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Dictyota dichotoma is a brown alga found in rocky littoral and sublittoral zones from the Atlantic to the western Indian Ocean. Thyme (Thymus vulgaris L.) is a Mediterranean herb that belongs to the Lamiaceae family and is known in folk medicine for its various health-promoting properties. Both D. dichotoma and T. vulgaris contain a variety of biologically active compounds, which include pigments. Pigments, especially chlorophylls and carotenoids, have been the subject of numerous studies due to their potential and utilization for commercial and industrial purposes. They are well known for their industrial applications as food colorants and antioxidants, and have beneficial effects on human health. In order to increase extraction efficiency and to eliminate degradation of the target compounds, novel extraction techniques such as Microwave-assisted extraction (MAE)have been employed. The type of the solvent and the ratio of material in the extraction mixture are important parameters for obtaining higher concentrations of pigments. In this study, MAE was used to isolate pigments from D. dichotoma and leaves of T. vulgaris. The content of ethanol in the aqueous mixture (30, 50, 70 and 96%) and sample:solvent ratio (1:10, 1:20 and 1:30) were varied, while other extraction parameters (temperature 60 °C ; microwave power 800 W ; irradiation time 10 min) were kept constant. The content of chlorophylls, carotenoids and total pigments in the extracts was determined spectrophotometrically. Both sources of variation studied had a significant effect on all evaluated pigments. The highest levels of chlorophylls (3.33 mg/g), carotenoids (1.12 mg/g) and total pigments (4.45 mg/g) in the algal extract were obtained using 96% ethanol and a ratio of 1:30. The same conditions were equally effective for thyme extract, where the highest content of total pigments and chlorophylls was 0.46 and 0.40 mg/g, respectively. However, the highest content of carotenoids (0.06 mg/g) in thyme extract was obtained using 30% ethanol and a ratio of 1:30. Algae contained more pigments when compared to thyme, making them an important subject of future research on pigments isolation. The results of this study also confirm the importance of developing optimal isolation conditions that lead to the most effective recovery of pigments.

Essential oils are volatile mixtures of compounds with characteristic flavor obtained from plant material. One of the plants rich in essential oil is fennel (Foeniculum vulgare Mill.). It is a perennial plant with a pleasant and aromatic odor, whose seeds are rich in essential oil (5-6%). Since the essential oil of fennel seeds has antimicrobial and antioxidant properties, nowadays there is a growing interest in its use in the food and pharmaceutical industries. However, its high volatility and susceptibility to oxidation in the presence of moisture, light and oxygen limit its use. Thus, encapsulation represents a suitable method to prolong the stability of essential oils and preserve their functional properties. One of the most commonly used encapsulation methods is spray drying, in which the suspension is dried in a stream of hot air with the addition of a suitable carrier to form stable powder in which flavor and aroma are preserved. Therefore, the aim of this research was to investigate the impact of temperature (120, 160 and 200 °C) and ratio of maltodextrin and β-cyclodextrin carriers (1:1, 3:1 and 1:3) on process yield, oil retention and encapsulation efficiency, and to determine the optimal conditions for producing powders with the best properties. The spray drying yield of fennel essential oil powder ranged from 60.89- 74.51%, oil retention ranged from 27.40-57.66%, and encapsulation efficiency ranged from 18.99- 42.96%. An increase in temperature increased the values of all three observed parameters, and an increase in maltodextrin content led to an increase in oil retention and encapsulation efficiency. However, the yield was highest at a higher β-cyclodextrin content. The optimal conditions for the production of powders with the best properties were a drying temperature of 200°C and a ratio of maltodextrin and β-cyclodextrin of 3:1. The application of the spray drying process for fennel essential oil encapsulation proved to be effective in producing powders with desirable properties.

The synthesis of silver nanoparticles (AgNPs) is an important area of research in nanotechnology due to their unusual size- and shape-dependent properties, strong antimicrobial activity and their attractive applications in medicine catalysis optoelectronics, and biotechnology. Various methods can be used for the synthesis of AgNPs such as the sol-gel method, chemical vapour deposition, or thermal decomposition, but these methods are often expensive and employ toxic chemicals. To overcome these drawbacks, biosynthetic approaches using water extracts from different organisms, including fungi, plants and algae, have recently emerged as simple and viable substitutes because they are simple, cheap, and environmentally friendly. Marine macroalgae or seaweeds, such as Fucus virsoides and Cystoseira barbata, are an abundant source of secondary metabolites such as polyphenols, polysaccharides, carotenoids, vitamins, minerals, amino acids, and proteins. Their aqueous extract can act as an efficient metal reducing agent as well as a capping agent to provide excellent stability to the formed nanoparticles. UV-visible spectroscopy is a very useful and reliable technique for the primary characterization of synthesized nanoparticles because the conducting electrons in the outer orbital of AgNPs resonate with specific wavelengths. Reduction of silver nitrate to AgNPs is confirmed with a peak in the range from 335 nm to 560 nm, while the absence of peaks indicates the absence of NP aggregation. In the present study, the water extracts of F. virsoides and C. barbata were used to prepare AgNPs by reducing Ag+ ions from a 1 mM silver nitrate solution to Ag0. Nanoparticle formation was confirmed by UV/Vis spectroscopy, with peaks detected at 380 nm for both algae. The antimicrobial activity of the synthesised nanoparticles against Bacillus subtilis, Pseudomonas aeruginosa Staphylococcus aureus, Salmonella thyphimunum, Enterococcus faecalis, Escherichia coli and Listera monocytogenes was investigated and compared with the antioxidant activity of the seaweed extracts.

Berries are a variety of small fruits characterized by their red, purple or blue color. Their production reaches an amount of over 12.2 million tons worldwide. Berries can be consumed raw or processed into various products. During processing, a large amount of by-products is generated, mainly pomace which contains stem cells, skins and seeds. However, these byproducts are still a rich source of bioactive, highly valuable compounds, such as phenolic compounds. Among phenolic compounds, berries are abundant with phenolic acids, anthocyanins, proanthocyanidins, and other flavonoids that have potential health-promoting effects. Conventional extraction (CE) of polyphenols has many disadvantages, such as long extraction time, high solvent and energy consumption, and usually results in lower yield. To overcome these drawbacks, advanced extraction methods such as microwave-assisted extraction (MAE), ultrasound-assisted extraction, or pressurised liquid extraction are frequently applied. The aim of this study was to extract polyphenols from the seeds of black currant (Ribes nigrum), red currant (Ribes rubrum), strawberry (Fragaria ananassa), black chokeberry (Aronia melanocarpa), and cranberry (Vaccinium macrocarpon), as well as from the pomace of black chokeberry, black currant, and red currant using MAE and CE. Both extraction methods were performed with water at 80°C for 10 minutes, MAE at 400 W and CE in a shaking water bath. UPLC-MS2 analysis of polyphenols was conducted and antioxidant capacity was measured by ORAC method. In general, MAE resulted in higher total phenolic content and extracts with higher ORAC values, confirming its superiority compared to CE. Strawberry and cranberry seeds had lower total phenolic content and antioxidant capacity, 200 while black chokeberry was the most abundant with polyphenols. The polyphenolic profile varied among species and differed between pomace and seeds. Pomaces were especially rich in anthocyanins. Phenolic acids were represented by hydroxycinnamic acids (e.g., ferulic acid, caffeic acid, p-coumaric acid), particularly in black currant and chokeberries, and hydrobenzoic acids (e.g., gallic acid, p- hydroxybenzoic acid, and ellagic acid) which were predominant in strawberry seed.

Fennel (Foeniculum vulgare Mill.) is a perennial aromatic and medicinal plant belonging to the Apiaceae family. It originates from the Mediterranean area, but it has spread worldwide through naturalization and cultivation. The use of fennel in culinary purposes and traditional medicine is known from ancient times, but nowadays its application has been extended to the pharmaceutical, cosmetic and food industries. Although different parts of fennel (leaves, young shoots, roots and seeds) can be utilized, fennel seeds are mostly exploited due to their abundance of essential oil (up to 5-6%) which is characterized by a strong and pleasant aroma. Fennel essential oil has been recognized to possess antimicrobial, antifungal and antioxidant properties, therefore it is widely used in various areas. The chemical composition of fennel essential oil showed up to 80 volatile compounds, among which trans-anethole, fenchone and estragole are major compounds, being the key compounds of the characteristic fennel flavor. Besides these compounds, the presence of other compounds such as α- and β-pinene, myrcene, α-phellandrene, limonene and p-anisaldehyde have also been reported. The isolation of essential oil can be accomplished by various extraction techniques, such as hydrodistillation (HD) and steam distillation (SD) which are known as conventional ones and still are the most common in use. They are effective for the extraction of essential oils from spices and herbs from which such oils are difficult to isolate and they do not include the use of chemical solvents. On the other hand, their main drawbacks are long duration, difficult regulation of heat and possible loss of thermolabile and light volatiles. Therefore, in order to overcome these deficiencies, advanced extraction techniques have been developed, including microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE), ultrasound-assisted extraction (UAE), subcritical water extraction (SWE) and supercritical fluids extraction (SFE), namely extraction with supercritical carbon dioxide (SC-CO2) which is considered “green” showing the most promising beneficial effects due to being sustainable, environmentally friendly and cost-effective. However, regardless of the selected extraction technique, it is necessary to define optimal process conditions taking into account all process parameters in accordance with the raw material used, and optimize the extraction process with the intention to achieve the maximum yield of essential oil of the best quality and unaltered composition.

This study aimed to investigate the effect of treatment with laurel (Laurus nobilis) essential oil (LEO) on the shelf life of fresh-cut potatoes (FCP). Peeled and sliced potatoes were dipped in the aqueous solution of different LEO concentrations (25, 125 and 250 mg/L) and water (control) for 15 minutes, then drained, vacuum packed and stored at 7 ᵒC for 14 days. The CIELAB color parameters and aerobic mesophilic bacteria count (AMBC) of the raw FCP and the sensory characteristics of the raw, cooked and fried samples were determined. With the increase of LEO concentration, AMBC decreased and, in general, this trend persisted during storage. Slight negative changes in color were observed with storage time. The characteristics of laurel flavor and odor in raw and cooked potatoes increased with the increase of LEO, while LEO aroma was not pronounced after frying. Despite the antibacterial activity of LEO, spoilage of FCP was not prevented during storage, as AMBC increased in all samples after 6 days of storage. However, in the samples treated with LEO, this AMBC increase was slightly pronounced in a dose-dependent manner. FCP treated with 125 and 250 mg/L LEO, after 6 days of storage, showed the best results in terms of absence of browning and off-odour of raw and off- taste and sour taste of cooked and fried FCP.

In recent times, increasing evidence has demonstrated that polyphenols, secondary plant metabolites, can be utilized by the gut microbiota which results in promising effects in the prevention and treatment of various diseases such as diabetes, obesity, autoimmune diseases, inflammatory bowel disease, colorectal cancer and other. Laurus nobilis L. is an evergreen Mediterranean shrub whose leaves have traditionally been used in folk medicine due to their beneficial health effects that can largely be attributed to the presence of polyphenols which include flavonoids, phenolic acids, tannins and lignans. Since polyphenols are unstable which limits their biological activities and aggravates the process of studying their association with gut microbiota, encapsulation technologies focused on protection against unfavorable conditions in the stomach are emerging. Microencapsulation by spray- drying is the most commonly used method for encapsulating bioactive molecules in which the liquid extract with the dissolved carrier is passed through a stream of hot air during which the solvent evaporates and a powder with bioactive molecules encapsulated in the protective coating of the carrier is formed. In the present study, hydroalcoholic (70% ethanol) extract of L. nobilis leaf polyphenols was encapsulated by spray-drying on Büchi Mini Spray-Dryer B-290 at 180°C using three different carriers (β-cyclodextrin ; β- cyclodextrin:maltodextrin (50:50) ; β- cyclodextrin:gum arabic (50:50)) at a ratio 1:2 (extract dry matter:carrier). The obtained powders were subjected to in-vitro simulated digestion and three phases (gastric, absorbed and intestinal) were analyzed by Folin-Ciocalteu spectrophotometric method for total phenolic content (TPC). The TPC in the intestinal phase, which is considered as bioavailable for the gut microbiota, ranged from 46.9–54.5% compared to the TPC in initial powders prior to digestion. β- cyclodextrin:maltodextrin (50:50) resulted in highest, and β-cyclodextrin:gum arabic in lowest bioavailability. The integrity of individual polyphenols present in the intestinal phase was confirmed by ultra-high performace liquid chromatography tandem mass spectrometry (UPLC/MS- MS).

In recent years, silver nanoparticles (AgNPs) have gained interest in the research community due to their unique physico-chemical and biological properties which allow for their strong antimicrobial activity against a variety of bacteria, viruses and fungi. Various methods such as sol-gel method, chemical vapour deposition or thermal decomposition can be applied for the synthesis of AgNPs. however they often include the use of toxic chemicals. Therefore, biogenic synthesis using plant extracts has emerged as an environmentaly friendly method where different bioactive molecules Oxidize the Ag+ to Ag0, leading to the formation of nanoparticles. Medicinal plants such as nettle (Urtica dioica L), myrtle (Myrtus communis L) and bay laurel (Laurus nobilis L) contain a variety of bioactive molecules such as phenolic compounds, organic acids, tocopherols and terpenoids which give them potential for use in the green synthesis of AgNPs. The synthetized nanoparticles are most often monitored by UV-visible spectroscopy since the conducting electrones in the outer orbital of AgNPs oscillate in resonance with certain wavelengths. The peaks in the area near 335-560 nm generally confirm the reduction of silver nitrate into AgNPs, while the absence of peaks indicates the absence of NP aggregation. In the present research, nettle, myrtle and bay laurel leaf water extracts were used to prepare silver nanoparticles by reducing the Ag+ ions from a 1 mM silver nitrate solution to Ag0. The formation of nanoparticles was confirmed by UV/Vis spectroscopy where peaks were detected at 320 nm, 400 nm and 480 nm for nettle, myrtle and bay laurel extracts, respectively. Antimicrobial activity of the synthetized nanoparticles against Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella thyphimurium, Enterococcus faecalis, Escherichia coli and Listeria monocytogenes was investigated and compared to the antimicrobial activity of the plant extracts.

Both nettle and fennel are valuable plants with high content of bioactive molecules. Beneficial effects of nettle are mainly attributed to polyphenols, while fennel is recognized for its essential oil (EO) content. Although chemically different, both nettle extract and fennel EO are characterized with loss of stability and bioactivity during prolonged storage and processing. Spray drying, as a method for encapsulation of both hydrophilic and lipophilic compounds, can provide stabilization, preservation as well as controlled release and delivery of both nettle bioactives and fennel EO. Therefore, the aim of this study was to evaluate and optimize the spray drying encapsulation of nettle leaves extract and fennel EO using different carrier materials and drying temperatures. Nettle leaves extract was obtained by microwave-assisted extraction and encapsulated using maltodextrin (MD) and β-cyclodextrin (CD) as single carriers or in mixtures with gum arabic (GA) in proportion 1:1 and 3:1, respectively. Carriers were used in sample:carrier ratios 1:1, 1:2 and 1:3, while spray drying was performed at 120, 160 and 200 °C. Fennel EO was spray dried at same temperatures and emulsified with following carrier mixtures, MD:CD, MD:GA and CD:GA in proportions 1:1, 1:3 and 3:1 at fixed EO:carrier ratio of 1:3. The highest yield and encapsulation capacity for nettle leaves extract was achieved with addition of MD as a carrier agent in ratio 1:3 at 120 °C, while optimal encapsulation conditions for fennel EO were mixture of CD:GA in proportion 3:1 at 200 °C which resulted in the highest EO retention in microcapsules and the highest encapsulation efficiency. The differences in obtained encapsulation conditions arise from the differences in chemical properties of encapsulated materials, showing that carrier agents such as CD and GA are suitable for non-polar constituents of EO, while MD is more efficient in encapsulation of polar compounds such as polyphenols. The encapsulation of nettle extract and fennel EO provided preservation and stabilization of respective bioactive compounds and increased their bioavailability in encapsulated form, indicating the great potential of such microcapsules for further application in food industry.

Thyme (Thymus vulgaris L.) is a Mediterranean herb belonging to the Lamiaceae family well known in the folk medicine for its various health beneficial properties. These properties can be attributed to the high content of biologically active molecules, such as polyphenols. In recent years, the growing demand on functional products enriched with naturally derived polyphenols has brought the need for more sustainable isolation technologies that would allow for their fast and effective isolation. Microwave-assisted extraction has emerged as a green extraction technology due to its main advantage of reducing the extraction time and solvent consumption while achieving higher extraction efficiency and lower degradation of targeted compounds compared to conventional extraction techniques. In the present study, the influence of different microwave-assisted extraction parameters on the isolation efficiency of Thymus vulgaris L. leaf polyphenols was examined in two phases. In the first phase, different percentages of aqueous ethanol (0, 30, 50, 70 and 96%) and sample:solvent ratios (1:10, 1:20 and 1:30) were varied while other extraction parameters (temperature 60°C ; microwave power 800W ; irradiation time 10 min) were kept constant. The total phenolic content (TPC) of the extracts was determined by Folin-Ciocalteu spectrophotometric method. Both ethanol percentage and sample:solvent ratio have shown significant influence on the TPC of the Thymus vulgaris L. leaf extracts, and the highest TPC (10.59 mg GAE/g leaf) was achieved when 30% ethanol and a ratio of 1:20 were applied. In the second research phase, the ethanol percentage and sample:solvent ratio were kept constant (30% ethanol and 1:20), while the temperature (40, 60 and 80°C) and irradiation time (5, 10 and 15 min) were varied. The results of Folin-Ciocalteu analysis showed that temperature had a significant influence on the TPC of the Thymus vulgaris L. leaf extracts, while the influence of irradiation time was not significant. The highest TPC (11.99 mg GAE/g leaf) was achieved at 60°C after 5 min of irradiation. The results showed how different parameters of microwave-assisted extraction influence the TPC of Thymus vulgaris L. extracts, proving the importance of establishing optimal isolation methodologies that would result in the highest recovery effectiveness and utilization of the plants’ beneficial properties.

Komorač (Foeniculum vulgare Mill.) je višegodišnja, ljekovita i aromatična biljka koja pripada obitelji štitarki (lat. Apiaceae). Od davnina se koristi u narodnoj medicini i kulinarstvu, a danas se sve više koristi u farmaceutskoj, kozmetičkoj i prehrambenoj industriji. Sjemenke komorača obiluju eteričnim uljem (5-6%) koje karakterizira bogata aroma te je značajno zbog svojih antimikrobnih i antioksidativnih svojstava [1]. Međutim, visoka hlapljivost eteričnog ulja i podložnost oksidaciji u prisutnosti svjetlosti, zraka i vlage te nestabilnost tijekom prerade ograničava njegovu upotrebu u industriji. Slijedom navedenog, inkapsulacija sušenjem raspršivanjem predstavlja pogodnu metodu za produljenje stabilnosti eteričnih ulja i zadržavanje njihovih funkcionalnih svojstava tijekom manipulacije, obrade i skladištenja. Stoga je cilj ovog rada bio ispitati utjecaj omjera dvokomponentne kombinacije nosača maltodekstrina i arapske gume (1:1, 1:3 i 3:1) te temperature sušenja (120, 160 i 200 °C) na iskorištenje procesa, zadržavanje ulja i učinkovitost inkapsulacije. Porastom udjela arapske gume dolazi do povećanja vrijednosti sva tri promatrana parametra, dok porast temperature do 160 °C dovodi do povećanja zadržavanja i učinkovitosti. Daljnjim porastom temperature dolazi do povećanja iskorištenja. Optimalni uvjeti za učinkovitu inkapsulaciju eteričnog ulja iz sjemenki komorača su omjer maltodekstrina i arapske gume 1:3 te temperatura sušenja 160 °C.

Recently, various techniques have been developed for encapsulating bioactive compounds to convert them into a more stable form. One of them is electrostatic extrusion, which is highly recommended for hydrophobic bioactive compounds such as essential oils (EOs). Among the various polymers, alginate is most commonly used as a core material. This is a naturally occurring polysaccharide found in brown algae and is characterized by high viscosity, gelling properties, high stability, low cost and non-toxicity. Sage (Salvia officinalis L.) is a perennial aromatic and medicinal plant of the Lamiaceae family. In addition to various phytochemicals, it also contains EOs which are found to have antioxidant, antimicrobial, antifungal, insecticidal and antiproliferative properties. Therefore, this study investigated the development of alginate-based beads containing sage EO prepared by electrostatic extrusion. For the preparation of beads, the content of alginate (0.5, 1 and 1.5%, w/v) and calcium chloride (CaCl2) (3 and 5%, w/v) was varied. Alginic acid sodium salt (low viscosity), previously dissolved in distilled water, sage EO (5%, w/v) and Tween 20 (0.5%, w/v) were homogenized at 10 000 rpm for 4 min. Beads were prepared with Büchi encapsulator B-390 (Flawil Switzerland) using a 1 mm stainless steel needle at a frequency of 80 Hz, a pressure of 1000 mbar, an amplitude of 6 and an electrostatic potential of 500 V. After collection in CaCl2 solution, the beads were washed in distilled water, drained and used for further analysis. Encapsulation yield (%) was expressed as the ratio between the amount of beads obtained and the amount of emulsion used for the encapsulation. The size of the beads was measured using a micrometer screw gauge and the average dmax, dmin and sphericity factor (SF) were calculated. All analyzed parameters were significantly affected by alginate and CaCl2 content, except for SF (Table 1). The highest encapsulation yield and bead size were obtained at the highest concentrations of alginate and CaCl2. In addition, the beads generally maintained their roundness. Although not significant, most spherical beads were produced with 1.5% alginate, while a lower CaCl2 content resulted in slightly elongated shape of the beads.

In recent years, a growing demand on functional products enriched with naturally derived ingredients has raised interest in finding new sources of bioactive molecules as well as establishing optimal isolation technologies that would allow their fast and efficient isolation. Various green extraction technologies, such as ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) and pressurized liquid extraction (PLE) have emerged due to their main advantages of reducing the extraction time, energy and solvent consumption while achieving higher extraction efficiency and lower degradation of targeted compounds compared to conventional extraction techniques. Carob tree (Ceratonia siliqua L.) is a Mediterranean plant belonging to the Fabiaceae family which has recently drawn attention due to the nutritional value of its pods, while other plant parts, such as leaves, have been researched to a lesser extent. Since the health beneficial properties of polyphenols are well known, the aim of this research was to evaluate carob leaves grown in south Croatia as a source of polyphenols by analyzing the phenolic content and antioxidant activity of carob leaf extracts obtained by three different green extraction techniques (UAE, MAE and PLE). The extractions were carried out on a sample of grinded dry carob leaves for 10 min at a temperature of 80°C, sample: solvent ratio 1:20 and 50% aqueous ethanol as a solvent. The frequency in UAE was 37 kHz, microwave power in MAE 500 W and PLE was set to 1 static cycle. The total phenolic content (TPC), hydroxycinnamic acids content (HAC) and flavonol content (FC) were determined by spectrophotometric methods, while the antioxidant activity was determined by DPPH Radical Scavenging and Ferric Reducing Antioxidant Power (FRAP) assays. It was shown that carob leaves can be considered a source of phenolic compounds since the TPC was in the range of 51.86–64.81 mg gallic acid equivalents (GAE) g-1 . The extracts have also shown high antioxidant activity with values of 25, 10–28, 90 mM Trolox equivalent (TE) g-1 and 22, 92– 51, 23 mM TE g-1 as determined by DPPH and FRAP, respectively. The extraction techniques have significantly influenced all of the examined parameters and MAE was shown to be the most suitable for achieving maximum TPC, HAC, FC and antioxidant activity as determined by DPPH. The results highlight the importance of research of different extraction techniques that would allow the highest recovery effectiveness and utilization of the plants’ beneficial properties.

Sea buckthorn (Hippophae rhamnoides L.) is a valuable and unique plant, rich in various bioactive compounds contained in the different parts of the plant, especially in the fruits and leaves. Due to its great potential, the scientific community is showing a great interest in this plant, and numerous studies have reported beneficial health effects, such as antioxidant, anticancer, antiinflammatory, etc. Compounds of interest can be isolated by various extraction methods, either conventional or advanced, however it is of great importance to optimize the process conditions to obtain maximum yield of target compounds. Therefore, this study examined the influence of temperature (80, 100, and 120 °C), static extraction time (5, 10, and 15 min) and number of extraction cycles (1, 2, and 3) during the pressurized liquid extraction (PLE) of phenols from freeze-dried sea buckthorn leaves using an aqueous ethanol solution (70%) as extraction solvent. The extracts obtained were analyzed spectrophotometrically for the content of total phenols (TPC) using the Folin-Ciacolteau method, while the FRAP method was used to determine antioxidant capacity (AC). All results were statistically analyzed by multifactorial analysis of variance and Tukey's HSD test. The TPC was determined in a range of 69.05-112.96 mg GAE g-1 of dry matter (DM) and the values of AC ranged from 766.72-1182.02 µmol TE g-1 DM. Statistical analysis showed a significant influence of all tested PLE parameters on the TPC as well as on the AC of the extracts. The highest TPC were measured in extracts obtained at the highest temperature and cycle number, while there was no significant difference in the TPC extracted during a static extraction time of 10 or 15 min. On the other hand, the AC values of the extracts were highest at the highest level of all three PLE parameters tested. In conclusion, PLE using 70% ethanol showed to be an effective method for the successful extraction of phenols from sea buckthorn leaves, where PLE conditions of 120 °C/10 min/3 cycles provided the highest TPC, while the highest value of AC was obtained at 120 °C/15 min/3 cycles.

Dictyota dichotoma is a species of brown algae found in rocky littoral and sublittoral zones in a wide range of habitats, from the Atlantic Ocean and the Mediterranean Sea, to the western Indian Ocean. Research has shown that Dictyota dichotoma contains a variety of chemical compounds, including pigments, phenols, flavonoids, alkaloids, steroids, tannins, coumarins, quinones, and glycosides. The presence of these biologically active molecules, especially polyphenols, is often associated with numerous health-promoting properties, which is why they are frequently used to fortify functional foods. Microwave-assisted extraction (MAE) is one of the more sustainable isolation techniques that enable rapid and more effective isolation of these substances. In this study, MAE was applied to isolate Dictyota dichotoma polyphenols in two research phases. In the first phase, the influence of different percentages of aqueous ethanol (0, 30, 50, 70, and 96%) and sample-to- solvent ratio (1:10, 1:20, and 1:30) were investigated, while temperature (60°C), irradiation time (10 min), and microwave power (800W) were kept constant. The total phenolic content (TPC) of the extracts was determined by the Folin-Ciocalteu spectrophotometric method. The choice of solvent and sample-to-solvent ratio showed significant influence on Dictyota dichotoma TPC, and the highest TPC (6.42 mg GAE g-1) was achieved when 30% ethanol and a ratio of 1:60 were applied. In the second phase of the research, temperature (40, 60, and 80°C) and irradiation time (5, 10, and 15 min) were varied, while the ethanol content (30%) and sample-to-solvent ratio (1:60) were kept constant. The results of the statistical analysis showed that temperature had a significant influence (p£0.05) on Dictyota dichotoma TPC, while the influence of irradiation time was not significant (p³0.05). The highest TPC (3.33 mg GAE g-1) was achieved at 40°C after 5 min of irradiation. The results of this study showed the influence of various MAE parameters on Dictyota dichotoma TPC and confirmed the importance of developing optimal isolation method that can lead to the most effective polyphenol recovery.

Since bioactive molecules are extremely sensitive to a number of external factors and are often unstable, they must be protected and stabilized by encapsulation methods such as spray drying and electrostatic extrusion. Myrtle (Myrtus communis L.) has long been known for its beneficial therapeutic effects on disorders of various organic systems. Its essential oil is obtained by distillation of the leaves and contains various terpenoids, with 1, 8-cineole, myrtenyl acetate, and α-pinene predominating. Alginates isolated from brown seaweed are often used as carriers for encapsulation due to their gel forming property in the presence of divalent cations such as calcium where alginate solution containing bioactive compounds is first dispersed into small droplets and then solidified by gelation. Therefore, the aim of this study was to investigate the possibility of stabilization of myrtle essential oil by the formation of brown algae alginate beads. Myrtle essential oil beads were prepared by electrostatic extrusion encapsulation and the effect of the concentrations of sodium alginate as carrier (0.5, 1 and 1.5%) and calcium chloride as recipient (3 i 5%) on the yield and physical properties of the beads was studied. Myrtle essential oil (5%) was added to sodium alginate solutions together with 0.5% Tween 20 as emulsifier and homogenized with a mechanical stirrer at 10, 000 rpm for 4 min. Droplets were formed by extrusion on Büchi encapsulator by applying electrostatic potential of 500 V, frequency 80 Hz with 1 mm needle tip. Yield (Figure 1) was calculated as percentage of wet beads weight and showed significant differences between formulations. The lowest yields were obtained for the samples with the lowest concentration of Na-alginate (0.5%). For both CaCl2 concentrations an increase in encapsulation yield was observed with increasing Na-alginate concentration with the highest value determined in the sample prepared with 3% CaCl2 solution. Largest beads (Table 1) were produced with 1.5% alginate and 5% CaCl3 while 3% CaCl3 caused less variation between samples. Sphericity improved greatly with the addition of higher levels of Na-alginate.

Fennel (Foeniculum vulgare Mill.) is a ubiquitous member of the Apiaceae family whose fruits (seeds) are used extensively as flavoring agents in food, cosmetic and pharmaceutical products. Fennel seeds are rich in essential oils (EO), the content and composition of which may vary according to geographical origin. Therefore, this study aimed to evaluate EO variation in wild fennel seeds collected from five natural habitats located in Istria region (Croatia): Poreč, Pula, Plomin, Raša and Vodnjan. For this purpose, dry mature fennel seeds were subjected to hydrodistillation and the obtained EO were evaluated by GC-MS analysis. All obtained results were statistically analyzed. The samples differed significantly according to the EO yield, which ranged from 4.90 (Plomin) to 6.30% (Pula). A total of 20 volatiles were identified and quantified: α-pinene, camphene, sabinene, β-pinene, myrcene, α-phellandrene, α-terpinene, p-cymene, D-limonene, eucalyptol, γ-terpinene, cis-sabinene hydrate, L-fenchone, linalool, camphor, α-terpineol, estragole, carvone, p-anisaldehyde and trans-anethole. Despite significant differences among samples, phenylpropanoids dominated in all samples (71.33-77.31%), followed by oxygenated monoterpenes (14.40-18.32%) and monoterpene hydrocarbons (7.48-12.02%). Trans-anethole (15.57-70.94%), estragole (6.18-55.89%) and L-fenchone (11.60-16.85%) were the major constituents, while α-pinene, myrcene and D-limonene were present in lower but noticeable amounts (1.85-3.78, 1.66-2.63 and 1.04-1.57%, respectively).

The aim of this study was to investigate the effect of fennel essential oil (FEO) treatment on the shelf-life of fresh-cut potatoes (FCP). Peeled and sliced potatoes were immersed in the aqueous solution of various FEO levels (25, 125 and 250 mg/L) and water (control) for 15 minutes, subsequentely drained, packaged in vacuum and stored at 8 °C for 12 days. The CIELAB color parameters and aerobic mesophilic bacteria count (AMBC) of the raw FCP and sensory properties of the raw, boiled and fried samples were determined. AMBC decreased with increasing FEO level and generally this trend remained during storage. Slight negative changes in color were observed with increase of FEO content and with storage duration. The attributes of fennel taste and odor in raw and boiled potatoes increased with the increase of FEO, while FEO aroma was not pronounced after frying. Despite the antibacterial activity of FEO, spoilage of FCP was not prevented during storage. In general, after 6 days, the best results were obtained in terms of the absence of browning and off-odor of raw and off-taste and sour taste of boiled and fried FCP with 25 mg/L FEO treatment.

Trnina (Prunus spinosa L.) je divlja biljka čiji gotovo svi dijelovi pokazuju ljekovita svojstva te su bogat izvor antioksidativnih fenolnih spojeva. Cvijet trnine je još uvijek nedovoljno istražen, a ima velik potencijal za proizvodnju biljnih ekstrakata, prahova i sl.. Stoga je cilj ovog rada bio je ispitati kako odabrani uvjeti sušenja raspršivanjem (temperatura od 120-200 °C, omjer nosača i suhe tvari ekstrakta od 0,70-2,00 i udio nosača arapske gume u iznosu od 0,20-0,80) utječu na fizikalno-kemijska svojstva (iskorištenje, topljivost, sadržaj vlage, nasipnu gustoću, veličinu čestica) praha ekstrakta cvijeta trnine te odrediti optimalne uvjete za proizvodnju praha najboljih svojstava. Općenito, povećanjem temperature i udjela nosača u procesu sušenja raspršivanjem, iskorištenje se povećava, sadržaj vlage smanjuje, topljivost, nasipna gustoća i veličina čestica rastu. Omjer nosača i suhe tvari ekstrakta u iznosu 2,44, bez dodatka arapske gume i pri temperaturi sušenja 164,13 °C su optimalni uvjeti za proizvodnju praha najboljih osobina, kod kojih iskorištenje procesa iznosi 62,67 %, sadržaj vlage u prahu je 2,35 %, a topljivost praha je 76,84 %. Blackthorn (Prunus spinosa L.) is a wild plant in which almost all parts have healing properties and are a rich source of antioxidant phenolic compounds. The flower is still insufficiently explored and has great potential for the production of herbal extracts, powders etc.. Therefore, the aim of this study was to examine how the selected conditions of spray drying (temperature of 120 to 200 ° C, ratio of carrier agent and dry extract substance ranging from 0.70 to 2.00 and the proportion of gum Arabic in the amount from 0.20 to 0.80) influence the physicochemical properties (yield, solubility, moisture content, bulk density, particle size) of the blackthorn aqueous extract powder and also to determine optimal conditions for the production of the best quality powders. Generally, by increasing the temperature and the proportion of the carrier agent in the spray drying process, the yield increases, the moisture content decreases, while solubility, bulk density and particle size increase. The ratio of carrier agent and dry extract substance in the amount of 2.44, without the proportion of gum Arabic and at the drying temperature of 164.13 ° C are the optimal conditions for the production of the best powders, where the yield of the process is 62.67%, the moisture content of the powder is 2, 35% and the solubility of the powder is 76.84%.