Sušenje i ekstrakcija lista sremuša (Allium ursinum L.) u cilju dobijanja funkcionalnih proizvoda sa bioaktivnim potencijalom / Drying and extraction of the wild garlic leaves (Allium ursinum L.) in order to obtain functional products with bioactive poten

The aim of this doctoral dissertation was to determine various technological procedures that would enable the use of fresh and dryed wild garlic leaves in foods and pharmaceutical industry, as a herbal drug or nutraceuticals. The availability period of fresh wild garlic is very short and only during the spring season. After harvest, the leaves are quite perishable, wither very quickly and lose their sensory, nutritive and functional properties. This makes the availability time of this herbal raw material very limited. Therefore, the conditions for storing the fresh leaves of wild garlic and the influences of storing conditions on composition of bioactive compounds were examined in order to extend their use in fresh state. In order to obtain dry herbal drug for extraction, influence of various drying techniques (convection and vacuum drying) and drying temperatures (40, 50, 60, 70 °C) were examinated. The stability and availability of wild garlic in food and pharmaceutical industries was extended by drying. The influence of process parameters of different modern extraction techniques - ultrasonic extraction (temperature, extraction time, ultrasonic power, solvent effect) and subcritical water extraction , extraction time, modifier addition), supercritical carbon dioxide extraction (pressure and temperature) - was examined, while maceration (as a conventional extraction technique) was used to evaluate the efficiency of modern extraction methods. The obtained extracts were analysed in terms of the polyphenolic content, the antioxidant activity and the content of sulfur compounds in order to optimize the extraction parameters and determine the extraction conditions for achieving the highest quality of extracts in terms of the content of the target bioactive components. Antimicrobial potential for different Gram positive and Gram negative bacterial strains was tested for selected extracts. To obtain more stable forms of selected extracts encapsulation techniques - spray drying and spray congeling - were applied. Encapsulated extracts were evaluated in terms of physico-chemical properties (chemical composition, moisture content, hygroscopicity, rehydration power, WAI and WSI) and biological activity (antimicrobial and antioxidant activity).