engleski

Encapsulation of Mediterranean plants extracts obtained by means of non-conventional high voltage electrical discharges method

Mediterranean plants are rich in biologically active compounds (BACs) such as essential oils, antioxidants and volatile compounds, which often have unique features, from nutritive to medicinal properties, as well as antioxidant and antimicrobial activities. These remarkable properties of BACs can be used in the production of functional foods. From the economical point of the view, there are challenges to reduce the processing costs and to minimize the use of organic solvents. Thus, there is a need towards the implementation of innovative strategies and non-conventional methods, which are following the concept of Green Technology [1]. Extractions by means of high voltage electrical discharges (HVED) resulted to be very efficient in recovering BACs from plants. HVED can give highly valuable plant extracts with regards to an environmentally friendly way that follows the nowadays preferred „green concepts“. These procedures are rapid, convenient, economical, sustainable, and efficient, and with great potential for industrial upscaling [2, 3]. Most of these biologically active compounds have low water solubility, strong flavors/odors and are generally unstable and degrade easily under conventional processing and storage conditions. Encapsulation of these compounds is an excellent choice to stabilize them and mask their strong flavors and odors, thus protect them and enable their delivery in food systems as well as the controlled and targeted release. In our research, extracts and essential oils obtained by means of the non-conventional HVED method and with use of „green“ solvents, are to be implemented into different food matrices in order to obtain food products with high added values, e.g. functional foods. However, in order to successfully implement BACs into these food matrices, encapsulation technology was employed. Use of different biopolymeric carriers for the proper optimization and production of the microcapsules was investigated. Obtained HVED extracts with the highest share of sought BACs were encapsulated with Büchi Encapsulator B-390 via the simple ionic gelation method. Also, lyophilization was used as a method to compare the stability and longevity of encapsulated BACs vs non- encapsulated. Either hydrophilic BACs or lipophilic as well as the combination of both were encapsulated into different biopolymeric carriers with different number of layers. Combination of the main carrier, sodium alginate, different co-biopolymers was more thoroughly investigated. Physicochemical analyses were performed for different combinations as well as the morphology of obtained microcapsules. Additional coatings were also applied to obtain microcapsules with optimal properties for desired retention and release of the encapsulated bioactive compounds. Release kinetics of BACs from microcapsules were also evaluated and statistical predictions for desired achievements were performed. In the end, obtained optimal microcapsules will be implemented into desired food matrices with sought properties.

Green technology ; Non-conventional extraction ; Encapsulation ; Bioactive compounds

nije evidentirano