NUS scientists enhance the flavor of carob-based chocolate alternatives with novel methods. Credit: Faculty of Science, National University of Singapore
Beyond its climate resilience, carob also offers some nutritional advantages. With its natural sugar content, it could be used to create chocolate alternatives without added sweeteners – an increasingly desirable feature for health-conscious consumers. Carob is also caffeine-free and rich in d-pinitol, a compound that has been shown to have anti-diabetic effects.
Carob pulp is generated as a by-product during the production of locust bean gum, a common thickening agent in the food industry. Its flavor differs significantly from chocolate, with less bitterness and fewer of the rich, roasted notes that define cocoa-based products. These differences have so far limited the widespread use of carob pulp as a cocoa-substitute.
Two innovations to mimic the flavor of cocoa
To overcome carob pulp’s sensory limitations, the research team devised two innovative techniques using easy-to-obtain enzymes that alter the profile of flavor precursors (substances which affect the flavors of a product during processing) in roasted carob pulp, enabling it to more closely mimic the taste and aroma of cocoa:
- Enzyme-treated soy protein enhancement to increase bitterness – A novel application of enzyme-treated soy protein that intensifies roasted carob pulp’s cocoa-like aroma and balances its overall flavor. This enzyme increases amino acid and peptide content, which gives the product the rich, bitter taste associated with dark cocoa chocolate. The research findings were published in Journal of Food Science on July 18, 2025.
- Enzyme-aided monosaccharide generation to enhance sweetness – A process that promotes the generation of naturally occurring simple sugars, which then react during roasting to generate sweet, roasted, and caramel-like aroma compounds. The steps and results of this technique were published in the journal Food Chemistry on June 16, 2025.
The first method targets the creation of two key flavor compounds – 2-methylbutanal and 3-methylbutanal – which are essential to chocolate’s distinctive aroma. This novel technique also modulates some of carob’s less desirable intrinsic odors, resulting in a smoother and more familiar chocolaty taste.
The second method focuses on the production of a group of compounds known as oxygenated heterocycles, which impart a sweet, roasted aroma.
Enzyme treatment is a straightforward and clean method that requires minimal processing, compared to other methods, which involve harsh chemicals such as hydrochloric acid to enhance flavor. In addition, as the enzymes are widely used in conventional food processing, these innovative approaches can be easily scaled for commercial production.
Carob’s impact on the industry and sustainability
By improving carob pulp’s flavor profile, these techniques could encourage confectioners to incorporate carob into food products that require cocoa, such as chocolate bars, cocoa powders, malt drinks, and other cocoa-based products. If adopted at scale, this could significantly reduce the chocolate industry’s dependence on cocoa, making supply chains more resilient to climate change and crop disease outbreaks.
“Our research is not just about replicating the flavor of cocoa – it’s about diversifying the ingredients we use to make chocolate alternatives,” explained Manfred Ku, first author of the research paper, and a PhD student at NUS FST. “By turning to hardy, climate-resilient crops like carob, we can help the industry adapt to environmental challenges while giving consumers a product they will enjoy.”v
The NUS researchers also anticipate that carob’s lower production costs will make it an attractive alternative. Since carob pulp is a byproduct of locust bean gum manufacturing, its utilization in the production of chocolate substitutes could add value to an existing supply chain, reduce agricultural waste, and potentially lower prices for manufacturers and consumers alike.
Next steps and commercialization
The NUS team aims to continue investigating other techniques to further enhance the flavor of carob during roasting. They also plan to explore new techniques to introduce pleasant, novel flavor notes into carob-based chocolate alternatives, catering to diverse consumer preferences worldwide.
Looking ahead, the NUS researchers plan to collaborate with industry partners to commercialize these techniques through licensing, venture co-creating, or other modes of partnership.
