Production and quality evaluation of green and black herbal tea from Solanum aethiopicum (Garden egg leaf) and Lasianthera africana (Editan leaf)

Imagine a world where your morning cup of tea isn't just a warm hug for your brain, but a tiny, liquid pharmacy. For centuries, people have brewed "herbal teas" by steeping plant parts like leaves, roots, or flowers in hot water. Think of these not as the standard black tea you might find in a teabag, but as nature's own smoothies, packed with special chemicals called "phytochemicals." These are the plant's secret weapons—antioxidants that fight off the rust-like damage inside our bodies, and compounds that might help calm inflammation or keep our hearts happy. While the big tea companies have dominated the market for ages, scientists are starting to wonder: what if we swapped the usual leaves for local, wild plants that grow right in our backyards? Could these forgotten greens be just as tasty, and maybe even healthier, than the famous brands we know?

This is exactly the question a team of researchers from Nigeria set out to answer. They decided to play a high-stakes game of "Leaf vs. Leaf," turning two specific local plants into both "green" and "black" teas to see how they stacked up. The stars of the show were the Garden Egg leaf (from a plant that looks like a small eggplant) and the Editan leaf (a leafy green known locally as Lasianthera africana). To make sure they weren't just making things up, they used Moringa (a super-healthy leaf famous around the world) as a control group, and they even pitted their homemade brews against a commercial giant, Lipton, to see if the locals could beat the pro.

Here is how they played the game: To make green tea, they treated the fresh leaves like delicate vegetables, quickly steaming them to stop them from changing color, then rolling and drying them. This keeps the leaves fresh and green, like preserving a summer garden in a jar. To make black tea, they let the leaves "wither" in the shade, rolled them up, and then let them sit and "ferment" (basically, let them turn dark and oxidize) before drying. This process changes the flavor and the chemical makeup, much like how a green apple turns into something totally different when you bake it into a pie.

The results were a mix of nutritional powerhouses and sensory surprises. When the scientists looked at the "nutrition facts" of these teas, they found some heavy hitters. The Editan Green Tea was a protein monster, packing in 26.82% protein and a massive 335.09 kcal/100 g of energy, making it a serious fuel source. On the other hand, the Editan Black Tea was loaded with carbohydrates, clocking in at 58.86%, which is great for quick energy. If you were looking for minerals, the Moringa Green Tea won the trophy with the highest ash content at 10.01%, suggesting it's a mineral goldmine.

The vitamin scores were where things got really interesting. The Garden Egg Black Tea turned out to be a vitamin bomb, especially for Vitamin A (at 850.02 µg/100 g), Vitamin E (6.57 mg/100 g), and Vitamin K (1.03 mg/100 g). Meanwhile, the Editan Black Tea was the only one that managed to squeeze in the most Vitamin D (0.07 µg/100 g), even if the amount was small. The researchers also checked for "good guys" like flavonoids and tannins (the compounds that give tea its health benefits and astringent taste). The Garden Egg Black Tea had the highest levels of flavonoids, tannins, and saponins, while the Moringa Green Tea was the champion for alkaloids.

But here is the twist in the story: just because something is nutritious doesn't mean it tastes good. When the researchers asked people to taste-test the teas, the commercial Lipton tea was the undisputed king, scoring the highest in appearance, taste, aroma, and overall acceptability. The local teas were a mixed bag. The Garden Egg Green Tea and Moringa Black Tea were the local heroes, scoring surprisingly high and being almost as acceptable as the famous brand. However, the Editan teas struggled; they were rated the lowest for taste and mouthfeel, with tasters describing them as bitter and having a rough texture.

Safety was also a major checkpoint. The team checked the teas for bacteria and found that while all samples had some microbial growth (ranging from 1.0 × 10⁴ to 2.3 × 10⁴ CFU/g), they were within safe limits. However, they did find some unwanted guests like Staphylococcus aureus and Bacillus spp., which suggests that while the teas are safe to drink if prepared correctly (like using boiling water), the makers need to be much cleaner during the production process to avoid contamination.

In the end, the paper suggests that while the Editan leaf might be too bitter for a straight-up tea, the Garden Egg and Moringa leaves are serious contenders. They have the nutrients, the vitamins, and the taste to compete with the big commercial brands. The researchers conclude that with a little bit of process optimization and better hygiene, these local leaves could become a healthy, diverse alternative to the teas we drink every day, proving that sometimes the best ingredients are the ones growing right outside your door.