In the heart of Thailand, researchers are brewing up a storm, not with coffee, but with its often-discarded by-product: coffee pulp. Pittaya Chaikham, from the Division of Food Science and Technology Management at Phranakhon Si Ayutthaya Rajabhat University, has been leading a study that could revolutionize the way we view and utilize coffee by-products. The research, published in the Journal of Agriculture and Food Research (or as it’s known in English, the Journal of Food and Agricultural Science), delves into the effects of different drying techniques on the quality, phytochemicals, and antioxidant capacity of Coffea arabica var. typica pulp.
The study, which is a first of its kind, explores the potential of coffee pulp as a valuable resource, rather than a waste product. “We wanted to understand how different drying methods affect the quality and bioactive compounds of coffee pulp,” Chaikham explains. “The goal was to find a method that preserves these beneficial compounds while ensuring microbiological safety.”
The research team investigated six drying methods: freeze drying (FD), sun drying (SD), hot air drying at 60°C and 70°C (HA60, HA70), and vacuum drying at 60°C and 70°C (VC60, VC70). The results were revealing. Freeze drying, while preserving the highest levels of chlorogenic acid, caffeine, proanthocyanidins, total phenolic content, total flavonoid content, and antioxidant activity, did not completely eliminate microorganisms. On the other hand, all thermal drying methods effectively sterilized the coffee pulp, but at the cost of degrading some of its beneficial compounds.
The study found that vacuum drying at 70°C (VC70) struck a balance between microbial safety and retention of phytochemicals and antioxidant activity. “VC70 emerged as a promising alternative,” Chaikham notes. “It provides a balance between microbial safety, retention of phytochemicals, antioxidant activity, and lower HMF (5-hydroxymethylfurfural) accumulation.”
The implications of this research are significant for the coffee industry and the food sector at large. With coffee production on the rise, so is the generation of coffee pulp. According to the International Coffee Organization, global coffee production was estimated at 169.94 million bags in 2022. If even a fraction of this pulp can be repurposed into a value-added product, it could open up new revenue streams for coffee producers and create a more sustainable industry.
Moreover, the findings could pave the way for the development of functional foods enriched with coffee pulp. The high antioxidant capacity and phytochemical content of properly dried coffee pulp make it an attractive ingredient for health-conscious consumers.
As for the future, Chaikham hopes to see more research in this area. “We need to explore other drying techniques and conditions to optimize the process,” he says. “There’s so much potential in coffee pulp, and we’ve only just scratched the surface.”
In the meantime, the coffee industry has a new by-product to consider, and the food industry has a new ingredient to explore. All thanks to a groundbreaking study from a team of researchers in Thailand. The next time you enjoy a cup of coffee, remember, there’s more to that bean than meets the eye. And perhaps, in the not-too-distant future, you might just find coffee pulp in your pantry, not your trash can.
The research was published in the Journal of Agriculture and Food Research, a peer-reviewed journal that focuses on the latest advancements in agricultural and food science. The study, titled “Comparative evaluation of drying techniques on quality attributes, phytochemicals, and antioxidant capacity of Coffea arabica var. typica pulp,” is a testament to the innovative work being done in the field of agritech. As the world grapples with food waste and sustainability issues, research like this offers a glimmer of hope and a path forward.