Influence of harvest location on phenolic composition and antioxidant activity of sea fennel

One of the most widespread Mediterranean halophytes is sea fennel, which is widely used for its nutritional value and beneficial health properties. This study aimed to investigate the differences in phenolic composition and biological properties of sea fennel collected from river shore, estuary, and sea coastal zone, where it was exposed to different salinity levels. The extracts were prepared by microwave-assisted extraction (MAE) and analysed for total phenolics, flavonoids, and tannins, while the content of dominant chlorogenic acid was detected by high-performance liquid chromatography with a diode array detector (HPLC-DAD). Antioxidant activity was tested by the Ferric Reducing Antioxidant Power (FRAP) assay and against two free radicals; Nitric Oxide (NO•) and 2,2-diphenyl-1-picrilhydrazil (DPPH•). The highest content of total phenolics and flavonoids was found in sea fennel collected from the river coast, while the highest concentration of chlorogenic acid (1.64 mg/g) and highest FRAP and DPPH• antioxidant activities were found in the samples growing near brackish water. This study confirmed the influence of a plant`s habitat (salinity level) on its phenolic composition, as well as the influence of an individual compound/phenolic group on the total antioxidant activity of the samples

Preventive effect of herb extracts on lipid oxidation in fish oil

Oxidative decay of oil is causing changes in its chemical, sensory and nutritional properties and is considered a major problem effecting loses in quality and nutritional value. This paper investigated the influence of the Lamiaceae plant extracts addition on oxidative stability of fish oil. The test was performed under accelerated oxidation by Rancimat method where different concentrations of herb extracts (basil, thyme and oregano) as well as effect of different temperatures were studied. Fatty acid profile of oil was analysed using gas chromatography. As expected, the applied temperature had significant impact on fish oil stability and the induction periods were prolonged after the addition of herb extracts. The best results at 80°C were obtained after addition of basil extract what resulted with induction period of 4.60 h. The addition of higher concentrations also resulted with prolonged induction periods; for oregano extract the results were dose-dependent, after addition of 50 and 100 µL of thyme extract the induction period remained the same (0.32 h), while the highest concentration of basil extract, probably due to presence of some components that acts as a prooxidants, resulted with lower IP value

Insight in the phenolic composition and antioxidative properties of Vitis vinifera leaves extracts

In the present investigation, leaf ethanolic extracts of Vitis vinifera were assayed for their polyphenolic composition and antioxidative properties. The leaves were collected during lush vegetation period (May leaves) and after the harvest (September leaves). Air dried plant material was homogenized and the polyphenolic constituents were extracted using conventional solvent extraction procedure. Total phenolics, flavonoids, non-flavonoids, catechins and flavanols were determined using spectrophotometric methods. Both extracts were very rich in phenolic compounds. The concentration of total phenols in September leaves extract was about 30 % higher compared to May leaves extract, due to the increase of flavonoid (catechin) fraction. Non-flavonoid compound content was almost equal in both extracts. The amount of flavanols, determined with p-dimethylaminocinnamaldehyde method, was taken as indicator of flavan-3-ol monomers, while high catechin content determined by vanillin method, indicated the presence of polymeric fraction. The total catechin content in September leaves extract was more than 3 folds higher in comparison to May leaves extract. Principal phenolic compounds were separated by high pressure liquid chromatography on reverse phase. Antioxidant properties, determined as: 2,2-diphenyl-1-picrylhydrazyl radical and 2,2\u27-azinobis-(3-ethylbenzthiazoline-6-sulfonate) radical cation scavenging ability, ferric reducing/antioxidant power, Fe2+ chelating activity, and using β-carotene bleaching assay, were total phenol concentration dependent. September leaves extract had better free radical scavenging capacity, higher reducing power, and was more efficient in protecting the oxidation of emulsified linoleic acid, in comparison with May leaves extract which showed better chelating ability. The presence of active phenolic compounds: phenolic acids (3-hydroxybenzoic acid, caffeic acid, gallic acid, vanillin acid), flavonoids ((+)-catechin, (-)-epicatechin, apigenin, myricetin, quercetin, quercetin-4\u27-glucoside, rutin), and stilbenes (trans-resveratrol and resveratrol derivatives) was confirmed in both extracts. According to the results achieved, vine leaf extracts can be considered rich natural source of polyphenols with significant antioxidant properties

The Effect of Selected Herb Extracts on Oxidative Stability of Vegetable Oils

The aim of this study was to investigate the effect of different herb extracts on the oxidative stability of hemp, flax, sesame and sunflower seed oils by means of Rancimat test. The dominant phenolic acids in herb extracts were detected by HPLC, while fatty acid profiles of oils, before and after oxidation, were determined by GC-FID. As expected, autoxidation increased the content of saturated fatty acids. The sesame oil showed the longest oxidative stability (3.43 h), while the shortest induction period was obtained for the flax oil. Lemon balm and oregano extracts accelerated the oxidation of hemp and flax oil, while in all other cases the addition of extracts had a positive effect on oil oxidative stability. The best results were obtained for lemon balm extract added to sesame and sunflower oil which resulted with OSI values of 1.33 and 1.48, respectively, while extremely prooxidative activity was obtained for lemon balm extract added to the hemp oil. This work is licensed under a Creative Commons Attribution 4.0 International License

Determination of Phenolic Content and DPPH Radical Scavenging Activity of Functional Fruit Juices Fortified with Thymus serpyllum L. and Salvia officinalis L. Extracts

The objective of this study was to spectrophotometric determinate the total phenolic, flavonoid, hydroxycinnamic acid, and flavonol content of orange, pineapple, and apple juices fortified with wild thyme (Thymus serpyllum L.), Dalmatian sage (Salvia officinalis L.), and wild thyme-Dalmatian sage (3 : 1, v / v) extracts, and to evaluate their DPPH radical scavenging activity as a contribution to the development of a new functional beverage. The plant extracts addition increased the amount of phenolic compounds in fruit juices and improved their antioxidant properties. The highest concentrations of bioactive compounds and the greatest DPPH radical activity were obtained by adding Dalmatian sage extract to orange juice. Our study provides the novelty of fortifying fruit juices with wild thyme and Dalmatian sage extracts and offers significant potential for the creation of functional beverages

Effect of the extraction solvent on the oleuropein content and antioxidant properties of olive leaf (cv. Oblica, Lastovka and Levantinka) extracts

In the last few decades numerous studies have proved that an olive leaf is a rich source of bioactive phenolic compounds, mainly oleuropein and its derivatives. The aim of this study was to investigate the influence of the extraction solvent on the phenolic and oleuropein content in the leaf extracts of Dalmatian autochthonic olive cultivars: Oblica, Lastovka and Levantinka. The antioxidant activity of leaf extracts was determined using FRAP method and by metal chelating activity evaluation. The recovery obtained using methanol and ethanol (50:50, v/v) was higher than by use of water solvents. The highest share of total phenols and oleuropein was detected in ethanolic extract of Lastovka, while almost two-fold lower amounts were obtained using water extracts, both hot water and room temperature water. The extremely significant correlation between the FRAP and oleuropein/phenolic content points out the importance of these compounds in the total reducing activity of the extracts. All tested extracts provided good chelating activity probably due to the high concentrations of oleuropein but also the presence of other compounds with catechol structure, which is the most important structural feature of strong chelating activity. According to the obtained results it can be concluded that the extraction of polyphenols from olive leaves, especially from Lastovka cultivar, could present an interesting means of increasing the value of this cheap plant material that often remains unused after the harvest

Variations in the Composition, Antioxidant and Antimicrobial Activities of Cystoseira compressa during Seasonal Growth

The underexplored biodiversity of seaweeds has recently drawn great attention from researchers to find the bioactive compounds that might contribute to the growth of the blue economy. In this study, we aimed to explore the effect of seasonal growth (from May to September) on the in vitro antioxidant (FRAP, DPPH, and ORAC) and antimicrobial effects (MIC and MBC) of Cystoseira compressa collected in the Central Adriatic Sea. Algal compounds were analyzed by UPLC-PDAESI- QTOF, and TPC and TTC were determined. Fatty acids, among which oleic acid, palmitoleic acid, and palmitic acid were the dominant compounds in samples. The highest TPC, TTC and FRAP were obtained for June extract, 83.4 4.0 mg GAE/g, 8.8 0.8 mg CE/g and 2.7 0.1 mM TE, respectively. The highest ORAC value of 72.1 1.2 M TE was obtained for the August samples, and all samples showed extremely high free radical scavenging activity and DPPH inhibition (>80%). The MIC and MBC results showed the best antibacterial activity for the June, July and August samples, when sea temperature was the highest, against Listeria monocytogenes, Staphylococcus aureus, and Salmonella enteritidis. The results show C. compressa as a potential species for the industrial production of nutraceuticals or functional food ingredients

In vitro Antioxidant and Antibacterial Activity of Lamiaceae Phenolic Extracts: A Correlation Study

U radu je spektrofotometrijski određen udjel ukupnih fenola i fenolnih podgrupa u ekstraktima pet biljaka iz porodice Lamiaceae (kadulja, majčina dušica, matičnjak, menta i mravinac), a udjel je pojedinih fenola utvrđen pomoću visokodjelotvorne tekućinske kromatografije. Antioksidacijska je aktivnost ekstrakata ispitana pomoću različitih metoda, a njihov antibakterijski učinak s pomoću najvažnijih patogenih bakterija prisutnih u hrani, kao što su: Campylobacter coli, Salmonella Infantis, Escherichia coli, Bacillus cereus, Listeria monocytogenes i Staphylococcus aureus. Najveći su udjeli ukupnih fenola i neflavonoida pronađeni u ekstraktu kadulje, koji je imao i najbolji antibakterijski učinak, osobito na Gram-pozitivne bakterije i C. coli. Najbolja je reducirajuća snaga i sposobnost uklanjanja molekula slobodnih radikala dokazana za ekstrakt matičnjaka, koji je imao najveći udjel ružmarinske kiseline. Nadalje, analizom glavnih komponenata ispitan je utjecaj fenola, osobito ružmarinske kiseline, na biološka svojstva ekstrakata biljaka iz porodice Lamiaceae. Udjel je ružmarinske kiseline bio u pozitivnoj korelaciji sa svim antioksidacijskim parametrima, što potvrđuje njezin značajan doprinos antioksidacijskoj aktivnosti ispitanih ekstrakata.Total phenols and phenolic subgroups of five Lamiaceae plant extracts (sage, thyme, lemon balm, peppermint and oregano) were determined spectrophotometrically, whereas the individual phenolics were determined by high-performance liquid chromatography. The antioxidant activity of the extracts was evaluated by means of a multiple method approach, while the antibacterial activity was tested against major foodborne pathogens such as Campylobacter coli, Escherichia coli, Salmonella Infantis, Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus. The highest content of total phenolics and non-flavonoids was detected in the sage extract, which also showed the best antibacterial activity, especially against Gram-positive bacteria and C. coli. The best reducing power and free radical scavenging activity were obtained in lemon balm extract, with the highest content of rosmarinic acid. Additionally, the effect of the phenolics, especially rosmarinic acid, on biological properties of Lamiaceae plant extracts was investigated using principal component analysis. Rosmarinic acid showed good correlation with all antioxidant parameters, confirming its significant contribution to antioxidant activity of investigated plant extracts

With food to health : proceedings of 11th International symposium

Proceedings contains 13 original scientific papers, 10 professional papers and 2 review papers which were presented at "10th International Scientific and Professional Conference WITH FOOD TO HEALTH", organised in following sections: Nutrition, Dietetics and diet therapy, Functional food and food supplemnents, Food safety, Food analysis, Production of safe food and food with added nutritional value