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Production of natural compounds from medicinal plants with numerous biological effects has become very popular due to increasing concerns about the safety of using synthetic substances and the effects of COVID -19 on health. Sea buckthorn (Elaeagnus rhamnoides (L.) A. Nelson), (SB) is known as an important source of natural antioxidant and antimicrobial bioactive molecules (BAM), but also, when added to foods, improves sensory properties, microbiological stability, and shelf life of products. The best-known sea buckthorn product is berry oil (SBO) (Yu et al., 2017), which contains large amounts of lipophilic BAM such as unsaturated fatty acids, tocopherols, carotenoids, and sterols (Koskovac e al., 2017), but differences in composition have been found depending on the cultivar, growing conditions and extraction methods used (Christe et al., 2020 ; Cenkowski, 2006). Supercritical CO2 extraction of oil as an advanced method is gaining popularity due to its better extraction efficiency compared to conventional extraction methods. Moreover, CO2 as an environmentally friendly and safe solvent (GRAS) can be easily removed from oil. Therefore, the aim of this study was to determine the content of fatty acids, sterols, and α-tocopherols, as well as the antioxidant capacity (AC) of SBO obtained by supercritical CO2 extraction from SB berries from Croatia. The tocopherol content of the SBO extracts was determined by HPLC/FLD, the content of fatty acids and sterols by GC-MS and AC by the lipophilic ORAC method. A total of 16 sterols were determined, with sitosterol (589.28 mg/100 g oil) being the most abundant, followed by campesterol (31.97 mg/100 g oil), uvaol (21.79 mg/100 g oil), and obtusifoliol (12.99 mg/100 g oil). High content of unsaturated fatty acids such as omega-7 palmitoleic acid (34.54%) and omega-6- γ-linolenic acid (10.78%) was also found. SBO was characterized by high content of α-tocopherol (275.63 mg/100 g oil) and high antioxidant ORAC capacity (1676.90 μmol TE /100 g oil). The results suggest that the SBO obtained by supercritical CO2 extraction is a rich source of various lipophilic BAM with high antioxidant capacity, which could be used for the production of natural products, functional foods and as food additives.

Sea buckthorn (Hippophaë rhamnoides L.) oil (SBO) as the most valuable part of berries receives increasing attention worldwide due to health effects. It is rich source of bioactive compounds like tocopherols, carotenoids, flavonoids, essential and polyunsaturated fatty acids and essential amino acids. These compounds are relatively unstable and susceptible to degradation and it is important to improve their stability during handling, processing and storage. Spray drying method is the most commonly used microencapsulation method in the food industry for oil protection. Therefore, the objective of this study was to evaluate the influence of the spray drying conditions at different temperatures (120 to 180 °C) and wall to core ratio (2 to 4) on the total carotenoid (TC) and tocopherol (TT) content and antioxidant capacity (AC) of sea buckthorn oil microencapsulated using gum Arabic as wall material. The TC and TT was determined using HPLC methods and AC by the ORAC method, respectively. The carotenoid retention in powders compared to SBO was in range from 8.19 to 47.13 % and tocopherol retention from 34.75 to 45.33 %, respectively. The results showed that increase in a wall to core ratio favors carotenoid and tocopherol retention, while carotenoids were more susceptible on increase of drying temperature than tocopherols. Temperature and wall to core ratio significantly affected the AC. The highest retention of carotenoids (88.36 mg/100 g dm) and tocopherols (50.79 mg/100 g dm) showed sea buckthorn powder obtained at 120 °C and wall to core ratio of 2 while the highest ORAC value (305.8 μmol TE/L) was determined in powder obtained at same drying temperature but wall to core ratio of 4. The sea buckthorn oil powders obtained by spray drying showed carotenoid and tocopherol stability with antioxidant properties and potential to be used for the development of functional products.

Sea buckthorn (Hippophae rhamnoides L.) is rich source of bioactives such as phenolics and lipophilic compounds and used as food and medicinal plant. Higher phenolic contents (PC) and antioxidant capacities (AC) were determined in sea buckthorn leaves (SBL) than in berries. Phenolic extraction from plants is the first step in utilization of these compounds and more efficient extraction processes such as microwave assisted extraction (MAE) have been developed in recent years due to reduction of extraction time and solvent. Therefore, the aim of this study was to evaluate the PC and AC in SBL extracts obtained under different MAE conditions of microwave power (300, 500 and 700 W) and extraction time (5, 10 and 15 minutes) at 60 ºC using 70% ethanol (v/v) as the extraction solvent. Phenolic profile of SBL extracts was determined using UPLC-MS2 and AC by ORAC method, respectively. A total of 30 phenolic compounds were determined comprising flavonols (FOL), flavones (FON), flavan-3-ols (F-3-OL) and phenolic acids (PA). The FOL (372.35 to 538.69 mg 10-2g-1 dm) showed to be the predominant phenolic group in SBL represented by rutin and kaempferol as the most abundant. Considerably lower content of total PA (71.29-132.29 mg 10-2g-1 dm), FON (7.99-22.49 mg 10-2g-1 dm) and F-3-ON (2.70-3.72 mg 10-2g-1 dm) were determined. The all SBL extracts had high AC (8779.17-9186.42 μmol TE 10- 2g-1 dm). Applied MAE conditions significantly affected the concentration of FOL, FON, PA and AC. Generally, the highest content of FOL, FON and AC was observed in extracts obtained under microwave power of 500 W and extraction time of 15 minutes, while the highest content of PA was observed under microwave power of 700 W and shorter extraction time of 5 minutes. Therefore, MAE is effective method for the production of valuable extracts from SBL with potential beneficial applications.

The sage (Salvia officinalis), laurel (Laurus nobilis), thyme (Thymus vulgaris), mastic tree (Pistacia lenticus L.), carob (Ceratonia siliqua) and myrtle (Myrtus communis) has many potential applications due to large number of bioactive molecules (BAM) with high antioxidant capacity (AOC). Currently it is an increasing interest in using these plants in the production of plant extracts (PE) and essential oils (EO) for food, pharmaceutical and cosmetic industries. However, extraction yield and antioxidant activity of PE depend on selection of appropriate extraction technique and solvent used for extraction. Therefore, the aim of this study was to determine the AOC of PE obtained by successive extraction with three different extraction solvents (hexane, 80 % acetone and 96 % ethanol) and extraction techniques (ultrasound assisted (UAE), accelerated solvent (ASE) and shaking water bath extraction). The plant extracts were analysed using the ORAC method. Results showed that ASE is the most appropriate method for extraction BAC’s from thyme, mastic tree and carob while UAE was better method for sage and laurel, whose extracts contribute the highest AOA.

The present research was undertaken to evaluate the polyphenol content of two Marasca sour cherry ecotypes (Recta and Brač 2) grown in two areas in Croatia (Zadar and Split), their stability during freezing storage at -18 °C for six months and contribution to antioxidant capacity (AOC), respectively. Polyphenolic content was assessed by high performance liquid chromatography (HPLC UV/VIS PDA) and anthocyanins (ANT), hydroxycinnamic acids (HCA), flavonol glycosides (FG) and flavanols (FLAV) were determined. ANT dominated in fresh and frozen cherry ecotypes (321.90 – 774.61 mg/100 g dm) and cyanidin-3- glucosylrutinoside (CYGR) was present in the highest concentration (223.22 – 501.04 mg/100 g dm). The contents of other phenolics were considerably lower compared to ANT: HCA=40.72 – 86.28 mg/100 g dm, FG=22.34 – 41.03 mg/100 g dm and FLAV=0.16 – 0.59 mg/100 g dm, where major compounds presented in HCA were p-coumaric and neochlorogenic acids, in FG quercetin-3-glucoside and in FLAV catehin. Furthermore, statistical analysis showed that all sour cherry samples significantly differed according to the ANT, HCA, FG and FLAV content (p≤0.01). Generally, ecotype Recta and Zadar growing area had higher polyphenolic content. Freezing storage caused decrease of almost all polyphenolic groups, particularly ANT (16 – 30 %) and HCA (26 – 36 %) while better stability of FG (10.5 – 20 %) and higher variation of FLAV content was observed. For determination of AOC three methods (DPPH, FRAP, ABTS) were used and the AOC was as follows: DPPH=3.284 – 6.38 mmol TE/100 g dm, FRAP=7.18 - 18 mmol TE/100 g dm and ABTS=73.16 - 119.93 mmol TE/100 g dm. The results indicate higher AOC in samples of Brač 2 ecotype from Zadar growing area., Ovo istraživanje provedeno je radi utvrđivanja razlike u masenom udjelu polifenola dva ekotipa višnje Maraske (Recta i Brač 2) uzgojenih na dva područja u Hrvatskoj (Zadar i Split), utvrđivanja stabilnosti polifenola tijekom skladištenja na -18 ° C tijekom šest mjeseci i doprinosa polifenolnih spojeva antioksidacijskom kapacitetu (AOC). Primjenom tekućinske kromatografije visoke djelotvornosti (HPLC UV/VIS PDA) identificirani su fenolni spojevi iz skupine antocijana (ANT), hidroksicimetnih kiselina (HCA), flavonol glikozida (FG) i flavanola (FLAV). ANT su dominirali u svim uzorcima višanja, svježim i zamrznutim (321,90 - 774,61 mg/100 g st), a u najvećim masenim udjelima određen je cijanidin-3-glukozilrutinozid (CYGR) (223,22-501,04 mg/100 g st). Maseni udjeli drugih polifenolnih spojeva: HCA (40,72–86.28 mg/100 g st), FG (22,34–41,03 mg/100 g st) i FLAV (0,16–0,59 mg/100 g st) bili su znatno niži u odnosu na ANT. Glavni spojevi iz skupine HCA bili su p-kumarinska i neoklorogenska kiselina, iz skupine FG kvercetin-3-glukozid te iz skupine FLAV katehin. Statistička analiza pokazala je da su se svi uzorci višanja značajno razlikovali prema masenom udjelu ANT, HCA, FG, FLAV i AOC (p ≤ 0, 01). Ekotip Recta i zadarsko uzgojno područje su općenito imali veći maseni udio fenolnih spojeva. Skladištenje zamrznutih plodova višnje pri temperaturi od -18 °C tijekom 6 mjeseci uzrokovalo je smanjenje gotovo svih skupina fenolnih spojeva, naročito ANT (16 - 30 %) i HCA (26-36 %) dok je uočena bolja stabilnost FG (10.5 – 20 %) te veće varijacije u masenom udjelu FLAV. Za određivanje AOC korištene su tri metode (DPPH, FRAP, ABTS), a AOC je iznosila kako slijedi: DPPH (3,28- 6,38 mmol TE/100 g st); FRAP (7,18-18 mmol TE/100 g st) te ABTS (73,16-119,93 mmol TE/100 g st). Viši AOC određen je u uzorcima ekotipa Brač 2/Zadar.

Stability of bioactive compounds (phenols and carotenoids) during drying process and the antioxidant capacities of two different coloured carrot varieties (domestic yellow and conventional purple carrot) were examined. Sliced carrots were dehydrated either by using conventional or freeze drying process. In fresh and dried samples total phenolic content was determined by the Folin-Ciocalteu method and antioxidant capacity according to the DPPH radical scavenging method. Four types of carotenoids were determined by the use of HPLC methods. Purple carrot contained 5.9 fold total phenols (1235 mg GAE /100 g d.w.) than domestic yellow carrot and remarkable higher antioxidant capacity (4155 µmol in purple and 213 µmol TE/100 g d.w. in yellow).The most common carotenoid was lutein in amount of 6.18 mg in purple and 4.00 mg/100 g d.w. in yellow carrot. Yellow carrot contained slightly more β-carotene (2.60 mg/100 g d.w.). Lycopene was not detected and α-carotene was detected only in freeze dried sample of purple carrot. Drying process did not affect remarkable on antioxidant capacity and on total phenolic content, but the amount of carotenoids decreased remarkably in conventionally dried yellow carrot sample. This study highlights purple carrot as a rich source of polyphenol with very high antioxidant capacity. Dried carrots, especially purple carrot, could presents very valuable source of health-promoting compounds in diet.

The aim of this study was to evaluate the polyphenolic content and antioxidant capacity of three wild fruits, cornelian cherry (Cornus mass L.), blackthorn (Prunus spinosa L) and elderberry (Sambucus nigra L) grown at different regions in Croatia. The polyphenolic content was evaluated by high performance liquid chromatography and antioxidant capacity was measured using 2, 2-diphenylpicrylhydrazyl methods. Among the studied fruits cornelian cherries and especially elderberries showed to be the most important sources of anthocyanins (750.45-1118.82 and 5012.07-7113.24 mg/kg fresh weight (fw), respectively), whereas the lowest anthocyanin content was found in the blackthorn fruit. Obtained results indicated that cyanidin-3-sambubioside (approximately 88 %) has the highest contribution to the anthocyanin content in elderberries and pelargonidin-3-galactoside (approximately 65 %) in cornelian cherries. In elderberries, flavonols quercetin-3-glucoside (136.54 mg/kg fw) and quercetin-3-xyloside (98.17-129.26 mg/kg fw) were found in remarkable quantities, while regarding phenolic acids, ferulic (67.05-88.45 mg/kg) and gallic acid (68.20-80.08 mg/kg fw) were determined in appreciably amounts. In blackthorn, neochlorogenic acid (420.5-735 mg/kg fw), flavan-3-ols (312.08-645 mg/kg fw) and quercetin-3-rutinoside (89.54-168.11 mg/kg fw) were the predominant components. The most abundant phenolic acid in cornelian cherry is vanillic acid (111.20-182.32 mg/kg fw), whereas in elderberry the phenolic acids are not present in remarkable content (total amount of neochlorogenic, caffeic, p-coumaric, ferulic and gallic acid is 272.30 mg/kg f.w.). The results showed significant antioxidant capacity and linear correlation was observed between the antioxidant capacity, anthocyanins and especially flavonols concentrations for all researched fruit. Growing area significantly affected the anthocyanins and flavonol concentration (p≤0.05), whereas the significant influence on phenolic acid concentrations was not found. The results of this study indicated that cornelian cherry, elderberry and blackthorn are good sources of natural antioxidants (bioactive polyphenols) which might exert beneficial health effects.