@article{RohnPetzkeRaweletal.2006, author = {Rohn, Sascha and Petzke, Klaus-J{\"u}rgen and Rawel, Harshadrai Manilal and Kroll, J{\"u}rgen}, title = {Reactions of chlorogenic acid and quercetin with a soy protein isolate - Influence on the in vivo food protein quality in rats}, series = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology}, volume = {50}, journal = {Molecular nutrition \& food research : bioactivity, chemistry, immunology, microbiology, safety, technology}, publisher = {Wiley}, address = {Weinheim}, issn = {1613-4125}, doi = {10.1002/mnfr.200600043}, pages = {696 -- 704}, year = {2006}, abstract = {Plant phenolic compounds are known to interact with proteins producing changes in the food (e.g., biological value (BV), color, taste). Therefore, the in vivo relevance, especially, of covalent phenolprotein reactions on protein quality was studied in a rat bioassay. The rats were fed protein derivatives at a 10\% protein level. Soy proteins were derivatized with chlorogenic acid and quercetin (derivatization levels: 0.056 and 0.28 mmol phenolic compound/gram protein). Analysis of nitrogen in diets, urine, and fecal samples as well as the distribution of amino acids were determined. Depending on the degree of derivatization, the rats fed with soy protein derivatives showed an increased excretion of fecal and urinary nitrogen. As a result, true nitrogen digestibility, BV, and net protein utilization were adversely affected. Protein digestibility corrected amino acid score was decreased for lysine, tryptophan, and sulfur containing amino acids.}, language = {en} } @article{KlopschBaldermannVossetal.2019, author = {Klopsch, Rebecca and Baldermann, Susanne and Voss, Alexander and Rohn, Sascha and Schreiner, Monika and Neugart, Susanne}, title = {Narrow-Banded UVB Affects the Stability of Secondary Plant Metabolites in Kale (Brassica oleracea var. sabellica) and Pea (Pisum sativum) Leaves Being Added to Lentil Flour Fortified Bread: A Novel Approach for Producing Functional Foods}, series = {Foods}, volume = {8}, journal = {Foods}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {2304-8158}, doi = {10.3390/foods8100427}, pages = {20}, year = {2019}, abstract = {Young kale and pea leaves are rich in secondary plant metabolites (SPMs) whose profile can be affected by ultraviolet B (UVB) radiation. Carotenoids and flavonoids in kale and pea exposed to narrow-banded UVB, produced by innovative light-emitting diodes (LEDs), and subsequently used for breadmaking were investigated for the first time, thus combining two important strategies to increase the SPMs intake. Breads were also fortified with protein-rich lentil flour. Antioxidant activity in the 'vegetable breads' indicated health-promoting effects. Lentil flour increased the antioxidant activity in all of the 'vegetable breads'. While carotenoids and chlorophylls showed a minor response to UVB treatment, kaempferol glycosides decreased in favor of increasing quercetin glycosides, especially in kale. Additionally, breadmaking caused major decreases in carotenoids and a conversion of chlorophyll to bioactive degradation products. In 'kale breads' and 'pea breads', 20\% and 84\% of flavonoid glycosides were recovered. Thus, kale and pea leaves seem to be suitable natural ingredients for producing innovative Functional Foods.}, language = {en} } @article{RohnRawelRoberetal.2005, author = {Rohn, Sascha and Rawel, Harshadrai Manilal and Rober, M. and Kroll, J{\"u}rgen}, title = {Reactions with phenolic substances can induce changes in some physico-chemical properties and activities of bromelain - the consequences for supplementary food products}, issn = {0950-5423}, year = {2005}, abstract = {Bromelain was allowed to react with phenolic compounds. The activity and selected physico-chemical properties of the resulting derivatives were characterized. In vitro experiments showed that the proteolytic activity of bromelain was inhibited. Bromelain also serves as a food protein, because food stuffs based on pineapple contain relatively high concentrations of bromelain. In vitro digestion of bromelain derivatives with the main proteolytic enzymes of the gastrointestinal tract was also adversely affected. A covalent attachment of the phenolic compounds was identified at the tryptophan, free amino (lysines and N-terminal) and thiol groups of bromelain. A decrease in solubility of the derivatives was observed. The isoelectric point was shifted to lower pH values and high molecular weight fractions were identified. All effects observed depended on the reactivity of the phenolic substances. Two supplementary food products containing both bromelain and quercetin were also tested in terms of their proteolytic activity and digestibility}, language = {en} } @article{RawelRohnKroll2005, author = {Rawel, Harshadrai Manilal and Rohn, Sascha and Kroll, J{\"u}rgen}, title = {Characterisation of 11S protein fractions and phenolic compounds from green coffee beans under special consideration of their interactions - A review}, issn = {0012-0413}, year = {2005}, abstract = {The intention of this study was to increase the knowledge on the composition and structure of coffee bean proteins and the changes induced in them especially with regard to their interactions with the phenolic compounds also present. For this purpose green coffee beans were extracted by means of standard methanol extraction to quantify the chlorogenic acid content. Different solubilisation buffers were applied to extract the protein fractions with or without prior fat removal. The protein samples thus obtained were analysed by different methods (RP-HPLC, SDS-PAGE and SELDI-TOF- MS). Preliminary model studies were performed to characterize the interactions between the isolated green coffee protein fractions and chlorogenic acid (the major phenolic compound in coffee beans) with the intention of fulfilling the ultimate goal of characterizing such reactions in roasted coffee. The results show that the content of chlorogenic bound covalently to the protein increases. A reaction with the nucleophilic protein side chains (tryptophan, cystein and lysine) was recorded. Cross-inked protein polymers were also detected, whereby the a-chain was found to be more reactive. These reactions effect the solubility of the coffee bean proteins, the latter in turn becoming more acidic in nature. The secondary structure was affected only slightly as determined by circular dichroism. The in-vitro tryptic digestibility was also influenced, where again the cc-chain seems to be more susceptible. The observed polymerisation due to derivatisation by chorogenic acid declines the digestion. Similar digestion behaviour was also observed during tryptic hydrolysis of roasted coffee compared to that of green coffee, roasting allowing more stronger denaturation caused by the accompanying Maillard reaction. The derivatised green coffee bean proteins were found to have moderate antioxidative capacity}, language = {en} } @article{KrollRantersRaweletal.2004, author = {Kroll, J{\"u}rgen and Ranters, Holger and Rawel, Harshadrai Manilal and Rohn, Sascha}, title = {Isoflavones as constituents of plant foods : Isoflavone als Bestandteile pflanzlicher Lebensmittel}, year = {2004}, abstract = {Vor dem Hintergrund der Diskussion {\"u}ber die ern{\"a}hrungsphysiologische Bedeutung von Isoflavonen befasst sich die vorliegende {\"U}bersichtsarbeit auf der Basis von 186 Literaturquellen mit der Struktur, dem Vorkommen, der Aufnahme, der Biosynthese, der Resorption, dem Metabolismus und der biologischen Wirkung dieser Untergruppen der Pflanzenphenole. Diskutiert werden sowohl positive als auch negative biologische Wirkungen dieser Verbindungen. Strukturabh{\"a}ngig k{\"o}nnen die Isoflavone mit anderen Lebensmittelinhaltsstoffen in Wechselwirkung treten. With the background of the actual ongoing discussion on the nutritional}, language = {de} } @article{RawelRohnKrolletal.2005, author = {Rawel, Harshadrai Manilal and Rohn, Sascha and Kroll, J{\"u}rgen and Schweigert, Florian J.}, title = {Surface enhanced laser desorptions ionization-time of flight-mass spectrometry analysis in complex food and biological systems}, year = {2005}, language = {en} } @article{PetzkeSchuppeRohnetal.2005, author = {Petzke, Klaus-J{\"u}rgen and Schuppe, S. and Rohn, Sascha and Rawel, Harshadrai Manilal and Kroll, J{\"u}rgen}, title = {Chlorogenic acid moderately decreases the quality of whey proteins in rats}, issn = {0021-8561}, year = {2005}, abstract = {During processing and storage, phenolic compounds (PCs) may react with food protein bound amino acids (AAs). Such reactions have been reported to change physicochemical and to decrease in vitro digestion properties of proteins. A rat growth and nitrogen (N) balance study was conducted to prove whether derivatization with chlorogenic acid (CA) affects the nutritional quality of beta-lactoglobulin (beta-LG). Test diets (10\% protein level) contained nonderivatized beta-LG (LG, treated under omission of CA), low derivatization level beta-LG (LGL), high derivatization level beta-LG (LGH), or casein supplemented with L-methionine (0.3\% of diet; C+met) as an internal standard. An additional group received untreated beta-LG supplemented with pure CA (1.03\% of diet; LG+CA). The AA composition of test proteins, plasma AAs, and liver glutathione (GSH) concentrations were determined. Protein digestibility-corrected amino acid score (PDCAAS) was calculated using human or rat AA requirement patterns and rat fecal digestibility values. N excretion was significantly higher in feces and lower in urine of rats fed with LGH as compared to LG and LGL. Consequently, true N digestibility (TND) was significantly lower with LGH as compared to LG and LGL. The lower content of methionine, cysteine, lysine, and tryptophan in LGH corresponded to a reduced TND. Net protein utilization (NPU) was not different between treated beta-LG fed diet groups but was lower than in LG+CA and C+met fed groups. Only at a relatively high level of derivatization with CA, the otherwise good nutritional quality of beta-LG is affected so that TND is reduced, while NPU still remains unaffected. Derivatization of beta-LG with CA does not seem to lead to an additional deficiency in a specific indispensable AA in growing rats fed with 10\% protein}, language = {en} } @article{RohnRawelKroll2004, author = {Rohn, Sascha and Rawel, Harshadrai Manilal and Kroll, J{\"u}rgen}, title = {Antioxidant activity of protein-bound quercetin}, year = {2004}, abstract = {Bovine serum albumin (BSA) was derivatized by covalent attachment of different amounts of quercetin (ratios of BSA : quercetin were 20:1, 10:1, 7:1, 5:1, 2:1 (w/w)). The antioxidant activity of the protein-phenol derivatives was investigated using a modified TEAC assay. The results show that the covalent attachment of quercetin to BSA decreases the total antioxidant activity in comparison to an equivalent amount of free quercetin depending on the degree of derivatization. The derivative with the highest amount of covalently bound quercetin (2:1 derivative) showed an antioxidant activity of only 79\% compared to an equivalent amount of free quercetin. After the enzymatic proteolysis of the BSA quercetin derivatives with trypsin, the total antioxidant activity of the degradation products increases in comparison to the respective undigested derivatives, but does not reach the activity of an equivalent amount of free quercetin. Even after 240 minutes of tryptic degradation there is still a lack in antioxidant activity (for the 7:1 derivative nearly 33\%) as compared to free quercetin.}, language = {en} } @article{RawelRantersRohnetal.2004, author = {Rawel, Harshadrai Manilal and Ranters, Holger and Rohn, Sascha and Kroll, J{\"u}rgen}, title = {Assessment of the reactivity of selected isoflavones against proteins in comparison to quercetin}, year = {2004}, abstract = {Selected isoflavones (genistein, daidzein, formononetin, prunetin, biochanin A and two synthetic isoflavones) were allowed to interact with soy and whey proteins. The reaction products were analyzed in terms of covalent binding at the nucleophilic side chains of proteins. Changes in molecular properties of the proteins derivatives were documented by SDS-PAGE, IEF and SELDI-TOF-MS. The structural changes induced were studied using circular dichroism (CD). The in vitro digestibility was assessed with trypsin. The results show that the occurrence of the catechol moiety, i.e. the two adjacent (ortho) aromatic hydroxyl groups on ring B of the flavonoid structural skeleton appears to be perquisite condition for covalent binding to proteins. The catechol moiety on ring A was less reactive. Its absence lead to a slight or no significant reaction, although non-covalent interactions may still be possible even when lacking this structural element. A comparison of the data is also made with quercetin representing the flavonols.}, language = {en} } @article{KrollRohnRawel2004, author = {Kroll, J{\"u}rgen and Rohn, Sascha and Rawel, Harshadrai Manilal}, title = {Einsatz von MALDI- und SELDI-Massenspectrometrie zur Charakterisierung ausgew{\"a}hlten Nahrungsproteine und Proteinmodifikationen}, issn = {0250-1554}, year = {2004}, abstract = {The application of mass spectrometry for the characterization of food proteins represents one of the most important tools in food chemistry and nutritional science. In the last few years there has been a tremendous development in the classical questions with regard to determination of molecular mass, identification amino acid sequence and structure of proteins. With these technical improvements, it is becoming more and more interesting to characterize the changes involved in proteins embedded in the food matrix as a result of their technological processing, especially in terms of the influence on their functional, nutritional and phsiological properties. Many such posttransational protein modifications occuring due to reactions with other food constituents (e.g. secondary plant metabolites) provide a series of possible fields for application of a sample preparation with a soft ionisation technique using mass spectrometry. The matrix assisted laser desorptions/ionisation ? time of flight ? mass spectrometry (MALDI-TOF-MS) and the surface enhanced laser desorptions/ionisation ? time of flight ? mass spectrometry (SELDI-TOF-MS) have become since than two of the most important methods of choice for solving of such questions and these both techniques have been described here with correponding examples.}, language = {de} } @article{KrollRohnRawel2003, author = {Kroll, J{\"u}rgen and Rohn, Sascha and Rawel, Harshadrai Manilal}, title = {Sekund{\"a}re Inhaltsstoffe als funktionelle Bestandteile pflanzlicher Lebensmittel}, year = {2003}, language = {de} } @article{RohnRawelWollenbergeretal.2003, author = {Rohn, Sascha and Rawel, Harshadrai Manilal and Wollenberger, Ursula and Kroll, J{\"u}rgen}, title = {Enzyme acitivity of alpha-chymotrypsin after derivatization with phenolic compounds}, year = {2003}, language = {en} } @article{RawelRohnKroll2003, author = {Rawel, Harshadrai Manilal and Rohn, Sascha and Kroll, J{\"u}rgen}, title = {Influence of a sugar moiety (rhamnosylglycoside) at 3-O position on the reactivity of quercetin with whey proteins}, year = {2003}, language = {en} } @article{KrollRawelRohn2003, author = {Kroll, J{\"u}rgen and Rawel, Harshadrai Manilal and Rohn, Sascha}, title = {Reactions of plant phenolics with food proteins and enzymes under special consideration of covalent bonds : a Review}, year = {2003}, language = {en} } @article{RohnRawelKroll2002, author = {Rohn, Sascha and Rawel, Harshadrai Manilal and Kroll, J{\"u}rgen}, title = {Inhibitory effects of plant phenols on the activity of selected enzymes}, year = {2002}, abstract = {Selected enzymes (alpha-amylase, trypsin, and lysozyme) were allowed to react with some simple phenolic and related compounds (caffeic acid, chlorogenic acid, ferulic acid, gallic acid, m-, o-, and p-dihydroxybenzenes, quinic acid, and p-benzoquinone). The derivatized enzymes obtained were characterized in terms of their activity. In vitro experiments showed that the enzymatic activity of the derivatives was adversely affected. This enzyme inhibition depended on the reactivity of the phenolic and related substances tested as well as on the kind of substrate applied. The decrease in the activity was accompanied by a reduction in the amount of free amino and thiol groups, as well as tryptophan residues, which resulted from the covalent attachment of the phenolic and related compounds to these reactive nucleophilic sites in the enzymes. The enzyme inhibition correlates well with the blocking of the mentioned amino acid side chains.}, language = {en} } @article{RohnRawelKroll2002, author = {Rohn, Sascha and Rawel, Harshadrai Manilal and Kroll, J{\"u}rgen}, title = {Influence of plant phenols on selected enzymes}, year = {2002}, abstract = {Secondary plant metabolites are important native food components, which are becoming more and more interesting due to their physiological effects on humans. Some representatives of these compounds are very reactive and can interact with other main food components like proteins resp. enzymes. This work deals with the reactions of selected enzymes (trypsin, alpha-chymotrypsin and alpha-amylase) with simple phenolic and related substances (caffeic acid, chlorogenic acid, ferulic acid, gallic acid, meta-, ortho- and para-dihydroxybenzene, 1,4-benzoquinone, quinic acid). The derivatives formed were characterized in terms of their activity and selected physicochemical properties. In vitro experiments showed that the proteolytic digestion of food proteins with trypsin and alpha-chymotrypsin derivatives was adversely affected. This decrease depends on the reactivity of the phenolic and related substances tested as well as on the kind of substrate applied. Reactions of phenolic compounds with other enzymes (alpha-amylase and lysozyme) showed similar results with regard to physicochemical properties and their activities.}, language = {en} } @article{RawelRohnKruseetal.2002, author = {Rawel, Harshadrai Manilal and Rohn, Sascha and Kruse, Hans-Peter and Kroll, J{\"u}rgen}, title = {Structural changes induced in bovine serum albumin by covalent attachment of chlorogenic acid}, year = {2002}, abstract = {Bovine serum albumin (BSA) was modifed by covalent attachment of chlorogenic acid using different concentrations at pH 9. The derivatization was accompanied by a reduction of lysine, cysteine and tryptophan residues. The isoelectric points were shifted to lower pH values and formation of high molecular weight fractions was noted. The structural changes were studied using circular dichroism, differential scanning calorimetry (DSC), intrinsic fluorescence, and binding of anilinonaphthalenesulfonic acid. The results showed that the content of alpha-helix decreased with a parallel increase in unordered structures with higher degrees of derivatization. DSC revealed a decrease in both denaturation temperature and enthalpy. Surface hydrophobicity declined, indicating that hydrophilic regions were exposed on the molecular surface. Proteolytic digestion showed that, at a lower degree of derivatization,the tryptic degradation was most adversely effected, whereas the peptic digestion declined with increasing modification. A trypsin inhibitory effect of the breakdown products released from derivatized BSA was also observed.}, language = {en} } @article{RawelCzajkaRohnetal.2002, author = {Rawel, Harshadrai Manilal and Czajka, D{\"o}rte and Rohn, Sascha and Kroll, J{\"u}rgen}, title = {Interactions of different phenolic acids and flavonoids with soy proteins}, year = {2002}, abstract = {Soy glycinin (SG) and soy trypsin inhibitor (STI) were derivatized by chlorogenic- and caffeic acid (cinnamic acids, C6 - C3 - structure), and by gallic acid representing hydroxybenzoic acids (C6 - C1 - structure). Further, the flavonoids, flavone, apigenin, kaempferol, quercetin and myricetin (C6 - C3 - C6 - structure) were also caused to react with soy proteins to estimate the influence of the number and the position of hydroxy substituents. The derivatization caused a reduction of lysine, cysteine and tryptophan residues in the soy proteins. The isoelectric points of the derivatives were shifted to lower pH values and formation of high molecular fractions was documented. The derivatives were characterized in terms of their solubility at different pH-values to document the influence on the functional properties. The structural changes induced were studied using circular dichroism (CD), differential scanning calorimetry (DSC) , intrinsic fluorescence, and binding of anilinonaphthalenesulfonic acid. The influence of derivatization on the in-vitro digestibility with trypsin, chymotrypsin, pepsin and pancreatin was also assessed. The effect on the trypsin inhibitor activity of all the resulting STI derivatives was studied, the latter being reduced.}, language = {en} } @article{ReinkensmeierSteinbrennerHomannetal.2016, author = {Reinkensmeier, Annika and Steinbrenner, Katrin and Homann, Thomas and Bussler, Sara and Rohn, Sascha and Rawel, Harshadrai Manilal}, title = {Monitoring the apple polyphenol oxidase-modulated adduct formation of phenolic and amino compounds}, series = {Food chemistry}, volume = {194}, journal = {Food chemistry}, publisher = {Elsevier}, address = {Oxford}, issn = {0308-8146}, doi = {10.1016/j.foodchem.2015.07.145}, pages = {76 -- 85}, year = {2016}, abstract = {Minimally processed fruit products such as smoothies are increasingly coming into demand. However, they are often combined with dairy ingredients. In this combination, phenolic compounds, polyphenoloxidases, and amino compounds could interact. In this work, a model approach is presented where apple serves as a source for a high polyphenoloxidase activity for modulating the reactions. The polyphenoloxidase activity ranged from 128 to 333 nakt/mL in different apple varieties. From these, 'Braeburn' was found to provide the highest enzymatic activity. The formation and stability of resulting chromogenic conjugates was investigated. The results show that such adducts are not stable and possible degradation mechanisms leading to follow-up products formed are proposed. Finally, apple extracts were used to modify proteins and their functional properties characterized. There were retaining antioxidant properties inherent to phenolic compounds after adduct formation. Consequently, such interactions may also be utilized to improve the textural quality of food products.}, language = {en} } @misc{KlopschBaldermannVossetal.2018, author = {Klopsch, Rebecca and Baldermann, Susanne and Voss, Alexander and Rohn, Sascha and Schreiner, Monika and Neugart, Susanne}, title = {Bread enriched with legume microgreens and leaves}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1064}, issn = {1866-8372}, doi = {10.25932/publishup-46870}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-468707}, pages = {21}, year = {2018}, abstract = {Flavonoids, carotenoids, and chlorophylls were characterized in microgreens and leaves of pea (Pisum sativum) and lupin (Lupinus angustifolius) as these metabolites change during ontogeny. All metabolites were higher in the leaves for both species. Acylated quercetin and kaempferol sophorotrioses were predominant in pea. Genistein and malonylated chrysoeriol were predominant in lupin. Further, the impact of breadmaking on these metabolites using pea and lupin material of two ontogenetic stages as an added ingredient in wheat-based bread was assessed. In "pea microgreen bread" no decrease of quercetin was found with regard to the non-processed plant material. However kaempferol glycosides showed slight decreases induced by the breadmaking process in "pea microgreen bread" and "pea leaf bread." In "lupin microgreen bread" no decrease of genistein compared to the non-processed plant material was found. Chrysoeriol glycosides showed slight decreases induced by the breadmaking process in "lupin microgreen bread" and "lupin leaf bread." In all breads, carotenoids and chlorophylls were depleted however pheophytin formation was caused. Thus, pea and lupin microgreens and leaves are suitable, natural ingredients for enhancing health-promoting secondary plant metabolites in bread and may even be used to tailor bread for specific consumer health needs.}, language = {en} } @article{KlopschBaldermannVossetal.2018, author = {Klopsch, Rebecca and Baldermann, Susanne and Voss, Alexander and Rohn, Sascha and Schreiner, Monika and Neugart, Susanne}, title = {Bread enriched with legume microgreens and leaves}, series = {Frontiers in chemistry}, volume = {6}, journal = {Frontiers in chemistry}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {2296-2646}, doi = {10.3389/fchem.2018.00322}, pages = {19}, year = {2018}, abstract = {Flavonoids, carotenoids, and chlorophylls were characterized in microgreens and leaves of pea (Pisum sativum) and lupin (Lupinus angustifolius) as these metabolites change during ontogeny. All metabolites were higher in the leaves for both species. Acylated quercetin and kaempferol sophorotrioses were predominant in pea. Genistein and malonylated chrysoeriol were predominant in lupin. Further, the impact of breadmaking on these metabolites using pea and lupin material of two ontogenetic stages as an added ingredient in wheat-based bread was assessed. In "pea microgreen bread" no decrease of quercetin was found with regard to the non-processed plant material. However kaempferol glycosides showed slight decreases induced by the breadmaking process in "pea microgreen bread" and "pea leaf bread." In "lupin microgreen bread" no decrease of genistein compared to the non-processed plant material was found. Chrysoeriol glycosides showed slight decreases induced by the breadmaking process in "lupin microgreen bread" and "lupin leaf bread." In all breads, carotenoids and chlorophylls were depleted however pheophytin formation was caused. Thus, pea and lupin microgreens and leaves are suitable, natural ingredients for enhancing health-promoting secondary plant metabolites in bread and may even be used to tailor bread for specific consumer health needs.}, language = {en} } @article{KlopschBaldermannHanschenetal.2019, author = {Klopsch, Rebecca and Baldermann, Susanne and Hanschen, Franziska S. and Voss, Alexander and Rohn, Sascha and Schreiner, Monika and Neugart, Susanne}, title = {Brassica-enriched wheat bread: Unraveling the impact of ontogeny and breadmaking on bioactive secondary plant metabolites of pak choi and kale}, series = {Food chemistry}, volume = {295}, journal = {Food chemistry}, publisher = {Elsevier}, address = {Oxford}, issn = {0308-8146}, doi = {10.1016/j.foodchem.2019.05.113}, pages = {412 -- 422}, year = {2019}, abstract = {Consumption of Brassica vegetables is linked to health benefits, as they contain high concentrations of the following secondary plant metabolites (SPMs): glucosinolate breakdown products, carotenoids, chlorophylls, and phenolic compounds. Especially Brassica vegetables are consumed as microgreens (developed cotyledons). It was investigated how different ontogenetic stages (microgreens or leaves) of pak choi (Brassica rapa subsp. chinensis) and kale (Brassica oleracea var. sabellica) differ in their SPM concentration. The impact of breadmaking on SPMs in microgreens (7 days) and leaves (14 days) in pak choi and kale as a supplement in mixed wheat bread was assessed. In leaves, carotenoids, chlorophylls, and phenolic compounds were higher compared to those of microgreens. Breadmaking caused a decrease of SPMs. Chlorophyll degradation was observed, leading to pheophytin and pyropheophytin formation. In kale, sinapoylgentiobiose, a hydroxycinnamic acid derivative, concentration increased. Thus, leaves of Brassica species are suitable as natural ingredients for enhancing bioactive SPM concentrations in bread.}, language = {en} } @article{SchroeterNeugartSchreineretal.2019, author = {Schr{\"o}ter, David and Neugart, Susanne and Schreiner, Monika and Grune, Tilman and Rohn, Sascha and Ott, Christiane}, title = {Amaranth's 2-Caffeoylisocitric Acid—An Anti-Inflammatory Caffeic Acid Derivative That Impairs NF-κB Signaling in LPS-Challenged RAW 264.7 Macrophages}, series = {Nutrients}, volume = {11}, journal = {Nutrients}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2072-6643}, doi = {10.3390/nu11030571}, pages = {14}, year = {2019}, abstract = {For centuries, Amaranthus sp. were used as food, ornamentals, and medication. Molecular mechanisms, explaining the health beneficial properties of amaranth, are not yet understood, but have been attributed to secondary metabolites, such as phenolic compounds. One of the most abundant phenolic compounds in amaranth leaves is 2-caffeoylisocitric acid (C-IA) and regarding food occurrence, C-IA is exclusively found in various amaranth species. In the present study, the anti-inflammatory activity of C-IA, chlorogenic acid, and caffeic acid in LPS-challenged macrophages (RAW 264.7) has been investigated and cellular contents of the caffeic acid derivatives (CADs) were quantified in the cells and media. The CADs were quantified in the cell lysates in nanomolar concentrations, indicating a cellular uptake. Treatment of LPS-challenged RAW 264.7 cells with 10 µM of CADs counteracted the LPS effects and led to significantly lower mRNA and protein levels of inducible nitric oxide synthase, tumor necrosis factor alpha, and interleukin 6, by directly decreasing the translocation of the nuclear factor κB/Rel-like containing protein 65 into the nucleus. This work provides new insights into the molecular mechanisms that attribute to amaranth's anti-inflammatory properties and highlights C-IA's potential as a health-beneficial compound for future research.}, language = {en} } @article{CarlsohnRohnMayeretal.2010, author = {Carlsohn, Anja and Rohn, Sascha and Mayer, Frank and Schweigert, Florian J.}, title = {Physical activity, antioxidant status, and protein modification in adolescent athletes}, issn = {0195-9131}, doi = {10.1249/Mss.0b013e3181c74f7b}, year = {2010}, abstract = {Exercise may increase reactive oxygen species production, which might impair cell integrity and contractile function of muscle cells. However, little is known about the effect of regular exercise on the antioxidant status of adolescents. Purpose: This study aimed to evaluate the impact of exercise on the antioxidant status and protein modifications in adolescent athletes. Methods: In 90 athletes and 18 controls (16 +/- 2 yr), exercise-related energy expenditure was calculated on the basis of a 7-d activity protocol. Antioxidant intake and plasma concentrations of alpha-tocopherol, carotenoids, and uric acid were analyzed. Plasma antioxidant activity was determined by Trolox equivalent (TE) antioxidant capacity and electron spin resonance spectrometry. Protein modifications were assessed with structural changes of transthyretin using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Data were analyzed by two-way ANOVA and post hoc by the Tukey-Kramer test (alpha = 0.05). Results: Antioxidant intake correlated with energy intake and was within the recommended daily allowance for vitamins C and E and beta-carotene. Plasma levels of neither nutritional antioxidants nor uric acid differed between the groups. TE antioxidant capacity was higher in athletes (men = 1.47 perpendicular to 0.2 mmol TE per liter, women = 1.45 perpendicular to 0.2 mmol TE per liter) compared with controls (men = 1.17 +/- 0.04 mmol TE per liter, women = 1.14 +/- 0.04 mmol TE per liter) and increased with exercise-related energy expenditure (P = 0.007). Transthyretin cysteinylation rate differed between the groups, with the highest rate of protein modifications in moderately active subjects (P = 0.007). Conclusions: Results suggest that if the nutritional choice of athletes is well balanced, enough antioxidants are provided to meet recommended amounts. Moreover, regular exercise increases blood antioxidant capacity in young athletes, whereas chronic exercise was not shown to promote protein modifications. Thus, in young athletes who are sufficiently supplied with antioxidants, beneficial effects of exercise on antioxidant status rather than on oxidative stress may be anticipated.}, language = {en} } @article{ReinkensmeierBasslerSchlueteretal.2015, author = {Reinkensmeier, Annika and Bassler, Sara and Schlueter, Oliver and Rohn, Sascha and Rawel, Harshadrai Manilal}, title = {Characterization of individual proteins in pea protein isolates and air classified samples}, series = {Food research international}, volume = {76}, journal = {Food research international}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0963-9969}, doi = {10.1016/j.foodres.2015.05.009}, pages = {160 -- 167}, year = {2015}, abstract = {Generally, pea proteins are extracted at comparatively acidic or basic pH values to provide a basis for protein isolate production. Such processing steps result in partial denaturation of the proteins rendering them in most cases insoluble at food processing pH conditions and limiting their application in food products. Here, the comparison of the solubility properties of pea proteins in protein enriched fractions deriving from air classification is reported. Protein content, solubility, and physicochemical parameters of different fractions of the pea (Pisum sativum) variety 'Salamanca' were investigated as a function of pH using SDS-PAGE and surface hydrophobicity. Whole pea flour (20\% protein), air classified, protein-enriched pea flour (48\% protein), pea flour made from hulls (2.8\% protein), and pea protein isolate (81\% protein) served as test materials. Fractionation and pH value affected the composition and surface hydrophobicity of the proteins as well as the content of trypsin inhibitors. All samples showed a high buffering capacity in the range of pH 4 to 10. The direct comparison documents the comparatively better protein quality of the air classified, protein enriched pea fraction. The solubility of the pea protein isolate can be improved by using selected additives, giving new possibilities for plant protein application. Relevant technofunctional properties were determined and compared with two commercially available pea-based products (whole pea flour and an isolate). Water binding capacity was highest for the commercially available pea flour followed by the pea hull flour. Fat binding capacity remained more or less unchanged. (C) 2015 Elsevier Ltd. All rights reserved.}, language = {en} } @article{RailaRohnSchweigertetal.2011, author = {Raila, Jens and Rohn, Sascha and Schweigert, Florian J. and Abraham, Getu}, title = {Increased antioxidant capacity in the plasma of dogs after a single oral dosage of tocotrienols}, series = {The British journal of nutrition : an international journal devoted to the science of human and animal nutrition}, volume = {106}, journal = {The British journal of nutrition : an international journal devoted to the science of human and animal nutrition}, number = {7}, publisher = {Cambridge Univ. Press}, address = {Cambridge}, issn = {0007-1145}, doi = {10.1017/S0007114511000511}, pages = {S116 -- S119}, year = {2011}, abstract = {The intestinal absorption of tocotrienols (TCT) in dogs is, to our knowledge, so far unknown. Adult Beagle dogs (n 8) were administered a single oral dosage of a TCT-rich fraction (TRF; 40 mg/kg body weight) containing 32\% alpha-TCT, 2\% beta-TCT, 27\% gamma-TCT, 14\% delta-TCT and 25\% alpha-tocopherol (alpha-TCP). Blood was sampled at baseline (fasted), 1, 2, 3, 4, 5, 6, 8 and 12 h after supplementation. Plasma and chylomicron concentrations of TCT and alpha-TCP were measured at each time point. Plasma TAG were measured enzymatically, and plasma antioxidant capacity was assessed by the Trolox equivalent antioxidant capacity assay. In fasted dogs, levels of TCT were 0.07 (SD 0.03) mu mol/l. Following the administration of the TRF, total plasma TCT peaked at 2 h (7.16 (SD 3.88) mu mol/l; P<0.01) and remained above baseline levels (0.67 (SD 0.44) mu mol/l; P, 0.01) at 12 h. The TCT response in chylomicrons paralleled the increase in TCT in plasma with a maximum peak (3.49 (SD 2.06) mu mol/l; P, 0.01) at 2 h post-dosage. alpha-TCP was the major vitamin E detected in plasma and unaffected by TRF supplementation. The Trolox equivalent values increased from 2 h (776 (SD 51.2) mu mol/l) to a maximum at 12 h (1130 (SD 7.72) mmol/l; P<0.01). The results show that TCT are detected in postprandial plasma of dogs. The increase in antioxidant capacity suggests a potential beneficial role of TCT supplementation in the prevention or treatment of several diseases in dogs.}, language = {en} } @phdthesis{Rohn2002, author = {Rohn, Sascha}, title = {Reaktionen von phenolischen Verbindungen als Inhaltsstoffe pflanzlicher Lebensmittel mit ausgew{\"a}hlten Enzymen : Einfluss auf physikochemische Proteineigenschaften und Enzymaktivit{\"a}t}, publisher = {Logos}, address = {Berlin}, isbn = {3-8325-0079-0}, pages = {152 S.}, year = {2002}, language = {de} } @article{KrollRawelRohnetal.2001, author = {Kroll, J{\"u}rgen and Rawel, Harshadrai Manilal and Rohn, Sascha and Czajka, D{\"o}rte}, title = {Interactions of glycinin with plant phenols : influence on chemical properties and proteolytic degradation of the proteins}, year = {2001}, abstract = {Soya glycinin was derivatized with different phenolic substances (caffeic-, chlorogenic-, gallic acid and quercetin). The protein derivatives formed have been characterized in terms of their properties where they showed changes in the content of free epsilon-amino groups, tryptophan and thiol groups. The derivatives have also been characterized in terms of their solubility at different pH-values to document the influence on the functional properties. Another objective of this paper was to demonstrate the influence on the digestibility of the proteins with one of the main enzymes of the gastro-intestinal tract (pancreatin) on the basis of in vitro experiments after derivatization with phenolic substances. The enzymatic digestion of the derivatized proteins was promoted.}, language = {en} } @article{RohnRawelPietruschinskietal.2001, author = {Rohn, Sascha and Rawel, Harshadrai Manilal and Pietruschinski, Nadine and Kroll, J{\"u}rgen}, title = {In vitro inhibition of alpha -chymotryptic activity by phenolic compounds}, year = {2001}, abstract = {alpha-Chymotrypsin was modified by covalent attachment of selected phenolic and related compounds (caffeic acid, chlorogenic acid, ferulic acid, gallic acid, quinic acid, m-/o-/p-dihydroxybenzene and p-benzoquinone) at pH 9. The derivatives formed were characterised in terms of their activity and selected physicochemical properties. In vitro experiments showed that the proteolytic digestion of food proteins with alpha-chymotrypsin derivatives was adversely affected. This decrease depended on the reactivity of the phenolic and related substances tested as well as on the kind of substrate applied. The derivatisation was accompanied by a reduction in the amount of free lysine and tryptophan residues. Moreover, the solubility of the derivatives decreased over a broad pH range, with a parallel increase in the hydrophobicity. The isoelectric point was shifted to a lower pH value, and formation of high-molecular-weight fractions was documented by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE).}, language = {en} } @article{RawelKrollRohn2000, author = {Rawel, Harshadrai Manilal and Kroll, J{\"u}rgen and Rohn, Sascha}, title = {Reactions of phenol substances with lysozyme - physicochemical characterisation and proteolytic digestion of the derivatives}, year = {2000}, language = {en} } @article{RawelRohnKroll2000, author = {Rawel, Harshadrai Manilal and Rohn, Sascha and Kroll, J{\"u}rgen}, title = {Reactions of selected secondary plant metabolites (glucosinolates and phenols) with food proteins and enzymes - Influence on physicochemical properties, enzyme activity and proteolytic dagradation}, year = {2000}, language = {en} } @misc{RailaRohnSchweigertetal.2011, author = {Raila, Jens and Rohn, Sascha and Schweigert, Florian J. and Abraham, Getu}, title = {Increased antioxidant capacity in the plasma of dogs after a single oral dosage of tocotrienols}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {571}, issn = {1866-8372}, doi = {10.25932/publishup-41308}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413085}, pages = {4}, year = {2011}, abstract = {The intestinal absorption of tocotrienols (TCT) in dogs is, to our knowledge, so far unknown. Adult Beagle dogs (n 8) were administered a single oral dosage of a TCT-rich fraction (TRF; 40 mg/kg body weight) containing 32 \% a-TCT, 2 \% b-TCT, 27 \% g-TCT, 14 \% d-TCT and 25 \% a-tocopherol (a-TCP). Blood was sampled at baseline (fasted), 1, 2, 3, 4, 5, 6, 8 and 12 h after supplementation. Plasma and chylomicron concentrations of TCT and a-TCP were measured at each time point. Plasma TAG were measured enzymatically, and plasma antioxidant capacity was assessed by the Trolox equivalent antioxidant capacity assay. In fasted dogs, levels of TCT were 0·07 ( SD 0·03) mmol/l. Following the administration of the TRF, total plasma TCT peaked at 2 h (7·16 ( SD 3·88) mmol/l; P, 0·01) and remained above baseline levels (0·67 ( SD 0·44) mmol/l; P, 0·01) at 12 h. The TCT response in chylomicrons paralleled the increase in TCT in plasma with a maximum peak (3·49 ( SD 2·06) mmol/l; P, 0·01) at 2 h post-dosage. a-TCP was the major vitamin E detected in plasma and unaffected by TRF supplementation. The Trolox equivalent values increased from 2 h (776 ( SD 51·2) mmol/l) to a maximum at 12 h (1130 ( SD 7·72) mmol/l; P,0·01). The results show that TCT are detected in postprandial plasma of dogs. The increase in antioxidant capacity suggests a potential beneficial role of TCT supplementation in the prevention or treatment of several diseases in dogs.}, language = {en} }