The increasing rate of obesity and health problems associated with metabolic syndrome (diabetes, cardiovascular disease, blood pressure) turn consumers to healthier dietary choices with reduced sugars and fats. In the current food market, synthetic sweeteners are available, such as aspartame, sucralose, cyclamates, etc. Although these sweeteners provide a sweet taste, with no calories, they are often accused of toxicity. This, promotes the growing need of consumption of natural sweeteners, such as sweeteners from Stevia rebaudiana Bertoni plant (200-300 times sweeter than sugar, no calories).
However, although its use as a natural sweetener has been approved by European legislation (EC 1131/2011), consumer response is still moderate due to its undesirable metallic and bitter aftertaste. The objective of the proposed project is to optimize and consequently to promote the sensory characteristics of Greek stevia by removing or covering the bitter and metallic aftertaste. This aim will be achieved by intervening throughout the cultivation cycle, the post-harvest treatment, the processing of stevia for the production of raw materials (sweeteners) with excellent taste, to the development of new or improved food products, with innovative methods aiming at improving quality of life through reduction of sugar intake. The holistic approach at all the stages of agri-food chain of sweeteners production from stevia plant (steviol glycosides) is crucial for the in-depth investigation and afterwards the improvement of bitter-metal aftertaste.
Specific objectives are:
• Optimization of cultivation using innovative precision agriculture applications, to optimize the concentration and quality of glycosides
• Recovery of glycosides through green extraction methods (microwaves, ultrasound, extraction in the presence of enzymes) and their isolation at high purity
• Promotion of stevia sweeteners by covering or removing their bitter and metallic aftertaste through innovative encapsulation methods (electrospraying method), enzymatic transglycosylation and use of membranes
• Use of improved steviol glycosides for the development of new or improved food products (refrigerated chocolate cream, refrigerated rice paddy) without addition of sugar, and sweeteners
• Evaluation of the biological activity of steviol glycosides isolated from plant extract through in vitro studies (anti-cancer, intestinal barrier effect, drug interaction)
• Techno-economic analysis and evaluation of the environmental footprint of processes and products through Life Cycle Analysis Methodology
The development and application of innovative technologies in the agri-food sector, as well as the improvement of isolation and processing of stevia leaf extracts techniques, which will lead to the production of sweet powder or liquid to be used as a ready-to-use sweetener, will contribute to the dynamic introduction of Greece into the International stevia sweetener market, combining domestic stevia leaf cultivation with the ability to place the final product on the market as an E960 sweetener, with outstanding sensory properties. The development of innovative products based on steviol glycosides will benefit human health, contributing to the reduction of obesity and diabetes. Finally, it will benefit socially, environmentally and economically not only the participating institutions and the company, but also the Greek society.