Utjecaj ekstrakcije potpomognute mikrovalovima na izolaciju polifenola kadulje (Salvia officinalis L.)

In order to determine the optimal conditions for the extraction of sage polyphenols, the influence of extraction solvent (water, 30 % (by volume) aqueous ethanol and 30 % (by volume) aqueous acetone), extraction time (3, 5, 7, 9 and 11 min) and microwave power (500, 600 and 700 W) on the composition and concentration of phenolic compounds of dry wild sage (Salvia officinalis L.) during microwave-assisted extraction (MAE) was studied. Optimized MAE method was compared with conventional extraction (CE). Based on the amount of total phenols, microwave power of 500 W and extraction time of 9 min were selected as optimal extraction conditions, resulting in higher content of polyphenols when compared with CE. Ethanol and acetone solutions were equally effective extraction solvents, both producing higher extraction capacity than water. Using HPLC coupled with UV/PDA, fourteen polyphenols were identified (caffeic and rosmarinic acid derivatives, luteolin- and apigenin-glycosides) with rosmarinic acid and luteolin glycosides at the highest concentrations. The mass fractions of all individual polyphenols were higher in the MAE extracts than in the CE ones.Da bi se odredili optimalni uvjeti ekstrakcije polifenola iz kadulje, ispitan je utjecaj otapala (voda, 30 %-tna vodena otopina etanola i 30 %-tna vodena otopina acetona), vremena ekstrakcije (3, 5, 7, 9 i 11 min) i snage mikrovalova (500, 600 i 700 W) na sastav i koncentraciju fenolnih spojeva tijekom ekstrakcije potpomognute mikrovalovima (MAE). Optimirana MAE metoda je zatim uspoređena s konvencionalnom metodom ekstrakcije (CE). Na temelju količine ukupnih fenola odabrani su optimalni uvjeti snage mikrovalova od 500 W i vremena ekstrakcije od 9 min pri kojima je ekstrahirana veća količina fenolnih spojeva u usporedbi s CE. Etanol i aceton bili su podjednako učinkovita otapala s većom djelotvornošću ekstrakcije od vode. Primjenom HPLC UV/PDA identificirano je četrnaest fenolnih spojeva (derivati kafeinske i ružmarinske kiseline, glikozidi luteolina i apigenina) i to najveći udjeli ružmarinske kiseline i glikozida luteolina. Svih pojedinačnih fenolnih spojeva bilo je više u ekstraktima dobivenim MAE metodom

The Influence of Processing on Physico-chemical Parameters, Phenolics, Antioxidant Activity and Sensory Attributes of Elderberry (Sambucus nigra L.) Fruit Wine

Production of elderberry fruit wine in Croatia is very limited and primarily conducted in small family farms, so the aim of this research was to determine the quality parameters of elderberry fruit and elderberry fruit wine as the fi nal product. Six types of elderberry fruit wines (A, B, C, D, E and F) were produced with addition of different amounts of sugar (0, 0.5, 1, 1.5, 1.5 and 0.5 kg per 4 kg of elderberry fruit) and water (wines C, D, E). Quality of wines was evaluated using physico-chemical analysis, determination of phenolic compounds (total phenols, total flavonoids, hydrolised tannins and anthocyanins), antioxidant activity and sensory evaluation. According to the amount of total sugar after the fermentation, wines A, B, C and F can be considered as dry wines while wines D and E can be categorized as semi-dry wines. Total acidity in all wines was higher when compared to fresh elderberry fruit. Fresh elderberry fruit as well as wines had high concentration of phenolic compound with anthocyanins in the highest extent, although the winemaking process decreased the amount of phenolics. Both elderberry fruit and wine show high antioxidant activity and present a rich source of biologically active compounds. Consumers found the wine with high sugar amount and low acidity to be the most acceptable

The Influence of Processing on Physico-chemical Parameters, Phenolics, Antioxidant Activity and Sensory Attributes of Elderberry (Sambucus nigra L.) Fruit Wine

Production of elderberry fruit wine in Croatia is very limited and primarily conducted in small family farms, so the aim of this research was to determine the quality parameters of elderberry fruit and elderberry fruit wine as the fi nal product. Six types of elderberry fruit wines (A, B, C, D, E and F) were produced with addition of different amounts of sugar (0, 0.5, 1, 1.5, 1.5 and 0.5 kg per 4 kg of elderberry fruit) and water (wines C, D, E). Quality of wines was evaluated using physico-chemical analysis, determination of phenolic compounds (total phenols, total flavonoids, hydrolised tannins and anthocyanins), antioxidant activity and sensory evaluation. According to the amount of total sugar after the fermentation, wines A, B, C and F can be considered as dry wines while wines D and E can be categorized as semi-dry wines. Total acidity in all wines was higher when compared to fresh elderberry fruit. Fresh elderberry fruit as well as wines had high concentration of phenolic compound with anthocyanins in the highest extent, although the winemaking process decreased the amount of phenolics. Both elderberry fruit and wine show high antioxidant activity and present a rich source of biologically active compounds. Consumers found the wine with high sugar amount and low acidity to be the most acceptable

The Influence of Processing on Physico-chemical Parameters, Phenolics, Antioxidant Activity and Sensory Attributes of Elderberry (Sambucus nigra L.) Fruit Wine

Production of elderberry fruit wine in Croatia is very limited and primarily conducted in small family farms, so the aim of this research was to determine the quality parameters of elderberry fruit and elderberry fruit wine as the fi nal product. Six types of elderberry fruit wines (A, B, C, D, E and F) were produced with addition of different amounts of sugar (0, 0.5, 1, 1.5, 1.5 and 0.5 kg per 4 kg of elderberry fruit) and water (wines C, D, E). Quality of wines was evaluated using physico-chemical analysis, determination of phenolic compounds (total phenols, total flavonoids, hydrolised tannins and anthocyanins), antioxidant activity and sensory evaluation. According to the amount of total sugar after the fermentation, wines A, B, C and F can be considered as dry wines while wines D and E can be categorized as semi-dry wines. Total acidity in all wines was higher when compared to fresh elderberry fruit. Fresh elderberry fruit as well as wines had high concentration of phenolic compound with anthocyanins in the highest extent, although the winemaking process decreased the amount of phenolics. Both elderberry fruit and wine show high antioxidant activity and present a rich source of biologically active compounds. Consumers found the wine with high sugar amount and low acidity to be the most acceptable

Kinetics of the Degradation of Anthocyanins, Phenolic Acids and Flavonols During Heat Treatments of Freeze-Dried Sour Cherry Marasca Paste

Istražen je utjecaj temperature (80-120 C) i vremena (5-50 min) na stabilnost antocijana (cijanidin-3-glukozilrutinozida, cijanidin-3-rutinozida i cijanidin-3-glukozida), kvercetin-3-glukozida i fenolnih kiselina (klorogenske, neoklorogenske, p-kumarinske i ferulinske kiseline) u liofiliziranoj pasti višnje maraske. Brzina razgradnje antocijana, kvercetin-3-glukozida i fenolnih kiselina slijedila je kinetiku reakcija prvoga reda. Najnestabilniji od svih antocijana bio je cijanidin-3-glukozid, a od fenola p-kumarinska i neoklorogenska kiselina. Energije aktivacije za degradaciju antocijana kretale su se od 41,88 (za cijanidin-3-glikozilrutinozid) do 54,76 kJ/mol (za cijanidin-3-glukozid), a za degradaciju ostalih fenola od 8,12 (za klorogensku kiselinu) do 26,70 kJ/mol (za neoklorogensku kiselinu). Povećanjem temperature od 80 na 120 C povećala se konstanta brzine reakcije (k) za cijanidin-3-glukozilrutinozid s 2,15·10-2 na 8,48·10-2 min-1, za p-kumarinsku kiselinu s 1,12·10-2 na 2,49·10-2 min-1, a za kvercetin-3-glukozid s 1,47·10-2 na 2,57·10-2 min-1. Dobiveni rezultati pokazuju da je vrijeme poluraspada antocijana bilo u rasponu od 32,10 min za cijanidin-3-glukozilrutinozid do 45,69 min za cijanidin-3-rutinozid pri 80 C, a ostalih fenolnih spojeva od 43,39 min za neoklorogensku kiselinu do 66,99 min za klorogensku kiselinu. Zaključeno je da temperatura i vrijeme zagrijavanja značajnije utječu na degradaciju antocijana nego na degradaciju ostalih fenola.The effect of heating temperature (80–120 °C) and processing time (5–50 min) on the stability of anthocyanins (cyanidin-3-glucosylrutinoside, cyanidin-3-rutinoside and cyanidin- 3-glucoside), quercetin-3-glucoside and phenolic acids (chlorogenic, neochlorogenic, p-coumaric and ferulic acids) in freeze-dried Marasca sour cherry pastes was studied. The degradation rates of individual anthocyanins, quercetin-3-glucoside and phenolic acids followed the first order reaction kinetics. Cyanidin-3-glucoside was found to be the most unstable among the anthocyanins, together with p-coumaric and neochlorogenic acids among other phenols. Activation energies for anthocyanin degradation ranged from 42 (cyanidin-3-glucosylrutinoside) to 55 kJ/mol (cyanidin-3-glucoside), and for other phenols from 8.12 (chlorogenic acid) to 27 kJ/mol (neochlorogenic acid). By increasing the temperature from 80 to 120 °C, the reaction rate constant of cyanidin-3-glucosylrutinoside increased from 2.2·10–2 to 8.5·10–2 min–1, of p-coumaric acid from 1.12·10–2 to 2.5·10–2 min–1 and of quercetin-3-glucoside from 1.5·10–2 to 2.6·10–2 min–1. The obtained results demonstrate that at 80°C the half-life of anthocyanins ranges from 32.10 min for cyanidin-3-glucosylrutinoside to 45.69 min for cyanidin-3-rutinoside, and of other phenolic compounds from 43.39 for neochlorogenic acid to 66.99 min for chlorogenic acid. The results show that the heating temperature and duration affect the anthocyanins considerably more than the other phenols in terms of degradation

Mogućnosti i perspektive svježe narezanog voća i povrća na zagrebačkom tržištu

The fresh-cut fruits and vegetables (FCFV) are defined as products that have been trimmed and/or peeled and/or cut into 100% usable product that is bagged or pre-packaged to offer consumers a high nutrition, convenience and flavor while still maintaining its freshness. Fruits and vegetables (FV) are abundant with phytochemicals that indicate beneficial influence on human health when consumed frequently and as a part of daily diet. Healthy conscious consumers appreciate convenience of FCFV, but due to its extreme perishability sometimes their quality and safety may be questionable leading to its shortened shelf-life. Optimal processing as well as distribution conditions are imperative for prolonging their shelf-life. Hence, the prototype of vending machine (VM) for FCFV which could replace usual salad bars in food services and maintaining the highest hygiene criteria was constructed by funding of the BICRO-project and implemented at Faculty of Food Technology and Biotechnology University of Zagreb. In the first part of this study, performance of VM prototype in the cold storage of fresh-cut (FC) apple during 7 days was investigated and interest for FCFV by oral survey with Zagreb citizens was examined in the second part. Quality and sensory characteristics of FC apples stored in VM remained satisfactory for 4 days and microbial analysis showed that VM could provide a safe product for 7 days. Furthermore, the need for such device confirmed the tendency of consumers to choose their own FCFV combinations and purchase such products near the workplace. In general, market analysis proved increased consumers demand for FCFV.Svježe rezano (eng. fresh-cut; FC) voće ili povrće predstavlja voće ili povrće oprano, oguljeno i/ili narezano i zapakirano, u potpunosti iskoristivo, praktično te sačuvane nutritivne vrijednosti, okusa i svježine. Voće i povrće obiluje biološki aktivnim spojevima koji imaju blagotvorni učinak na zdravlje ljudi ako se konzumiraju često i svakodnevno. Zdravstveno osviješteni potrošači cijene takve proizvode zbog njihove praktičnost iako su skloni brzom kvarenju što utječe na skraćenje roka trajanja tih proizvoda. Optimalni uvjeti proizvodnje kao i uvjeti prodaje nužni su za održavanje njihove ispravnosti u predviđenom roku trajanja. U okviru BICRO-projekta koji se provodio na Prehrambeno-biotehnološkom fakultetu Sveučilišta u Zagrebu izrađen je prototip automata koji bi mogao zamijeniti serviranje FC voća i povrća na način tzv. salad-bara i osigurati najviše higijenske uvjete serviranja takve hrane. U prvom dijelu ovog istraživanja ispitan je rad prototipa sa svježe narezanom jabukom tijekom 7 dana, a u drugom dijelu provedena je usmena anketa građana Zagreba o njihovim navikama i interesu vezano za FC voće i povrće. Kvaliteta i senzorske osobine FC jabuka skladištenih u prototipu bile su zadovoljavajuće 4 dana, a mikrobiološka analiza pokazala je da prototip daje siguran proizvod kroz 7 dana. Temeljem odgovora građana koji su iskazali interes da prilikom kupovine FC voća i povrća sami biraju vlastitu kombinaciju te da im je moguće kupovati takve proizvode i blizu radnog mjesta, čini se da postoji potreba za postojanjem ovakvog automata. Općenito, analiza tržišta ukazala je da građani kupuju FC proizvode i da postoji interes za proširenjem ponude

Effect of Spray Drying Encapsulation on Nettle Leaf Extract Powder Properties, Polyphenols and Their Bioavailability

Nettle (Urtica dioica L.) is a plant rich in a health-promoting compounds such as polyphenols, which are sensitive and unstable compounds with low bioavailability, that need to be stabilized and protected from external influences. Therefore, the aim of this study was to examine how the temperature, type of carrier and sample to carrier ratio influence the physicochemical properties and encapsulation and loading capacity of the nettle leaf extract powder and examine the effect of encapsulation on the antioxidant capacity and bioavailability of polyphenols. The process yield ranged from 64.63–87.23%, moisture content from 1.4–7.29%, solubility from 94.76–98.53% and hygroscopicity from 13.35–32.92 g 100 g−1. The highest encapsulation (98.67%) and loading (20.28%) capacities were achieved at 160 ◦C, β- CD:GA (3:1) and sample:carrier ratio of 1:3. Extracts encapsulated at selected conditions showed high antioxidant capacity and distinct polyphenolic profile comprised of 40 different compounds among which cinnamic acids were the most abundant. Moreover, the encapsulation increased the bioavailability of nettle leaf polyphenols, with the highest amount released in the intestinal phase. Thus, the obtained encapsulated extract represents a valuable source of polyphenols and may therefore be an excellent material for application in value-added and health-promoting products

Utjecaj ekstrakcije potpomognute mikrovalovima na izolaciju polifenola kadulje (Salvia officinalis L.)

In order to determine the optimal conditions for the extraction of sage polyphenols, the influence of extraction solvent (water, 30 % (by volume) aqueous ethanol and 30 % (by volume) aqueous acetone), extraction time (3, 5, 7, 9 and 11 min) and microwave power (500, 600 and 700 W) on the composition and concentration of phenolic compounds of dry wild sage (Salvia officinalis L.) during microwave-assisted extraction (MAE) was studied. Optimized MAE method was compared with conventional extraction (CE). Based on the amount of total phenols, microwave power of 500 W and extraction time of 9 min were selected as optimal extraction conditions, resulting in higher content of polyphenols when compared with CE. Ethanol and acetone solutions were equally effective extraction solvents, both producing higher extraction capacity than water. Using HPLC coupled with UV/PDA, fourteen polyphenols were identified (caffeic and rosmarinic acid derivatives, luteolin- and apigenin-glycosides) with rosmarinic acid and luteolin glycosides at the highest concentrations. The mass fractions of all individual polyphenols were higher in the MAE extracts than in the CE ones.Da bi se odredili optimalni uvjeti ekstrakcije polifenola iz kadulje, ispitan je utjecaj otapala (voda, 30 %-tna vodena otopina etanola i 30 %-tna vodena otopina acetona), vremena ekstrakcije (3, 5, 7, 9 i 11 min) i snage mikrovalova (500, 600 i 700 W) na sastav i koncentraciju fenolnih spojeva tijekom ekstrakcije potpomognute mikrovalovima (MAE). Optimirana MAE metoda je zatim uspoređena s konvencionalnom metodom ekstrakcije (CE). Na temelju količine ukupnih fenola odabrani su optimalni uvjeti snage mikrovalova od 500 W i vremena ekstrakcije od 9 min pri kojima je ekstrahirana veća količina fenolnih spojeva u usporedbi s CE. Etanol i aceton bili su podjednako učinkovita otapala s većom djelotvornošću ekstrakcije od vode. Primjenom HPLC UV/PDA identificirano je četrnaest fenolnih spojeva (derivati kafeinske i ružmarinske kiseline, glikozidi luteolina i apigenina) i to najveći udjeli ružmarinske kiseline i glikozida luteolina. Svih pojedinačnih fenolnih spojeva bilo je više u ekstraktima dobivenim MAE metodom

Comparison of Conventional and Ultrasound-assisted Extraction Techniques on Mass Fraction of Phenolic Compounds from Sage (Salvia officinalis L.)

An innovative ultrasound-assisted extraction (UAE) is the rapid non-thermal extraction technique, which in comparison to conventional extraction (CE), offers high reproducibility in a short time with simplified manipulation, reduced solvent consumption and lower energy. Optimization of ultrasonic conditions was conducted for devices with nominal output power of 100 and 400 W, including the influence of geometrical parameters of probes regarding ultrasound-assisted extraction. The results showed that the optimal parameters for extraction of total phenols and rosmarinic acid as a dominant compound in sage extracts were as follows: solvent: 30 % ethanol, extraction duration of 11 minutes, and ultrasonic device output power of 400 W. The antioxidant capacity of the obtained extract correlated with the concentration of total phenols and flavonoids, and among individual phenols the rosmarinic acid contributed the most to the antioxidant capacity. The achieved results and statistical analysis (p ≤ 0.05) have shown how UAE resulted in shorter extraction time, and increased extraction capacity of phenolic compounds by using solvents with a less amount of organic phase

The Mastic Tree (Pistacia lentiscus L.) Leaves as Source of BACs: Effect of Growing Location, Phenological Stage and Extraction Solvent on Phenolic Content

Pozadina istraživanja. Tršlja (Pistacia lentiscus L.) je zimzeleni grm iz porodice Anacardiaceae, rasprostranjen u mediteranskim zemljama, gdje se koristi u narodnoj medicini. Dosadašnja istraživanja ekstrakata lista, stapke, ploda i korijena P. lentiscus pokazuju da biljka sadržava veliku koncentraciju sekundarnih metabolita (flavonoida, fenolnih kiselina i tanina), što upućuje na zaključak da ima izvrstan biološki potencijal. Stoga je svrha ovoga rada bila procijeniti utjecaj okolišnih čimbenika i vrste ekstrakcijskog otapala na koncentraciju fenola u listu tršlje uzgojene na četiri različite lokacije duž Jadranske obale (Barbariga, Lun, Hvar i Vela Luka) tijekom tri fenološke faze (faze cvatnje, ranog ploda i zrelog ploda). Eksperimentalni pristup. Budući da listovi tršlje sadržavaju fenolne spojeve koji se razlikuju po strukturi i kemijskim svojstvima, ispitivanje etanolnih i metanolnih ekstrakata provedeno je visokodjelotvornom tekućinskom kromatografijom (HPLC) s UV-Vis PDA detektorom. Fenolni spojevi su identificirani usporedbom retencijskih vremena i dobivenih spektara s odgovarajućim standardima pri 280 i 340 nm. Rezultati i zaključci. U svim su uzorcima određene koncentracije fenolnih kiselina i flavonol glikozida, dok je koncentracija katehina određena samo u metanolnim ekstraktima. Prevladavajući fenolni spoj bila je 5-O-galoilkininska kiselina, zatim su slijedili monogaloil-glukoza, 3,5-di-O-galoilkininska kiselina, 3,4,5-tri-O-galoilkininska kiselina i galna kiselina. Dominantni flavonol glikozid bio je miricetin-3-O-ramnozid, zatim miricetin-3-O-glukozid, miricetin-3-O-glukuronid, kvercetin-3-O-ramnozid i derivat flavonol glikozida. Rezultati pokazuju da masene koncentracije navedenih spojeva variraju ovisno o fenološkoj fazi, lokaciji i korištenom otapalu. Najveće masene koncentracije fenola utvrđene su u uzorcima lista tršlje ubranim na lokaciji Hvar te ekstrahiranim s 80 %-tnom otopinom metanola. Najveće masene koncentracije ukupnih fenola pronađene su u uzorcima lista tršlje ubranim tijekom fenološke faze cvatnje, a ukupnih flavonoida u uzorcima lista tršlje ubranim tijekom fenološke faze ranog ploda. Novina i znanstveni doprinos. Dobiveni rezultati omogućuju bolje razumijevanje fenolnog sadržaja vrste P. lentiscus, što može potaknuti daljnja ispitivanja valorizacije lista tršlje kao farmaceutskog pripravka ili hrane s dodanom vrijednošću.Research background. Mastic tree (Pistacia lentiscus L.) of the Anacardiaceae family is an evergreen shrub from Mediterranean countries where it is used in traditional medicine. Analysis of P. lentiscus leaf, stem, fruit and root extracts showed high concentrations of principal groups of secondary metabolites (flavonoids, phenolic acids and tannins), suggesting the plant possesses great biological potential. Therefore, the aim of this research is to evaluate the impact of environmental parameters and the extraction solvent type on the concentration of phenols in mastic tree leaf extracts grown at four different locations along the Adriatic coast (Barbariga, Lun, Hvar and Vela Luka) during three phenological stages (early flowering, early fruiting and late fruiting). Experimental approach. Since mastic tree plant has phenolic compounds with different structures and chemical properties, ethanolic and methanolic leaf extracts were analysed using high-performance liquid chromatography (HPLC) coupled with UV/Vis PDA detector. Phenolic compounds were identified by comparing the retention times and spectral data with those of standards at 280 and 340 nm. Results and conclusions. In all samples, phenolic acids and flavonol glycosides were quantified, while catechin was quantified only in methanolic extracts. The 5-O-galloylquinic acid was determined as a predominant phenolic compound in all samples followed by monogalloyl glucose, 3,5-di-O-galloylquinic acid, 3,4,5-tri-O-galloylquinic acid and gallic acid, respectively. Myricetin-3-O-rhamnoside was found to be the predominant flavonol glycoside followed by myricetin-3-O-glucoside, myricetin-3-O-glucuronide, quercetin-3-O-rhamnoside and derivative of flavonol glycoside. The mass concentration of these compounds significantly varied during different phenological stages, at different growing locations and used extraction solvents. The highest phenolic mass concentration was determined in the samples harvested at Hvar growing location and extracted in 80 % methanol. The highest total phenolic acid mass concentration was obtained in the samples harvested during the flowering phenological stage and the highest total flavonoid mass concentration in the samples harvested during the early fruiting stage. Novelty and scientific contribution. The obtained data provide a better understanding of the P. lentiscus species phenolic concentration, which can lead to further investigations regarding the valorisation of mastic tree leaves as pharmaceutical products or as food products with added value