Research aims to help cacao producers, chocolate makers boost profits

UNIVERSITY PARK, Pa. — Craft chocolate — made with fine flavor cacao beans and valued for its distinctive flavors and high quality — is gaining a fast following, and research underway in Penn State's College of Agricultural Sciences is aimed at helping bean growers and bar makers benefit from this trend.

"Like craft beer and specialty coffee, craft chocolates are a popular indulgence among consumers who are searching for something different," said Allison Brown, food science doctoral candidate in the college's International Agriculture and Development (INTAD) dual-title degree program. "The craft chocolate market in the United States is estimated to be worth $100 million with new chocolate makers entering the industry almost every day."

Through a partnership with the Fundación Hondureña de Investigación Agrícola, or FHIA, an agricultural research facility in La Lima, Cortés, Honduras — a country recognized for producing fine flavor cacao beans — Penn State food scientists are studying how plant cultivars, climate, soil and processing methods influence flavor and aroma characteristics of cacao beans, and how consumers might respond to those characteristics.

The goal is to help boost farmers' and chocolate makers' businesses by enabling them to make informed decisions about what cultivars to grow and what varieties to use in chocolate making.

Craft chocolate is in such high demand that consumers are willing to pay between $5 and $10 per bar. In addition, fine flavor cacao beans are fetching up to $10,000 per ton, while "bulk" cacao beans — the kind used to make conventional chocolate products — sell for about $2,200 a ton, according to Brown.

"This could be a windfall for some of the 6 million smallholder cacao farmers living at or below the poverty line," she said, adding that Theobroma cacao (cocoa) trees can thrive only in tropical climates that are near the equator.

When describing what makes craft chocolate unique, Brown said the answer varies among aficionados, but she said most agree that it involves a distinctive flavor (earthy, floral and smoky are popular), which often originates from the cacao bean.

What some people don't think about when indulging in their favorite chocolate bar is how it's made, which is a labor-intensive process, according to Helene Hopfer, assistant professor of food science. After harvesting, the beans are fermented, dried and roasted before being turned into chocolate liquor or cocoa powder, the base ingredients of confectionary products.

"Chocolate is interesting because its flavor is influenced by many factors, including plant genetics, where it is grown and how it is processed," Hopfer said.

Last year, Brown, Hopfer and Gregory Ziegler, professor of food science, cultivated a relationship with Honduran cacao researchers, who, in turn, sent nine varieties of cacao beans to Penn State for comprehensive chemical analysis, after which the samples were processed into chocolate liquors.

With the help of undergraduate student workers and Tiffany Murray, coordinator of the Sensory Evaluation Center in the Department of Food Science, Brown trained a panel to quantify their perception of chocolate liquor sensory characteristics.

After completion of the training, panelists rated the samples on appearance, texture, aroma and flavor attributes. Based on that feedback, the researchers made connections between the chemical compounds present in the chocolate liquor and the flavors perceived by humans.

The knowledge gained from laboratory studies was enriched by a November trip to Honduras, where Brown, Hopfer and Ziegler met FHIA Director of Agroforestry and Cacao Javier Diaz and other collaborative partners. They toured six cacao bean cooperatives in the north coast region of the country, where they got a firsthand look at cacao production, including cultivation, fermentation and drying of the cacao beans.

"We were impressed by the rigorous research that FHIA has conducted in tropical agroforestry, such as the use of plantain and mahogany trees to improve cultivation of the Theobroma cacao trees," Brown noted. "Honduras has the longest history of the presence of cacao. It was amazing to be there and actually see the trees that produced the seeds we used in our studies. It made our research more meaningful."

Ziegler, who has researched chocolate processing for 30 years, echoed Brown's observations: "I was impressed with FHIA's agroforestry approach that yielded valuable crops throughout the life of the farm — plantain in the early years before the cacao starts producing, cacao for the bulk of the time, then mahogany just at the point when the cacao needs to be replanted. This appears to be much more economically sustainable from the farmers' point of view."

Moving forward, the researchers plan to study the same nine cultivated varieties of cacao over several harvests to confirm the results found during the first harvest. This research will help growers and chocolate makers understand the characteristic flavors attributed to the varieties studied.

"This study is distinctive because it is highly controlled," Hopfer said. "The relationship with FHIA is unique as they not only grow cacao plants but also conduct the postharvest processes of fermentation and drying by controlling time and temperature. On our end, Allison has spent hours perfecting the roasting and chocolate liquor-making process to maintain this highly controlled process."

"In effect, the differences in flavors that we find among the cacao cultivars can be attributed truly to the plant itself, rather than nuances in harvest or production methods, as we have seen in other studies."

The researchers' visit to Honduras was supported by the College of Agricultural Sciences' Office of International Programs, which promotes the development of new international research collaborations.

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Last Updated February 15, 2018