Istovremeno određivanje ohratoksina A i ostataka pesticida u grožđu i vinu LC-MS/MS tehnikom

A fast, selective and sensitive reversed-phased liquid chromatography with tandem mass spectrometry (LC–MS/MS) method was developed and validated for simultaneous quantification of 41 pesticide residues and ochratoxin A (ОТА) in grapes and wine. For increasing sensitivity of mass spectrometer multiple reaction monitoring (MRM) was transferred into time segmented method, dynamic multiple reaction monitoring (dMRM). Grape and wine extraction and purification for both, pesticide residues and OTA, were performed with a modified Quick Easy Cheap Effective Rugged and Safe (QuEChERS) method. For OTA LC-MS/MS analysis acetonitrile extract was directly injected into system, and for pesticide analysis extracts were purified with dispersive solid phase extraction for pigmented samples (black grapes and red wine) and for fruits and vegetables (white grapes and wine). MS/MS conditions were optimized in order to increase selectivity, selecting the corresponding product ions (precursor-to-fragment m/z 404 → 239 and m/z 404 → m/z 221) for quantification and identification. For pesticide residues, MS/MS aquisition parameters, SRM transitions, fragment and colision energies, from database were used. For method validation, the performance of the method was assessed and compared with the European Commission (EC) Regulations 401/2006 for OTA and with the SANTE/11813/2017 document for pesticide residues, by studying the linearity, limit of detection (LOD), limit of quantification (LOQ), matrix effect, accuracy and precision. Linearity for quantification pesticide residues in grapes and wine was performed in mobile phase and in sample matrixes (0.005 – 0.500 mg/kg) and by standard addition (0.010 – 0.200 mg/kg). Correlation coefficients for most pesticides, in all four matrixes, were over 0.99. Linearity for OTA quantification in grapes was performed in acetonitrile and in the sample matrixes (0.001 – 0.050 μg/ml) and in acetonitrile and in wine matrixes (0.0005 – 0.010 μg/ml).Razvijena je brza, selektivna i osetljiva tečno-hromatografska metoda sa masenom spektrometrijom (LC-MS/MS) za istovremeno kvantitativno određivanje ostataka 41 aktivne supstance pesticida i ohratoksina A (OTA) u grožđu i vinu. Zbog povećanja osetljivosti masenog spektrometra za ispitivane analite postavljena multirezidualna metoda (MRM) je prebačena u vremenski segmentisanu metodu, tzv. metodu u dinamičkom modu (dMRM). Ekstrakcija i prečišćavanje analita iz uzoraka grožđa i vina su rađene modifikovanom Quick Easy Cheap Effective Rugged and Safe (QuEChERS) metodom. Za analizu OTA acetonitrilni ekstrakt je direktno analiziran LC-MS/MS tehnikom, dok je prečišćavanje ekstrakta za analizu ostataka rađeno pomoću kolona za disperziju na čvrstoj fazi za pigmentisane uzorke (crno grožđe i crveno vino) i za voće i povrće (belo grožđe i belo vino). Za detekciju OTA uslovi masenog spektrometra su optimizovani u cilju povećanja selektivnosti izborom jona sa najosetljivijim odgovorom (m/z 404 239 i m/z 404 221) za kvantifikaciju i identifikaciju. Za detekciju aktivnih supstanci pesticida akvizicioni parametri masenog spektrometra, SRM prelazi, fragmentacione energije i kolizione energije su preuzete iz baze podataka. U cilju razvoja metode ispitani su parametri linearnost odgovora detektora, granica detekcije (LOD), granica merenja (LOQ), matriks efekat, tačnost, preciznost i pouzdanost, a dobijene vrednosti su upoređene sa kriterijumima Uredbe 401/2006 za OTA i SANTE/11813/2017 dokumenta za aktivne supstance pesticida. Linearnost metode za ostatake u grožđu i vinu je ispitivana u mobilnoj fazi i matriksima uzoraka (0,005 do 0,500 mg/kg) i metodom standardnog dodatka (0,010 - 0,200 mg/kg)..

Fatty acid profiles and mineral content of Serbian traditional white brined cheeses

This study deals with fatty acid profiles and mineral contents of traditional Serbian white cheeses in brine. Study covered four Serbian traditional white brined cheeses: Zlatar cheese, Sjenica cheese, Svrljig cheese and Homolje cheese prepared from raw cow and ovine milk. Fatty acid profiles of traditional cheeses were qualitatively and quantitatively different. The content of saturated fatty acids was in the range of 65.97 %-76.61 % (cow cheeses) and 69.68 %-74.52 % (ovine cheeses). Unsaturated fatty acids range of cow and ovine cheeses was 23.39 %-34.03 % and 25.48 %-30.08 %, respectively. Depending on the type of cheese, the ratio of polyunsaturated fatty acids was 1.66 %-11.03 %. The lowest content of saturated fatty acids was observed in Sjenica cow cheeses. Thus, this type of traditional cheeses had the most favorable health indices including atherogenicity index (1.89), thrombogenicity index (1.37) and desirable fatty acid ratio (46.34 %). Mineral content of traditional cheeses was also different. The ratio Ca:P was in the range of 0.70-1.33. The highest level of Ca, P, K, Mg, Zn, Cu and Cr was detected in Sjenica cheeses prepared from cow milk. The absence of Cd was observed in all cheeses

Selection of Non-Mycotoxigenic Inulinase Producers in the Group of Black Aspergilli for Use in Food Processing

Research background. Inulinases are used for fructooligosaccharide production and they are of interest for both scientific community and industry. Black aspergilli represent a diverse group of species that has use for enzyme production, in particular some species are known as potent inulinase producers. Finding new potential producers from the environment is as important as improving the production with known strains. Safe use of enzymes produced by aspergilli in food industry is placed ahead of their benefit for inulinase production. Experimental approach. Here we show a specific approach to finding/screening of newly isolated fungal inulinase producers that combines a newly developed screening method and an equally important assessment of the toxigenic potential of the fungus. In this study 39 black aspergilli collected from different substrates in Serbia were identified and assessed for inulinase production. Results and conclusions. The most common species were Aspergillus tubingensis (51.2 %), followed by A. niger (23.1 %), A. welwitschiae (23.1 %) and A. uvarum (2.6 %). The isolates for inulinase production were selected using a cheap and easy, fast and non-hazardous alternative inulinase screening test developed in this work. Enzymatic activity of selected inulinase-producing strains was confirmed spectrophotometrically. Since some A. niger and A. welwitschiae strains are able to produce mycotoxins ochratoxin A (OTA) and fumonisins (FB), the toxigenic potential of selected inulinase producers was assessed analytically and genetically. Fungal enzyme producer can be considered safe for use in food industry only after comparing the results of both approaches for investigating toxic potential, the direct presence of mycotoxins in the enzyme preparation (analytically) and the presence of mycotoxin gene clusters (genetically). In some strains the absence of OTA and FB production capability was molecularly confirmed by the absence of complete or critical parts of biosynthetic gene clusters, respectively. The two best inulinase producers and mycotoxin non-producers (without mycotoxin production capability as additional safety) were selected as potential candidates for further development of enzyme production. Novelty and scientific contribution. The presented innovative approach for the selection of potential fungal enzyme producer shows that only non-toxigenic fungi could be considered as useful in food industry. Although this study was done on local isolates, the approach is applicable globally

Preliminarno ispitivanje sastava masnih kiselina u semenkama šipurka: primena ultrazvučne ekstrakcije

Rosehip seeds represent waste material which is obtained duringthe production of jams, marmalades, juices, teas, etc. Two methods were used forthe extraction of fatty acids from rosehip seeds: ultrasound-assisted extractioncombined with organic solvent extraction (UAE/OSCE) and organic solventconventional extraction (OSCE). Different solvent-to-sample ratio was used. Theidentification and quantitation of fatty acids was done by gas chromatography witha flame ionization detector (GC/FID). Applied methods yielded different types offatty acids, with stearic acid and linoleic acid, as the most abundant ones.Semenke šipurka predstavljaju otpadni materijal, bogat uljem, koji nastaje tokom proizvodnje džemova, marmelada, sokova, čajeva itd. Za ekstrakciju masnih kiselina iz semenki šipurka korišćene su dve metode: ultrazvučna ekstrakcija u kombinaciji sa ekstrakcijom organskim rastvaračem (UZE/KEOR)i konvencionalna ekstrakcija organskim rastvaračem (KEOR). Korišćeni su različiti odnosi zapremine rastvarača i mase uzoraka. Identifikacija i kvantifikacija masnih kiselina izvršena je metodom gasne hromatografije sa plameno-jonizujućim detektorom (GC/FID). Primenjenim ekstrakcionim metodama dobijene su različite masne kiseline, od kojih su stearinska i linolna bile najzastupljenije

Pesticide residues in maize by LC-MS/MS

The liquid chromatography tandem-mass spectrometry (LC–MS/MS) with ESI was applied for the detection of 60 pesticides residues in maize, extracted with QuEChERS. The average recoveries for all analites were 83.7-121.9% (RSDs 4.82-15.34%). The obtained R2 values for all investigated pesticides were higher than 0.99. The LOQs of 0.01 mg/kg confirm that the method is appropriate for the determination of pesticide residues in all investigated vegetables according to the regulations of the Serbian and EU MRLs. One sample was with no detected pesticide residues and in three samples only one pesticide residue was detected. The multiple detections were confirmed in three analyzed samples. All the detections were below the MRLs

Screening of neonicotinoids in surface water samples by liquid chromatography quadrupole time-of-flight mass spectrometry

The EU Decision 2015/495 concerning the watch list of substances for Union-wide monitoring in the field of water policy pursuant to Directive 2008/105/EC,among others, includes neonicotinoid insecticides, as well. The LC-QTof-MS technique was used for screening analysis of the surface water samples from Serbia. The residues of thiamethoxam, acetamiprid and imidacloprid were detected

Linuron residue findings in chamomile flowers

Text The aim of this study was to highlight the influence of herbicide usage in agriculture on linuron residues in chamomile flower. It was collected six chamomile flower samples. The validated LC-MS/MS method according to SANTE/11813/2017 was applied in the quantitative analyses. Two samples were with no linuron detection, while all the other detected concentrations exceeded maximum residue limit of 0.1 mg/kg. The detected concentrations were in the range 0.89 to 1.90 mg/kg

Bioprospecting of Selected Species of Polypore Fungi from the Western Balkans

Growing mushrooms means meeting challenges while aiming for sustainability and circularity. Wherever the producer is located, commercial strains are the same originating from several producers. Customized strains adapted to local conditions are urgently needed. Before introducing new species to the strain development pipeline, the chemical characterization and biological activity of wild ones need to be assessed. Accordingly, the mycoceutical potential of five polypore mushroom species from Serbia was evaluated including: secondary metabolite composition, oxidative damage prevention, anti-tyrosinase, and anti-angiotensin converting enzyme (ACE). The phenolic pattern was comparable in all samples, but the amounts of specific chemicals varied. Hydroxybenzoic acids were the primary components. All samples had varying quantities of ascorbic acid, carotene, and lycopene, and showed a pronounced inhibition of lipid peroxidation (LPx) and ability to scavenge HO•. Extracts were more potent tyrosinase inhibitors but unsuccessful when faced with ACE. Fomitopsis pinicola had the strongest anti-tumor efficacy while Ganoderma lucidum demonstrated strong selectivity in anti-tumor effect in comparison to normal cells. The evaluated species provided a solid foundation for commercial development while keeping local ecology in mind

Identifying the Biological Potential of Western Balkan Polypore Mushroom Species to Mitigate the Negative Effects of Global Mushroom Cultivation

Growing mushrooms is meeting challenges while aiming for sustainability and circularity. Wherever the producer is located, commercial strains are the same originating from several producers. Following the harvest, enormous quantities of spent mushroom substrate containing spores are disposed presenting a type of foreign material pressure on the ecosystem in the form of the loss of genetic diversity in wild mushroom populations. This challenge can be mitigated by bioprospecting local strains and using them to generate commercial inoculum. Accordingly, the mycoceutical potential of five polypore mushroom species from Serbia was evaluated: secondary metabolite composition, oxidative damage prevention, anti-tyrosinase, and antiangiotensin converting enzyme (ACE) properties. The phenolic pattern was comparable in all samples, but the amounts of specific chemicals varied. Hydroxybenzoic acids were the primary components. All samples had varying quantities of ascorbic acid, carotene, and lycopene, and showed a pronounced inhibition of lipid peroxidation (LPx) and ability to scavenge HO•. Extracts were more potent tyrosinase inhibitors but unsuccessful when faced with ACE. Fomitopsis pinicola had the strongest anti-tumor efficacy while Ganoderma lucidum demonstrated strong selectivity in anti-tumor effect in comparison to healthy cells. The evaluated species provided a solid foundation for commercial development while keeping the local ecology in mind.This is not peer-reviewed version.The supplementary information: [https://cer.ihtm.bg.ac.rs/handle/123456789/7058

Comparison of phenylurea pesticides recovery from different soil types

The subject of this research work is to determine the recoveries of the studied analytes from the chemical group of phenylurea: isoproturon, diuron and linuron, depending on the physicalchemical soil properties within the validation of multi-residual method for the determination of the herbicide residues in soil by (LC-MS/MS) after QuEChERS extraction of spiked soil samples. The factorial ANOVA did not show any statistical significances regarding the influence of the paired values of different pesticides and soil types. The same result was obtained by the one-way ANOVA calculated for different soil types (ps=0.151060 for p˂0.05) and different pesticides (pp=0.165207 for p˂0.05) regarding the values of average recoveries. Fishers LSD post hoc test emphasized the homogenity and similarity among average recovery values in both cases