KAUNAS UNIVERSITY OF TECHNOLOGY VAIDA KRAUJALIENĖ BIOREFINING OF BERGENIA CRASSIFOLIA L., FAGOPYRUM ESCULENTUM MOENCH. AND SOLIDAGO VIRGAUREA L. BY HIGH PRESSURE EXTRACTION METHODS AND EVALUATION OF OBTAINED PRODUCTS Doctoral Dissertation Physical Sciences, Chemistry (03P) 2018, Kaunas This doctoral dissertation was prepared at Kaunas University of Technology, Faculty of Chemical Technology, Department of Food Science and Technology during the period of 2012–2018. Dissertation was prepared externally. Scientific supervisor: Prof. dr. Petras Rimantas VENSKUTONIS (Kaunas University of Technology, Physical Sciences, Chemistry, 03P). Edited by: Ilona Gritėnienė. Dissertation Defence Board of Chemistry Science Field: Prof. habil. dr. Algirdas ŠAČKUS, Kaunas University of Technology, Physical Sciences, Chemistry, 03P – chairman; Prof. dr. Valdas JAKŠTAS, Lithuanian University of Health Science, Biomedical Sciences, Pharmacy, 08B; Prof. dr. Daiva LESKAUSKAITĖ, Kaunas University of Technology, Technological Sciences, Chemical Engineering, 05T; Prof. dr. Vytas MARTYNAITIS, Kaunas University of Technology, Physical Sciences, Chemistry, 03P; Dr. Thierry TALOU, ENSIACET, National Politechnic Insitute of Toulouse, France, Physical Sciences, Chemistry, 03P. The official defence of the dissertation will be held at 2 p.m. on 18th of May, 2018 at the public meeting of Dissertation Defence Board of Chemistry Science Field in Dissertation Defence Hall (403) at Kaunas University of Technology. Address: K. Donelaičio St. 73-403 44249 Kaunas, Lithuania. Tel. no. (+370) 37 300 042; fax. (+370) 37 324 144; e-mail [email protected]. Doctoral dissertation was sent on 18th of April, 2018. The doctoral dissertation is available on the internet http://ktu.edu and at the library of Kaunas University of Technology (K. Donelaičio St. 20, 44239 Kaunas, Lithuania). © V. Kraujalienė, 2018 ISBN The bibliographic information about the publication is available in the National Bibliographic Data Bank (NBDB) of the Martynas Mažvydas National Library of Lithuania. KAUNO TECHNOLOGIJOS UNIVERSITETAS VAIDA KRAUJALIENĖ STORALAPĖS BERGENIJOS (BERGENIA CRASSIFOLIA L.), GRIKIŲ ŽIEDYNŲ (FAGOPYRUM ESCULENTUM MOENCH.) BEI RYKŠTENĖS (SOLIDAGO VIRGAUREA L.) BIORAFINAVIMAS, TAIKANT AUKŠTO SLĖGIO EKSTRAKCIJOS METODUS, IR GAUTŲ PRODUKTŲ SAVYBIŲ ĮVERTINIMAS Daktaro disertacija Fiziniai mokslai, Chemija (03P) 2018, Kaunas Disertacija rengta 2012 – 2018 metais Kauno technologijos universitete, cheminės technologijos fakultete, maisto mokslo ir technologijos katedroje. Disertacija ginama eksternu. Mokslinis vadovas: Prof. Dr. Petras Rimantas VENSKUTONIS (Kauno technologijos universitetas, fiziniai mokslai, chemija, 03P). Redagavo: Ilona Gritėnienė. Chemijos mokslo krypties disertacijos gynimo taryba: Prof. Dr. Habil. Algirdas ŠAČKUS, Kauno technologijos universitetas, fiziniai mokslai, chemija, 03P – pirmininkas; Prof. Dr. Valdas JAKŠTAS, Lietuvos sveikatos mokslų universitetas, biomedicinos mokslai, farmacija, 08B; Prof. Dr. Vytas MARTYNAITIS, Kauno technologijos universitetas, fiziniai mokslai, chemija, 03P; Prof. Dr. Daiva LESKAUSKAITĖ, Kauno technologijos universitetas, technologijos mokslai, cheminė inžinerija, 05T; Dr. Thierry TALOU, ENSIACET, nacionalinis Tulūzos politechnikos institutas, Prancūzija, fiziniai mokslai, chemija, 03P. Disertacija bus ginama viešame chemijos mokslo krypties disertacijos gynimo tarybos posėdyje 2018 m. gegužės 18 d. 14 val. Kauno technologijos universiteto disertacijos gynimo (403) salėje. Adresas: K. Donelaičio g. 73-403, 44249 Kaunas, Lietuva. Tel. (370) 37 300 042; faks. (370) 37 324 144; el. paštas [email protected]. Disertacija išsiųsta 2018 m. balandžio 18 d. Su disertacija galima susipažinti internetinėje svetainėje http://ktu.edu ir Kauno technologijos universiteto bibliotekoje (K. Donelaičio g. 20, 44239 Kaunas). © V. Kraujalienė, 2018 ISBN Leidinio bibliografinė informacija pateikiama Lietuvos nacionalinės Martyno Mažvydo bibliotekos Nacionalinės bibliografijos duomenų banke (NBDB). TABLE OF CONTENT Abreviations ............................................................................................................................. 8 I. INTRODUCTION ................................................................................................................ 9 1.1. Relevance of doctoral dissertation .................................................................................... 9 1.2. Aim and tasks of the work .............................................................................................. 10 1.3. Practical significance ...................................................................................................... 10 1.4. Scientific novelty ............................................................................................................ 11 1.5. Key points of the thesis ................................................................................................... 11 1.6. Approbation of results .................................................................................................... 11 1.7. Structure and content of the dissertation ......................................................................... 11 II. LITERATURE REVIEW.................................................................................................. 12 2.1. Characterization of plants used in this study .................................................................. 12 2.1.1. Bergenia (Bergenia crassifolia L.) .............................................................................. 12 2.1.2. Buckwheat (Fagopyrum esculentum) .......................................................................... 13 2.1.3. Golden rod (Solidago virgaurea L.) ............................................................................ 15 2.2. Secondary metabolites in plants...................................................................................... 16 2.2.1. Terpenes ....................................................................................................................... 16 2.2.2. Phenolic compounds .................................................................................................... 17 2.2.2.1. Phenolic acids ........................................................................................................... 17 2.2.2.2. Flavonoids................................................................................................................. 19 2.2.2.3. Biosynthesis of phenolic compounds ........................................................................ 21 2.2.2.4. Antioxidative activity measurements in vitro ........................................................... 23 2.2.3. Nitrogen containing compounds .................................................................................. 25 2.2.4. Medicinal and aromatic plants in food and medicine .................................................. 25 2.3. The improved utilization of plant biomass ..................................................................... 28 2.3.1. Supercritical fluid extraction ....................................................................................... 29 2.3.2. Pressurized liquid extraction ........................................................................................ 30 2.4. Summary of literature survey.......................................................................................... 31 III. MATERIALS AND METHODS ..................................................................................... 32 3.1. Chemicals and plant material .......................................................................................... 32 3.2. Sample preparation and extraction .................................................................................. 32 3.3. Measurements of antioxidant capacity using traditional procedure ................................ 33 3.3.1. ABTS•+ scavenging assay ........................................................................................... 33 3.3.2. ORAC assay................................................................................................................. 33 3.3.3. Measurement of total phenolic content (TPC) ............................................................. 35 3.4. Measurement of antioxidant capacity of solid substances by QUENCHER procedure .. 35 3.5. UPLC/ESI–QTOF–MS analysis ..................................................................................... 35 3.6. Determination of tocopherols by high performance liquid chromatography (HPLC) .... 36 3.7. Measurement of the effect of extracts on oil oxidation ................................................... 36 3.7.1. Measurement of the effect of extracts on oil oxidation in Oxipres apparatus .............. 36 3.7.2. Oil and emulsions oxidation measurement in Rancimat apparatus .............................. 37 3.8. Statistical analysis ........................................................................................................... 37 IV. RESULTS AND DISCUSION ........................................................................................ 37 4.1. Biorefining of Bergenia crassifolia L. roots and leaves by high pressure extraction methods and evaluation of antioxidant properties and main phytochemicals in extracts and plant material ......................................................................................................................... 37 4.1.1. Yields of Bergenia crassifolia L. extracts ..................................................................