123 research outputs found
Carotenoids and antioxidant enzymes as biomarkers of the impact of heavy metals in food chain
Antioxidant enzymes (catalase and peroxidase) and carotenoids (lutein and â-carotene) are often used as biomarkers of metal contamination of water and agricultural soils. In this study, the effects of heavy metals present in irrigation water on the aforementioned carotenoids of potatoes (Solanum tuberosum L.) and carrots (Daucus carota L.), cultivated in a greenhouse and irrigated with a water solution including different levels of Cr(VI) and Ni(II) were investigated. These results were compared to the levels of the same metabolites that had been assessed in market-available potato and carrot samples. The findings indicated that the levels of the examined metabolites on the treated with Cr and Ni samples, resemble the levels of the same parameters in the market samples, originating from polluted areas. Therefore, the antioxidant enzymes, catalase and peroxidase, and the carotenoids, lutein and â-carotene, could be handled as indicators of heavy metal pollution
Prirodni antioksidativni sastojci odabranog aromatičnog bilja i njihovo djelovanje protiv pojedinih patogenih mikroorganizama
Aromatic plants contain natural antioxidant constituents such as phenolic compounds, which have attracted a great deal of public and scientific interest because of their health-promoting effects as antioxidants. Five plants, Filipendula ulmaria (meadow sweet), Crataegus monogyna (hawthorn), Polygonum aviculare (polygonum), Potentilla anserina (silverweed),and Pelargonium purpureum (little robin), have been examined in order to determine their phenolic composition. Reversed-phase high performance liquid chromatography (RP-HPLC) was employed for the identification and quantification of phenolic compounds ofthe aforementioned plants. Gas chromatography–mass spectrometry method (GC-MS) was also used for identification of phenolic compounds after silylation. Analysis of the non-volatile and thermolabile phenolic compounds by GC-MS presupposes their conversion intovolatile and thermotolerant derivatives. The derivatization process was optimized againstreagents, temperature and reaction time. The antioxidant capacity was determined in driedplants and in their methanol extracts with the Rancimat test using sunflower oil as substrate. Both pulverized plants and extracts showed antioxidant capacity. Total phenoliccontent in the extracts was determined spectrometrically applying the Folin-Ciocalteu assay and it ranged from 7.2 to 28.2 gallic acid equivalents (GAE)/(mg/mL). Antimicrobial activity of the extracts against selected microorganisms was performed using the disk diffusion method. Gram-(+) bacteria were more sensitive to the plant extracts than Gram-(–) bacteria.Aromatično bilje sadrži prirodne antioksidanse poput fenolnih spojeva koji su zbog pozitivnog utjecaja na zdravlje privukli pozornost javnosti i znanstvenika. Istražen je fenolni sastav pet vrsta biljaka: končare (Filipendula ulmaria), bijeloga gloga (Crataegus monogyna), troskota (Polygonum aviculare), petoprsta (Potentilla anserina) i purpurne iglice (Pelargonium purpureum). Za određivanje koncentracije i sastava fenolnih spojeva upotrijebljena je visokodjelotvorna tekućinska kromatografija obrnutih faza, a za određivanje sastava fenolnih spojeva, nakon supstitucije vodikova atoma sa -SiMe3 skupinom, primijenjena je plinska kromatografija u kombinaciji s masenom spektrometrijom, kojom je utvrđeno da je došlo do konverzije iz nehlapljivih derivata u hlapljive derivate i iz termolabilnih derivata u termotolerantne derivate. Da bi se dobili derivati željenih svojstava, optimirani su koncentracija reagensa, temperatura i vrijeme reakcije. Primjenom Rancimat metode (kao supstrat je upotrijebljeno suncokretovo ulje) dokazana su antioksidativna svojstva sušenog bilja i ekstrakta dobivenog s metanolom. Primjenom Folin-Ciocalteau metode spektrofotometrijski je određen ukupni udjel fenola u ekstraktima, koji je iznosio 7,2-28,2 mg/mL (izraženo kao galna kiselina). Antimikrobna aktivnost ekstrakata dokazana je disk-difuzijskom metodom, pri čemu je ustanovljeno da su ekstrakti više utjecali na rast Gram-(+) bakterija nego na rast Gram-(-) bakterija
Prirodni antioksidativni sastojci odabranog aromatičnog bilja i njihovo djelovanje protiv pojedinih patogenih mikroorganizama
Aromatic plants contain natural antioxidant constituents such as phenolic compounds, which have attracted a great deal of public and scientific interest because of their health-promoting effects as antioxidants. Five plants, Filipendula ulmaria (meadow sweet), Crataegus monogyna (hawthorn), Polygonum aviculare (polygonum), Potentilla anserina (silverweed),and Pelargonium purpureum (little robin), have been examined in order to determine their phenolic composition. Reversed-phase high performance liquid chromatography (RP-HPLC) was employed for the identification and quantification of phenolic compounds ofthe aforementioned plants. Gas chromatography–mass spectrometry method (GC-MS) was also used for identification of phenolic compounds after silylation. Analysis of the non-volatile and thermolabile phenolic compounds by GC-MS presupposes their conversion intovolatile and thermotolerant derivatives. The derivatization process was optimized againstreagents, temperature and reaction time. The antioxidant capacity was determined in driedplants and in their methanol extracts with the Rancimat test using sunflower oil as substrate. Both pulverized plants and extracts showed antioxidant capacity. Total phenoliccontent in the extracts was determined spectrometrically applying the Folin-Ciocalteu assay and it ranged from 7.2 to 28.2 gallic acid equivalents (GAE)/(mg/mL). Antimicrobial activity of the extracts against selected microorganisms was performed using the disk diffusion method. Gram-(+) bacteria were more sensitive to the plant extracts than Gram-(–) bacteria.Aromatično bilje sadrži prirodne antioksidanse poput fenolnih spojeva koji su zbog pozitivnog utjecaja na zdravlje privukli pozornost javnosti i znanstvenika. Istražen je fenolni sastav pet vrsta biljaka: končare (Filipendula ulmaria), bijeloga gloga (Crataegus monogyna), troskota (Polygonum aviculare), petoprsta (Potentilla anserina) i purpurne iglice (Pelargonium purpureum). Za određivanje koncentracije i sastava fenolnih spojeva upotrijebljena je visokodjelotvorna tekućinska kromatografija obrnutih faza, a za određivanje sastava fenolnih spojeva, nakon supstitucije vodikova atoma sa -SiMe3 skupinom, primijenjena je plinska kromatografija u kombinaciji s masenom spektrometrijom, kojom je utvrđeno da je došlo do konverzije iz nehlapljivih derivata u hlapljive derivate i iz termolabilnih derivata u termotolerantne derivate. Da bi se dobili derivati željenih svojstava, optimirani su koncentracija reagensa, temperatura i vrijeme reakcije. Primjenom Rancimat metode (kao supstrat je upotrijebljeno suncokretovo ulje) dokazana su antioksidativna svojstva sušenog bilja i ekstrakta dobivenog s metanolom. Primjenom Folin-Ciocalteau metode spektrofotometrijski je određen ukupni udjel fenola u ekstraktima, koji je iznosio 7,2-28,2 mg/mL (izraženo kao galna kiselina). Antimikrobna aktivnost ekstrakata dokazana je disk-difuzijskom metodom, pri čemu je ustanovljeno da su ekstrakti više utjecali na rast Gram-(+) bakterija nego na rast Gram-(-) bakterija
Emerging Trends in Biogenic Amines Analysis
Biogenic amines are low-molecular-mass substances, essential for proper health for all organisms. These compounds could be detrimental to human health with various toxicological effects when they are present in high concentrations. Therefore, biogenic amines monitoring in food samples is a matter of utmost importance, and their accurate determination is considered indispensable. Under this context, we provide an overview over the most widely employed analytical techniques for biogenic amines determination such as chromatographic techniques and biosensors, emphasizing on new approaches. A critical comparison of the techniques is also given, presenting their advantages and drawbacks regarding important analytical characteristics such as sensitivity. Finally, we focus on foods in which biogenic amines mainly occur such as fish, meat and wine and other fermented products
Antimikrobni učinak ekstrakta biljke Filipendula ulmaria na patogene bakterije i uzročnike kvarenja na laboratorijskoj podlozi, te u ribljem mesu i ikri
Water-methanol extract from Filipendula ulmaria contains a variety of phenolic compounds, such as caffeic, p-coumaric and vanillic acid, myricetin, etc, which demonstrate antibacterial activity. Monitoring this activity in the broth using absorbance measurements showed that species of the Enterobacteriaceae family were more resistant than other Gram-negative and Gram-positive bacteria tested. Acidic environment enhanced the antibacterial activity of Filipendula ulmaria extract when it was tested against Salmonella Enteritidis PT4 and Listeria monocytogenes Scott A. The efficacy of Filipendula ulmaria extract against selected foodborne psychrotrophic bacteria was also tested using solid laboratory media and low incubation temperatures for better simulation of food preservation conditions. Higher concentrations of the extract, compared to minimum inhibitory concentration determined in the broth, were needed for satisfactory inhibition of spoilage bacteria. Potential use of Filipendula ulmaria extract as natural food preservative was also examined against natural spoilage flora and inoculated pathogenic bacteria on fish flesh and fish roe product (tarama salad). No significant differences of viable populations of spoilage or pathogenic bacteria were found between the treated samples and controls. Further trials of Filipendula ulmaria extract should be carried out in acidic foods with low fat and protein content, supplemented with additional adjuncts, in order to explore its potential as effective natural food antimicrobial agent.Ekstrakt biljke Filipendula ulmaria sadržava različite fenolne spojeve, npr. kafeinska, p-kumarinska i vanilinska kiselina, miricetin i drugo, koji imaju antibakterijski učinak. Mjerenjem apsorbancije praćena je aktivnost tih spojeva u bujonu, te je utvrđeno da su bakterije iz porodice Enterobacteriaceae puno otpornije od ostalih Gram-negativnih i Gram-pozitivnih bakterija. Kisela je sredina pojačala antibakterijski učinak ekstrakta biljke Filipendula ulmaria na bakterije Salmonella Enteritidis PT4 i Listeria monocytogenes Scott A. Ispitan je učinak ekstrakta na odabrane psihrotrofne mikroorganizme na čvrstoj laboratorijskoj podlozi pri niskim temperaturama. Za uspješnu inhibiciju uzročnika kvarenja bila je potrebna veća koncentracija ekstrakta od minimalne inhibicijske koncentracije. Pri prirodnom konzerviranju hrane ispitana je mogućnost primjene ekstrakta na uzročnicima kvarenja i inokuliranim patogenim bakterijama u ribljem mesu i ikri (tarama salata). Nije utvrđena značajna razlika u broju živih stanica uzročnika kvarenja ili patogenih bakterija između obrađenih i kontrolnih uzoraka. Da bi se istražila mogućnost prirodnog konzerviranja hrane dodatkom ekstrakta biljke Filipendula ulmaria, potrebno je provesti daljna istraživanja u tzv. kiseloj hrani, s malim udjelom proteina i masti
Saponin-Based, Biological-Active Surfactants from Plants
Plants have the ability to synthesize almost unlimited number of substances. In many cases, these chemicals serve in plant defense mechanisms against microorganisms, insects, and herbivores. Generally, any part of the plant may contain the various active ingredients. Among the plant, active compounds are saponins, which are traditionally used as natural detergents. The name ‘saponin’ comes from the Latin word ‘sapo,’ which means ‘soap’ as saponins show the unique properties of foaming and emulsifying agents. Steroidal and triterpenoid saponins can be used in many industrial applications, from the preparation of steroid hormones in the pharmaceutical industry to utilization as food additives that exploit their non‐ionic surfactant properties. Saponins also exhibit different biological activities. This chapter has been prepared by participants of the Marie Sklodowska‐Curie Action—Research and Innovation Staff Exchange (RISE) in the framework of the proposal ‘ECOSAPONIN.’ Interactions between the participants, including chemists, physicists, technologists, microbiologists and botanists from four countries, will contribute to the development of collaborative ties and further promote research and development in the area of saponins in Europe and China. Although this chapter cannot provide a comprehensive account of the state of knowledge regarding plant saponins, we hope that it will help make saponins the focus of ongoing international cooperation
Development of simultaneous antioxidant and visual pH-sensing films based on guar gum loaded with Aronia melanocarpa extract
Anthocyanins have attracted increasing attention for different packaging systems due to having functional features such as biocompatibility, antioxidative activity, visible colour response at varying pH values. In this study, the extract of Aronia melanocarpa as anthocyanins source was incorporated into guar gum films to take advantage of both antioxidant and pH responsive attributes. Aronia addition did not affect the thermal stability of guar gum films. Radical scavenging activity of the films (%) was measured by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, and aronia added films exhibited very strong antioxidant activity (up to 85%). The colour of aronia solution varied from pink to brown with pH ranging from 1 to 13. Similarly, when the films were immersed in buffer solutions at different pH values, the visual colour varied from pink to brownish yellow. ΔE values of GR_AR_3 (guar gum films having the highest aronia concentration) ranged between 23.31 and 40.62 at pH 1–13. This result proved colour change of the films can be even detected by untrained consumers. Furthermore, the films were found to be very sensitive to ammonia vapour. Aronia incorporated guar gum films could be suggested as both antioxidant films to prevent foods oxidation from oxidation and promising intelligent films to monitor the deterioration of foods
Enhancing effect of chia seeds on heterocyclic amine generation in meatball
The impact of using chia seeds at different rates (0%, 0.5%, 1%, and 1.5%) in meatball on the water content, pH and lipid oxidation (thiobarbituric acid reactive substances, TBARS), cooking loss and heterocyclic aromatic amines (HAAs) content of meatballs cooked at 150, 200, and 250 °C was investigated. The chia seed significantly affected water content (P 0.05) was detected on TBARS value. With cooking, water content decreased (P < 0.01), while the pH and TBARS values increased (P < 0.01). Cooking temperatures significantly affected (P < 0.01) the water content, cooking loss and total HAAs content. The content of total HAAs of the meatballs increased with increasing the cooking temperature. The results illustrated that IQ, 7,8-DiMeIQx, 4,8-DiMeIQx, AαC and MeAαC were below the detectable limit (<LOD) in all samples, while MeIQx was the dominant compound among the detected HAAs compounds. The research indicated that the use of chia seeds increased the total HAA content, and the highest level was found in meatballs prepared with 1% chia seeds
Thorough investigation of the phenolic profile of reputable Greek honey varieties:varietal discrimination and floral markers identification using liquid chromatography–high-resolution mass spectrometry
Honey is a highly consumed commodity due to its potential health benefits upon certain consumption, resulting in a high market price. This fact indicates the need to protect honey from fraudulent acts by delivering comprehensive analytical methodologies. In this study, targeted, suspect and non-targeted metabolomic workflows were applied to identify botanical origin markers of Greek honey. Blossom honey samples (n = 62) and the unifloral fir (n = 10), oak (n = 24), pine (n = 39) and thyme (n = 34) honeys were analyzed using an ultra-high-performance liquid chromatography hybrid quadrupole time-of-flight mass spectrometry (UHPLC-q-TOF-MS) system. Several potential authenticity markers were revealed from the application of different metabolomic workflows. In detail, based on quantitative targeted analysis, three blossom honey markers were found, namely, galangin, pinocembrin and chrysin, while gallic acid concentration was found to be significantly higher in oak honey. Using suspect screening workflow, 12 additional bioactive compounds were identified and semi-quantified, achieving comprehensive metabolomic honey characterization. Lastly, by combining non-targeted screening with advanced chemometrics, it was possible to discriminate thyme from blossom honey and develop binary discriminatory models with high predictive power. In conclusion, a holistic approach to assessing the botanical origin of Greek honey is presented, highlighting the complementarity of the three applied metabolomic approaches
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