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Authentication of coffee is highly required. This study aimed to understand the relative abundance of volatiles of green coffee harvested during two years. Using volatiles (GC-MS) and Linear Discriminant Analysis, we focused on the geographical origin identification. We analyzed samples of green Coffea arabica from Africa, Central America, and South America, harvested in 2018 and the same samples harvested in 2019. A total of 215 different volatiles were detected. Based on their chemical structure and the functional chemical group, they were divided into categories: furan derivates, aldehydes, ketones, alcohols, organic acids, hydrocarbons (alkanes, alkenes, alkynes, aromatic hydrocarbons), terpenoids, heterocyclic compounds, nitriles, amines. Green Arabica contained mostly organic acids and esters, aldehydes, hydrocarbons, and alcohols. We observed significant differences in aromatic hydrocarbons and furan derivates by comparing the volatiles profiles of African coffee beans collected in 2018 and 2019. The profile of Central American samples (both years) was homogenous; thus, no significant differences were observed. The aroma profile of South American coffees had significant differences in aromatic hydrocarbons and alkanes (p-value < 0.05). Rao’s approximation and Bartlett’s test proved a significant difference between 3 continents by applying LDA. More than 94% of the variability between Africa, Central, and South America coffees harvested in 2018 was explained by organic acids and esters, alkenes, aldehydes, and ketones. By adding samples from 2019, LDA calculations reduced input parameters to aldehydes and ketones, organic acids and esters, alkenes, terpenoids, and aldehydes. These appear to be useful for geographical authentication regardless of the year of harvesting. [ABSTRACT FROM AUTHOR]

This study was aimed to understand and analyze the variability of volatile compounds in green and roasted coffee. We observed the influence and change in the profile of volatiles in samples roasted on medium roasting level, originating from different growing areas. We analyzed 9 samples, which we differentiated into three groups: Africa (Burundi, Uganda, Rwanda), Central America (Guatemala, Costa Rica, Honduras), South America (Colombia, Brazil, Bolivia). Volatiles were analyzed using GC-MS. Approximately 350 volatile compounds have been identified in green coffee. The main compounds identified in coffee samples included furan derivatives, aldehydes, alcohols, organic acids and their esters, hydrocarbons (alkanes, alkenes, alkynes, and aromatic hydrocarbons), terpenoids, heterocyclic compounds, ketones, amines, alkynes, and nitriles. Content of volatiles was expressed as concentration (%). The results show that the roasting process significantly affects the presence and concentration of volatiles, given the formation of new volatile compounds and degradation of several occurred. In our research, aldehydes, alcohols, organic acids and esters, alkanes, terpenoids, alkenes, nitriles, aromatic hydrocarbons decreased due to the roasting process. Nevertheless, only in Central America samples, aromatic hydrocarbons increase due to roasting. Furan derivates, heterocyclic compounds, ketones, amine, alkynes increased due to the roasting process. However, only in South America samples, alkynes decreased due to roasting. However, alkynes in Central America samples remained unchanged due to the roasting. [ABSTRACT FROM AUTHOR]

This research was focused on the evaluation of selected parameters of coffee quality, regarding the beverage preparation method, using high-performance liquid chromatography. Samples of Coffea arabica from South America were analyzed. For the preparation of the final beverage were used filtration and moka methods. All samples roasted at medium dark roasting level Full City ++, contained less than 5% of moisture. The values of pH and dry matter content did not show a significant difference. The lowest content of chlorogenic acid reached value (1.41 g·100 g−1) prepared from filtration and 1.49 g·100 g−1 prepared from moka method. The highest content of chlorogenic acid ranged from 2.94 g. 100 g−1 filtration method and 3.36 g. 100 g−1 moka. Similarly, caffeine content, showed lower values using the filtration method. Values ranged from 1.37 to 1.57% (filtration) and from 1.54 to 1.78% (moka). However, PCA didn't show a significant difference. [ABSTRACT FROM AUTHOR]