Aside from being an incredible source of natural sweetness, Stevia rebaudiana has seen an emergence as a leader in the healthy revolution that is currently sweeping the food industry. As the world looks to fundamentally change how we make our food and alter our understanding of our diets, stevia has rapidly become the key to unlocking a healthier future. But how has SWT learned to maximise the very best of the plant, while refusing to compromise on quality? What is the secret to a sweetness that is so powerful, but without any of the negative side effects usually related to the sweetening of foods?

The health properties of stevia leaves go further than just tasting great. Steviol glycosides – the active elements of the leaves that give it the beneficial properties for which it is known – are powerful antioxidants, thanks to a rich profile of phenolic compounds found inside each and every stevia crop we cultivate.

A study at Leuven Catholic University by biologists Stijn Ceunen and Jan M. C. Geuns noted that “During the past few decades, the nutritional and pharmacological benefits of
these secondary metabolites have become increasingly apparent…For the past few decades, S. rebaudiana has been the subject of extensive phytochemical analysis, during which time a large number of molecular structures have been identified. Most studies were done on the isoprenoids and phenolic compounds, but many other constituents such as macro- and micro- nutrients, fatty acids, and vitamins have also been found in S. rebaudiana.”

It is these nutrients and vitamins – as well as positive fats – that have seen stevia become increasingly widely used by nutritionists looking to rebalance global diets and decrease waistlines.

The exhaustive study by Ceunen and Geuns comprehensively broke down the stevia plant in a manner that few researchers had managed before – despite the discovery of the plant by western biologists in the late 19^th century. Scientific reports on steviol glycosides (and the seasonal variations that accompanied them) first emerged at the beginning of the 1970s – giving cultivators a unique insight into when the best time to harvest would be – it also allowed them to locate the best sources of these glycosides within the plant, analysing the content of leaves, roots, stems and branches to determine where the areas richest in glycosides could be found.

These glycosides are found most abundantly within the leaves – which is exactly why SWT has refined harvesting processes to focus on getting the maximum out of every single leaf . By waiting for the moment when the stevia plant is about to flower, and harvesting it, Ceunen and Geuns agree that SWT have found the moment when the plant is richest in steviol glycosides, and therefore at the most perfect moment for harvest.

In line with the findings in the study, SWT harvest their stevia plants several times a year (dependent on atmospheric conditions in our fields), as repeated harvesting of the same plant is able to increase the number of glycosides in each leaf, ensuring that our stevia is as naturally sweet as our consumers demand. Close to the tropics, the plants are harvested four times per year, as the plant grows fast as a result of high radiation and enter flowering frequently as a result of short days all year round – meaning that the plants reach their sweetest and most delicious once every 3 months.

As well as knowing when the best time to harvest a crop, it is essential to understand which variants of stevia rebaudiana yield the highest number of glycosides in order to create an outstanding extract – SWT grows plants that are rich in Rebaudioside A, but still containing all other glycosides. Stevia plants contain around 35-40 sweet molecules, from which Rebaudioside a and Stevioside are the more abundant. Rebaudisoide M – a very minor variant but one that is quite sweet – is specially selected for the ability to be intensely cultivated and to deliver outstanding sweetness in every leaf.

Beginning in 2017 with 10,000 varieties, SWT has carefully selected the 50 best strains of stevia to cultivate in our fields, prioritising the production of glycosides to give our extracts the best and most natural flavours, all without any added chemicals or enzymes in our processes.

While the antioxidant properties of stevia leaves are well known, it is often underestimated just how effective an oxidant they are. Steviol glycosides display an ROS scavenging ability of between 1.5 and 2.5mM, which can be further enhanced during the cultivating and processing portions. This helps to keep the body healthy by ensuring good oxygenation of the blood.

With the cutting edge 100% water-only processing used by SWT, no part of the leaf is wasted, and every ounce of goodness is extracted in order to form part of an eco-friendly solution to global nutrition. Thanks to the technical staff behind our incredible product, we are learning how to harness more of the power of the stevia leaf with every harvest, ensuring that the healthy sweetness revolution is stronger than ever.