Spekboom (Portulacaria afra) is an unpretentious shrub, small tree, or hedge. In its natural habitat, it grows on steep slopes and rocky hills in the Karoo and Eastern Cape regions of South Africa, where it functions to stabilize soil and prevent erosion. Furthermore, this species is an effective carbon absorber, removing carbon dioxide from the atmosphere.
Because its fleshy green leaves contain an exceptionally high average moisture content—over 93%, Spekboom serves as a natural water source for both people and wildlife in arid areas.
Scientists studying how underutilized local plants, crops, and insects can be transformed into safe, nutritious, and appealing food sources began researching Spekboom, which is already known as a good source of Vitamin C. The researchers set two goals. First, they tested raw Spekboom leaves, as well as leaves subjected to various processing methods: baking, roasting, steaming, or blanching, evaluating their color, appearance, texture, moisture, acidity, and Vitamin C content.
Second, the scientists investigated whether consumers were aware of Spekboom as a food and if they were willing to consume it. The results showed that thermal processing makes Spekboom leaves softer and lighter while retaining characteristics similar to other leafy vegetables. Although respondents knew little about Spekboom as a food, most expressed willingness to try and buy it, even without prior consumption experience.
Raw Spekboom leaves have a juicy and crunchy taste with a sharp flavor reminiscent of lemon juice. Their natural acidity allows them to be used in both raw and cooked dishes, as it balances sweetness and spices. These leaves can be eaten fresh or used to make savory marinades, crunchy pickles, and sweet preserves.
To expand the consumption of Spekboom, an optimal method for preparing it in everyday dishes needed to be found. Student researcher Rosanne MacDonald developed several Spekboom recipes that were tested in the Sensory Laboratory of the Department of Sustainable Food Systems and Development at the University of the Free State. For instance, to make Spekboom lemon curd, fresh leaves were mixed with lemon juice, and then the mixture was cooked with eggs, sugar, lemon zest, and a small amount of cornstarch until thickened, after which butter was incorporated. This resulted in a smooth, sweet-sour sauce that can be stored in a sterilized jar for up to ten days.
Spekboom can also be used in savory preserves. Fresh leaves were added to tomato chutney made from onion, garlic, vinegar, sugar, garam masala, mustard, and herbs. The tomatoes were slowly simmered until reduced, and then the Spekboom was added for the last thirty minutes.
Fresh leaves were also marinated with thinly sliced red onion in a warm mixture of red wine vinegar, honey, olive oil, fennel, mustard, cinnamon, and cardamom, left for seven days before serving. Dried Spekboom leaves can be turned into dukkah—a crunchy Egyptian spice blend. For this, ground dried leaves and Spekboom powder were mixed with roasted coriander, cumin, sesame and sunflower seeds, walnuts, peanuts, salt, and black pepper. Spekboom provided a tanginess to the rich mix of nuts and spices.
These dishes demonstrate that balancing its lemon flavor with sweet, savory, or spicy ingredients allows for the creation of products that people genuinely enjoy. Overall, it was found that the cooked leaves remain acidic and moist, similar to other fresh leafy vegetables. After steaming, the Vitamin C content in Spekboom was found to be higher than in raw leaves.
The plant can be resilient, but if people do not like the taste and do not want to eat it, it will not help solve food security problems. One hundred and twenty people participated in the study. About 84% of participants had previously seen Spekboom, but only 22% had tried it more than once in the previous year. Only 3% of the group knew about the nutritional value of Spekboom, but 82.5% stated they were more likely to eat it if they learned more about its health benefits.
Overall, most participants showed interest in consuming Spekboom: 79.2% stated they were willing to include it in their diet, and 75% said they would buy it if it were available in supermarkets. More than 77.5% would consider buying it if the price were lower than other vegetables. This indicates that Spekboom is a widely known but rarely considered product, and people are open to consuming it. Additional information about its health benefits, preparation methods, supermarket availability, and acceptable price could stimulate its use as another leafy vegetable.
South Africa's food system faces challenges for many people: poverty, inequality, and unemployment prevent households from affording sufficiently nutritious food. In 2024, about 63.5% of households in the country experience food shortages, and 17.5% are classified as critically malnourished.
Spekboom requires minimal water, grows well in poor soils, and is very resilient. Processing it into long-lasting products, such as marinades and preserves, can reduce post-harvest losses and create sustainable value chains. This opens opportunities for local community agro-processing initiatives, transforming garden plants into value-added commercial products.
Spekboom should not remain merely an emergency harvest item or a salad garnish. Thanks to the right culinary approach and support from food science, our research shows that Spekboom has the potential to transform from a decorative hedge into an integrated element of modern African cuisine.
