TY  - JOUR
A1  - Figueroa Campos, Gustavo A.
A1  - Sagu Tchewonpi, Sorel
A1  - Saravia Celis, Pedro
A1  - Rawel, Harshadrai Manilal
T1  - Comparison of batch and continuous wet-processing of coffee
BT  - changes in the main compounds in beans, by-products and wastewater
JF  - Foods
N2  - Many technical challenges still need to be overcome to improve the quality of the green coffee beans. In this work, the wet Arabica coffee processing in batch and continuous modus were investigated. Coffee beans samples as well as by-products and wastewaters collected at different production steps were analyzed in terms of their content in total phenols, antioxidant capacity, caffeine content, organic acids, reducing sugars, free amino group and protein content. The results showed that 40% of caffeine was removed with pulp. Green coffee beans showed highest concentration of organic acids and sucrose (4.96 ± 0.25 and 5.07 ± 0.39 g/100 g DW for the batch and continuous processing). Batch green coffee beans contained higher amount of phenols. 5-caffeoylquinic Acid (5-CQA) was the main constituent (67.1 and 66.0% for the batch and continuous processing, respectively). Protein content was 15 and 13% in the green coffee bean in batch and continuous processing, respectively. A decrease of 50 to 64% for free amino groups during processing was observed resulting in final amounts of 0.8 to 1.4% in the processed beans. Finally, the batch processing still revealed by-products and wastewater with high nutrient content encouraging a better concept for valorization.
KW  - Arabica coffee beans
KW  - coffee by-products
KW  - batch process
KW  - continuous process
KW  - nutritional characteristics
Y1  - 2020
U6  - https://doi.org/10.3390/foods9081135
SN  - 2304-8158
VL  - 9
IS  - 8
PB  - MDPI
CY  - Basel
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  - GEN
A1  - Figueroa Campos, Gustavo A.
A1  - Sagu Tchewonpi, Sorel
A1  - Saravia Celis, Pedro
A1  - Rawel, Harshadrai Manilal
T1  - Comparison of batch and continuous wet-processing of coffee
BT  - changes in the main compounds in beans, by-products and wastewater
T2  - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe
N2  - Many technical challenges still need to be overcome to improve the quality of the green coffee beans. In this work, the wet Arabica coffee processing in batch and continuous modus were investigated. Coffee beans samples as well as by-products and wastewaters collected at different production steps were analyzed in terms of their content in total phenols, antioxidant capacity, caffeine content, organic acids, reducing sugars, free amino group and protein content. The results showed that 40% of caffeine was removed with pulp. Green coffee beans showed highest concentration of organic acids and sucrose (4.96 ± 0.25 and 5.07 ± 0.39 g/100 g DW for the batch and continuous processing). Batch green coffee beans contained higher amount of phenols. 5-caffeoylquinic Acid (5-CQA) was the main constituent (67.1 and 66.0% for the batch and continuous processing, respectively). Protein content was 15 and 13% in the green coffee bean in batch and continuous processing, respectively. A decrease of 50 to 64% for free amino groups during processing was observed resulting in final amounts of 0.8 to 1.4% in the processed beans. Finally, the batch processing still revealed by-products and wastewater with high nutrient content encouraging a better concept for valorization.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1010 
KW  - Arabica coffee beans
KW  - coffee by-products
KW  - batch process
KW  - continuous process
KW  - nutritional characteristics
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-481691
SN  - 1866-8372
IS  - 1010
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  - JOUR
A1  - Borremans, An
A1  - Bußler, Sara
A1  - Sagu Tchewonpi, Sorel
A1  - Rawel, Harshadrai Manilal
A1  - Schlüter, Oliver K.
A1  - Leen, Van Campenhout
T1  - Effect of blanching plus fermentation on selected functional properties of mealworm (Tenebrio molitor) powders
JF  - Foods : open access journal
N2  - The aim of this study was to determine the effect of blanching followed by fermentation of mealworms (Tenebrio molitor) with commercial meat starter cultures on the functional properties of powders produced from the larvae. Full fat and defatted powder samples were prepared from non-fermented and fermented mealworm pastes. Then the crude protein, crude fat, and dry matter contents, pH, bulk density, colour, water and oil binding capacity, foaming capacity and stability, emulsion capacity and stability, protein solubility, quantity of free amino groups, and protein composition of the powders were evaluated. Regardless of the starter culture used, the blanching plus fermentation process reduced the crude and soluble protein contents of the full fat powders and in general impaired their water and oil binding, foaming, and emulsifying properties. Defatting of the powders improved most functional properties studied. The o-phthaldialdehyde assay revealed that the amount of free amino groups was higher in the fermented powders while sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that the soluble proteins of the fermented powders were composed of molecules of lower molecular mass compared to non-fermented powders. As molecular sizes of the soluble proteins decreased, it was clear that the protein structure was also modified by the fermentation process, which in turn led to changes in functional properties. In general, it was concluded that fermentation of mealworms with blanching as a pre-treatment does not contribute to the functional properties studied in this work. Nevertheless, the results confirmed that the properties of non-fermented powders are comparable to other food protein sources.
KW  - mealworm
KW  - fermentation
KW  - functional properties
KW  - insect proteins
KW  - SDS-PAGE
Y1  - 2020
U6  - https://doi.org/10.3390/foods9070917
SN  - 2304-8158
VL  - 9
IS  - 7
PB  - MDPI
CY  - Basel
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  - Nso, Emmanuel Jong
A1  - Homann, Thomas
A1  - Kapseu, Cesar
A1  - Rawel, Harshadrai Manilal
T1  - Extraction and purification of beta-amylase from stems of Abrus precatorius by three phase partitioning
JF  - Food chemistry
N2  - The stems of Abrus precatorius were used to extract a beta-amylase enriched fraction. A three phase partitioning method and a Doehlert design with 3 variables (ratio of crude extract/t-butanol, the ammonium sulphate saturation and pH) were used. The data was fitted in a second-order polynomial model and the parameters were optimized to enrich beta-amylase. Experimental responses for the modulation were recovery of activity and the purification factor. The optimal conditions were: a ratio of crude extract/t-butanol of 0.87 (v/v), saturation in ammonium sulphate of 49.46% (w/v) and a pH of 5.2. An activity recovery of 156.2% and a purification factor of 10.17 were found. The enriched enzyme was identified as a beta-amylase and its molecular weight was 60.1 kDa. K-m and V-max values were 79.37 mg/ml and 5.13 U/ml, respectively and the highest activity was registered at a temperature of 70 degrees C and a pH between 6 and 6.5. A significant stabilization of the beta-amylase was observed up to 65 degrees C. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Purification
KW  - Beta-amylase
KW  - Abrus precatorius
KW  - Three phase partitioning
KW  - Doehlert design
Y1  - 2015
U6  - https://doi.org/10.1016/j.foodchem.2015.03.028
SN  - 0308-8146
SN  - 1873-7072
VL  - 183
SP  - 144
EP  - 153
PB  - Elsevier
CY  - Oxford
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  - 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  - 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  - Figueroa Campos, Gustavo Adolfo
A1  - G. K. T. Kruizenga, Johannes
A1  - Sagu Tchewonpi, Sorel
A1  - Schwarz, Steffen
A1  - Homann, Thomas
A1  - Taubert, Andreas
A1  - Rawel, Harshadrai Manilal
T1  - Effect of the post-harvest processing on protein modification in green coffee beans by phenolic compounds
JF  - Foods : open access journal
N2  - The protein fraction, important for coffee cup quality, is modified during post-harvest treatment prior to roasting. Proteins may interact with phenolic compounds, which constitute the major metabolites of coffee, where the processing affects these interactions. This allows the hypothesis that the proteins are denatured and modified via enzymatic and/or redox activation steps. The present study was initiated to encompass changes in the protein fraction. The investigations were limited to major storage protein of green coffee beans. Fourteen Coffea arabica samples from various processing methods and countries were used. Different extraction protocols were compared to maintain the status quo of the protein modification. The extracts contained about 4–8 µg of chlorogenic acid derivatives per mg of extracted protein. High-resolution chromatography with multiple reaction monitoring was used to detect lysine modifications in the coffee protein. Marker peptides were allocated for the storage protein of the coffee beans. Among these, the modified peptides K.FFLANGPQQGGK.E and R.LGGK.T of the α-chain and R.ITTVNSQK.I and K.VFDDEVK.Q of β-chain were detected. Results showed a significant increase (p < 0.05) of modified peptides from wet processed green beans as compared to the dry ones. The present study contributes to a better understanding of the influence of the different processing methods on protein quality and its role in the scope of coffee cup quality and aroma. View Full-Text
KW  - Arabica coffee
KW  - coffee processing
KW  - protein modification
KW  - bound phenolic compounds
KW  - peptide biomarkers
KW  - LC-MS/MS
Y1  - 2022
U6  - https://doi.org/10.3390/foods11020159
SN  - 2304-8158
VL  - 11
PB  - MDPI
CY  - Basel, Schweiz
ET  - 2
ER  - 
TY  - GEN
A1  - Figueroa Campos, Gustavo A.
A1  - G. K. T. Kruizenga, Johannes
A1  - Sagu Tchewonpi, Sorel
A1  - Schwarz, Steffen
A1  - Homann, Thomas
A1  - Taubert, Andreas
A1  - Rawel, Harshadrai
T1  - Effect of the Post-Harvest Processing on Protein Modification in Green Coffee Beans by Phenolic Compounds
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The protein fraction, important for coffee cup quality, is modified during post-harvest treatment prior to roasting. Proteins may interact with phenolic compounds, which constitute the major metabolites of coffee, where the processing affects these interactions. This allows the hypothesis that the proteins are denatured and modified via enzymatic and/or redox activation steps. The present study was initiated to encompass changes in the protein fraction. The investigations were limited to major storage protein of green coffee beans. Fourteen Coffea arabica samples from various processing methods and countries were used. Different extraction protocols were compared to maintain the status quo of the protein modification. The extracts contained about 4–8 µg of chlorogenic acid derivatives per mg of extracted protein. High-resolution chromatography with multiple reaction monitoring was used to detect lysine modifications in the coffee protein. Marker peptides were allocated for the storage protein of the coffee beans. Among these, the modified peptides K.FFLANGPQQGGK.E and R.LGGK.T of the α-chain and R.ITTVNSQK.I and K.VFDDEVK.Q of β-chain were detected. Results showed a significant increase (p < 0.05) of modified peptides from wet processed green beans as compared to the dry ones. The present study contributes to a better understanding of the influence of the different processing methods on protein quality and its role in the scope of coffee cup quality and aroma. View Full-Text
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1256 
KW  - Arabica coffee
KW  - coffee processing
KW  - protein modification
KW  - bound phenolic compounds
KW  - peptide biomarkers
KW  - LC-MS/MS
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-557643
SN  - 1866-8372
VL  - 11
SP  - 1
EP  - 19
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ET  - 2
ER  - 
TY  - GEN
A1  - Figueroa Campos, Gustavo A.
A1  - Perez, Jeffrey Paulo H.
A1  - Block, Inga
A1  - Tchewonpi Sagu, Sorel
A1  - Saravia Celis, Pedro
A1  - Taubert, Andreas
A1  - Rawel, Harshadrai Manilal
T1  - Preparation of activated carbons from spent coffee and coffee parchment and assessment of their adsorbent efficiency
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The valorization of coffee wastes through modification to activated carbon has been considered as a low-cost adsorbent with prospective to compete with commercial carbons. So far, very few studies have referred to the valorization of coffee parchment into activated carbon. Moreover, low-cost and efficient activation methods need to be more investigated. The aim of this work was to prepare activated carbon from spent coffee grounds and parchment, and to assess their adsorption performance. The co-calcination processing with calcium carbonate was used to prepare the activated carbons, and their adsorption capacity for organic acids, phenolic compounds and proteins was evaluated. Both spent coffee grounds and parchment showed yields after the calcination and washing treatments of around 9.0%. The adsorption of lactic acid was found to be optimal at pH 2. The maximum adsorption capacity of lactic acid with standard commercial granular activated carbon was 73.78 mg/g, while the values of 32.33 and 14.73 mg/g were registered for the parchment and spent coffee grounds activated carbons, respectively. The Langmuir isotherm showed that lactic acid was adsorbed as a monolayer and distributed homogeneously on the surface. Around 50% of total phenols and protein content from coffee wastewater were adsorbed after treatment with the prepared activated carbons, while 44, 43, and up to 84% of hydrophobic compounds were removed using parchment, spent coffee grounds and commercial activated carbon, respectively; the adsorption efficiencies of hydrophilic compounds ranged between 13 and 48%. Finally, these results illustrate the potential valorization of coffee by-products parchment and spent coffee grounds into activated carbon and their use as low-cost adsorbent for the removal of organic compounds from aqueous solutions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1158 
KW  - coffee by-products
KW  - spent coffee grounds
KW  - parchment
KW  - valorization
KW  - calcination
KW  - activated carbon
KW  - organic compounds adsorption
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-521914
SN  - 1866-8372
IS  - 8
ER  - 
TY  - JOUR
A1  - Silva, Bibiana
A1  - Oliveira Costa, Ana Carolina
A1  - Tchewonpi, Sorel Sagu
A1  - Bönick, Josephine
A1  - Huschek, Gerd
A1  - Gonzaga, Luciano Valdemiro
A1  - Fett, Roseane
A1  - Baldermann, Susanne
A1  - Rawel, Harshadrai Manilal
T1  - Comparative quantification and differentiation of bracatinga (Mimosa scabrella Bentham) honeydew honey proteins using targeted peptide markers identified by high-resolution mass spectrometry
JF  - Food research international
N2  - Honey traceability is an important topic, especially for honeydew honeys, due to the increased incidence of adulteration. This study aimed to establish specific markers to quantify proteins in honey. A proteomics strategy to identify marker peptides from bracatinga honeydew honey was therefore developed. The proteomics approach was based on initial untargeted identification of honey proteins and peptides by LC-ESI-Triple-TOF-MS/MS, which identified the major royal jelly proteins (MRJP) presence. Afterwards, the peptides were selected by the in silico digestion. The marker peptides were quantified by the developed targeted LC-QqQ-MS/MS method, which provided good linearity and specificity, besides recoveries between 92 and 100% to quantify peptides from bracatinga honeydew honey. The uniqueness and high response in mass spectrometry were backed by further complementary protein analysis (SDS-PAGE). The selected marker peptides EALPHVPIFDR (MRJP 1), ILGANVK (MRJP 2), TFVTIER (MRJP 3), QNIDVVAR (MRJP 4), FINNDYNFNEVNFR (MRJP 5) and LLQPYPDWSWTK (MRJP 7), quantified by LC-QqQ-MS/MS, highlighted that the content of QNIDVVAR from MRJP 4 could be used to differentiate bracatinga honeydew honey from floral honeys (p < 0.05) as a potential marker for its authentication. Finally, principal components analysis highlighted the QNIDVVAR content as a good descriptor of the analyzed bracatinga honeydew honey samples.
KW  - Honeydew honey
KW  - Major royal jelly proteins
KW  - Marker peptides
KW  - High-resolution mass spectrometry
KW  - Principal component analysis
Y1  - 2020
U6  - https://doi.org/10.1016/j.foodres.2020.109991
SN  - 0963-9969
SN  - 1873-7145
VL  - 141
PB  - Elsevier
CY  - New York, NY [u.a.]
ER  - 
TY  - JOUR
A1  - Figueroa Campos, Gustavo Adolfo
A1  - Perez, Jeffrey Paulo H.
A1  - Block, Inga
A1  - Sagu Tchewonpi, Sorel
A1  - Saravia Celis, Pedro
A1  - Taubert, Andreas
A1  - Rawel, Harshadrai Manilal
T1  - Preparation of activated carbons from spent coffee and coffee parchment and assessment of their adsorbent efficiency
JF  - Processes : open access journal
N2  - The valorization of coffee wastes through modification to activated carbon has been considered as a low-cost adsorbent with prospective to compete with commercial carbons. So far, very few studies have referred to the valorization of coffee parchment into activated carbon. Moreover, low-cost and efficient activation methods need to be more investigated. The aim of this work was to prepare activated carbon from spent coffee grounds and parchment, and to assess their adsorption performance. The co-calcination processing with calcium carbonate was used to prepare the activated carbons, and their adsorption capacity for organic acids, phenolic compounds and proteins was evaluated. Both spent coffee grounds and parchment showed yields after the calcination and washing treatments of around 9.0%. The adsorption of lactic acid was found to be optimal at pH 2. The maximum adsorption capacity of lactic acid with standard commercial granular activated carbon was 73.78 mg/g, while the values of 32.33 and 14.73 mg/g were registered for the parchment and spent coffee grounds activated carbons, respectively. The Langmuir isotherm showed that lactic acid was adsorbed as a monolayer and distributed homogeneously on the surface. Around 50% of total phenols and protein content from coffee wastewater were adsorbed after treatment with the prepared activated carbons, while 44, 43, and up to 84% of hydrophobic compounds were removed using parchment, spent coffee grounds and commercial activated carbon, respectively; the adsorption efficiencies of hydrophilic compounds ranged between 13 and 48%. Finally, these results illustrate the potential valorization of coffee by-products parchment and spent coffee grounds into activated carbon and their use as low-cost adsorbent for the removal of organic compounds from aqueous solutions.
KW  - coffee by-products
KW  - spent coffee grounds
KW  - parchment
KW  - valorization
KW  - calcination
KW  - activated carbon
KW  - organic compounds adsorption
Y1  - 2021
U6  - https://doi.org/10.3390/pr9081396
SN  - 2227-9717
VL  - 9
IS  - 8
PB  - MDPI
CY  - Basel
ER  -