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Institute
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.
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.
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.
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.
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.
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.
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.
Microalgae are one of the most promising food source of the future.
Nowadays, extracts of high-value active substances of biomass are business aims for the development of food additives in personalized nutrition, in cosmetics and pharmaceuticals.
A new-patented vertical farming cultivation technology was used for production of Porphyridium purpureum. In this work, microwave assisted extraction was used to extract B-phycoerythrin from Porphyridium purpureum biomass.
Response surface methodology was implemented for optimization.
Numerical optimization established the best point of the experimental domain (biomass/solvent of 16.8 mg/mL, time of 172 s, and temperature of 30 degrees C) with a desirability value of 0.82.
Corresponding experimental responses values of 7.2 mg, 8.5 % and 13,961 PA/mu g biomass were obtained for extracted proteins, extraction yield and extracted B-phycoerythrin, respectively.
Final freeze-dried product indicated protein content of 55 % using Kjeldahl while targeted mass spectrometry analysis revealed that B-phycoerythrin represented 93 % of the total protein.
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.
Cocoa Bean Proteins
(2019)
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.