While conventional food production to a large extent has started using pure steviol glycoside extract from stevia as a sweetener in foods, it has not yet been possible to use this powerful sugar substitute in the production of organic foods, despite strong pressure from many sides.

In a new research project led by scientists at Aarhus University and with collaboration from several industrial partners the ambition is to develop a stevia product that the food industry can use as a sweetener in organic food. The parties behind the project argue that it is only a matter of time before the EU gives the go-ahead for the use of stevia for food production. We will both push on to get the approval of stevia plant for food in the EU and also be ready with our product when the approval comes through.

The explanation for the reluctance to use of pure steviol glycoside in organic production is that it has an E number (E 960), and that the current productions use chemical ion exchange for purification of the extract from the plant leaves.

- The project aims to meet the food industry's demand for natural no-calorie sweeteners that can replace sugar and be used in the manufacture of healthier foods and beverages, not least in organic foods. The market for organic and healthy foods has increased strongly in recent years, and a further growth in demand is expected, explains senior scientist Kai Grevsen from the Department of Food Science who is the leader of the research project "Green Stevia - organic sweetener for food."

The project has received 4.26 million DKK from the Green Development and Demonstration Programme under the Ministry of Food, Agriculture and Fisheries and runs from 1 September 2013 until 31 august 2017. During this period, the parties are intending, among other things, to develop a technique for a bio-friendly extraction of steviol glycoside from the stevia plant and purification of plant leaves, which will use membrane filtration rather than ion exchange. This experiment has the participation of the companies DSS Silkeborg and Dairy Fruit in Odense.

The scientists will at the same time screen selections of stevia ‘varieties’ to identify the ones that produce the best result and are best suited to cultivation in Denmark.

- Based on existing knowledge of the content of steviol glycosides and other flavorants in different gene pools, we will pick ‘varieties’ from comparable countries where cultivation is already taking place. These plants will be grown on our fields and we will then analyse the leaves for steviol glycosides and particularly the rebaudiosides, which are the glycosides that give the best taste as a sweetener, explains Kai Grevsen.

In the project he will also help to develop a concept for the cultivation of organic stevia plants, where the focus will be on methods of establishment, fertilization, different planting and harvesting times and drying conditions.

The companies Thise Dairy and Dairy Fruit will collaborate to develop organic dairy test products sweetened with organic steviol glycosides/rebaudiosides. Once authorisation for the use of stevia in organic foods has been obtained, the test products from Thise Dairy will be introduced to the Danish market.

Kai Grevsen also points out that the cultivation of stevia has some potential environmental gains. If, for example, the cultivation of stevia replaces 30 per cent of the consumption of organic sugar extracted from sugar beet, then nutrient use can be reduced by 310,000 kg nitrogen and 77,500 kg phosphorus annually. There is also the socioeconomic merits of the sweetener in that it does not contain calories and therefore may have potential health benefits by reducing the number of people suffering from obesity and related complications.

Further information: Senior scientist Kai Grevsen, Department of Food Science, telephone: +45 8715 8342, e-mail: kai.grevsen@agrsci.dk

In addition to Aarhus University, project participants include Dairy Fruit A/S, DSS Silkeborg, the organic farming association (Økologisk Landsforening), CEBI Invest Aps and Thise Dairy.

Facts about stevia:

Stevia rebaudiana belongs to the Asteraceae family and is grown in Denmark as an annual to a height of about 50-80 cm.

The plant forms flowers when there are less than 13-14 daylight hours in a day. The long days in the summer half year in Denmark are an advantage when the intention is to produce the maximum number of leaves – rather than flowers – for harvest in the autumn. The leaves have the highest content of the so-called steviol glycosides.

Steviol glycosides are unique because they are natural plant ingredients that contain no calories and their functional and sensory properties are more like sucrose, unlike many synthetic sweeteners.