A research project conducted at the University of Aveiro demonstrates that coffee grounds can be repurposed into an emulsion to protect coffee oil from oxidation, the institution announced today.
The work, carried out by researchers Cláudia Passos and Sílvia Petronilho, from the Department of Chemistry at the University of Aveiro, focuses on valorizing a residue “produced on a large scale by the industry” and discarded without any utilization.
The researchers demonstrated that coffee grounds “can be repurposed to create sustainable food emulsions capable of protecting coffee oil from oxidation and preserving its aroma.”
According to the text published on the University’s website, the research focused on extracting and utilizing the oil itself from coffee grounds and on antioxidant compounds and polysaccharides, which are usually wasted after the beverage is prepared.
After oil extraction, the defatted grounds were used to obtain extracts rich in polysaccharides, via microwave-assisted extraction.
Two extracts were obtained, one at 150 °C designated MW1Sn and another at 180 °C designated MW2Sn, both consisting mainly of galactomannans and arabinogalactans.
The MW1_Sn extract stood out for showing higher levels of chlorogenic acids, compounds associated with antioxidant properties.
“With these extracts, the researchers developed water-in-oil-in-water emulsions, structures used to encapsulate and protect compounds susceptible to oxidation,” the text describes, adding that “the emulsions created showed good stability and maintained their structural integrity.”
“Beyond stability, the results showed that these emulsions helped preserve compounds responsible for the characteristic aroma of coffee, such as furans, while limiting the release of markers associated with lipid oxidation, such as aldehydes, which can cause undesirable odors and flavors.”
Taken together, the study “demonstrates the viability of reusing coffee grounds to produce stable food emulsions that are effective in protecting the aroma of coffee oil.”
According to the University of Aveiro, “the study results pave the way for the development of new circular and sustainable-based food applications, reducing the waste of a globally abundant byproduct.”
