Did you know that fermenting and drying cocoa beans are critical steps in creating chocolate? And beyond those steps, cocoa farming relies on growing seasons with a delicate balance of wet and dry weather conditions.
Climate change can disrupt growing seasons and produce unsuitable variability in drying conditions, negatively impacting bean quality, and posing new challenges for farmers.
At UWI St Augustine’s Department of Physics, PhD student Priscilla Sahadeo is currently researching the role of solar greenhouse dryers to assist in the drying process.
Sahadeo and two of her three supervisors, Dr Ricardo Clarke, and Dr Darin Sukha spoke to UWI TODAY about the research which is also being supported by the Cocoa Research Centre (CRC), the Campus’s Research and Development Impact (RDI) Fund, and a UWI postgraduate scholarship. Sahadeo is also supervised by Dr Xsitaaz Chadee.
Trinidad and Tobago is one of eight countries in the world that is recognised by the International Cocoa Organisation (ICCO) for producing 100 percent fine flavour cocoa. This accounts for only 12 percent of global cocoa volumes sold, and the sought after distinctive taste, aromas and flavour profiles are used in craft and premium gourmet dark chocolates. This is in contrast to bulk cocoa, which accounts for the remaining 88 percent of global cocoa volumes used to produce mainstream chocolates.
Sahadeo said that the optimal drying of cocoa beans plays a crucial role in ensuring local farmers realise the fine flavour potential of local varieties.
If cocoa beans are not dried properly due to variations in the environment, the quality of the beans and the expression of their fine flavour profiles are affected. This affects their marketability and the quality of chocolate that can be produced.
Sahadeo explained, “The drying rate is really critical to the flavour development of the beans. Our project comes into play in terms of ensuring the quality is optimum through the drying process.”
One of the first steps in researching the effectiveness of solar greenhouse dryers was gathering data on the traditional open floor sun drying of cocoa beans. Uncovered drying floors using natural sunlight are the traditional and most popular method used locally, but its efficiency is uncertainty in poor weather.
“It was important that we actually go out there and monitor the sun drying of cocoa beans, and better understand the problems associated with it,” said Sahadeo. “So, we collaborated with five different farms in five different areas in Trinidad.
We did this because the CRC has divided Trinidad into six agro-ecological zones which have different microclimatic conditions that would affect open air drying.”
At these farms, the drying rates of the cocoa beans were monitored by tracking the beans’ moisture content, acidity (pH), as well as the ambient temperature and relative humidity.
At UWI St Augustine, cocoa beans were dried in a specially outfitted solar greenhouse dryer to monitor and assess the same drying parameters measured at the different farms. Forced convection was also used to assist drying beans in the solar greenhouse dryer.
“From the data that I have so far, the solar greenhouse dryer does increase the drying rate compared to traditional open floor drying. The forced convection also further increased the drying rate,” Sahadeo said.
The team is carrying out comprehensive assessments using sensory evaluations to understand the impact of the different drying methods on the fine flavour attributes.
Sahadeo said working with cocoa farmers has been helpful in collecting data and gauging their interest in using the technology on their farms in the future.
In addition to drying cocoa beans, there is the possibility that these solar greenhouse dryers can be put to other uses.
Dr Clarke explained, “It’s definitely possible that the greenhouses and the technology can be used for drying other crops. In the past, renewable energy research at the [Physics] Department has looked at drying for other produce, and we’ve used different types of greenhouses to dry crops, tomato, peppers and fish.”
However, given this solar greenhouse is being developed and outfitted for drying cocoa beans, Clarke said testing and further research will have to be done to ensure the conditions are right for other crops.
Dr Clarke said this research joins a long line of work done by the Faculty of Science and Technology that dates as far back to the late 80s, when the faculty was formally named the Faculty of Natural Sciences. In 2014, the Department of Physics launched the Renewable Energy Technology master’s programme.
“It’s been 10 years now that we’ve been training people to work in the field of renewable energy in the Caribbean, and all the different aspects of renewable energy,” he explained. “So, every piece of what we do is to impact different sectors by improving their technologies and processes.”
Dr Clarke said climate change is an ever-present crisis for farmers, and contributing to mitigating its effects, and helping farmers adapt, is important.
While the research is being done in Trinidad, Dr Sukha said its findings and the solar greenhouse dryer technology can be used in other countries in the region producing cocoa. These include Grenada, Dominica and Belize.
“There’s a direct economic potential for the farmers that can access the learnings from this project,” he said. “Basically, we want to make cocoa farming more profitable, and that profitability starts with having a higher quality, more consistent product for sale.”
He added, “Whether you export beans, sell it to a local chocolate maker, or make your own chocolates, this research is all geared at maintaining the quality of our fine flavour cocoa beans.”
