Iveta Pugajeva

Acute anti-hyperglycaemic effects of an unripe apple preparation containing phlorizin in healthy volunteers: a preliminary study.

BACKGROUND The health-promoting properties of apples are directly related to the biologically active compounds that they contain, such as polyphenols. The objective of this study was to prepare a low-sugar, fibre- and phlorizin-enriched powder from unripe apples and to gain insight regarding its anti-hyperglycaemic activity in healthy volunteers. RESULTS The unripe apples (Malus domestica Borkh.) were collected 30 days after the full bloom day; blanched and pressed to obtain apple pomace which was then processed with a food cutter, oven-dried and milled to prepare apple powder. The concentrations of total sugars, water-soluble pectin and phlorizin in the apple preparation were 153.44 ± 2.46, 27.73 ± 0.51 and 12.61 ± 0.15 g kg(-1), respectively. Acute ingestion of the apple preparation improved glucose metabolism in the oral glucose tolerance test (OGTT) in six healthy volunteers by reducing the postprandial glucose response at 15 to 30 min by approximately two-fold (P < 0.05) and by increasing urinary glucose excretion during the 2- to 4-h interval of the OGTT by five-fold (P < 0.05). CONCLUSION The results obtained indicate that the dried and powdered pomace of unripe apples can be used as a health-promoting natural product for the reduction of postprandial glycaemia and to improve the health of patients with diabetes.

Ultra high performance liquid chromatography-time-of-flight high resolution mass spectrometry in the analysis of hexabromocyclododecane diastereomers: method development and comparative evaluation versus ultra high performance liquid chromatography coupled to Orbitrap high resolution mass spectrometry and triple quadrupole tandem mass spectrometry.

An efficient ultra high performance liquid chromatography (UHPLC)-time-of-flight high resolution mass spectrometry (TOF-HRMS) method was elaborated for the determination of hexabromocyclododecane (HBCD) diastereomers in fish samples and compared against UHPLC-Orbitrap-HRMS and UHPLC-triple quadrupole (QqQ) tandem MS (MS/MS) techniques. The TOF-HRMS analyzer was operated at high resolution (>10000 full width at half maximum (FWHM)) with scanning the m/z range from 600 to 700, to achieve picogram quantitation limits. The effects of various operational parameters on the instrumental response were systematically investigated. Evaluation of the influence of sample clean-up procedure steps on signal suppression effect including removal of the matrix components by means of destructive acidic treatment or non-destructive gel permeation chromatography (GPC), and additional Florisil column chromatography step showed that the analytical response of UHPLC-TOF-HRMS system is much more affected by the presence of matrix components in the final extracts in comparison with UHPLC-Orbitrap-HRMS and UHPLC-QqQ-MS/MS systems. The method was robustly validated and used for the analysis of eel (Anquilla anquilla) samples originating from a Latvian lake. UHPLC-TOF-HRMS showed a suitable performance under the optimized conditions: recoveries for three selected diastereomers in the range of 99-116%; repeatability and intermediate precision expressed as relative standard deviation (RSD) in the ranges of 2.3-7.1% and 2.9-8.1%, respectively. The elaborated method achieved instrumental limits of quantification (i-LOQ) of 0.9-4.5pg on column that were suitable for the trace analysis of three HBCD diastereomers, corresponding to the method limits of quantification (m-LOQ) of 7.0-29pgg(-1) wet weight (w.w.). The efficiency of UHPLC-TOF-HRMS method was evaluated by comparing the performance characteristics and analytical data from real samples with the validation data and real sample results obtained by applying UHPLC-Orbitrap-HRMS and UHPLC-QqQ-MS/MS techniques for the analysis of HBCD in the same fish samples. Statistical assessment of the experimental data by means of the Fiedmans test revealed that UHPLC-TOF-HRMS, UHPLC-QqQ-MS/MS and UHPLC-Orbitrap-HRMS techniques produced adequate and similar results regarding the HBCD content in fish samples. The presence of HBCD diastereomers was confirmed in all the analyzed eels at concentrations up to 554pgg(-1) w.w. for total HBCD and a diastereomer pattern typical for aquatic biota was observed with strong predominance of α-HBCD. The UHPLC-TOF-HRMS is an appropriate technique for diastereomer-specific quantification of HBCD content in fish samples.

Effect of lactic acid fermentation of lupine wholemeal on acrylamide content and quality characteristics of wheat-lupine bread

Abstract The effect of supplementing wheat flour at a level of 15% with lupine (Lupinus angustifolius L.) wholemeal fermented by different lactic acid bacteria on acrylamide content in bread crumb as well as on bread texture and sensory characteristics was analysed. The use of fermented lupine resulted in a lower specific volume and crumb porosity of bread on an average by 14.1% and 10.5%, respectively, while untreated lupine lowered the latter parameters at a higher level (30.8% and 20.7%, respectively). The addition of lupine resulted in a higher by 43.3% acrylamide content compared to wheat bread (19.4 µg/kg dry weight (d.w.)). Results showed that acrylamide was significantly reduced using proteolytic Lactobacillus sakei and Pediococcus pentosaceus 10 strains for lupine fermentation. Although the bread supplemented with lupine spontaneous sourdough had the lowest level of acrylamide (15.6 µg/kg d.w.), it had the malodorous flavour and was unacceptable to the consumers. The lactofermentation could increase the potential use of lupine as a food ingredient while reducing acrylamide formation and enriching bread with high quality proteins.

Determination of pharmaceutical residues in wastewater using high performance liquid chromatography coupled to quadrupole-Orbitrap mass spectrometry

HIGHLIGHTSA method for the determination of 24 emerging pharmaceuticals has been developed.The analysis of 21 samples revealed the occurrence of 20 selected pharmaceuticals.The highest concentration was found for caffeine and acetaminophen. ABSTRACT A multi‐class method for the determination of 24 emerging pharmaceutical residues has been developed and validated. The method is based on solid‐phase extraction of wastewater samples using Strata‐X cartridges followed by high performance liquid chromatography coupled to hybrid quadrupole − Orbitrap high resolution mass spectrometry (HPLC‐Q‐Orbitrap‐HRMS). A single‐laboratory validation procedure showed satisfactory analytical performance. The analysis of 21 samples collected at the wastewater treatment plant in Riga revealed the occurrence of 20 compounds of different therapeutic classes. The highest concentration was found for the central nervous system stimulator caffeine − up to 12 &mgr;g L−1, the analgesic acetaminophen up to 4.2 &mgr;g L−1, the antibiotic ciprofloxacin in the concentration range of 250–400 ng L−1, and the non‐steroidal anti‐inflammatory drug (NSAID) ibuprofen at 100–325 ng L−1.

Sesamin and sesamolin as unexpected contaminants in various cold-pressed plant oils: NP-HPLC/FLD/DAD and RP-UPLC-ESI/MS(n) study.

Thirteen cold-pressed oils (Japanese quince seed, black caraway, flaxseed, rapeseed, hemp, peanut, sunflower, pumpkin, hazelnut, poppy, walnut, almond and sesame oil) manufactured by the same company over a 2-year period (2011–12) were assessed for lipophilic compounds. The presence of sesamin and sesamolin, two characteristic lignans of sesame oil, were detected in all tested plant oils. Both lignans were identified by NP-HPLC/FLD/DAD and confirmed by a RP-UPLC-ESI/MSn method. The lowest amount of sesamin and sesamolin was found for Japanese quince seed oil (0.10 and 0.27 mg/100 g), and the highest, excluding sesame oil, for almond oil (36.21 and 105.42 mg/100 g, respectively). The highly significant correlation between sesamolin and sesamin concentrations was found in all samples tested (r = 0.9999; p < 0.00001). These results indicate contamination of cold-pressed oils from the same source. This investigation highlights the fact that increasing the range of products manufactured by the same company can contribute to a lesser regard for the quality of the final product. Moreover, less attention paid to the quality of final product can be related to the health risks of consumers especially sensitive to allergens. Therefore, proper cleaning of processing equipment is needed to prevent cross-contact of cold-pressed oils.

The effects of woodchip- and straw-derived biochars on the persistence of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) in soils.

Sorption and degradation are the primary processes controlling the efficacy and runoff contamination risk of agrochemicals. This study assessed the influence of two biochars, made from woodchips and straw at a pyrolysis temperature of 725°C and applied to a loamy sand and a sandy soil in the concentration of 5.3 g 100 g(-1) sandy soil and 4.1 g 100 g(-1) loamy sand soil, or 53 t ha(-1) for both soil types, on degradation of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA). Soils were spiked with 50 mg MCPA kg(-1) soil. In the sandy soil, significantly more MCPA remained after 100 days if amended with straw-derived biochar in comparison to wood-derived biochar. Both biochars types significantly increased urease activity (p<0.05) after 37 days in the loamy sand soil, but these differences disappeared after 100 days. A root and shoot elongation test demonstrated that the soils containing straw-derived biochar and spiked with MCPA, showed the highest phytotoxicity. Both biochars were found to retard MCPA degradation in loamy sand and sandy soils. This effect could not be explained only by sorption processes due to comparatively low developed micro/mesoporous structure of both biochars shown by BET surface analysis. However, an enhanced MCPA persistence and soil toxicity in sandy soil amended with straw biochar was observed and further studies are needed to reveal the responsible mechanisms.

The application of phospholipid removal columns and ultra-high performance liquid chromatography—tandem quadrupole mass spectrometry for quantification of multi-class antibiotics in aquaculture samples

In this study a robust and sensitive method based on a proposed sample purification procedure, using zirconia-coated Phree™ columns and analysis by ultra-high performance liquid chromatography with triple quadrupole tandem mass spectrometry are presented for the assessment of multi-class antibiotics in farmed fish species. The sample preparation procedure benefited from combined precipitation of proteins and selective removal of phospholipids by Phree™ columns, resulting in a high sensitivity of the method (LOQ 0.3-9mgkg(-1)). The in-house validation results (precision, repeatability, decision limit CCα, detection capability CCβ, etc.) indicate that the elaborated method is fully suitable for the analysis of the main classes of antibiotics in accordance with the European Union (EU) Commission Decision 2002/657/EC. The method was applied to the analysis of antibiotics in trout and sturgeon samples obtained from the local inland aquacultures in Latvia. The results revealed the presence of two antibiotics (enrofloxacin and trimethoprim) in 12 out of the 20 analysed fish samples at concentrations (0.33-12.2μgkg(-1)) below the MRLs, thus causing no acute risks to consumers.

Determination of pharmaceutical residues and assessment of their removal efficiency at the Daugavgriva municipal wastewater treatment plant in Riga, Latvia

Pharmaceutical products (PPs) belong to emerging contaminants that may accumulate along with other chemical pollutants in wastewaters (WWs) entering industrial and/or urban wastewater treatment plants (WWTPs). In the present study, the technique of ultra-high-performance liquid chromatography coupled to Orbitrap high-resolution mass spectrometry (Orbitrap-HRMS) was applied for the analysis of 24 multi-class PPs in WW samples collected at different technological stages of Daugavgriva WWTP located in Riga, Latvia. Caffeine and acetaminophen levels in the range of 7,570-11,403 ng/L and 810-1,883 ng/L, respectively, were the predominant compounds among 19 PPs determined in the WW. The results indicate that aerobic digestion in biological ponds was insufficiently effective to degrade most of the PPs (reduction efficiency <0-50.0%) with the exception of four PPs that showed degradation efficiency varying from 55.0 to 99.9%. Tests of short-term chemical and enzymatic hydrolysis for PP degradation in WW samples were performed, and the results reflected the complexity of different degradation mechanisms and physicochemical transformations of PPs. The toxicological studies of WW impact on Daphnia magna indicated gradual reduction of the total toxicity through the treatment stages at the WWTP.

The application of headspace gas chromatography coupled to tandem quadrupole mass spectrometry for the analysis of furan in baby food samples.

Selective methodology employing a tandem quadrupole mass spectrometer coupled to a gas chromatograph with headspace autosampler (HS-GC-MS/MS) was elaborated in this study. Application of the elaborated procedure resulted in a limit of detection of 0.021μgkg(-1) and a limit of quantification of 0.071μgkg(-1). The mean recoveries during in-house validation ranged from 89% to 109%, and coefficients of variation for repeatability ranged from 4% to 11%. The proposed analytical method was applied for monitoring the furan content of 30 commercial baby food samples available on the Latvian retail market. The level of furan found in these samples varied from 0.45 to 81.9μgkg(-1), indicating that infants whose sole diet comprises baby food sold in jars and cans are exposed constantly to furan. Samples containing vegetables and meat had higher levels of furan than those containing only fruits.

Development of a sensitive method for the determination of acrylamide in coffee using high-performance liquid chromatography coupled to a hybrid quadrupole Orbitrap mass spectrometer

The emerging trend towards high-resolution mass spectrometry (MS) alternatives was evaluated by the application of Orbitrap MS for the determination of acrylamide in coffee samples. The high resolving power of the Orbitrap MS provided the high selectivity and sensitivity that enabled quantitative analysis of acrylamide in complex matrices, such as coffee. Several sample preparation methods and scanning modes of the MS (full MS, t-SIM, t-MS2) were assessed in order to optimise parameters of the analytical method. The final procedure involved the extraction of acrylamide with acetonitrile, solid-phase extraction with dispersive primary secondary amine (PSA) and amino columns, and the detection by ultra-performance liquid chromatography coupled to a hybrid quadrupole-Orbitrap MS (HPLC-Q-Orbitrap) operated in targeted MS2 scanning mode. The repeatability of the method at the lowest calibration level (10 μg kg−1), expressed as relative standard deviation, was 7.8% and the average recovery of acrylamide was 111%. The proposed method was applied to the determination of acrylamide in 22 samples of roasted coffee obtained from the Latvian retail market. Acrylamide concentration in coffee samples was in the range of 166–503 μg kg−1. Graphical Abstract