The volatile organic compounds (VOCs) of fresh (FrCC) and air-dried (DrCC)
and fresh (FrEA) and air-dried (DrEA)
from the Adriatic Sea were investigated by headspace solid-phase microextraction ...(HS-SPME) and hydrodistillation (HD) and analysed by gas chromatography and mass spectrometry (GC-MS). In HS-FrCC and HS-DrCC, aliphatic compounds were dominant, with decan-5-ol as the most abundant in HS-FrCC, but in HS-DrCC pentadecane dominated. Monoterpenes (β-cyclocitral, β-citral, and β-cyclohomocitral) and sesquiterpenes (cubenol) were abundant in HS-FrCC. Notable differences between fresh and air-dried samples were found for benzene derivatives. Fatty acids and their derivatives were the most abundant in HD-FrCC and HD-DrCC. In HS-FrEA and HS-DrEA, saturated aliphatic compounds as well as unsaturated aliphatic compounds (particularly hexan-1-ol and (
)-hex-3-en-1-ol) predominantly showed decrements after drying. Pentadecane, heptadecane, pentadecanal, and hexan-1-ol were predominant in HD-FrEA, and their percentage decreased in HD-DrEA. The percentage of monoterpenes decreased after drying, but the percentages of diterpenes and especially sesquiterpenes increased. δ-Selinene was the major terpene and the most abundant in HD-DrEA. A significant increment after drying could be noticed for fatty acids and their derivatives. The great diversity of identified VOCs among these two macroalgae supports their different botanical classifications.
Dictyotaceae, the large family of brown algae with the genus
as the richest one among them, produce a significant number of secondary metabolites, like diterpenes. The aim of this study was to ...investigate the variations in the composition of the volatile organic compounds (VOCs) of the brown alga
collected from the Adriatic Sea. For the first time, both seasonal changes and the impact of air drying were examined. Headspace solid-phase microextraction (HS-SPME) on two fibres with different polarities and hydrodistillation (HD), followed by gas chromatography and mass spectrometry (GC-MS) analysis, was performed on both fresh (FrDd) and air-dried (DrDd)
. The major compounds of HS-FrDd were pentadecane and oct-1-en-3-ol. The percentage of pentadecane in HS-DrDd was increased up to 7.8 times in comparison with HS-FrDd. Principal component analysis (PCA) identified differences between the variability of data among fresh and dried samples over months and clearly dissociated the fresh May samples from the others in the HS-SPME results. The most abundant group of VOCs in HD were terpenes, with diterpenes isopachydictyol A and cembra-4,7,11,15-tetraen-3-ol as the major compounds. Diterpene pachydictyol A was also found and among sesquiterpenes and gleenol was the most abundant. Based on the dominant compound analyses, the PCA showed distinct separation of the fresh and dried samples, indicating similarities between the samples and allowing the establishment of typical VOCs significant for the chemotaxonomy of
.
The limited availability of phosphate, nitrogen and silicon in the growth media affects the growth, cellular processes, and metabolism of diatoms. Silicon deficiency primarily affects diatom ...morphology, while phosphate deficiency reduces the production of nucleic acids and phospholipids. Differences in pigment and protein composition are mainly due to nitrogen deficiency. In this study,
and
were cultured under phosphate, nitrogen, and silicon deprivation conditions. The diatom biomass was collected during the stationary growth phase and extracted with 70% ethanol under ultrasonication. The chemical profiles of the extracts were analyzed by high-performance liquid chromatography with high-resolution mass spectrometry with electrospray ionisation (UHPLC-ESI-HRMS), while the antioxidant capacity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbance capacity (ORAC) assays. Pigments, fatty acids, sterols, and derivatives were detected in both species. The total phenolic content in the extracts ranged from 46.25 ± 1.08 to 89.38 ± 6.21 mg of gallic acid equivalent (GAE)/L and from 29.58 ± 1.08 to 54.17 ± 1.18 mg GAE/L. for
and
, respectively. Antioxidant activity was higher in
extracts, especially those obtained from nitrogen-deprived media. The results of this study contribute to the existing knowledge and the ongoing efforts to overcome application and commercialization barriers of microalgae for wide-ranging potential in different industries.
The present study aimed to isolate volatile organic compounds (VOCs) from fresh (FrHSc) and air-dried (DrHSc)
(from the Adriatic Sea) by headspace solid-phase microextraction (HS-SPME) and ...hydrodistillation (HD) and to analyse them by gas chromatography and mass spectrometry (GC-MS). The impact of the season of growth (May-September) and air-drying on VOC composition was studied for the first time, and the obtained data were elaborated by principal component analysis (PCA). The most abundant headspace compounds were benzaldehyde, pentadecane (a chemical marker of brown macroalgae), and pentadec-1-ene. Benzaldehyde abundance decreased after air-drying while an increment of benzyl alcohol after drying was noticed. The percentage of pentadecane and heptadecane increased after drying, while pentadec-1-ene abundance decreased. Octan-1-ol decreased from May to September. In HD-FrHSc, terpenes were the most abundant in June, July, and August, while, in May and September, unsaturated aliphatic compounds were dominant. In HD-DrHSc terpenes, unsaturated and saturated aliphatic compounds dominated. (
)-Phytol was the most abundant compound in HD-FrHSc through all months except September. Its abundance increased from May to August. Two more diterpene alcohols (isopachydictyol A and cembra-4,7,11,15-tetraen-3-ol) and sesquiterpene alcohol gleenol were also detected in high abundance. Among aliphatic compounds, the dominant was pentadec-1-ene with its peak in September, while pentadecane was present with lower abundance. PCA (based on the dominant compound analyses) showed distinct separation of the fresh and dried samples. No correlation was found between compound abundance and temperature change. The results indicate great seasonal variability of isolated VOCs, as well among fresh and dried samples, which is important for further chemical biodiversity studies.
and
from the Adriatic Sea (Croatia) were investigated with respect to the presence of less-polar compounds for the first time after fractionation by solid-phase extraction (SPE). The composition of ...less-polar fractions of freeze-dried
(FdEc) and
(FdEa) were analyzed by high-performance liquid chromatography-high-resolution mass spectrometry with electrospray ionization (UHPLC-ESI-HRMS). The major identified compounds were: amides of higher aliphatic acids (palmitoleamide, linoleamide, palmitamide, oleamide and erucamide) and related compounds, carotenoid (fucoxanthin), chlorophyll derivatives (pheophytin
and
and their derivatives) and higher terpenes (loliolide, isoamijiol with its oxidation product), β-stigmasterol and (3β,6α)-14-methylergosta-8,24(28)-diene-3,6-diol). The toxic effects observed on the less-polar fractions obtained from
species on zebrafish
embryos could be associated with the high abundance of all five detected amides. The antioxidant activity of the fractions was evaluated by means of five independent assays, including the reduction of the radical cation (ABTS), the oxygen radical absorbance capacity (ORAC), ferric-reducing antioxidant power (FRAP), the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay and the Folin-Ciocalteu method. A higher antioxidant activity of
in comparison to that of the
fractions was found with IC
concentrations of 0.072 and 1.177 mg/mL, respectively. The correlation between the activity and the chemical composition revealed that the synergistic effect of different compounds impacted their antioxidant response.
was harvested once a month during its growing season (from May to August) from the Adriatic Sea. Algal volatile organic compounds (VOCs) were obtained by headspace solid-phase microextraction ...(HS-SPME) and hydrodistillation (HD) and analysed by gas chromatography and mass spectrometry (GC-MS). The effects of air drying and growing season on VOCs were determined. Two different extraction methods (ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE)) were used to obtain ethanolic extracts of
. In addition, the seasonal antioxidant potential of the extracts was determined, and non-volatile compounds were identified from the most potent antioxidant extract. Aliphatic compounds (e.g., pentadecane) were predominantly found by HS-SPME/GC-MS. Hydrocarbons were more than twice as abundant in the dry samples (except in May). Aliphatic alcohols (e.g., hexan-1-ol, octan-1-ol, and oct-1-en-3-ol) were present in high percentages and were more abundant in the fresh samples. Hexanal, heptanal, nonanal, and tridecanal were also found. Aliphatic ketones (octan-3-one, 6-methylhept-5-en-2-one, and (
,
)-octa-3,5-dien-2-one) were more abundant in the fresh samples. Benzene derivatives (e.g., benzyl alcohol and benzaldehyde) were dominant in the fresh samples from May and August. (
)-Verbenol and
-cymen-8-ol were the most abundant in dry samples in May. HD revealed aliphatic compounds (e.g., heptadecane, pentadecanal, (
)-heptadec-8-ene, (
)-heptadec-3-ene), sesquiterpenes (germacrene D, epi-bicyclosesquiphellandrene, gleenol), diterpenes (phytol, pachydictyol A, (
)-geranyl geraniol, cembra-4,7,11,15-tetraen-3-ol), and others. Among them, terpenes were the most abundant (except for July). Seasonal variations in the antioxidant activity of the ethanolic extracts were evaluated via different assays. MAE extracts showed higher peroxyl radical inhibition activity from 55.1 to 74.2 µM TE (Trolox equivalents). The highest reducing activity (293.8 µM TE) was observed for the May sample. Therefore, the May MAE extract was analysed via high-performance liquid chromatography with high-resolution mass spectrometry and electrospray ionisation (UHPLC-ESI-HRMS). In total, 17 fatty acid derivatives, 9 pigments and derivatives, and 2 steroid derivatives were found. The highest content of pheophorbide
and fucoxanthin, as well as the presence of other pigment derivatives, could be related to the observed antioxidant activity.
Cultivated nettle Urtica dioica L., a member of the Urticaceae family, is widely distributed throughout the temperate regions of the world and can be used as a nutritious feed for animals through the ...winter period. The aim of this research was to determine (i) the nutritional value of freshly cultivated nettle Urtica dioica L grown in the open field and (ii) the fermentation value of cultivated nettle Urtica dioica L ensiled with additives, including a commercial inoculant containing bacteria that produce lactic acid and molasses from sugar beet after 60 days of ensiling. Cultivated nettle Urtica dioica L was ensiled in six treatments: without additions (control); with sugar beet molasses (2,4, and 6%) per 1 kg of fresh mass and a commercial inoculant (2 and 4 g/t of fresh mass) in five replicates. The results of this research showed that the cultivated nettle Urtica dioica L contains a large proportion of proteins and some essential minerals, including calcium, and is especially rich in magnesium and iron. Without the addition of sugar beet molasses and without treatment with a commercial inoculant, poorly preserved silage from cultivated nettle was obtained. With 2% molasses, poorly preserved silage was obtained, but with 4 and 6% molasses, well-preserved silage from cultivated nettle was obtained. Based on the results of these studies, it is recommended to use sugar beet molasses during ensiling in a concentration of 4 to 6% of the fresh mass of cultivated nettle. In future research, it would be interesting to test the joint application of commercial inoculants and sugar beet molasses when preparing cultivated nettle Urtica dioica L. for silage on the farm. Keywords: cultivated nettle, silage, molasses, commercial inoculant, chemical composition, fermentation parameters Kultivirana kopriva Urtica dioica L., clan porodice Urticaceae, siroko je rasprostranjena u umjerenim dijelovima svijeta i moze se koristiti kao krma za hranidbu zivotinja u zimskom razdoblju. Cilj je ovog istrazivanja bio utvrditi (i) hranjivu vrijednost svjeze kultivirane koprive Urtice dioica L. uzgojene na otvorenom polju i (ii) fermentacijske vrijednosti kultivirane koprive Urtica dioica L. silirane s dodacima, ukljucujuci komercijalni inokulant koji sadrzi bakterije koje proizvode mlijecnu kiselinu te melasu od secerne repe 60 dana nakon siliranja. Kultivirana kopriva Urtica dioica L. silirana je u sest tretmana: bez dodataka (kontrola); s melasom secerne repe (2, 4 i 6%) na 1 kg svjeze mase i komercijalnim inokulantom (2 i 4 g/t svjeze mase) u pet ponavljanja. Istrazivanjem je utvrdeno da kultivirana kopriva Urtica dioica L. sadrzi velik udio bjelancevina i nekih neophodnih minerala, ukljucujuci kalcij, a posebice je bogata magnezijem i zeljezom. Bez dodavanja melase od secerne repe i bez tretmana komercijalnim inokulantom dobivena je lose ocuvana silaza od kultivirane koprive. Sa 2% melase dobivena je slabo ocuvana silaza, ali sa 4 i 6% melase dobivena je dobro ocuvana silaza od kultivirane koprive. Na temelju rezultata ovih istrazivanja moze se preporuciti upotreba melase od secerne repe prilikom siliranja u koncentraciji od 4 do 6% svjeze mase kultivirane koprive. U buducim istrazivanjima, bilo bi zanimljivo testirati i zajednicku primjenu komercijalnih inokulanata i melase od secerne repe kod spremanja kultivirane koprive Urtica dioica L. za silazu na farmi. Kljucne rijeci: kultivirana kopriva, silaza, melasa, komercijalni inokulant, kemijski sastav, parametri fermentacije Cultivated nettle Urtica dioica L., a member of the Urticaceae family, is widely distributed throughout the temperate regions of the world and can be used as a nutritious feed for animals through the winter period. However, cultivated nettle Urtica dioica L. is difficult to ensile due to the low content of water-soluble carbohydrates and moisture and the high buffering capacity of the fresh mass. Because it does not contain the required sugar minimum for successful lactic acid fermentation, it is necessary to apply chemical or bacterial inoculants in the conservation of cultivated nettle Urtica dioica L Otherwise, untreated silage accelerates the activity of Clostridium butyricum which uses existing sugars for its activity which leads to the production of small amounts of lactic acid an increase in the content of butyric acid, and intense degradation of proteins and amino acids. However, very little data is available on the fermentation properties of cultivated nettle Urtica dioica L ensiled with supplements (inoculants, molasses, grains). The aim of this research was to determine (i) the nutritional value of freshly cultivated nettle Urtica dioica L grown in the open field and (ii) the fermentation value of cultivated nettle Urtica dioica L ensiled with additives, including a commercial inoculant containing bacteria that produce lactic acid and molasses from sugar beet after 60 days of ensiling. Cultivated nettle Urtica dioica L was ensiled in six treatments: without additions (control); with sugar beet molasses (2, 4, and 6%) per 1 kg of fresh mass and a commercial inoculant (2 and 4 g/t of fresh mass) in five replicates. The results of this research showed that the cultivated nettle Urtica dioica L contains a large proportion of proteins and some essential minerals, including calcium, and is especially rich in magnesium and iron. Without the addition of molasses and without treatment with a commercial inoculant, poorly preserved silage from cultivated nettle was obtained. With 2% molasses, poorly preserved silage was obtained, but with 4 and 6% molasses, well-preserved silage from cultivated nettle was obtained. Based on the results of these studies, it is recommended to use molasses during ensiling in a concentration of 4 to 6% of the fresh mass of cultivated nettle. In future research, it would be interesting to test the joint application of commercial inoculants and sugar beet molasses when preparing cultivated nettle Urtica dioica L for silage on the farm.
More than ever, traditional agricultural practices need a shift towards more resilient, sustainable, modern and adaptable practices that benefit the health of the planet and people. Today's consumers ...are constantly on the lookout for novel, highly nutritious foods that have a positive impact on their overall health and well-being. Nettle (Urtica dioica L.) is gaining recognition not only as a popular medicinal plant, but also as a desirable green leafy vegetable rich in phytonutrients. As it is difficult and even expensive to control the quality standards of wild-collected plants, the implementation of sustainable cultivation methods, especially hydroponics, with effective greenhouse management could be a possible solution to obtain a standardized product with high nutritional value. Therefore, the aim of this study was to investigate the effects of four nutrient solutions differing in the content of macro- and micronutrients (especially nitrogen, potassium, calcium, magnesium and iron) and two consecutive cuts on the number of leaves, yield, nitrate and mineral content and the content of specialized metabolites of stinging nettle from a floating hydroponic system.
Nettle plants were cultivated in a hydroponic system using the floating hydroponics technique. The two-factorial experiment was performed with nutrient solution and consecutive cuts as factors.
The highest yield (2.49 kg/m2) was achieved after the 1st cut with plants cultivated in the nutrient solution with higher nutrient concentration. All tested nutrient solutions resulted in high levels of minerals and bioactive compounds in the plant material (ascorbic acid content of 102.30 mg/100 g fw and total phenolics content of 465.92 mg GAE/100 g fw), confirming floating hydroponics as a sustainable approach for cultivating nettle with enhanced nutritional value and antioxidant potential.
It is important to highlight that the nutrient solution with the lowest nutrient composition yielded the highest concentrations of calcium (5.54%) and iron (180.67 mg/kg dw). Furthermore, it exhibited elevated levels of specific phenolic compounds, including caffeoylmaleic acid, ellagic acid, ferulic acid, naringin, and rutin trihydrate. Notably, this solution demonstrated the lowest nitrate content (4225.33 mg/kg fw) in the plant material. Therefore, it can be recommended as a preferable formulation for hydroponic nettle cultivation.
As food production faces major challenges, modern agricultural practices are increasingly focused on conserving resources, reducing negative environmental impacts and sustainably producing food with ...a high content of health-promoting phytochemicals. During production, many factors can affect the quality and chemical composition of a final food product. Proper selection of cultivating conditions, especially a balanced nutrition, can significantly increase nutritional value and result in foods with strong biological and functional properties. Stinging nettle is a rich source of minerals, vitamins, pigments, phenols and other bioactive compounds and can be consumed as a green leafy vegetable with beneficial effects on human health. Therefore, the aim of this study is to determine the nutritional quality and antioxidant capacity of stinging nettle leaves under the influence of different nutrient solution (NS) treatments and three harvest cycles.
The experiment was conducted in a floating hydroponic system in which treatments with different nutrient solutions were applied and three harvest cycles were carried out. After each harvest, the following treatments were applied: treatment 1 - depletion of nutrient solution by adding water, treatment 2 - supplementation of nutrient solution by adding initial nutrient solution and treatment 3 - correction of nutrient solution by adding nutrients. Among the bioactive compounds, minerals, ascorbic acid, phenols and photosynthetic pigments content, as well as antioxidant capacity were analysed spectrophotometrically, while individual phenols were determined by liquid chromatography.
Different nutrition solution treatments and the number of harvest cycles had a significant effect on the content of the analysed bioactive compounds. The highest mass fraction (on fresh mass basis) of total phenols expressed as gallic acid equivalents (377.04 mg/100 g), total flavonoids expressed as catechol equivalents (279.54 mg/100 g), ascorbic acid (112.37 mg/100 g) and pigments (total chlorophylls 1.84, and total carotenoids 0.36 mg/g) as well as the highest antioxidant capacity expressed as Trolox equivalents (35.47 µmol/g) were recorded in the samples supplemented with nutrient solution (treatment NS2) and analysed after the third harvest.
This is the first time that stinging nettle leaves have been produced in a floating hydroponic system by controlled plant nutrition. We have set this type of nutritional manipulation with multiple harvest cycles as an innovative technique for the production of novel food with improved nutritional value that can be consumed as green leafy vegetables.
Chamomile (
L.) dried flowers contain a group of interesting biologically active compounds such as sesquiterpenes, flavonoids, coumarins, vitamins, phenolic acids and glucosides. Therefore, the aim ...of the present study was to characterize the composition in bioactive compounds (specialized metabolites) present in water and ethanol extracts of chamomile flowers, together with monitoring the impact of different extraction techniques (conventional vs. ultrasound-assisted extraction (UAE)) on the parameters under investigation. UAE treatment significantly decreased the extraction time of bioactive compounds from herbal material. Polyphenolic compounds content and antioxidant capacity were significantly higher in UAE extracts. Moreover, solvent type had a significant impact on the specialized metabolites content, while the highest vitamin C and polyphenols content were recorded in 50% ethanol (
/
) extracts. Optimization of basic extraction factors: solvent type, temperature and technique is crucial for obtaining the extracts with the highest content of specialized metabolites and antioxidant capacity.
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