The enigmatic quality that imbues Black Ivory coffee with its velvety, chocolate-like essence might originate deep within the digestive systems of the planet’s largest terrestrial mammals.
Emerging from a recent investigation into the microbial communities inhabiting the gastrointestinal tracts of Asian elephants (Elephas maximus), scientific inquiry has identified specific bacterial populations implicated in the degradation of chemical compounds responsible for coffee’s inherent bitterness.
“Our prior research indicated that Gluconobacter represented the predominant genus within the digestive tracts of civets, and it possesses the capacity to generate volatile compounds from coffee beans, thereby suggesting that microbial metabolic processes contribute to the characteristic coffee aroma,” stated genomicist Takuji Yamada from the Institute of Science Tokyo in Japan.
“These revelations prompted the inquiry into whether the gut microbiome of elephants similarly influences the flavor profile of Black Ivory coffee.”
Black Ivory coffee ranks among the most highly valued coffee varieties globally, significantly surpassing kopi luwak—coffee processed through the digestive systems of civets (which are not feline species)—in terms of prestige and exclusivity.
This premium coffee is exclusively produced at a single elephant sanctuary situated in Thailand. Within this facility, a select group of elephants are provided with unprocessed coffee cherries as part of their diet. The sanctuary’s caretakers subsequently gather the coffee beans from the elephants’ excrement, followed by a meticulous cleaning and roasting process before their introduction to the market for consumer enjoyment.
The coffee is widely celebrated for its distinctive flavor, frequently described as exceptionally superior.
Following their discovery that civet gut bacteria might influence the taste of kopi luwak, Yamada and his research associates sought to ascertain if an analogous biological mechanism was instrumental in shaping the flavor characteristics of Black Ivory coffee.
Their investigative approach involved an examination of elephant feces rather than the coffee beans themselves, enabling them to meticulously catalog the gut microorganisms. Samples were procured from six elephants at the sanctuary: three that had consumed coffee cherries and three that had not, serving as a control cohort.
The singular dietary variance for the elephants consuming coffee cherries was an additional supplement comprising bananas, coffee cherries, and rice bran. Consequently, any discernible variations in their gut microbiomes were most likely attributable to this supplementary dietary component.
The inherent bitterness of coffee is partly attributed to a component known as pectin, present in plant cell walls, alongside cellulose. During the thermal processing of roasting, pectin and cellulose undergo breakdown, yielding compounds with a bitter taste.
Upon sequencing the fecal samples, the researchers observed a significantly elevated abundance of gut microbes in the coffee-consuming elephants that are actively involved in the enzymatic breakdown of pectin and cellulose. Certain bacterial species were entirely absent from the samples obtained from the control group.
Leveraging previously disseminated research data, the scientists also conducted a comparative analysis of the elephant microbiomes against those of cattle, swine, and fowl, in an effort to identify any other potential microbial agents involved in coffee digestion.
Although certain relevant bacterial species were detected, only the intestinal tracts of elephants possessed the comprehensive biological machinery requisite for the degradation of pectins and cellulose.
A study published in 2018 revealed that Black Ivory coffee exhibits a substantially reduced concentration of a compound known as 2-furfuryl furan compared to conventional coffee beans. This compound is one of the bitter substances generated through pectin degradation during the roasting phase.
The current investigation into elephant microbiomes suggests that the partial digestion of coffee cherries assists in the removal of those constituents within the coffee beans that develop bitterness during roasting, thereby yielding a significantly more palatable flavor profile.
The subsequent phase of this research will focus on the direct examination of the coffee beans themselves.
“Our findings may elucidate a potential molecular pathway through which the gastrointestinal microbiota of elephants consuming Black Ivory coffee contributes to its distinct flavor,” Yamada remarked.
“Further experimental validation is essential to substantiate this hypothesis. This could involve a detailed biochemical analysis of coffee bean components both prior to and subsequent to their passage through the elephant’s digestive tract.”
