TY - JOUR A1 - Khozroughi, Amin Ghadiri A1 - Braga, Tess Waldbach A1 - Wagner, Janine A1 - Rawel, Harshadrai Manilal T1 - Investigation of the post mortem zinc protoporphyrin IX fluorescence with respect to its protein-bound and unbound occurrence in aqueous meat extracts JF - Food chemistry N2 - Zinc protoporphyrin IX (ZnPP) is known to accumulate in most meat products during storage. However, the pathway of its formation is not yet completely clarified. To gain more insights into the specificity of ZnPP occurrence, a SEC-HPLC-UV-fluorescence setup was established to screen the proteins in aqueous meat extracts for their ZnPP fluorescence during incubation. In accordance with previous studies it was identified by SDS-PAGE and MALDI-TOF-MS that ZnPP formation takes place in myoglobin. In this study, valuable new insights into the ZnPP forming pathway were gained, as our results indicated that a significant part of ZnPP - after being formed within the protein - is transitioned into free ZnPP during incubation. Additionally, the obtained results implied that ZnPP may also occur in proteins of higher molecular weight (> 100 kDa). KW - Meat KW - Fluorescence screening KW - Post mortem chemistry KW - SDS-PAGE KW - SEC-HPLC KW - MALDI-TOF-MS Y1 - 2019 U6 - https://doi.org/10.1016/j.foodchem.2019.01.080 SN - 0308-8146 SN - 1873-7072 VL - 283 SP - 462 EP - 467 PB - Elsevier CY - Oxford 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 -