Earth.com staff writer Researchers have developed a new chocolate product by infusing bee honey with bioactive compounds extracted from cocoa bean shells – the husks usually discarded during chocolate production.
The team used honey not just as a sweetener, but as the extraction solvent itself. This allowed them to pull out stimulants such as theobromine and caffeine – linked with cardiovascular benefits – along with phenolic compounds known for their antioxidant and anti-inflammatory activity.
The appeal of chocolate honey
Study first author Felipe Sanchez Bragagnolo conducted the study during his postdoctoral work at the State University of Campinas ( UNICAMP
“Of course, the biggest appeal to the public is the flavor, but our analyses have shown that it has a number of bioactive compounds that make it quite interesting from a nutritional and cosmetic point of view,” said Sanchez Bragagnolo.
Depending on the proportion of honey to shells, taste testers reported a pronounced chocolate profile.
The team plans a full sensory campaign next, but the early chemistry and flavor readouts suggest the concentrate could be spooned straight from the jar or folded into foods, beverages, and even topical formulations.
A gentler, greener extraction method
Instead of petrochemical solvents or alcohols, the group leaned on an ultrasound-assisted method that agitates a mixture of honey and pulverized shells with sound waves.
A metal probe generates microscopic bubbles. When those bubbles collapse, they briefly create intense, localized energy that disrupts plant cell walls. That opens pathways for theobromine, caffeine, and phenolics to diffuse into the honey.
Because native stingless bee honeys typically have higher water content and lower viscosity than European honeybee ( Apis mellifera ) honeys, they behave more like fluid “edible solvents,” boosting mass transfer and speeding extraction.
The team benchmarked five Brazilian stingless bee honeys: borá ( Tetragona clavipes ), jataí ( Tetragonisca angustula ), mandaçaia ( Melipona quadrifasciata ), mandaguari ( Scaptotrigona postica ), and moça-branca ( Frieseomelitta varia
The researchers optimized the protocol with mandaguari honey, which sat in the sweet spot for water content and viscosity, then verified that the tuned process transfers across other native honeys.
Honey's chemistry isn't static. It shifts with climate, storage, and temperature. Bragagnolo emphasizes the method's portability:
“Therefore, it's possible to adapt the process to locally available honey, not necessarily mandaguari honey,” he said. That flexibility matters for a biodiversity-forward supply chain that values regional species and terroir.
Commercializing chocolate honey
The cocoa shells came via São Paulo's CATI unit in São José do Rio Preto, aligning the work with agricultural extension programs and waste-to-value efforts.
Using the Path2Green assessment developed at UNICAMP, the team scored the process against 12 green chemistry principles, including transport, purification, energy, and end-use.
Choosing an edible, local, ready-to-use solvent (honey), minimizing post-treatment, and accelerating extraction with ultrasound pushed the method to a positive sustainability index of +0.118 on a scale from −1 to +1.
“We believe that with a device like this, in a cooperative or small business that already works with both cocoa and native bee honey, it'd be possible to increase the portfolio with a value-added product, including for haute cuisine ,” said Mauricio Ariel Rostagno, who coordinated the study and the Path2Green analysis.
UNICAMP's innovation agency, INOVA, is now seeking partners to license the patented process and help commercialize it.
Shelf life, safety, and what comes next
Ultrasound's ability to rupture plant cells is well known, but it can also disturb microbial cell walls.
The group is preparing studies to see whether sonication alone reduces native microbial loads in stingless bee honey, which typically requires refrigeration, dehumidification, or pasteurization.
“Honey from native bees usually needs to be refrigerated, matured, dehumidified, or pasteurized, unlike honey from European bees, which can be stored at room temperature,” explained Rostagno.
“We suspect that, simply by being exposed to ultrasound, the microorganisms contained in the honey are eliminated, increasing the stability and shelf life of the product.”
On the application side, the concentrate's compositional profile – stimulant alkaloids plus phenolic antioxidants – opens multiple avenues.
In food and drink, the chocolate honey could act as a functional flavor base (think: chocolate-forward glazes, spreads, ice creams, espresso pairings) while supplying measurable bioactives.
In cosmetics, phenolics and theobromine are of interest for antioxidant and microcirculation claims, and honey's humectancy can support skin-feel.
Biodiversity as a feature, not a footnote
Choosing stingless bee honeys does more than improve extraction kinetics. It ties product value to native pollinators and landscapes.
Many Brazilian meliponine species produce distinct honeys tied to local flora. Channeling those differences into standardized processes could create regional SKUs, each with its own sensory signature and story.
That biodiversity framing dovetails with Brazil's bioeconomy goals, encouraging smallholders and cooperatives to elevate underused by-products (cocoa shells) and high value native inputs (stingless bee honey).
With licensing in motion, stability and sensory trials queued, and additional ultrasound extraction targets on the horizon, the scientists see a platform rather than a one-off recipe.
The study is published in the journal ACS Sustainable Chemistry & Engineering