TY - JOUR A1 - Goetz, Klaus-Peter A1 - Chmielewski, Frank M. A1 - Goedeke, Kristin A1 - Wolf, Kristine A1 - Jander, Elisabeth A1 - Sievers, Steven A1 - Homann, Thomas A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Assessment of amino acids during winter rest and ontogenetic development in sweet cherry buds (Prunus avium. L.) JF - Scientia horticulturae : an international journal sponsored by the International Society for Horticultural Science N2 - This study examined changes in sweet cherry buds of ‘Summit’ cultivar in four seasons (2011/12–2014/15) with respect to the nitrogen (N) content and the profile of eight free amino acids (asparagine (Asn), aspartic acid (Asp), isoleucine (Ile), glutamine (Gln), glutamic acid (Glu), arginine (Arg), alanine (Ala), histidine (His)). The presented results are to our knowledge the first under natural conditions in fruit tree orchards with a high temporal resolution from the dormant stage until cluster development. The N content in the buds from October, during endo- and ecodormancy until the beginning of ontogenetic development was a relatively stable parameter in each of the four seasons. The N accumulation into the buds began after ‘swollen bud’ and significant differences were visible at ‘green tip’ with an N content of 3.24, 3.12, 3.08, 2.40 which increased markedly to the mean of ‘tight’ and ‘open cluster’ by 3.77%, 3.78%, 3.44% and 3.10% in 2012–2015, respectively. In the buds, levels of asparagine were higher (up to 44 mg g−1 DW−1) than aspartic acid (up to 2 mg g−1 DW−1) and aspartic acid higher than isoleucine (up to 0.83 mg g−1 DW−1). Levels of glutamine were higher (up to 25 mg g−1 DW−1) than glutamic acid (up to 20 mg g−1 DW−1). The course of the arginine content was higher in 2011/12 compared to 2012/13, 2013/14 and 2014/15 which showed only slight differences. The alanine content in the buds was denoted in the four seasons only by relatively minor changes. The histidine content was higher in 2011/12 and 2012/13 compared to 2013/14 and 2014/15 which showed a comparable pattern. For 6 amino acids (Asn, Asp, Ile, Glu, Arg, Ala), the highest content was observed in 2012/13, the warmest period between swollen bud and open cluster. However in 2014/15, the season with the lowest mean temperature of 8.8 °C, only the content of Gln was the lowest. It was not possible to explain any seasonal differences in the amino acid content by environmental factors (air temperature) on the basis of few seasons. From none of the measured free amino acids could a clear determination of the date of endodormancy release (t1) or the beginning of the ontogenetic development (t1*) be derived. Therefore, these amino acids are no suitable markers to improve phenological models for the beginning of cherry blossom. KW - Amino acids KW - Flower buds KW - Prunus avium L. KW - Dormancy KW - Ontogenetic development Y1 - 2017 U6 - https://doi.org/10.1016/j.scienta.2017.05.001 SN - 0304-4238 SN - 1879-1018 VL - 222 SP - 102 EP - 110 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tchewonpi Sagu, Sorel A1 - Landgräber, Eva A1 - Henkel, Ina M. A1 - Huschek, Gerd A1 - Homann, Thomas A1 - Bußler, Sara A1 - Schlüter, Oliver K. A1 - Rawel, Harshadrai Manilal T1 - Effect of cereal α-amylase/trypsin inhibitors on developmental characteristics and abundance of digestive enzymes of mealworm larvae (Tenebrio molitor L.) JF - Insects N2 - The objective of this work was to investigate the potential effect of cereal α-amylase/trypsin inhibitors (ATIs) on growth parameters and selective digestive enzymes of Tenebrio molitor L. larvae. The approach consisted of feeding the larvae with wheat, sorghum and rice meals containing different levels and composition of α-amylase/trypsin inhibitors. The developmental and biochemical characteristics of the larvae were assessed over feeding periods of 5 h, 5 days and 10 days, and the relative abundance of α-amylase and selected proteases in larvae were determined using liquid chromatography tandem mass spectrometry. Overall, weight gains ranged from 21% to 42% after five days of feeding. The larval death rate significantly increased in all groups after 10 days of feeding (p < 0.05), whereas the pupation rate was about 25% among larvae fed with rice (Oryza sativa L.) and Siyazan/Esperya wheat meals, and only 8% and 14% among those fed with Damougari and S35 sorghum meals. As determined using the Lowry method, the protein contents of the sodium phosphate extracts ranged from 7.80 ± 0.09 to 9.42 ± 0.19 mg/mL and those of the ammonium bicarbonate/urea reached 19.78 ± 0.16 to 37.47 ± 1.38 mg/mL. The total protein contents of the larvae according to the Kjeldahl method ranged from 44.0 and 49.9 g/100 g. The relative abundance of α-amylase, CLIP domain-containing serine protease, modular serine protease zymogen and C1 family cathepsin significantly decreased in the larvae, whereas dipeptidylpeptidase I and chymotrypsin increased within the first hours after feeding (p < 0.05). Trypsin content was found to be constant independently of time or feed material. Finally, based on the results we obtained, it was difficult to substantively draw conclusions on the likely effects of meal ATI composition on larval developmental characteristics, but their effects on the digestive enzyme expression remain relevant. KW - growth behavior KW - Tenebrio molitor larvae KW - feeding KW - cereal meals KW - α-amylase/trypsin inhibitors KW - digestive enzymes quantification KW - LC-MS/MS Y1 - 2021 U6 - https://doi.org/10.3390/insects12050454 SN - 2075-4450 VL - 12 IS - 5 PB - MDPI CY - Basel ER - TY - JOUR A1 - Sagu Tchewonpi, Sorel A1 - Huschek, Gerd A1 - Homann, Thomas A1 - Rawel, Harshadrai Manilal T1 - Effect of sample preparation on the detection and quantification of selected nuts allergenic proteins by LC-MS/MS JF - Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International N2 - The detection and quantification of nut allergens remains a major challenge. The liquid chroma-tography tandem mass spectrometry (LC-MS/MS) is emerging as one of the most widely used methods, but sample preparation prior to the analysis is still a key issue. The objective of this work was to establish optimized protocols for extraction, tryptic digestion and LC-MS analysis of almond, cashew, hazelnut, peanut, pistachio and walnut samples. Ammonium bicar-bonate/urea extraction (Ambi/urea), SDS buffer extraction (SDS), polyvinylpolypyrroli-done (PVPP) extraction, trichloroacetic acid/acetone extraction (TCA/acetone) and chloro-form/methanol/sodium chloride precipitation (CM/NaCl) as well as the performances of con-ventional tryptic digestion and microwave-assisted breakdown were investigated. Overall, the protein extraction yields ranged from 14.9 ± 0.5 (almond extract from CM/NaCl) to 76.5 ± 1.3% (hazelnut extract from Ambi/urea). Electrophoretic profiling showed that the SDS extraction method clearly presented a high amount of extracted proteins in the range of 0–15 kDa, 15–35 kDa, 35–70 kDa and 70–250 kDa compared to the other methods. The linearity of the LC-MS methods in the range of 0 to 0.4 µg equivalent defatted nut flour was assessed and recovery of internal standards GWGG and DPLNV(d8)LKPR ranged from 80 to 120%. The identified bi-omarkers peptides were used to relatively quantifier selected allergenic protein form the inves-tigated nut samples. Considering the overall results, it can be concluded that SDS buffer allows a better protein extraction from almond, peanut and walnut samples while PVPP buffer is more appropriate for cashew, pistachio and hazelnut samples. It was also found that conventional overnight digestion is indicated for cashew, pistachio and hazelnut samples, while microwave assisted tryptic digestion is recommended for almond, hazelnut and peanut extracts. KW - nut allergenic proteins KW - protein extraction KW - sample preparation KW - tryptic digestion KW - microwave assisted digestion KW - SDS PAGE KW - LC-MS/MS Y1 - 2021 U6 - https://doi.org/10.3390/molecules26154698 SN - 1420-3049 VL - 26 IS - 15 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bönick, Josephine A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Determination of wheat, rye and spelt authenticity in bread by targeted peptide biomarkers JF - Journal of Food Composition and Analysis N2 - Adulteration of food and mislabeled products in global market is a major financial and reputational risk for food manufacturers and trade companies. Consequently, there is a necessity to develop analytical methods to meet these issues. An analytical strategy to check the authenticity of wheat, spelt and rye addition in bread products was developed based on database research, in silico digestion confirming peptide specificity and finally quantification by liquid chromatography-tandem mass spectrometry analysis. Peptide markers for wheat (SQQQISQQPQQLPQQQQIPQQPQQF; QQHQIPQQPQQFPQQQQF and QPHQPQQPYPQQ), spelt (ASIVVGIGGQ; SQQPGQIIPQQPQQPSPL) and rye (LPQSHKQHVGQGAL; AQVQGIIQPQQL and QQFPQQPQQSFPQQPQQPVPQQPL) were identified, verified by protein Basic Local Alignment Search Tool and database research and used for quantification in bread. The specific use of multi-reaction monitoring transitions of selected peptides permitted the identification of closely related species wheat and spelt. Other cereal species (emmer, einkorn, barley, maize, rye and oat) were also checked. The target peptides were quantified at different levels using own reference baked products (bread) after in-solution chymotryptic digestion. Sensitivity of the identification was 0.5-1% using flour-based (0-25%) matrix calibration and the analytical recovery in bread was 80-125%. The analytical strategy described here supplies an emerging, independent and flexible tool in controlling the labeling of bread. KW - Food analysis KW - Food composition KW - Food safety KW - Plant authentication KW - Wheat KW - Spelt KW - Rye KW - LC-MS-MS KW - Quantification of peptides KW - Food labeling Y1 - 2017 U6 - https://doi.org/10.1016/j.jfca.2017.01.019 SN - 0889-1575 SN - 1096-0481 VL - 58 SP - 82 EP - 91 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Huschek, Gerd A1 - Bönick, Josephine A1 - Merkel, Dietrich A1 - Huschek, Doreen A1 - Rawel, Harshadrai Manilal T1 - Authentication of leguminous-based products by targeted biomarkers using high resolution time of flight mass spectrometry JF - LWT - food science and technology : an official journal of the Swiss Society of Food Science and Technology (SGLWT/SOSSTA) and the International Union of Food Science and Technology (IUFoST) N2 - A growing number of health-conscious individuals supplements their diet with protein-rich plant-based products to reduce their meat consumption. Analytical methods are needed to authenticate these new vegetarian products not only for the correct labelling of ingredients according to European legislation but also to discourage food fraud. This paper presents new biomarkers for a targeted proteomics LC-MS/MS work-flow that can simultaneously prove the presence/absence of garden pea, a protein-rich legume, meat and honey and quantify their content in processed vegan food. We show a novel rapid strategy to identify biomarkers for species authentication and the steps for the multi-parameter LC-MS/MS method validation and quantification. A high resolution triple time of flight mass spectrometer (HRMS) with SWATH Acquisition was used for the rapid discovery of all measurable trypsin-digested proteins in the individual ingredients. From these proteins, species-selective biomarkers were identified with BLAST and Skyline. Vicilin and convicilin (UniProt: D3VND9, Q9M3X6) allow pea authentication with regard to other legume species. Myostatin (UniProt: 018831) is a single biomarker for all meat types. For honey, we identified three selective proteins (UniProt: C6K481, C6K482, Q3L6329). The final LC-MS/MS method can identity and quantify these markers simultaneously. Quantification occurs via external matrix calibration. KW - Vegan KW - Food authentication KW - Legume KW - Honey KW - Meat peptide biomarker KW - MS quantification of leguminous additives KW - Food labelling Y1 - 2018 U6 - https://doi.org/10.1016/j.lwt.2017.12.034 SN - 0023-6438 SN - 1096-1127 VL - 90 SP - 164 EP - 171 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Uhr, Linda A1 - Buchholz, Tina A1 - Homann, Thomas A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Targeted proteomics-based analysis of technical enzymes from fungal origin in baked products JF - Journal of cereal science N2 - The application of technical enzymes is a potential tool in modulating the dough and baking quality of cereal products. No endogenous amylases (alpha- and beta-forms) are present in mature wheat grains; they may be synthesized or activated during germination. Hence, microbial alpha-amylases are added to the dough, being resistant to the endogenous alpha-amylase/trypsin inhibitors. Here, we report on the initial identification of two technical enzymes from a commercial sample based on an in-gel tryptic digestion coupled with MALDI-MS analysis. The primary component of the protein fraction with 51.3 kDa was alpha-amylase from Aspergillus species. A second major protein with 24.8 kDa was identified as endo-1,4-xylanase from Thermomyces lanuginosus. In the following experimental work up, a targeted proteomics approach utilizing the combination of specific proteolytic digestion of the added amylase and xylanase in wheat flour, dough or baked products, solid phase extraction of released peptides and their detection using LC-MS/MS was optimized. The targeted (MRM) MS/MS peptide signals showed that the peptide "ALSSALHER" (MW = 983) originating from amylase and "GWNPGLNAR" (MW = 983) from xylanase can be used to identify the corresponding technical enzymes added. Consequently, locally available baked products were tested and found to contain these enzymes as supplementary ingredients. (C) 2014 Elsevier Ltd. All rights reserved. KW - Technical enzymes KW - Amylase KW - Xylanase KW - Mass spectrometry Y1 - 2014 U6 - https://doi.org/10.1016/j.jcs.2014.04.007 SN - 0733-5210 SN - 1095-9963 VL - 60 IS - 2 SP - 440 EP - 447 PB - Elsevier CY - London ER - TY - JOUR A1 - Goetz, Klaus-Peter A1 - Chmielewski, Frank M. A1 - Homann, Thomas A1 - Huschek, Gerd A1 - Matzneller, Philipp A1 - Rawel, Harshadrai Manilal T1 - Seasonal changes of physiological parameters in sweet cherry (Prunus avium L.) buds JF - Scientia horticulturae : an international journal sponsored by the International Society for Horticultural Science N2 - The transition from dormant stage to the beginning of growth was first obvious by markedly changes of the water content. The phase from green tip to tight cluster, with a length of only 4 days, was the period of the most physiological activity in single buds, because of the highest daily accumulation rates of fresh/dry weight, C, N. We assume a concentration dependant regulation of the member of the aspartate family (asparagine, aspartic acid, isoleucine) during dormancy, growth and development in sweet cherry buds. The ABA content showed 2011/12 a clear bimodal pattern which was at lower level similar in 2012/13, but not so strong incisive. In both years, the first peak was probably related to the end of endodormancy. However the ABA-isomer content showed in both seasons a unimodal pattern. The maximum of the ratio of ABA-isomer/ABA indicated the beginning of ontogenetic development which starts 3 and 2 weeks later, respectively. Our results suggest that ABA and the ABA-isomer in the sweet cherry buds regulate differentiated metabolic processes in the dormant stage and during bud growth and development. After replication in the season 2013/14 the estimated dates of release of endodormancy, beginning of ecodormancy and start of ontogenetic development will be used to validate and improve phenological models for the beginning of cherry blossom. (C) 2014 Elsevier B.V. All rights reserved. KW - Abscisic acid KW - Amino acids KW - Dormancy KW - Flower buds KW - Phenological modelling KW - Prunus avium L. Y1 - 2014 U6 - https://doi.org/10.1016/j.scienta.2014.04.012 SN - 0304-4238 SN - 1879-1018 VL - 172 SP - 183 EP - 190 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Huschek, Gerd A1 - Boenick, Josephine A1 - Loewenstein, Yvonne A1 - Sievers, Steven A1 - Rawel, Harshadrai Manilal T1 - Quantification of allergenic plant traces in baked products by targeted proteomics using isotope marked peptides JF - LWT - food science and technology : an official journal of the Swiss Society of Food Science and Technology (SGLWT/SOSSTA) and the International Union of Food Science and Technology (IUFoST) N2 - The right choice of analytical methods for plant allergen quantification is a deciding factor for the correct assessment and labeling of allergens in processed food in view of consumer protection. The aim of the present study was to develop a validated target peptide multi-method by LC/MS/MS providing high specificity and sensitivity for plant allergen protein detection, plant identification in vegan or vegetarian products using peptide markers for quantification. The methodical concept considers the selection of target peptides of thermostable allergenic plant proteins (Gly m6 soy, Ses i6 sesame and (beta-conglutin from white lupine) by data base research, BLAST and in silico digestion using Skyline software. Different allergenic concentration levels of these proteins were integrated into our own reference bakery products and quantified with. synthesized isotopically labeled peptides after in-solution digestion using LC/MS/MS. Recovery rates within the range of 70-113% and LOQ of 10 ppm-50 ppm (mg allergenic food/kg) could be determined. The results are independent of thermal processing applied during baking and of epitope binding site for the tested allergens. (C) 2016 Elsevier Ltd. All rights reserved. KW - Allergenic food KW - Plant allergen (soy, sesame, lupine) KW - LC/MS/MS; Quantification of allergenic plant traces KW - Food labeling Y1 - 2016 U6 - https://doi.org/10.1016/j.lwt.2016.07.057 SN - 0023-6438 SN - 1096-1127 VL - 74 SP - 286 EP - 293 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Uhr, Linda A1 - Wieland, Phillis A1 - Homann, Thomas A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Identification and LC-MS/MS-based analyses of technical enzymes in wheat flour and baked products JF - European food research and technology : official organ of the EuCheMS, Division of Food Chemistry N2 - The use of technical enzymes in bakery industry is necessary for a consistent and good quality of baked products. Since the cultivation of cereals leads to low amounts of endogenous enzymes being present, a need of their commercial alternatives is becoming a routine process in order to meet the consumer quality demands. Targeted quantification proteomics-based methods are necessary for their detection to meet the regulatory criteria. Here, we initially report on the identification of Lipase FE-01, a lipase from fungus Thermomyces lanuginosus, as analyzed by SDS-PAGE, in-Gel digestion, and MALDI-TOF-MS. In further experiments, the focus of the study was directed toward an extensive use and optimization of in-solution enzymatic digestion in combination with LC-MS/MS techniques in identification of specific peptide markers and finally in utilization of the latter in delivering reproducible quantification data for several different technical enzymes (alpha-amylases, xylanase, and lipases from microbial origin) in complex matrices such as baked bread and wheat flour. Two digestion protocols (a fast option using thermocycler program and the well-established overnight method) were tested, and both of these can be successfully applied. The application of isotopically labeled analogs of the MRM targeted peptides as internal standards and the addition of an internal protein standard during the extraction/digestion experiment were compared to determine the optimal quantification algorithm of the recovered enzyme concentrations. Thus, a standardized sensitive LC-MS/MS method could be developed to determine technical enzymes as forthcoming ingredients in the prefabricated food formulations in concentrations lower than 10 ppm. KW - Technical enzymes KW - Amylase KW - Xylanase KW - Lipase KW - Baked products KW - Mass spectrometry Y1 - 2016 U6 - https://doi.org/10.1007/s00217-015-2536-5 SN - 1438-2377 SN - 1438-2385 VL - 242 SP - 247 EP - 257 PB - Springer CY - New York ER - TY - JOUR A1 - Rawel, Harshadrai Manilal A1 - Huschek, Gerd A1 - Sagu Tchewonpi, Sorel A1 - Homann, Thomas T1 - Cocoa Bean Proteins BT - Characterization, Changes and Modifications due to Ripening and Post-Harvest Processing JF - Nutrients N2 - The protein fractions of cocoa have been implicated influencing both the bioactive potential and sensory properties of cocoa and cocoa products. The objective of the present review is to show the impact of different stages of cultivation and processing with regard to the changes induced in the protein fractions. Special focus has been laid on the major seed storage proteins throughout the different stages of processing. The study starts with classical introduction of the extraction and the characterization methods used, while addressing classification approaches of cocoa proteins evolved during the timeline. The changes in protein composition during ripening and maturation of cocoa seeds, together with the possible modifications during the post-harvest processing (fermentation, drying, and roasting), have been documented. Finally, the bioactive potential arising directly or indirectly from cocoa proteins has been elucidated. The “state of the art” suggests that exploration of other potentially bioactive components in cocoa needs to be undertaken, while considering the complexity of reaction products occurring during the roasting phase of the post-harvest processing. Finally, the utilization of partially processed cocoa beans (e.g., fermented, conciliatory thermal treatment) can be recommended, providing a large reservoir of bioactive potentials arising from the protein components that could be instrumented in functionalizing foods. KW - cocoa processing KW - cocoa proteins KW - classification KW - extraction and characterization methods KW - fermentation-related enzymes KW - bioactive peptides KW - heath potentials KW - protein–phenol interactions Y1 - 2019 U6 - https://doi.org/10.3390/nu11020428 SN - 2072-6643 VL - 11 IS - 2 PB - Molecular Diversity Preservation International CY - Basel ER - TY - GEN A1 - Rawel, Harshadrai Manilal A1 - Huschek, Gerd A1 - Sagu Tchewonpi, Sorel A1 - Homann, Thomas T1 - Cocoa Bean Proteins BT - Characterization, Changes and Modifications due to Ripening and Post-Harvest Processing T2 - Postprints der Universität Potsdam: Mathematisch-Naturwissenschaftliche Reihe N2 - The protein fractions of cocoa have been implicated influencing both the bioactive potential and sensory properties of cocoa and cocoa products. The objective of the present review is to show the impact of different stages of cultivation and processing with regard to the changes induced in the protein fractions. Special focus has been laid on the major seed storage proteins throughout the different stages of processing. The study starts with classical introduction of the extraction and the characterization methods used, while addressing classification approaches of cocoa proteins evolved during the timeline. The changes in protein composition during ripening and maturation of cocoa seeds, together with the possible modifications during the post-harvest processing (fermentation, drying, and roasting), have been documented. Finally, the bioactive potential arising directly or indirectly from cocoa proteins has been elucidated. The “state of the art” suggests that exploration of other potentially bioactive components in cocoa needs to be undertaken, while considering the complexity of reaction products occurring during the roasting phase of the post-harvest processing. Finally, the utilization of partially processed cocoa beans (e.g., fermented, conciliatory thermal treatment) can be recommended, providing a large reservoir of bioactive potentials arising from the protein components that could be instrumented in functionalizing foods. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 681 KW - cocoa processing KW - cocoa proteins KW - classification KW - extraction and characterization methods KW - fermentation-related enzymes KW - bioactive peptides KW - heath potentials KW - protein–phenol interactions Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-425953 SN - 1866-8372 IS - 681 ER - TY - GEN A1 - Tchewonpi Sagu, Sorel A1 - Landgräber, Eva A1 - Henkel, Ina M. A1 - Huschek, Gerd A1 - Homann, Thomas A1 - Bußler, Sara A1 - Schlüter, Oliver K. A1 - Rawel, Harshadrai Manilal T1 - Effect of cereal α-amylase/trypsin inhibitors on developmental characteristics and abundance of digestive enzymes of mealworm larvae (Tenebrio molitor L.) T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The objective of this work was to investigate the potential effect of cereal α-amylase/trypsin inhibitors (ATIs) on growth parameters and selective digestive enzymes of Tenebrio molitor L. larvae. The approach consisted of feeding the larvae with wheat, sorghum and rice meals containing different levels and composition of α-amylase/trypsin inhibitors. The developmental and biochemical characteristics of the larvae were assessed over feeding periods of 5 h, 5 days and 10 days, and the relative abundance of α-amylase and selected proteases in larvae were determined using liquid chromatography tandem mass spectrometry. Overall, weight gains ranged from 21% to 42% after five days of feeding. The larval death rate significantly increased in all groups after 10 days of feeding (p < 0.05), whereas the pupation rate was about 25% among larvae fed with rice (Oryza sativa L.) and Siyazan/Esperya wheat meals, and only 8% and 14% among those fed with Damougari and S35 sorghum meals. As determined using the Lowry method, the protein contents of the sodium phosphate extracts ranged from 7.80 ± 0.09 to 9.42 ± 0.19 mg/mL and those of the ammonium bicarbonate/urea reached 19.78 ± 0.16 to 37.47 ± 1.38 mg/mL. The total protein contents of the larvae according to the Kjeldahl method ranged from 44.0 and 49.9 g/100 g. The relative abundance of α-amylase, CLIP domain-containing serine protease, modular serine protease zymogen and C1 family cathepsin significantly decreased in the larvae, whereas dipeptidylpeptidase I and chymotrypsin increased within the first hours after feeding (p < 0.05). Trypsin content was found to be constant independently of time or feed material. Finally, based on the results we obtained, it was difficult to substantively draw conclusions on the likely effects of meal ATI composition on larval developmental characteristics, but their effects on the digestive enzyme expression remain relevant. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1153 KW - growth behavior KW - Tenebrio molitor larvae KW - feeding KW - cereal meals KW - α-amylase/trypsin inhibitors KW - digestive enzymes quantification KW - LC-MS/MS Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-520924 SN - 1866-8372 IS - 5 ER - TY - GEN A1 - Tchewonpi Sagu, Sorel A1 - Huschek, Gerd A1 - Homann, Thomas A1 - Rawel, Harshadrai Manilal T1 - Effect of sample preparation on the detection and quantification of selected nuts allergenic proteins by LC-MS/MS T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The detection and quantification of nut allergens remains a major challenge. The liquid chroma-tography tandem mass spectrometry (LC-MS/MS) is emerging as one of the most widely used methods, but sample preparation prior to the analysis is still a key issue. The objective of this work was to establish optimized protocols for extraction, tryptic digestion and LC-MS analysis of almond, cashew, hazelnut, peanut, pistachio and walnut samples. Ammonium bicar-bonate/urea extraction (Ambi/urea), SDS buffer extraction (SDS), polyvinylpolypyrroli-done (PVPP) extraction, trichloroacetic acid/acetone extraction (TCA/acetone) and chloro-form/methanol/sodium chloride precipitation (CM/NaCl) as well as the performances of con-ventional tryptic digestion and microwave-assisted breakdown were investigated. Overall, the protein extraction yields ranged from 14.9 ± 0.5 (almond extract from CM/NaCl) to 76.5 ± 1.3% (hazelnut extract from Ambi/urea). Electrophoretic profiling showed that the SDS extraction method clearly presented a high amount of extracted proteins in the range of 0–15 kDa, 15–35 kDa, 35–70 kDa and 70–250 kDa compared to the other methods. The linearity of the LC-MS methods in the range of 0 to 0.4 µg equivalent defatted nut flour was assessed and recovery of internal standards GWGG and DPLNV(d8)LKPR ranged from 80 to 120%. The identified bi-omarkers peptides were used to relatively quantifier selected allergenic protein form the inves-tigated nut samples. Considering the overall results, it can be concluded that SDS buffer allows a better protein extraction from almond, peanut and walnut samples while PVPP buffer is more appropriate for cashew, pistachio and hazelnut samples. It was also found that conventional overnight digestion is indicated for cashew, pistachio and hazelnut samples, while microwave assisted tryptic digestion is recommended for almond, hazelnut and peanut extracts. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1157 KW - nut allergenic proteins KW - sample preparation KW - protein extraction KW - tryptic digestion KW - microwave assisted digestion KW - SDS PAGE KW - LC-MS/MS Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-521871 SN - 1866-8372 IS - 15 ER - TY - GEN A1 - Sagu Tchewonpi, Sorel A1 - Huschek, Gerd A1 - Bönick, Josephine A1 - Homann, Thomas A1 - Rawel, Harshadrai Manilal T1 - A New Approach of Extraction of α-Amylase/trypsin Inhibitors from Wheat (Triticum aestivum L.), Based on Optimization Using Plackett–Burman and Box–Behnken Designs T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Wheat is one of the most consumed foods in the world and unfortunately causes allergic reactions which have important health effects. The α-amylase/trypsin inhibitors (ATIs) have been identified as potentially allergen components of wheat. Due to a lack of data on optimization of ATI extraction, a new wheat ATIs extraction approach combining solvent extraction and selective precipitation is proposed in this work. Two types of wheat cultivars (Triticum aestivum L.), Julius and Ponticus were used and parameters such as solvent type, extraction time, temperature, stirring speed, salt type, salt concentration, buffer pH and centrifugation speed were analyzed using the Plackett-Burman design. Salt concentration, extraction time and pH appeared to have significant effects on the recovery of ATIs (p < 0.01). In both wheat cultivars, Julius and Ponticus, ammonium sulfate substantially reduced protein concentration and inhibition of amylase activity (IAA) compared to sodium chloride. The optimal conditions with desirability levels of 0.94 and 0.91 according to the Doehlert design were: salt concentrations of 1.67 and 1.22 M, extraction times of 53 and 118 min, and pHs of 7.1 and 7.9 for Julius and Ponticus, respectively. The corresponding responses were: protein concentrations of 0.31 and 0.35 mg and IAAs of 91.6 and 83.3%. Electrophoresis and MALDI-TOF/MS analysis showed that the extracted ATIs masses were between 10 and 20 kDa. Based on the initial LC-MS/MS analysis, up to 10 individual ATIs were identified in the extracted proteins under the optimal conditions. The positive implication of the present study lies in the quick assessment of their content in different varieties especially while considering their allergenic potential. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 805 KW - wheat KW - α-amylase/trypsin inhibitors KW - extraction KW - Plackett–Burman design KW - Doehlert design KW - SDS-PAGE KW - MALDI-TOF/MS KW - LC-MS/MS Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-442229 SN - 1866-8372 IS - 805 ER - TY - JOUR A1 - Sagu Tchewonpi, Sorel A1 - Huschek, Gerd A1 - Bönick, Josephine A1 - Homann, Thomas A1 - Rawel, Harshadrai Manilal T1 - A New Approach of Extraction of α-Amylase/trypsin Inhibitors from Wheat (Triticum aestivum L.), Based on Optimization Using Plackett–Burman and Box–Behnken Designs JF - molecules N2 - Wheat is one of the most consumed foods in the world and unfortunately causes allergic reactions which have important health effects. The α-amylase/trypsin inhibitors (ATIs) have been identified as potentially allergen components of wheat. Due to a lack of data on optimization of ATI extraction, a new wheat ATIs extraction approach combining solvent extraction and selective precipitation is proposed in this work. Two types of wheat cultivars (Triticum aestivum L.), Julius and Ponticus were used and parameters such as solvent type, extraction time, temperature, stirring speed, salt type, salt concentration, buffer pH and centrifugation speed were analyzed using the Plackett-Burman design. Salt concentration, extraction time and pH appeared to have significant effects on the recovery of ATIs (p < 0.01). In both wheat cultivars, Julius and Ponticus, ammonium sulfate substantially reduced protein concentration and inhibition of amylase activity (IAA) compared to sodium chloride. The optimal conditions with desirability levels of 0.94 and 0.91 according to the Doehlert design were: salt concentrations of 1.67 and 1.22 M, extraction times of 53 and 118 min, and pHs of 7.1 and 7.9 for Julius and Ponticus, respectively. The corresponding responses were: protein concentrations of 0.31 and 0.35 mg and IAAs of 91.6 and 83.3%. Electrophoresis and MALDI-TOF/MS analysis showed that the extracted ATIs masses were between 10 and 20 kDa. Based on the initial LC-MS/MS analysis, up to 10 individual ATIs were identified in the extracted proteins under the optimal conditions. The positive implication of the present study lies in the quick assessment of their content in different varieties especially while considering their allergenic potential. KW - wheat KW - α-amylase/trypsin inhibitors KW - extraction KW - Plackett–Burman design KW - Doehlert design KW - SDS-PAGE KW - MALDI-TOF/MS KW - LC-MS/MS Y1 - 2019 U6 - https://doi.org/10.3390/molecules24193589 SN - 1420-3049 VL - 24 IS - 19 PB - MDPI CY - Basel ER - TY - JOUR A1 - Sagu Tchewonpi, Sorel A1 - Zimmermann, Lynn A1 - Landgräber, Eva A1 - Homann, Thomas A1 - Huschek, Gerd A1 - Özpinar, Haydar A1 - Schweigert, Florian J. A1 - Rawel, Harshadrai Manilal T1 - Comprehensive Characterization and Relative Quantification of α-Amylase/Trypsin Inhibitors from Wheat Cultivars by Targeted HPLC-MS/MS JF - Foods N2 - The α-amylase/trypsin inhibitors (ATIs) are discussed as being responsible for non-celiac wheat sensitivity (NCWS), besides being known as allergenic components for baker’s asthma. Different approaches for characterization and quantification including proteomics-based methods for wheat ATIs have been documented. In these studies generally the major ATIs have been addressed. The challenge of current study was then to develop a more comprehensive workflow encompassing all reviewed wheat-ATI entries in UniProt database. To substantially test proof of concept, 46 German and Turkish wheat samples were used. Two extractions systems based on chloroform/methanol mixture (CM) and under buffered denaturing conditions were evaluated. Three aspects were optimized, tryptic digestion, chromatographic separation, and targeted tandem mass spectrometric analysis (HPLC-MS/MS). Preliminary characterization with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) documented the purity of the extracted ATIs with CM mixture and the amylase (60–80%)/trypsin (10–20%) inhibition demonstrated the bifunctional activity of ATIs. Thirteen (individual/common) biomarkers were established. Major ATIs (7–34%) were differently represented in samples. Finally, to our knowledge, the proposed HPLC-MS/MS method allowed for the first time so far the analysis of all 14 reviewed wheat ATI entries reported. KW - α-amylase/trypsin inhibitors KW - wheat cultivars KW - SDS-PAGE KW - peptides markers KW - relative quantification KW - mass spectrometry KW - LC-MRM-MS Y1 - 2020 U6 - https://doi.org/10.3390/foods9101448 SN - 2304-8158 VL - 9 IS - 10 PB - MDPI CY - Basel ER - TY - GEN A1 - Sagu Tchewonpi, Sorel A1 - Zimmermann, Lynn A1 - Landgräber, Eva A1 - Homann, Thomas A1 - Huschek, Gerd A1 - Özpinar, Haydar A1 - Schweigert, Florian J. A1 - Rawel, Harshadrai Manilal T1 - Comprehensive Characterization and Relative Quantification of α-Amylase/Trypsin Inhibitors from Wheat Cultivars by Targeted HPLC-MS/MS T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The α-amylase/trypsin inhibitors (ATIs) are discussed as being responsible for non-celiac wheat sensitivity (NCWS), besides being known as allergenic components for baker’s asthma. Different approaches for characterization and quantification including proteomics-based methods for wheat ATIs have been documented. In these studies generally the major ATIs have been addressed. The challenge of current study was then to develop a more comprehensive workflow encompassing all reviewed wheat-ATI entries in UniProt database. To substantially test proof of concept, 46 German and Turkish wheat samples were used. Two extractions systems based on chloroform/methanol mixture (CM) and under buffered denaturing conditions were evaluated. Three aspects were optimized, tryptic digestion, chromatographic separation, and targeted tandem mass spectrometric analysis (HPLC-MS/MS). Preliminary characterization with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) documented the purity of the extracted ATIs with CM mixture and the amylase (60–80%)/trypsin (10–20%) inhibition demonstrated the bifunctional activity of ATIs. Thirteen (individual/common) biomarkers were established. Major ATIs (7–34%) were differently represented in samples. Finally, to our knowledge, the proposed HPLC-MS/MS method allowed for the first time so far the analysis of all 14 reviewed wheat ATI entries reported. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1028 KW - α-amylase/trypsin inhibitors KW - wheat cultivars KW - SDS-PAGE KW - peptides markers KW - relative quantification KW - mass spectrometry KW - LC-MRM-MS Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-486118 SN - 1866-8372 IS - 1028 ER - TY - JOUR A1 - Rawel, Harshadrai Manilal A1 - Huschek, Gerd A1 - Sagu Tchewonpi, Sorel A1 - Homann, Thomas T1 - Cocoa Bean Proteins-Characterization, Changes and Modifications due to Ripening and Post-Harvest Processing JF - Nutrients N2 - The protein fractions of cocoa have been implicated influencing both the bioactive potential and sensory properties of cocoa and cocoa products. The objective of the present review is to show the impact of different stages of cultivation and processing with regard to the changes induced in the protein fractions. Special focus has been laid on the major seed storage proteins throughout the different stages of processing. The study starts with classical introduction of the extraction and the characterization methods used, while addressing classification approaches of cocoa proteins evolved during the timeline. The changes in protein composition during ripening and maturation of cocoa seeds, together with the possible modifications during the post-harvest processing (fermentation, drying, and roasting), have been documented. Finally, the bioactive potential arising directly or indirectly from cocoa proteins has been elucidated. The state of the art suggests that exploration of other potentially bioactive components in cocoa needs to be undertaken, while considering the complexity of reaction products occurring during the roasting phase of the post-harvest processing. Finally, the utilization of partially processed cocoa beans (e.g., fermented, conciliatory thermal treatment) can be recommended, providing a large reservoir of bioactive potentials arising from the protein components that could be instrumented in functionalizing foods. KW - cocoa processing KW - cocoa proteins KW - classification KW - extraction and characterization methods KW - fermentation-related enzymes KW - bioactive peptides KW - heath potentials KW - protein-phenol interactions Y1 - 2019 U6 - https://doi.org/10.3390/nu11020428 SN - 2072-6643 VL - 11 IS - 2 PB - MDPI CY - Basel ER - TY - GEN A1 - Sagu Tchewonpi, Sorel A1 - Landgräber, Eva A1 - Rackiewicz, Michal A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Relative Abundance of Alpha-Amylase/Trypsin Inhibitors in Selected Sorghum Cultivars T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Sorghum is of growing interest and considered as a safe food for wheat related disorders. Besides the gluten, α-amylase/trypsin-inhibitors (ATIs) have been identified as probable candidates for these disorders. Several studies focused on wheat-ATIs although there is still a lack of data referring to the relative abundance of sorghum-ATIs. The objective of this work was therefore to contribute to the characterization of sorghum ATI profiles by targeted proteomics tools. Fifteen sorghum cultivars from different regions were investigated with raw proteins ranging from 7.9 to 17.0 g/100 g. Ammonium bicarbonate buffer in combination with urea was applied for protein extraction, with concentration from 0.588 ± 0.047 to 4.140 ± 0.066 mg/mL. Corresponding electrophoresis data showed different protein profiles. UniProtKB data base research reveals two sorghum ATIs, P81367 and P81368; both reviewed and a targeted LC–MS/MS method was developed to analyze these. Quantifier peptides ELAAVPSR (P81367) and TYMVR (P81368) were identified and retained as biomarkers for relative quantification. Different reducing and alkylating agents were assessed and combination of tris (2 carboxyethyl) phosphine/iodoacetamide gave the best response. Linearity was demonstrated for the quantifier peptides with standard recovery between 92.2 and 107.6%. Nine sorghum cultivars presented up to 60 times lower ATI contents as compared to wheat samples. This data suggests that sorghum can effectively be considered as a good alternative to wheat. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1068 KW - sorghum KW - α-amylase/trypsin inhibitors KW - reducing agents KW - cysteine alkylation KW - SDS PAGE KW - targeted proteomics KW - LC–MS/MS Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-488096 SN - 1866-8372 IS - 1068 ER - TY - GEN A1 - Sagu Tchewonpi, Sorel A1 - Huschek, Gerd A1 - Waldbach Braga, Tess A1 - Rackiewicz, Michal A1 - Homann, Thomas A1 - Rawel, Harshadrai Manilal T1 - Design of Experiment (DoE) for Optimization of HPLC Conditions for the Simultaneous Fractionation of Seven α-Amylase/Trypsin Inhibitors from Wheat (Triticum aestivum L.) T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Wheat alpha-amylase/trypsin inhibitors remain a subject of interest considering the latest findings showing their implication in wheat-related non-celiac sensitivity (NCWS). Understanding their functions in such a disorder is still unclear and for further study, the need for pure ATI molecules is one of the limiting problems. In this work, a simplified approach based on the successive fractionation of ATI extracts by reverse phase and ion exchange chromatography was developed. ATIs were first extracted from wheat flour using a combination of Tris buffer and chloroform/methanol methods. The separation of the extracts on a C18 column generated two main fractions of interest F1 and F2. The response surface methodology with the Doehlert design allowed optimizing the operating parameters of the strong anion exchange chromatography. Finally, the seven major wheat ATIs namely P01083, P17314, P16850, P01085, P16851, P16159, and P83207 were recovered with purity levels (according to the targeted LC-MS/MS analysis) of 98.2 ± 0.7; 98.1 ± 0.8; 97.9 ± 0.5; 95.1 ± 0.8; 98.3 ± 0.4; 96.9 ± 0.5, and 96.2 ± 0.4%, respectively. MALDI-TOF-MS analysis revealed single peaks in each of the pure fractions and the mass analysis yielded deviations of 0.4, 1.9, 0.1, 0.2, 0.2, 0.9, and 0.1% between the theoretical and the determined masses of P01083, P17314, P16850, P01085, P16851, P16159, and P83207, respectively. Overall, the study allowed establishing an efficient purification process of the most important wheat ATIs. This paves the way for further in-depth investigation of the ATIs to gain more knowledge related to their involvement in NCWS disease and to allow the absolute quantification in wheat samples. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1260 KW - wheat KW - α-amylase/trypsin inhibitors KW - fractionation KW - purification KW - reversed-phase chromatography KW - ion-exchange chromatography KW - design of experiment KW - LC–MS/MS KW - MALDI-TOF-MS Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-559282 SN - 1866-8372 SP - 1 EP - 18 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Sagu Tchewonpi, Sorel A1 - Huschek, Gerd A1 - Waldbach Braga, Tess A1 - Rackiewicz, Michal A1 - Homann, Thomas A1 - Rawel, Harshadrai Manilal T1 - Design of Experiment (DoE) for Optimization of HPLC Conditions for the Simultaneous Fractionation of Seven α-Amylase/Trypsin Inhibitors from Wheat (Triticum aestivum L.) JF - Processes : open access journal N2 - Wheat alpha-amylase/trypsin inhibitors remain a subject of interest considering the latest findings showing their implication in wheat-related non-celiac sensitivity (NCWS). Understanding their functions in such a disorder is still unclear and for further study, the need for pure ATI molecules is one of the limiting problems. In this work, a simplified approach based on the successive fractionation of ATI extracts by reverse phase and ion exchange chromatography was developed. ATIs were first extracted from wheat flour using a combination of Tris buffer and chloroform/methanol methods. The separation of the extracts on a C18 column generated two main fractions of interest F1 and F2. The response surface methodology with the Doehlert design allowed optimizing the operating parameters of the strong anion exchange chromatography. Finally, the seven major wheat ATIs namely P01083, P17314, P16850, P01085, P16851, P16159, and P83207 were recovered with purity levels (according to the targeted LC-MS/MS analysis) of 98.2 ± 0.7; 98.1 ± 0.8; 97.9 ± 0.5; 95.1 ± 0.8; 98.3 ± 0.4; 96.9 ± 0.5, and 96.2 ± 0.4%, respectively. MALDI-TOF-MS analysis revealed single peaks in each of the pure fractions and the mass analysis yielded deviations of 0.4, 1.9, 0.1, 0.2, 0.2, 0.9, and 0.1% between the theoretical and the determined masses of P01083, P17314, P16850, P01085, P16851, P16159, and P83207, respectively. Overall, the study allowed establishing an efficient purification process of the most important wheat ATIs. This paves the way for further in-depth investigation of the ATIs to gain more knowledge related to their involvement in NCWS disease and to allow the absolute quantification in wheat samples. KW - wheat KW - α-amylase/trypsin inhibitors KW - fractionation KW - purification KW - reversed-phase chromatography KW - ion-exchange chromatography KW - design of experiment KW - LC–MS/MS KW - MALDI-TOF-MS Y1 - 2022 U6 - https://doi.org/10.3390/pr10020259 SN - 2227-9717 VL - 10 SP - 1 EP - 18 PB - MDPI CY - Basel, Schweiz ET - 2 ER - TY - JOUR A1 - Sagu Tchewonpi, Sorel A1 - Landgräber, Eva A1 - Rackiewicz, Michal A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Relative Abundance of Alpha-Amylase/Trypsin Inhibitors in Selected Sorghum Cultivars JF - Molecules N2 - Sorghum is of growing interest and considered as a safe food for wheat related disorders. Besides the gluten, α-amylase/trypsin-inhibitors (ATIs) have been identified as probable candidates for these disorders. Several studies focused on wheat-ATIs although there is still a lack of data referring to the relative abundance of sorghum-ATIs. The objective of this work was therefore to contribute to the characterization of sorghum ATI profiles by targeted proteomics tools. Fifteen sorghum cultivars from different regions were investigated with raw proteins ranging from 7.9 to 17.0 g/100 g. Ammonium bicarbonate buffer in combination with urea was applied for protein extraction, with concentration from 0.588 ± 0.047 to 4.140 ± 0.066 mg/mL. Corresponding electrophoresis data showed different protein profiles. UniProtKB data base research reveals two sorghum ATIs, P81367 and P81368; both reviewed and a targeted LC–MS/MS method was developed to analyze these. Quantifier peptides ELAAVPSR (P81367) and TYMVR (P81368) were identified and retained as biomarkers for relative quantification. Different reducing and alkylating agents were assessed and combination of tris (2 carboxyethyl) phosphine/iodoacetamide gave the best response. Linearity was demonstrated for the quantifier peptides with standard recovery between 92.2 and 107.6%. Nine sorghum cultivars presented up to 60 times lower ATI contents as compared to wheat samples. This data suggests that sorghum can effectively be considered as a good alternative to wheat. KW - sorghum KW - α-amylase/trypsin inhibitors KW - reducing agents KW - cysteine alkylation KW - SDS PAGE KW - targeted proteomics KW - LC–MS/MS Y1 - 2020 U6 - https://doi.org/10.3390/molecules25245982 SN - 1420-3049 VL - 25 IS - 24 PB - MDPI CY - Basel ER - TY - JOUR A1 - Chmielewski, Frank M. A1 - Baldermann, Susanne A1 - Götz, Klaus Peter A1 - Homann, Thomas A1 - Gödeke, Kristin A1 - Schumacher, Fabian A1 - Huschek, Gerd A1 - Rawel, Harshadrai Manilal T1 - Abscisic acid related metabolites in sweet cherry buds (Prunus avium L.) JF - Journal of Horticulture N2 - As our climate changes, plant mechanisms involved for dormancy release become increasingly important for commercial orchards. It is generally believed that abscisic acid (ABA) is a key hormone that responds to various environmental stresses which affects bud dormancy. For this reason, a multi-year study was initiated to obtain data on plant metabolites during winter rest and ontogenetic development in sweet cherry buds (Prunus avium L.). In this paper, we report on metabolites involved in ABA synthesis and catabolism and its effect on bud dormancy in the years 2014/15-2016/17. In previous work, the timings of the different phases of para-, endo-, ecodormancy and ontogenetic development for cherry flower buds of the cultivar ‘Summit’ were determined, based on classical climate chamber experiments and changes in the bud’s water content. Based on these time phases, we focused now on the different aspects of the ABA-metabolism. The results show that there is a continual synthesis of ABA about 5 weeks before leaf fall, and a degradation of ABA during ecodormancy and bud development until the phenological stage ‘open cluster’. This is confirmed by relating the ABA content to that of the total precursor carotenoids, neoxanthin and violaxanthin. The tentative monitoring of individual intermediate metabolites revealed that dihydroxyphaseic acid is the most abundant catabolite of ABA and ABA glucosyl ester is in terms of mass intensity, the most abundant ABA metabolite observed in this study. The results suggest that the direct route for ABA biosynthesis from farnesyl pyrophosphate may also be relevant in cherry flower buds. KW - Dormancy KW - Abscisic acid KW - Synthesis KW - Catabolism KW - Prunus avium L. KW - Flower buds Y1 - 2018 U6 - https://doi.org/10.4172/2376-0354.1000221 SN - 2376-0354 VL - 5 IS - 1 ER - TY - GEN A1 - Baldermann, Susanne A1 - Homann, Thomas A1 - Neugart, Susanne A1 - Chmielewski, Frank M. A1 - Götz, Klaus-Peter A1 - Gödeke, Kristin A1 - Huschek, Gerd A1 - Morlock, Gertrud E. A1 - Rawel, Harshadrai Manilal T1 - Selected Plant Metabolites Involved in Oxidation-Reduction Processes during Bud Dormancy and Ontogenetic Development in Sweet Cherry Buds (Prunus avium L.) T2 - Molecules N2 - Many biochemical processes are involved in regulating the consecutive transition of different phases of dormancy in sweet cherry buds. An evaluation based on a metabolic approach has, as yet, only been partly addressed. The aim of this work, therefore, was to determine which plant metabolites could serve as biomarkers for the different transitions in sweet cherry buds. The focus here was on those metabolites involved in oxidation-reduction processes during bud dormancy, as determined by targeted and untargeted mass spectrometry-based methods. The metabolites addressed included phenolic compounds, ascorbate/dehydroascorbate, reducing sugars, carotenoids and chlorophylls. The results demonstrate that the content of phenolic compounds decrease until the end of endodormancy. After a long period of constancy until the end of ecodormancy, a final phase of further decrease followed up to the phenophase open cluster. The main phenolic compounds were caffeoylquinic acids, coumaroylquinic acids and catechins, as well as quercetin and kaempferol derivatives. The data also support the protective role of ascorbate and glutathione in the para- and endodormancy phases. Consistent trends in the content of reducing sugars can be elucidated for the different phenophases of dormancy, too. The untargeted approach with principle component analysis (PCA) clearly differentiates the different timings of dormancy giving further valuable information. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 467 KW - dormancy KW - redox-metabolites KW - phenolics KW - ascorbate KW - anti-oxidative capacity KW - Prunus avium L. KW - flower buds Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-417442 ER - TY - JOUR A1 - Baldermann, Susanne A1 - Homann, Thomas A1 - Neugart, Susanne A1 - Chmielewski, Frank M. A1 - Götz, Klaus-Peter A1 - Gödeke, Kristin A1 - Huschek, Gerd A1 - Morlock, Gertrud E. A1 - Rawel, Harshadrai Manilal T1 - Selected Plant Metabolites Involved in Oxidation-Reduction Processes during Bud Dormancy and Ontogenetic Development in Sweet Cherry Buds (Prunus avium L.) JF - Molecules N2 - Many biochemical processes are involved in regulating the consecutive transition of different phases of dormancy in sweet cherry buds. An evaluation based on a metabolic approach has, as yet, only been partly addressed. The aim of this work, therefore, was to determine which plant metabolites could serve as biomarkers for the different transitions in sweet cherry buds. The focus here was on those metabolites involved in oxidation-reduction processes during bud dormancy, as determined by targeted and untargeted mass spectrometry-based methods. The metabolites addressed included phenolic compounds, ascorbate/dehydroascorbate, reducing sugars, carotenoids and chlorophylls. The results demonstrate that the content of phenolic compounds decrease until the end of endodormancy. After a long period of constancy until the end of ecodormancy, a final phase of further decrease followed up to the phenophase open cluster. The main phenolic compounds were caffeoylquinic acids, coumaroylquinic acids and catechins, as well as quercetin and kaempferol derivatives. The data also support the protective role of ascorbate and glutathione in the para- and endodormancy phases. Consistent trends in the content of reducing sugars can be elucidated for the different phenophases of dormancy, too. The untargeted approach with principle component analysis (PCA) clearly differentiates the different timings of dormancy giving further valuable information. KW - dormancy KW - redox-metabolites KW - phenolics KW - ascorbate KW - anti-oxidative capacity KW - Prunus avium L. KW - flower buds Y1 - 2018 U6 - https://doi.org/10.3390/molecules23051197 SN - 1420-3049 VL - 23 IS - 5 SP - 1 EP - 19 PB - Molecular Diversity Preservation International CY - Basel ER -