Scientists at the State University of Campinas (Unicamp) have developed a sustainable method to extract caffeine and antioxidants from the shell of the guaraná fruit, a part that is normally thrown away. The study was published in Innovative Food Science & Emerging Technologies, with Felipe Sanchez Bragagnolo as first author and partners from Spain and Uruguay.
The process works in a single step, using a mixture of 1,3-propanediol, glucose and citric acid, all renewable ingredients. This removes the need for volatile, toxic solvents such as methanol, and for the step of removing them at the end: the extract comes out ready to use, with less preparation time and less energy.
The waste yields guaranine, chemically identical to caffeine, and antioxidants such as catechin, epicatechin and procyanidin B2. The potential is large: Brazil produced about 2,460 tonnes of guaraná seeds in 2025, according to IBGE, and the seed makes up only 15% to 20% of the fresh fruit’s weight.
The scientists now want to test the method on other fruit shells, replace glucose with honey and work with companies on new products. The work was supported by FAPESP.
