Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
8
result(s) for
"Velikonja Bolta, Špela"
Sort by:
Is Common Dandelion (Taraxacum officinale agg.) Foraged for Food in Vineyards Pesticide Residues Free?
by
Baša Česnik, Helena
,
Rusjan, Denis
,
Velikonja Bolta, Špela
in
Acetonitrile
,
Agricultural ecosystems
,
Agricultural practices
2025
Consumption of common dandelion (Taraxacum officinale agg.) can pose a risk when foraged in agroecosystems like vineyards where pesticides are frequently used. The aims of our study are to evaluate whether dandelion foraged in vineyards with different management practices (integrated pest management, organic, and biodynamic) in spring is suitable for consumption and to assess whether the contents of selected pesticide residues (PR) in integrated vineyards in dandelion vary throughout the seasons. Young dandelion leaves were sampled in spring, summer, and autumn in integrated vineyards, while in spring also in organic and biodynamic vineyards. The selected PR was analyzed using GC-MS/MS and LC-MS/MS, using extraction with acetonitrile. The method was validated on a dandelion matrix according to international guideline SANTE 11312/2021. Despite the use of many pesticides in integrated vineyards, only tebuconazole was detected in spring in one sample (0.005 mg/kg), while no PR was detected in dandelion from organic and biodynamic vineyards. However, at summer sampling seven different PR were detected, of which the kresoxim-methyl maximum residue limit was exceeded in five samples (0.012–0.029 mg/kg), while in autumn no PR was detected. Based on this study, it seems that dandelion leaves foraged in vineyards in spring could be unproblematic for consumption.
Journal Article
UHPLC-MS/MS determination of varietal thiol precursors in Sauvignon Blanc grapes
2017
Varietal thiol precursors in grapes are subject to metabolic changes during post-harvest treatments. Metabolic activity should therefore be limited after sampling to understand their biosynthesis in the berry and genetic regulation. In this study, berries were frozen in liquid nitrogen immediately after harvesting, transported in dry ice, stored briefly at −80 °C, cryo-milled and extracted without being thawed in cold methanol in a ratio of 1:4 (w/v). A UHPLC-MS/MS method for quantitative determination of the thiol precursors 3-
S
-glutathionylhexan-1-ol (G3MH), 3-
S
-cysteinylhexan-1-ol (Cys3MH), 4-
S
-glutathionyl-4-methylpentan-2-one (G4MMP) and 4-
S
-cysteinyl-4-methylpentan-2-one (Cys4MMP), glutathione, oxidized glutathione and L-methionine in grapes was developed. Reference material was provided through synthesis of precursors and their deuterium labelled analogues. The average thiol precursor content in grapes in 2013–15 was in the range 8–16 μg kg
−1
for G3MH, 1–6 μg kg
−1
for Cys3MH, 1–4 μg kg
−1
for Cys4MMP and 0.3 μg kg
−1
for G4MMP. In 2013 and 2014, the highest precursor content in mature Sauvignon Blanc grapes from vineyards located in Italy regarded G3MH, followed by Cys3MH, Cys4MMP and G4MMP. In 2015, G3MH was again the most abundant precursor, but followed by Cys4MMP, Cys3MH and G4MMP.
Journal Article
Pesticide Residues and Heavy Metals in Vineyard Soils of the Karst and Istria
by
Vrščaj, Borut
,
Velikonja Bolta, Špela
,
Radeka, Sanja
in
Agricultural management
,
Agricultural production
,
Arsenic
2022
Pesticide residues and heavy metal concentrations were determined in two depths (0–20 and 20–40 cm) of Chromic Cambisol in 69 vineyards in the Slovenian winegrowing region of the Karst. Similarly, pesticide residues and heavy metal concentrations were also determined in two depths of Calcaric Cambisol in 11 vineyards in the other Slovenian and Croatian winegrowing regions of Istria. The topsoil (0–20 cm) was analysed for the presence of 176 different pesticidal active substances using two multiresidue analytical methods: (a) gas chromatography coupled with mass spectrometry (GC/MS) and (b) liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). Seven active substances (five fungicides and two insecticides) were detected in the soil samples. Their concentrations were compared with the maximum concentrations observed in the vineyards of the winegrowing regions of France, Italy, and Spain. In addition to pesticides, the soil samples were analysed for the presence of nine heavy metals commonly detected in vineyard soils. The concentrations of arsenic, cadmium, cobalt, chromium, copper, molybdenum, nickel, lead, and zinc were below the critical thresholds set by Slovenian legislation, with the exception of one soil sample in which the Cu concentration exceeded the critical threshold. Compared with the maximum concentrations measured in other vineyard soils in Spain, Italy, and France, the heavy metal concentrations in the vineyard soils of Karst and Istria were lower. Both the heavy metal concentrations and the residual concentrations of pesticidal active substances in the vineyard soils of the Karst and Istria regions were significantly lower than the concentrations that are occasionally discussed in the literature.
Journal Article
Residues of Pesticides in Honeybee (Apis mellifera carnica) Bee Bread and in Pollen Loads from Treated Apple Orchards
by
Smodiš Škerl, Maja Ivana
,
Baša Česnik, Helena
,
Gregorc, Aleš
in
analysis
,
Animals
,
Apis mellifera
2009
Honey bee (Apis mellifera carnica) colonies were placed in two apple orchards treated with the insecticides diazinon and thiacloprid and the fungicide difenoconazole in accordance with a Protection Treatment Plan in the spring of 2007. Pollen and bee bread were collected from combs inside the hives. The residue of diazinon in pollen loads 10 days after orchard treatment was 0.09 mg/kg, and the same amount of residue was found in bee bread 16 days after treatment. In pollen loads 6 days after application 0.03 mg/kg of thiacloprid residues and 0.01 mg/kg of difenoconazole were found on the first day after application. Possible sub-lethal effects on individual honey bees and brood are discussed.
Journal Article
Determination of free amino acid content in the Slovenian drycured ham »Kraški pršut« and product characterization
by
ŠKRLEP, Martin
,
JANEŠ, Lucija
,
ČANDEK-POTOKAR, Marjeta
in
biceps femoris
,
chemical composition
,
dry-cured ham
2012
The aim of this study was to characterize the chemical profile of dry-cured ham selected and processed in accordance with the Slovenian consortium rules for »Kraški pršut« and to investigate the differences between the Biceps femoris (BF) and the Semimembranosus (SM) muscle. The free amino acid content, moisture, salt, protein, total nitrogen, non-protein nitrogen, proteolysis index, intramuscular fat and dry matter were analysed in 135 samples of dry-cured hams including both muscles. A modified method for sample preparation was developed for determination of free amino acids in dry-cured ham. The method was validated for linearity, limit of detection, limit of quantification, precision and uncertainty. According to the validation parameters the method is appropriate for the determination of free amino acid content in dry-cured ham. Higher content for several free amino acids and total free amino acids were determined in the BF muscle compared to the SM muscle.
Journal Article
Microbial community structure during composting with and without mass inocula
by
Bolta, Spela Velikonja
,
Lobnik, Franc
,
Lestan, Domen
in
Actinomycetales
,
Biological and medical sciences
,
Community structure
2003
Inoculation of a mixture of household organics and shredded wood with inocula from the active phase of composting enhanced mineralization of organic matter and yielded a biologically stabilized product with a more favorable C/N ratio than in a noninoculated treatment. Analysis of phospholipid fatty acids was used to determine total viable microbial biomass and relative amounts of bacteria, Gram positive and Gram negative bacteria, actinomycetes, fungi, thermophiles and nonthermophiles in compost. The initial viable microbial biomass was 6-fold higher in inoculated than in noninoculated compost. The thermophilic phase occurred immediately after inoculation and the total viable biomass afterwards followed the course of temperature. The ratio of viable (sum of phospholipid fatty acids) to dead (sum of diglyceride fatty acids) microbial biomass during this period was generally higher at lower composting temperatures in both inoculated and noninoculated compost. During composting, fluctuations in total viable microbial biomass and in the relative amounts of indicator PLFAs of all microbial groups except Gram negative bacteria was more intensive in noninoculated compost.
Journal Article
Pesticide residues in samples of apples, lettuce and potatoes from integrated pest management in Slovenia from 2005-2009
by
Ana GREGORČIČ
,
Helena BAŠA ČESNIK
,
Špela VELIKONJA BOLTA
in
apples
,
gc/ms
,
integrated pest management
2012
In the period from 2005 to 2009 225 samples of apples, lettuce and potatoes from Slovene producers included in integrated pest management (IPM) were analysed for plant protection product (PPP) residues. The samples were analysed for the presence of more than 200 different active compounds using four analytical methods. In 38.7% of apple samples residues were not detected, 58.6% of apple samples contained residues lower than or equal to Maximum Residue Levels (MRLs) while 2.7% of apple samples exceeded MRLs. In 84.6% of lettuce samples residues were not detected, 12.3% of lettuce samples contained residues lower than or equal to MRLs while 3.1% of lettuce samples exceeded MRLs. In 98.0% of potato samples residues were not detected, 2.0% of potato samples contained residues lower than or equal to MRLs and no potato samples exceeded MRLs. Multiple residues were found only in apples and lettuce. The trend observed during the years was the decrease of sample portion of samples containing multiple residues in apples from 2005 to 2008. The most frequently found active substance in apples and lettuce was dithiocarbamates. In potato only phosalone was found.
Journal Article
Pesticide residues in samples of apples, lettuce and potatoes from integrated pest management in Slovenia from 2005-2009
2012
In the period from 2005 to 2009 225 samples of apples, lettuce and potatoes from Slovene producers included in integrated pest management (IPM) were analysed for plant protection product (PPP) residues. The samples were analysed for the presence of more than 200 different active compounds using four analytical methods. In 38.7% of apple samples residues were not detected, 58.6% of apple samples contained residues lower than or equal to Maximum Residue Levels (MRLs) while 2.7% of apple samples exceeded MRLs. In 84.6% of lettuce samples residues were not detected, 12.3% of lettuce samples contained residues lower than or equal to MRLs while 3.1% of lettuce samples exceeded MRLs. In 98.0% of potato samples residues were not detected, 2.0% of potato samples contained residues lower than or equal to MRLs and no potato samples exceeded MRLs. Multiple residues were found only in apples and lettuce. The trend observed during the years was the decrease of sample portion of samples containing multiple residues in apples from 2005 to 2008. The most frequently found active substance in apples and lettuce was dithiocarbamates. In potato only phosalone was found. V obdobju od 2005 do 2009 smo na ostanke fitofarmacevtskih sredstev (FFS) analizirali 225 vzorcev jabolk, solate in krompirja slovenskih proizvajalcev vključenih v integrirano pridelavo (IP). Vse vzorce smo analizirali s štirimi analitskimi metodami na prisotnost več kot 200 različnih aktivnih spojin. V 38,7% vzorcev jabolk ostankov nismo določili, 58,6% vzorcev jabolk je vsebovalo ostanke manjše ali enake maksimalnim dovoljenim količinam ostankov (MRL) medtem ko je 2,7% vzorcev jabolk preseglo MRL vrednosti. V 84.6% vzorcev solate ostankov nismo določili, 12,3% vzorcev solate je vsebovalo ostanke manjše ali enake MRL vrednostim medtem ko je 3,1% vzorcev solate preseglo MRL vrednosti. V 98,0% vzorcev krompirja ostankov nismo določili, 2,0% vzorcev krompirja je vsebovalo ostanke manjše ali enake MRL vrednostim in nobeden vzorec krompirja ni presegel MRL vrednosti. Ostanke dveh ali več aktivnih spojin smo določili le v jabolkih in solati. Trend, ki smo ga opazili tekom let je, da delež vzorcev, ki vsebujejo ostanke dveh ali več aktivnih spojin v jabolkih, pada od leta 2005 do 2008. Najpogosteje najdena aktivna snov v jabolkih in solati je ditiokarbamati. V krompirju smo določili le fosalon.
Journal Article