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Goswami AK, Gogoi N, Sharma HK. Validated High-Performance Thin-Layer Chromatography-Mass Spectrometry Method and Stability Study of Linalool in the Volatile Oil of the Rhizomes of Homalomena aromatica Schott. J Chromatogr Sci 2023; 61:269-278. [PMID: 35178547 DOI: 10.1093/chromsci/bmac012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Indexed: 11/14/2022]
Abstract
Homalomena aromatica is a herb of tremendous ethnomedicinal importance to various communities residing in northeast India. In this study, a high-performance thin-layer chromatography-based densitometric method was developed for identification, quantification and stability study of linalool. Mass spectrometry was hyphenated to HPTLC for streamlining the method. The stability of linalool was studied by analyzing the effect of acid, base, UV, sunlight, thermal stress and H2O2 on linalool. The chromatographic plates were developed to a height of 70 mm in toluene:ethyl acetate solvent system at a ratio of 9.5:0.5 and visualized with p-anisaldehyde reagent. The developed method was found to be precise, accurate and reproducible according to International Conference on Harmonization guidelines, and compact bands of linalool were observed at Rf of 0.351 ± 0.001. The content of linalool in the volatile oil of H. aromatica was found to be 58% v/v. By application of the hyphenated MS technique, linalool was identified at m/z 137, (M + H)+. It was observed that acidic pH has the highest effect on linalool with a percentage degradation of 65. The developed method can be used in the analysis and quality control of herbal materials and volatile oils containing linalool and quality control of rhizomes of H. aromatica.
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Affiliation(s)
- Ashis Kumar Goswami
- Department of Pharmaceutical Sciences, Faculty of Science and Engineering, Dibrugarh University, Dibrugarh-786004, Assam, India
| | - Neelutpal Gogoi
- Department of Pharmaceutical Sciences, Faculty of Science and Engineering, Dibrugarh University, Dibrugarh-786004, Assam, India
| | - Hemanta Kumar Sharma
- Department of Pharmaceutical Sciences, Faculty of Science and Engineering, Dibrugarh University, Dibrugarh-786004, Assam, India
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Advances in analytical techniques coupled to in vitro bioassays in the search for new peptides with functional activity in effect-directed analysis. Food Chem 2022; 397:133784. [DOI: 10.1016/j.foodchem.2022.133784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 07/17/2022] [Accepted: 07/23/2022] [Indexed: 11/20/2022]
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High-Performance Thin-Layer Chromatography-Immunostaining as a Technique for the Characterization of Whey Protein Enrichment in Edam Cheese. Foods 2022; 11:foods11040534. [PMID: 35206011 PMCID: PMC8871023 DOI: 10.3390/foods11040534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/28/2022] [Accepted: 02/10/2022] [Indexed: 12/30/2022] Open
Abstract
Whey protein-enriched cheese can be produced by means of a high-temperature treatment of a part of the cheese milk. In this way, the nutritional quality of the resulting cheeses can be increased while resources are conserved. High-performance thin-layer chromatography-immunostaining (HPTLC-IS) using specific β-lactoglobulin (β-LG) antibodies was applied to study the implementation and stability of β-LG in two different sample sets of whey protein-enriched Edam model cheeses, including industrial-scale ones. Two methods were compared for the extraction of the proteins/peptides from the cheese samples. By applying tryptic hydrolysis directly from a suspended cheese sample instead of a supernatant of a centrifuged suspension, a better yield was obtained for the extraction of β-LG. When applying this method, it was found that selected epitopes in the tryptic β-LG peptides remain stable over the ripening period of the cheese. For four of the tryptic β-LG peptides detected by immunostaining, the amino acid sequence was identified using MALDI-TOF-MS/MS. One of the peptides identified was the semi-tryptic peptide VYVEELKPTP. A linear relationship was found between the content of this peptide in cheese and the proportion of high-heated milk in the cheese milk. β-LG enrichment factors of 1.72 (n = 3, sample set I) and 1.33 ± 0.19 (n = 1, sample set II) were determined for the cheese samples containing 30% high-heated milk compared to the non-enriched samples. The relative β-LG contents in the cheese samples with 30% high-heated milk were calculated to be 4.35% ± 0.39% (sample set I) and 9.11% ± 0.29% (sample set II) using a one-point calibration. It can be concluded that the HPTLC-IS method used is a suitable tool for the analysis of whey protein accumulation in cheese, being therefore potentially directly applicable on an industrial scale. For more accurate quantification of the whey protein content in cheese, an enhanced calibration curve needs to be applied.
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Treblin M, von Oesen T, Class LC, Kuhnen G, Clawin-Rädecker I, Martin D, Fritsche J, Rohn S. Two-dimensional high-performance thin-layer chromatography for the characterization of milk peptide properties and a prediction of the retention behavior - a proof-of-principle study. J Chromatogr A 2021; 1653:462442. [PMID: 34365201 DOI: 10.1016/j.chroma.2021.462442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 01/14/2023]
Abstract
High-performance thin-layer chromatography (HPTLC) is a suitable method for the analysis of peptides and proteins due to a wide selection of stationary and mobile phases and various detection options. Especially, two-dimensional HPTLC (2D-HPTLC) enables a higher resolution compared to one-dimensional HPTLC in the separation of complex peptide mixtures. Similar to 2D electrophoresis, characteristic peptide patterns can be obtained, allowing a differentiation of ingredients based on varying protein origins. The aim of this study was to evaluate 2D-HPTLC with regard to its suitability for the characterization of proteins/peptides and to verify whether it is possible to predict the retention behavior of peptides based on their properties. As models, the five most abundant milk proteins α-lactalbumin, β-lactoglobulin, α-, β-, and κ-Casein were used. In order to determine the repeatability of the peptide separation by 2D-HPTLC, each tryptic protein hydrolyzate was separated eight times. The standard deviations of the retardation factors for the separated peptides varied between 1.0 and 11.1 mm for the x-coordinate and 0.5-7.3 mm for the y-coordinate. It was also shown that after the chromatographic separation, peptides of the individual protein hydrolyzates were located in specific areas on the HPTLC plate, so that a clustering could be obtained for the whey proteins' as well as the caseins' hydrolyzates. For establishing correlations between the properties of the peptides and their retardation factors, 51 of 85 selected peptides were identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS/MS). On this basis, statistically significant correlations (α = 0.05) between the retardation factors of the peptides and their isoelectric points, as well as the percentage of anionic and non-polar amino acids in the peptides were established. Finally, it was investigated, whether the retardation factors for peptides can be predicted on the basis of a linear regression of the percentage of non-polar amino acids in a peptide. For this purpose, a mixture of artifical (synthetic) peptides (n = 14) was separated by 2D-HPTLC and the measured retardation factors were compared with the corresponding retardation factors calculated. Absolute deviations of 0.3-17.9 mm were obtained. In addition, the universal applicability of the method to other protein sources other than milk proteins (animal protein) was tested using a mixture of pea peptides (plant protein, n = 3) resulting in absolute deviations of 0.7-8.6 mm.
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Affiliation(s)
- Mascha Treblin
- University of Hamburg, Hamburg School of Food Science, Institute of Food Chemistry, Grindelallee 117, Hamburg D-20146, Germany
| | - Tobias von Oesen
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel D-24103, Germany
| | - Lisa-Carina Class
- University of Hamburg, Hamburg School of Food Science, Institute of Food Chemistry, Grindelallee 117, Hamburg D-20146, Germany
| | - Gesine Kuhnen
- University of Hamburg, Hamburg School of Food Science, Institute of Food Chemistry, Grindelallee 117, Hamburg D-20146, Germany
| | - Ingrid Clawin-Rädecker
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel D-24103, Germany
| | - Dierk Martin
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel D-24103, Germany
| | - Jan Fritsche
- Department of Safety and Quality of Milk and Fish Products, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Hermann-Weigmann-Straße 1, Kiel D-24103, Germany
| | - Sascha Rohn
- University of Hamburg, Hamburg School of Food Science, Institute of Food Chemistry, Grindelallee 117, Hamburg D-20146, Germany; Department of Food Chemistry and Analysis, Technische Universität Berlin, Institute of Food Technology and Food Chemistry, TIB 4/3-1, Gustav-Meyer-Allee 25, Berlin 13355, Germany.
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Spöttel J, Brockelt J, Badekow S, Rohn S. Immunological Analysis of Isothiocyanate-Modified α-Lactalbumin Using High-Performance Thin Layer Chromatography. Molecules 2021; 26:molecules26071842. [PMID: 33805932 PMCID: PMC8036266 DOI: 10.3390/molecules26071842] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 03/20/2021] [Accepted: 03/22/2021] [Indexed: 11/16/2022] Open
Abstract
Undirected modifications between food proteins and secondary plant metabolites can occur during food processing. The results of covalent interactions can alter the functional and biological properties of the proteins. The present work studied the extent of which covalent conjugation of the bioactive metabolite benzyl isothiocyanate (BITC; a glucosinolate breakdown product) to the whey protein α-lactalbumin affects the protein’s allergenicity. Additional to the immunological analysis of native untreated and BITC-modified α-lactalbumin, the analysis of antigenic properties of proteolytically digested protein derivatives was also performed by high performance thin layer chromatography and immunostaining. As a result of the chemical modifications, structural changes in the protein molecule affected the allergenic properties. In this process, epitopes are destroyed or inactivated, but at the same time, buried epitopes can be exposed or newly formed, so that the net effect was an increase in allergenicity, in this case. Results from the tryptic hydrolysis suggest that BITC conjugation sterically hindered the cleavage sites for the enzyme, resulting in reduced digestibility and allergenicity. Residual antigenicity can be still present as short peptide fragments that provide epitopes. The desire to make food safer for allergy sufferers and to protect sensitized individuals from an allergenic reaction makes it clear that the detection of food antigens is mandatory; especially by considering protein interactions.
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Affiliation(s)
- Jenny Spöttel
- Institute of Food Chemistry, Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany; (J.S.); (J.B.); (S.B.)
| | - Johannes Brockelt
- Institute of Food Chemistry, Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany; (J.S.); (J.B.); (S.B.)
| | - Svenja Badekow
- Institute of Food Chemistry, Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany; (J.S.); (J.B.); (S.B.)
| | - Sascha Rohn
- Institute of Food Chemistry, Hamburg School of Food Science, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany; (J.S.); (J.B.); (S.B.)
- Department of Food Chemistry and Analysis, Institute of Food Technology and Food Chemistry, Technische Universität Berlin, TIB 4/3-1, Gustav-Meyer-Allee 25, 13355 Berlin, Germany
- Correspondence: ; Tel.: +49-30-314-72583
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Analysis of Protein-Phenolic Compound Modifications Using Electrochemistry Coupled to Mass Spectrometry. Molecules 2018; 23:molecules23020264. [PMID: 29382123 PMCID: PMC6017572 DOI: 10.3390/molecules23020264] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 01/18/2018] [Accepted: 01/24/2018] [Indexed: 01/22/2023] Open
Abstract
In the last decade, electrochemical oxidation coupled with mass spectrometry has been successfully used for the analysis of metabolic studies. The application focused in this study was to investigate the redox potential of different phenolic compounds such as the very prominent chlorogenic acid. Further, EC/ESI-MS was used as preparation technique for analyzing adduct formation between electrochemically oxidized phenolic compounds and food proteins, e.g., alpha-lactalbumin or peptides derived from a tryptic digestion. In the first step of this approach, two reactant solutions are combined and mixed: one contains the solution of the digested protein, and the other contains the phenolic compound of interest, which was, prior to the mixing process, electrochemically transformed to several oxidation products using a boron-doped diamond working electrode. As a result, a Michael-type addition led to covalent binding of the activated phenolic compounds to reactive protein/peptide side chains. In a follow-up approach, the reaction mix was further separated chromatographically and finally detected using ESI-HRMS. Compound-specific, electrochemical oxidation of phenolic acids was performed successfully, and various oxidation and reaction products with proteins/peptides were observed. Further optimization of the reaction (conditions) is required, as well as structural elucidation concerning the final adducts, which can be phenolic compound oligomers, but even more interestingly, quite complex mixtures of proteins and oxidation products.
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