition and sensory attributes of green beans and roasted coffee beans from natural (CN) and semi-dry (CD) PHP. Samples were processed by coffee growers from a Brazilian coffee-producing region. The physico-chemical variables of green and roasted beans and sensory attributes were grouped in order to apply a multiple factorial analysis. This analysis showed that the description of CN and CD coffees depended on the group of variables employed. Certain aroma and flavor precursors, such as sucrose, proteins and 5-CQA, were associated with the year of production, whereas lipids, phenolic compounds, caffeine and chlorogenic acids, were associated with the PHP. Effects attributed to the occurrence of germination during drying were observed in both processes and had reflexes on the sensorial attributes. The results of the samples prepared by the producers are similar to the results obtained in laboratory experiments by other authors. The same attributes were found in the description of both processes, suggesting that they depend on the content of precursors in the green coffee beans. The formation of the precursors was influenced by factors related to peeling and drying of the green coffee. The control of these favor factors enabled the success of each PHP.
... Different producing countries have their own methodologies for coffee quality evaluation (Santos et al., 2012), but among the available methods for coffee sensory analysis, those of the "Specialty Coffee Association of America" (SCAA) classification are considered the most suitable for specialty coffees due to their recommended use of specific protocols to carry out sensory analysis. These protocols are based on objective assessment methods, such as the presence or absence of sweetness and defects, thus minimizing subjectivity relative to other methodologies (Leloup, Gancel, Liardon, Rytz, & Pithon, 2005;SCAA, 2009). Professional tasters, the 'cuppers', are often highly sensitive to the characteristics of the products (Di Donfrancesco, Guzman, & Chambers, 2014). ...
Article
Coffee cup quality, determined by the sensory attributes evaluated by professional tasters, is a decisive factor for evaluating coffee, with the "Specialty Coffee Association of America" (SCAA) classification being nowadays considered the most suitable. Panels of trained coffee tasters are used by the industry to describe and evaluate beverage quality, but those evaluations can be subjective and time demanding. Recent studies have demonstrated the potential of spectroscopy-based methods for establishing parameters of quality in the analysis of food products, including coffee. Thus, the aim of this study was to evaluate the potential of ATR-FTIR and chemometrics to discriminate espresso coffees with different sensory characteristics reported by a panel of coffee tasters. The results showed good consistency among coffee tasters. PLS-DA models based on spectroscopic data were able to classify samples according to sensory attributes, confirming the potential of FTIR and chemometrics in coffee quality evaluation.
... Atributos considerados positivos como, por exemplo, frutado, ácido, cítrico, caramelo, chocolate e outros de caráter negativo como amargo, madeira, adstringente, verde ou fermentado (LELOUP et al., 2004;NEBESNY;BUDRYN, 2006) são sempre mencionados nas provas de bebida de café. Outros atributos de aroma floral, malte, doce, caramelo, ácido, azedo, verde, terroso, amargo, queimado, químico foram empregados na análise de oito blends de café, por provadores de diferentes países europeus (JONG; HEIDEMA; KNAAP, 1998) e para descrever café comercializado como sachê (NARAIN;PATERSON;REID, 2003). ...
Article
The genetic characteristics together with environmental conditions determine the quality of coffee beverage, so the selection of new cultivars of coffee requires information from sensory attributes in different environmental conditions. The aim of the present study was to evaluate the physico-chemical and sensory characteristics of the coffee cultivars IPR 97, IPR 98, IPR 99, IPR 100, IPR 101, IPR 102, IPR 103, IPR 104, IPR 105, IPR 106, IPR 107, IPR 108 and IAPAR 59, Bourbon, Icatu and Tupi grown in the municipalities of Paranavaí and Itaguajé - PR, season 2007-2008. We evaluated the characteristics of the roasting of the beans and beverage. The sensory attributes were evaluated by descriptive sensory analysis of Free Choice Profilling. Significant correlations were observed between the different characteristics of the roasted bean and the beverage. In the Principal Component Analysis (PCA), the variables of roasted bean and beverage grouped the coffees, observing that most cultivars from Itaguajé showed darker coffees with higher acidity and density of roasted bean when compared to Paranavaí. The attributes of color appearance and brightness of coffee, coffee aroma, green aroma, sour and bitter taste, green flavor and body texture were the main attributes responsible for the separation between sites. Bean color and acidity of the beverage were physico-chemical and sensory characteristics important for discriminating coffee cultivars and production sites. This information serves to aid in the deployment of new crops enhancing desirable sensory attributes of each cultivar.
... These sensory variations may be the result of the different compositions of the final beverages but had no influence on their overall quality, aftertaste and balance. In the sensory descriptive analysis, positive attributes detected in this study, such as fruity, floral, acid, citric and caramel, are always mentioned in coffee beverage evaluations (Leloup, Gancel, Liardon, Rytz, & Pithon, 2004;Nebesny & Budryn, 2006). The perception of exotic sensory notes of 'apricot' and 'banana raisin' in beverages from uninoculated treatment can be associated with specific compounds detected in this process and strongly suggests an important role for wild microflora in the development of these flavors as mentioned above. ...
... Post-harvest coffee processing is another avenue which has a significant impact on coffee aroma but is still inadequately addressed (Bhumiratana, Adhikari, & Chambers, 2011). Analysis of the sensory profiles of dry-and wet-processed coffees found that the latter were more aromatic with fruity and acidic attributes and possessed lesser bitter, burnt and woody notes (Duarte, Pereira, & Farah, 2010;Leloup, Gancel, Liardon, Rytz, & Pithon, 2004). These differences in the sensory attributes could most likely be attributed to the fermentation process involved in mucilage removal in wet processing. ...
... It could be a reason for loss of CGAs in Arabica coffee in comparison to the Robusta coffee that is commonly processed by the dry method [23]. According to Leloup et al. [24] and Clifford [25], although green Robusta beans have a higher CGAs content, the sensitivity of CGAs in Robusta coffee matrix seems to be more than that in Arabica coffee matrix which could explain the same behaviour of Arabica and Robusta coffee brews in some cases. ...
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The influence of different brewing conditions on the concentration of the main caffeoylquinic acids (3-caffeoylquinic acid (3-CQA), 4-caffeoylquinic acid (4-CQA), and 5-caffeoylquinic acid (5-CQA)) was investigated. For this purpose, twenty-four coffee brews were extracted and analyzed using HPLC-DAD at 325 nm. Our findings demonstrate the great impact of brewing techniques on the caffeoylquinic acids (CQAs) content. The major isomer was 3-CQA, accounting for about 50% of the total CQAs, followed by 5-CQA and 4-CQA, accounting for about 24-36% for each one. The total content of CQAs was in the range of 45.79 to 1662.01 mg/L, found in iced cappuccino and pod espresso, respectively. In conclusion, this study demonstrates that coffee brews, in particular those prepared using pressurized methods, can be considered as the potential sources of antioxidants such as CQAs.
... Os grãos torrados desses genótipos são de coloração clara e bebida de baixa acidez (pH e acidez titulável). Essas características, juntamente com as baixas concentrações de ácidos clorogênicos, remetem a grãos maduros como foi demonstrado por vários autores (LELOUP et al., 2004;MAZZAFERA, 1999). ...
Article
RESUMO: As condições ambientais exercem forte influência na qualidade de bebida do café, de maneira que a seleção de novos cultivares requer informações sobre a composição e características do café produzido em diferentes locais. Objetivou-se, no presente estudo avaliar os componentes físico-químicos do grão verde e torrado dos cultivares de café (Coffea arabica L.) IPR e Icatu, colhidos em campos experimentais nos municípios de Paranavaí e Itaguajé – PR, na safra de 2007-2008. No café beneficiado determinou-se granulometria e densidade aparente e no grão verde moído, quantificaram-se proteínas, açúcares totais, açúcares redutores, sacarose, lipídios, taninos hidrossolúveis, ácidos clorogênicos e cafeína. A densidade aparente, expansão de volume e componentes cromáticos foram determinados no grão torrado. Observaram-se diferenças significativas na composição físico-química e nas características da bebida dos cafés de cada local. Através da ACP, observou-se que cultivares de Itaguajé e Paranavaí foram diferenciados em função da densidade e tamanho do grão, açúcares redutores, proteínas, lipídios, pH, acidez titulável e componentes de cor. Os cultivares de um mesmo local se diferenciaram principalmente em função da concentração de ácidos clorogênicos presente. Observou-se ainda que, cultivares reunidos em mesmo grupo na AAH (Análise de Agrupamento Hierárquico) apresentaram características similares entre si, demonstrando os efeitos ambientais na expressão genética dos cultivares. Palavras-chave: Genótipos, composição, análise multivariada. ABSTRACT: Environmental conditions exert strong influence on the quality of the coffee beverage in such a way that selection of new cultivars requires information about the composition and characteristics of coffee beans produced in different places. The objective of the present study was to evaluate the physico-chemical components of the green and roasted coffee beans (Coffea arabica L.) of the cultivars: and Icatu, harvested in experimental fields in Paranavaí and Itaguajé -PR, in the 2007-2008 harvest. In the processed coffee we determined the apparent density. Total proteins and sugars, reducing sugars, sucrose, hidrosoluble tannin, chlorogenic acids and caffeine were determined in the green coffee beans. The apparent density, expansion of volume and chromatic components had been determined in the roasted coffee beans. Significant differences were observed in the Physico-chemical composition and characteristics of the coffees beverage of each location. Through PCA we noted that Itaguajé and Paranavaí cultivars were differentiated according to the grain size and density, sugars, proteins, lipids, pH, titratable acidity and the color components. In the same location cultivars differ mainly in function of the concentration of chlorogenic acids. It was also noted that cultivars, grouped through HCA (Hierarchical Clustering Analysis), exhibited similar characteristics among themselves, demonstrating environmental effects on genetic expression in the cultivars.
... It has been pointed out that beverages from coffees processed by different methods have significant differences (Selmar et al., 2006;Leloup et al., 2008). The final quality of the beverage depends on several variables, such as the chemical composition of the beans. ...
Article
Fresh coffee fruits were subjected to different types of postharvest processing. Intact fruits were processed using the dry method (DI), peeled fruits were processed using the semi-dry method (DP) and fruits were processed using the wet method (W). The extraction of polysaccharides from the seeds from the unprocessed and processed fruits indicated that arabinogalactans and (galacto)mannans were the main polysaccharides. Higher amounts of polysaccharides were extracted from processed coffee. Among the treatments, lower amounts of water-soluble galactomannans were obtained from coffee beans processed by the dry and wet methods. The polysaccharides obtained from beverages prepared using beans from DI, DP and W methods showed different yields, total sugar and protein contents. Galactomannans and AGPs were also present in the coffee beverages. Although differences were found in the chemical compositions, no differences were observed in the viscosity or surface tension of coffee beverages from the DI, DP and W methods.
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In this study, green coffee beans were fermented using three yeast and three lactic acid bacteria (LAB) starters. The effects of each starter on the metabolite profiles of green coffee beans were comparatively analyzed. The principal component analysis (PCA) biplot showed a clear separation between the groups fermented with LAB (Leuconostoc mesenteroides, Lactobacillus plantarum, and Pediococcus pentosaceus) and the groups fermented with yeast (Saccharomyces cerevisiae, Candida parapsilosis, and Pichia guilliermondii). Various metabolites, including palmitic acid, stearic acid, and piperidine, were associated with the LAB strains. 2-Palmitoylglycerol, ribonic acid, and arabitol were related to C. parapsilosis and P. guilliermondii. Phenylethyl alcohol, succinic acid, shikimic acid, and methylamine contributed greatly to the separation of S. cerevisiae from the other strains in the PCA biplot. In addition, chlorogenic acid levels were higher in the LAB strains than in the yeast strains after fermentation. In particular, C. parapsilosis and P. guilliermondii showed much lower levels. The level of caffeine was highest in P. pentosaceus and lowest in C. parapsilosis after fermentation. This study provides comprehensive information on the metabolic changes after green coffee bean fermentation according to the type of microbes used.
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Currently, there is no technology for the storage of green coffee (GrC), that results in obtaining high-quality roasted coffee (RC). The aim of this study was to evaluate the effects of storage temperature (− 10, 5, 10, 18, 20 °C), postharvest treatment method (natural (N), washed (W)) and type of packaging material (GrainPro (G), jute (J) bags) on the content of chlorogenic acids (CQAs), caffeine and trigonelline as well as the sensory profile of RC from the specialty sector after 12 months of regulated storage. Sensory analysis showed that natural coffees have better taste and higher quality than washed coffees after 12 months of storage. The highest total scores were obtained from the natural coffee stored in a GrainPro bag at − 10 °C followed by coffee stored in a jute bag at 10 °C which had the smallest decreases compared to the initial recorded values. No notable differences among CQA contents in washed coffees stored in either type of bag was seen but natural coffees stored in jute bags at 10 °C and 18 °C displayed the lowest drops relative to the initial values.
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The balance between coffee phytochemicals and post-harvest handling is complex and delicate since these compounds are affected either negatively or positively. Studies have shown positive health effects arising from regular consumption of coffee, which are linked to phytochemicals present in the coffee bean. However, phytochemicals must be available in considerable amounts at the time of consumption in order for them to confer the beneficial health effects. This review aims at summarizing the available literature on the impact of coffee processing steps on the content as well as sensory and functional characteristics of phytochemicals. The phytochemicals in coffee include, majorly: Chlorogenic acids, caffeine, diterpenes and trigonelline. Literature reveals that variation in coffee post-harvest handling techniques such as degree of roast, processing method, brew preparation method and parameters results into brew with varied sensory and functional properties. This could be majorly attributed to the variation in the phytochemicals content in the cup. Further research on how coffee phytochemicals are affected during post-harvest handling practices would unlock the health benefits of this popular beverage and immensely benefit the consumer.
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