L. Dienaitė “Evaluation of phytochemical composition and functional properties of sea buckthorn (Hippophaë Rhamnoides) and guelder-rose (Viburnum Opulus) berry pomace extracts” doctoral dissertation defence

Thesis Defense

Author, Institution: Lijana Dienaitė, Kaunas University of Technology

Science area, field of science: Natural Sciences, Chemistry, N003

Scientific Supervisor: Prof. Dr. Petras Rimantas Venskutonis (Kaunas University of Technology, Natural Sciences, Chemistry, N003).

Dissertation Defence Board of Chemistry Science Field:
Prof. Dr. Daiva Leskauskaitė (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T 005) – chairwomen
Assoc. Prof. Dr. Vilma Kaškonienė (Vytautas Magnus University, Natural Sciences, Chemistry, N003)
Prof. Habil. Dr. Vytautas Mickevičius (Kaunas University of Technology, Natural Sciences, Chemistry, N003)
Prof. Dr. Dalija Seglina (Horticultural Institute of Latvia University of Life Sciences and Technologies, Natural Sciences, Chemistry, N003)
Prof. Dr. Pranas Viškelis (Lithuanian Research Centre for Agriculture and Forestry, Agricultural Sciences, Agronomy, A001)

The dissertation defence takes place in hybrid form, for online mode join here.

The doctoral dissertation is available at the library of Kaunas University of Technology (K. Donelaičio g. 20, Kaunas).


Recently, a lot of attention has been paid to sustainable and waste-free production as well as to increasing the naturalness and the added value of the obtained products. In the juice industry, after processing berries, especially such berries as the guelder-rose and the sea buckthorn which are not consumed fresh due to unpleasant organoleptic properties (the taste and the smell), a large number of by-products are generated. In most cases, berry pomaces are used inefficiently (as fertilizers, animal feed, or simply discarded). The biorefining scheme applied in this study enables to obtain high added value natural products and ingredients from very heterogeneous berry pomace. In this study, the whole dried pomaces of sea buckthorn and guelder-rose were extracted by using various extraction techniques and different polarity solvents. The obtained products (lipophilic and hydrophilic fractions) were comprehensively characterized by determining their phytochemical composition and bioactivity in vitro (antioxidant and inhibitory properties of cancer cells). It was established, that fractions of guelder-rose and sea buckthorn berry pomaces obtained by pressurized liquid extraction with polar solvents possess the strong antioxidant potential and antiproliferative properties, while obtained lipophilic fractions were rich in components beneficial to health. The separation of the biologically valuable fractions and compounds from the pomace provides an opportunity for a more rational and efficient use of the sea buckthorn and guelder-rose berry pomace. Therefore, the results of this study are of benefit to the producers of berries as well as for the food, cosmetic, pharmaceutical industries and for the researchers.