In the heart of South Africa, researchers are unlocking the potential of an ancient legume, offering a glimpse into the future of sustainable protein sources. Joel Gbenle, a dedicated researcher from the University of Mpumalanga, has been delving into the world of marama beans, a lesser-known legume with immense promise. His recent study, published in Future Foods, explores how fungal fermentation can transform these beans into a more nutritious and functional ingredient, with significant implications for the food and feed industries.
Marama beans, derived from the Tylosema esculentum plant, have long been a staple in some African communities. However, their high levels of antinutritional factors and low levels of certain essential amino acids have limited their widespread use. Gbenle’s research aims to change that. “Marama beans have the potential to partially or completely replace soybeans in human and animal diets,” Gbenle explains. “But to unlock this potential, we need to address their nutritional limitations.”
The study focuses on fungal-mediated solid-state fermentation (SSF) using Aspergillus oryzae, Aspergillus sojae, and their co-culture. The results are promising. Fermented marama beans showed lower levels of acid detergent fiber, acid detergent lignin, cellulose, and hemicellulose, indicating a reduction in certain fiber fractions. Moreover, beans fermented with A. sojae exhibited higher crude protein content, suggesting an enhancement in protein quality.
One of the most significant findings is the reduction of antinutritional factors. Fermented beans had lower phytic acid and trypsin inhibitor activity, which can inhibit nutrient absorption and digestion. However, the story doesn’t end there. Fermented beans also showed higher total phenolic content, which are beneficial plant compounds with antioxidant properties.
Despite these improvements, the study found that fermented beans did not exhibit enhanced in vitro enzyme protein digestibility. This unexpected result opens up new avenues for research. “While we’ve made strides in reducing antinutritional factors and enhancing protein content, the lack of improvement in digestibility is a puzzle we’re eager to solve,” Gbenle notes.
The commercial implications of this research are vast. As the world seeks sustainable and nutritious protein sources, marama beans could emerge as a viable alternative to soybeans. The food and feed industries are always on the lookout for innovative ingredients that can meet the growing demand for protein while addressing environmental concerns.
This study, published in Future Foods (which translates to ‘Future Foods’ in English), is just the beginning. Future research could explore different fermentation techniques, other fungal strains, or even combinations of fermentation with other processing methods. The goal is to create a more digestible and nutritious marama bean, ready to take its place in the global market.
As we stand on the brink of a protein revolution, studies like Gbenle’s are paving the way. They remind us that the future of food lies not just in creating new ingredients, but also in unlocking the potential of those that have been overlooked. The marama bean, with its humble origins and immense promise, is a testament to this vision. The journey from an orphan legume to a global protein source is long, but with each study, we take a step closer.