TY - JOUR A1 - Ali, Mostafa A1 - Homann, Thomas A1 - Khalil, Mahmoud A1 - Kruse, Hans-Peter A1 - Rawel, Harshadrai Manilal T1 - Milk whey protein modification by coffee-specific phenolics effect on structural and functional properties JF - Journal of agricultural and food chemistry : a publication of the American Chemical Society N2 - A suitable vehicle for integration of bioactive plant constituents is proposed. It involves modification of proteins using phenolics and applying these for protection of labile constituents. It dissects the noncovalent and covalent interactions of beta-lactoglobulin with coffee-specific phenolics. Alkaline and polyphenol oxidase modulated covalent reactions were compared. Tryptic digestion combined with MALDI-TOF-MS provided tentative allocation of the modification type and site in the protein, and an in silico modeling of modified beta-lactoglobulin is proposed. The modification delivers proteins with enhanced antioxidative properties. Changed structural properties and differences in solubility, surface hydrophobicity, and emulsification were observed. The polyphenol oxidase modulated reaction provides a modified beta-lactoglobulin with a high antioxidative power, is thermally more stable, requires less energy to unfold, and, when emulsified with lutein esters, exhibits their higher stability against UV light. Thus, adaptation of this modification provides an innovative approach for functionalizing proteins and their uses in the food industry. KW - coffee phenolic compounds KW - whey proteins KW - antioxidants KW - protein-phenol interactions KW - modeling KW - functionalizing proteins Y1 - 2013 U6 - https://doi.org/10.1021/jf402221m SN - 0021-8561 VL - 61 IS - 28 SP - 6911 EP - 6920 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Ali, Mostafa A1 - Homann, Thomas A1 - Kreisel, Janka A1 - Khalil, Mahmoud A1 - Puhlmann, Ralf A1 - Kruse, Hans-Peter A1 - Rawel, Harshadrai Manilal T1 - Characterization and modeling of the interactions between coffee storage proteins and phenolic compounds JF - Journal of agricultural and food chemistry : a publication of the American Chemical Society N2 - This study addresses the interactions of coffee storage proteins with coffee-specific phenolic compounds. Protein profiles, of Coffea arabica and Coffea canephora (var robusta) were compared. Major Phenolic compounds were extracted and analyzed with appropriate methods. The polyphenol-protein interactions during protein extraction have been addressed by different analytical setups [reversed-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS), and Trolox equivalent antioxidant capacity (TEAC) assays], with focus directed toward identification of covalent adduct formation. The results indicate that C. arabica proteins are more susceptible to these interactions and the polyphenol oxidase activity seems to be a crucial factor for the formation of these addition products. A tentative allocation of the modification type and site in the protein has been attempted. Thus, the first available in silico modeling of modified coffee proteins is reported. The extent of these modifications may contribute to the structure and function of "coffee melanoidins" and are discussed in the context of coffee flavor formation. KW - Coffee beans KW - storage proteins KW - phenolic compounds KW - antioxidants KW - protein-phenol interactions KW - modeling Y1 - 2012 U6 - https://doi.org/10.1021/jf303372a SN - 0021-8561 VL - 60 IS - 46 SP - 11601 EP - 11608 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Bachmann, Lutz A1 - Homeier, Timo A1 - Arlt, Sebastian A1 - Brueckner, Monika A1 - Rawel, Harshadrai Manilal A1 - Deiner, Carolin A1 - Hartmann, Helmut T1 - Influence of different oral rehydration solutions on abomasal conditions and the acid-base status of suckling calves N2 - The aim of the study was to investigate the influence of oral rehydration solutions (ORS) on milk clotting, abomasal pH, electrolyte concentrations, and osmolality, as well as on the acid-base status in blood of suckling calves, as treatment with ORS is the most common therapy of diarrhea in calves to correct dehydration and metabolic acidosis. Oral rehydration solutions are suspected to inhibit abomasal clotting of milk; however, it is recommended to continue feeding cow's milk or milk replacer (MR) to diarrheic calves to prevent body weight losses. Three calves with abomasal cannulas were fed MR, MR-ORS mixtures, or water-ORS mixtures, respectively. Samples of abomasal fluid were taken before and after feeding at various time points, and pH, electrolyte concentrations, and osmolality were measured. The interference of ORS with milk clotting was examined in vivo and in vitro. To evaluate the effects of ORS on systemic acid-base status, the Stewart variables strong ion difference ([SID]), acid total ([A(tot)]), and partial pressure of CO2 (pCO(2)) were quantified in venous blood samples drawn before and after feeding. Calves reached higher abomasal pH values when fed with MR-ORS mixtures than when fed MR. Preprandial pH values were re-established after 4 to 6 h. Oral rehydration solutions prepared in water increased the abomasal fluid pH only for 1 to 2 h. Oral rehydration solutions with high [SID3] ([Na+] + [K+] - [Cl-]) values produced significantly higher abomasal pH values and area under the curve data of the pH time course. Caseinomacropeptide, an indicator of successful enzymatic milk clotting, could be identified in every sample of abomasal fluid after feeding MR-ORS mixtures. The MR-ORS mixtures with [SID3] values >= 92 mmol/L increased serum [SID3] but did not change venous blood pH. Oral rehydration solutions do not interfere with milk clotting in the abomasum and can, therefore, be administered with milk. In this study, MR-ORS mixtures with high [SID3] values caused an increase of serum [SID3] in healthy suckling calves and may be an effective treatment for metabolic acidosis in calves suffering from diarrhea. Y1 - 2009 UR - http://www.journalofdairyscience.org/ U6 - https://doi.org/10.3168/jds.2008-1487 SN - 0022-0302 ER - TY - JOUR A1 - Baier, Daniel A1 - Purschke, Benedict A1 - Schmitt, Christophe A1 - Rawel, Harshadrai Manilal A1 - Knorr, Dietrich T1 - Effect of high pressure - low temperature treatments on structural characteristics of whey proteins and micellar caseins JF - Food chemistry N2 - In this study, structural changes in micellar caseins and whey proteins due to high pressure - low temperature treatments (HPLT) were investigated and compared to changes caused by high pressure treatments at room temperature. Whey protein isolate (WPI) solutions as well as micellar casein (MC) dispersions and mixtures were treated at 500 MPa (pH 7.0 and 5.8) at room temperature, -15 degrees C and -35 degrees C. Surface hydrophobicity and accessible thiol groups remained nearly unchanged after HPLT treatments whereas HP treatments at room temperature caused an unfolding of the WPI, resulting in an increase in surface hydrophobicity and exposure of the thiol groups. For HPLT treatments, distinct changes in the secondary structure (increase in the amount of beta-sheets) were observed while the tertiary structure remained unchanged. Large flocs, stabilized by hydrophobic interactions and hydrogen bonds, were formed in casein containing samples due to HPLT treatments. Depending on the pH and the applied HPLT treatment parameters, these interactions differed significantly from the interactions determined in native micelles. (C) 2015 Elsevier Ltd. All rights reserved. KW - High pressure - low temperature treatments KW - Whey proteins KW - Micellar caseins KW - Structural changes Y1 - 2015 U6 - https://doi.org/10.1016/j.foodchem.2015.04.049 SN - 0308-8146 SN - 1873-7072 VL - 187 SP - 354 EP - 363 PB - Elsevier CY - Oxford ER - TY - GEN A1 - Baldermann, Susanne A1 - Homann, Thomas A1 - Neugart, Susanne A1 - Chmielewski, Frank M. A1 - Götz, Klaus-Peter A1 - Gödeke, Kristin A1 - Huschek, Gerd A1 - Morlock, Gertrud E. A1 - Rawel, Harshadrai Manilal T1 - Selected Plant Metabolites Involved in Oxidation-Reduction Processes during Bud Dormancy and Ontogenetic Development in Sweet Cherry Buds (Prunus avium L.) T2 - Molecules N2 - Many biochemical processes are involved in regulating the consecutive transition of different phases of dormancy in sweet cherry buds. An evaluation based on a metabolic approach has, as yet, only been partly addressed. The aim of this work, therefore, was to determine which plant metabolites could serve as biomarkers for the different transitions in sweet cherry buds. The focus here was on those metabolites involved in oxidation-reduction processes during bud dormancy, as determined by targeted and untargeted mass spectrometry-based methods. The metabolites addressed included phenolic compounds, ascorbate/dehydroascorbate, reducing sugars, carotenoids and chlorophylls. The results demonstrate that the content of phenolic compounds decrease until the end of endodormancy. After a long period of constancy until the end of ecodormancy, a final phase of further decrease followed up to the phenophase open cluster. The main phenolic compounds were caffeoylquinic acids, coumaroylquinic acids and catechins, as well as quercetin and kaempferol derivatives. The data also support the protective role of ascorbate and glutathione in the para- and endodormancy phases. Consistent trends in the content of reducing sugars can be elucidated for the different phenophases of dormancy, too. The untargeted approach with principle component analysis (PCA) clearly differentiates the different timings of dormancy giving further valuable information. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 467 KW - dormancy KW - redox-metabolites KW - phenolics KW - ascorbate KW - anti-oxidative capacity KW - Prunus avium L. KW - flower buds Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-417442 ER - TY - JOUR A1 - Baldermann, Susanne A1 - Homann, Thomas A1 - Neugart, Susanne A1 - Chmielewski, Frank M. A1 - Götz, Klaus-Peter A1 - Gödeke, Kristin A1 - Huschek, Gerd A1 - Morlock, Gertrud E. A1 - Rawel, Harshadrai Manilal T1 - Selected Plant Metabolites Involved in Oxidation-Reduction Processes during Bud Dormancy and Ontogenetic Development in Sweet Cherry Buds (Prunus avium L.) JF - Molecules N2 - Many biochemical processes are involved in regulating the consecutive transition of different phases of dormancy in sweet cherry buds. An evaluation based on a metabolic approach has, as yet, only been partly addressed. The aim of this work, therefore, was to determine which plant metabolites could serve as biomarkers for the different transitions in sweet cherry buds. The focus here was on those metabolites involved in oxidation-reduction processes during bud dormancy, as determined by targeted and untargeted mass spectrometry-based methods. The metabolites addressed included phenolic compounds, ascorbate/dehydroascorbate, reducing sugars, carotenoids and chlorophylls. The results demonstrate that the content of phenolic compounds decrease until the end of endodormancy. After a long period of constancy until the end of ecodormancy, a final phase of further decrease followed up to the phenophase open cluster. The main phenolic compounds were caffeoylquinic acids, coumaroylquinic acids and catechins, as well as quercetin and kaempferol derivatives. The data also support the protective role of ascorbate and glutathione in the para- and endodormancy phases. Consistent trends in the content of reducing sugars can be elucidated for the different phenophases of dormancy, too. The untargeted approach with principle component analysis (PCA) clearly differentiates the different timings of dormancy giving further valuable information. KW - dormancy KW - redox-metabolites KW - phenolics KW - ascorbate KW - anti-oxidative capacity KW - Prunus avium L. KW - flower buds Y1 - 2018 U6 - https://doi.org/10.3390/molecules23051197 SN - 1420-3049 VL - 23 IS - 5 SP - 1 EP - 19 PB - Molecular Diversity Preservation International CY - Basel ER - TY - JOUR A1 - Behrens, Maik A1 - Frank, Oliver A1 - Rawel, Harshadrai Manilal A1 - Ahuja, Gaurav A1 - Potting, Christoph A1 - Hofmann, Thomas A1 - Meyerhof, Wolfgang A1 - Korsching, Sigrun T1 - ORA1, a Zebrafish Olfactory Receptor Ancestral to All Mammalian V1R Genes, Recognizes 4-Hydroxyphenylacetic Acid, a Putative Reproductive Pheromone JF - The journal of biological chemistry N2 - The teleost v1r-related ora genes are a small, highly conserved olfactory receptor gene family of only six genes, whose direct orthologues can be identified in lineages as far as that of cartilaginous fish. However, no ligands for fish olfactory receptor class A related genes (ORA) had been uncovered so far. Here we have deorphanized the ORA1 receptor using heterologous expression and calcium imaging. We report that zebrafish ORA1 recognizes with high specificity and sensitivity 4-hydroxyphenylacetic acid. The carboxyl group of this compound is required in a particular distance from the aromatic ring, whereas the hydroxyl group in the para-position is not essential, but strongly enhances the binding efficacy. Low concentrations of 4-hydroxyphenylacetic acid elicit increases in oviposition frequency in zebrafish mating pairs. This effect is abolished by naris closure. We hypothesize that 4-hydroxyphenylacetic acid might function as a pheromone for reproductive behavior in zebrafish. ORA1 is ancestral to mammalian V1Rs, and its putative function as pheromone receptor is reminiscent of the role of several mammalian V1Rs as pheromone receptors. Y1 - 2014 U6 - https://doi.org/10.1074/jbc.M114.573162 SN - 0021-9258 SN - 1083-351X VL - 289 IS - 28 SP - 19778 EP - 19788 PB - American Society for Biochemistry and Molecular Biology CY - Bethesda 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 - JOUR A1 - Bußler, Sara A1 - Rawel, Harshadrai Manilal A1 - Schlüter, Oliver K. T1 - Impact of plasma processed air (PPA) on phenolic model systems BT - suggested mechanisms and relevance for food applications JF - Innovative food science & emerging technologies : the official journal of the European Federation of Food Science and Technology N2 - Cold plasma is considered to be a novel, non-thermal, chemical-free and eco-friendly disinfection and surface modification technology. Plasma treatment of air to generate the so called plasma processed air (PPA) induces the formation of reactive oxygen (ROS) and nitrogen species (RNS). As a result, PPA has a different chemical composition compared to untreated air and suits therefore as an alternative method for microbial disinfection. However, depending on the product properties of the food matrix and its composition, a number of plasmainduced reactions also need to be taken into consideration. This necessitates also the elucidation and understanding of the basic interactions of plasma species with bioactive compounds. The intention here is to avoid the degradation of these valuable substances and to prevent other undesirable effects in future food related applications. In the present study, the effects of PPA treatment on selected antioxidants such as pyrocatechol and derivatives of hydroxycinnimic acid were investigated in model systems to specify possible reactions induced. Antioxidant capacity, pH value, UV-Vis spectroscopy, RP-HPLC and LC-MS analysis were applied to identify reaction products providing information on possible changes induced in food matrices by PPA treatment. Exposure to PPA caused a perceptible color change towards yellow-brown accompanied by a strong reduction of the pH and the formation of insoluble sediments in the model solutions. The accumulation of nitrate, nitrite, but not of hydrogen peroxide was shown. LC-MS analysis demonstrated the formation of plasma-modified derivatives in all tested systems. The main reactions in liquid model solutions exposed to PPA were attributed to oxidation, nitration and polymerization of the phenolic compounds. KW - cold atmospheric pressure plasma KW - reactive oxygen and nitrogen species KW - food safety KW - antioxidative phenolic ingredients KW - phenol oxidation KW - phenol nitration KW - plasma process indicators Y1 - 2020 U6 - https://doi.org/10.1016/j.ifset.2020.102432 SN - 1466-8564 SN - 1878-5522 VL - 64 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Bußler, Sara A1 - Rumpold, Birgit A. A1 - Fröhling, Antje A1 - Jander, Elisabeth A1 - Rawel, Harshadrai Manilal A1 - Schlüter, Oliver K. T1 - Cold atmospheric pressure plasma processing of insect flour from Tenebrio molitor: Impact on microbial load and quality attributes in comparison to dry heat treatment JF - Meteoritics & planetary science : journal of the Meteoritical Society N2 - In this study, the applicability of semi-direct cold atmospheric pressure plasma (CAPP) during postharvest processing of Tenebrio molitor flour is investigated. Besides analyzing the decontamination efficacy, plasma induced impact on techno-functionality, protein solubility, composition and structure was determined and compared to heat induced effects. Following CAPP treatment, the total microbial load of the Tenebrio flour of 7.72 log(10) cfu/g was reduced to 7.10 (1 min), 6.72 (2.5 min), 5.79 (5 min), 5.19 (7.5 min), 521 (10 min) and 4.73 (15 min) log(10) cfu/g. With increasing exposure to CAPP, protein solubility at pH 4 almost linearly decreased to a minimum of 54%. Water binding capacity decreased from 0.79 to 0.64 gwatedg whereas oil binding capacity increased from 0.59 to 0.66 g(oil)/g. Gel electrophoresis revealed a decrease of all protein fractions at pH 4 whereas at pH 10 the band pattern significantly shifted to protein fractions with higher molecular weights. Industrial relevance: Edible insects are rich in valuable protein, fat, fibre, minerals and micronutrients. Although a wide range of species represent a valuable alternative protein source that could contribute to food and feed security, they are industrially hardly exploited. The tailored application of proper processing technologies could lead to novel insect-based high-protein food and feed products with unique functional properties supporting the increase in acceptability among potential consumers. Current research concentrates on developing processing chains including innovative nonthermal approaches. Cold atmospheric pressure plasma (CAPP) has gained attention as an effective technology for the decontamination and modification of fresh and dry agricultural products. In the postharvest chain of edible insects, the application of CAPP could contribute to the development of safe and high-quality insect-based products in the food and feed sector. (C) 2016 Published by Elsevier Ltd. KW - Edible insects KW - Postharvest processing KW - Thermal and nonthermal treatment KW - Inactivation KW - Decontamination KW - Protein functionality and modification Y1 - 2016 U6 - https://doi.org/10.1016/j.ifset.2016.07.002 SN - 1466-8564 SN - 1878-5522 VL - 36 SP - 277 EP - 286 PB - Elsevier CY - Oxford ER -