Virginia García-Cañas

Foodomics: MS‐based strategies in modern food science and nutrition

Modern research in food science and nutrition is moving from classical methodologies to advanced analytical strategies in which MS-based techniques play a crucial role. In this context, Foodomics has been recently defined as a new discipline that studies food and nutrition domains through the application of advanced omics technologies in which MS techniques are considered indispensable. Applications of Foodomics include the genomic, transcriptomic, proteomic, and/or metabolomic study of foods for compound profiling, authenticity, and/or biomarker-detection related to food quality or safety; the development of new transgenic foods, food contaminants, and whole toxicity studies; new investigations on food bioactivity, food effects on human health, etc. This review work does not intend to provide an exhaustive revision of the many works published so far on food analysis using MS techniques. The aim of the present work is to provide an overview of the different MS-based strategies that have been (or can be) applied in the new field of Foodomics, discussing their advantages and drawbacks. Besides, some ideas about the foreseen development and applications of MS-techniques in this new discipline are also provided.

Present and Future Challenges in Food Analysis: Foodomics

The state-of-the-art of food analysis at the beginning of the 21st century is presented in this work, together with its major applications, current limitations, and present and foreseen challenges.

Capillary Electrophoresis Time-of-Flight Mass Spectrometry for Comparative Metabolomics of Transgenic versus Conventional Maize

In this work, capillary electrophoresis time-of-flight mass spectrometry (CE-TOF-MS) is proposed to identify and quantify the main metabolites in three lines of genetically modified (GM) maize and their corresponding nontransgenic parental lines grown under identical conditions. The shotgun-like approach for metabolomics developed in this work includes optimization of metabolite extraction from GM and non-GM maize, separation by CE, online electrospray-TOF-MS analysis, and data evaluation. A large number of extraction procedures and background electrolytes are tested in order to obtain a highly reproducible and informative metabolomic profile. Thus, using this approach, significant differences were systematically observed between the detected amounts of some metabolites in conventional varieties (Aristis, Tietar, and PR33P66 maize) compared with their corresponding transgenic lines (Aristis Bt, Tietar Bt, and PR33P66 Bt maize). Results point to some of these metabolites as possible biomarkers of transgenic Bt maize, although a larger number of samples needs to be analyzed in order to validate this point. It is concluded that metabolomics procedures based on CE-TOF-MS can open new perspectives in the study of transgenic organisms in order to corroborate (or not) their substantial equivalence with their conventional counterparts.

Comparative metabolomic study of transgenic versus conventional soybean using capillary electrophoresis–time-of-flight mass spectrometry

In this work, capillary electrophoresis-time-of-flight mass spectrometry (CE-TOF-MS) is proposed to identify and quantify the main metabolites found in transgenic soybean and its corresponding non-transgenic parental line both grown under identical conditions. The procedure includes optimization of metabolites extraction, separation by CE, on-line electrospray-TOF-MS analysis and data evaluation. A large number of extraction procedures and background electrolytes are tested in order to obtain a highly reproducible and sensitive analytical methodology. Using this approach, a large number of metabolites were tentatively identified based on the high mass accuracy provided by TOF-MS analyzer, together with the isotopic pattern and expected electrophoretic mobility of these compounds. In general, the same metabolites and in similar amounts were found in the conventional and transgenic variety. However, significant differences were also observed in some specific cases when the conventional variety was compared with its corresponding transgenic line. The selection of these metabolites as possible biomarkers of transgenic soybean is discussed, although a larger number of samples need to be analyzed in order to validate this point. It is concluded that metabolomic procedures based on CE-MS can open new perspectives in the study of transgenic foods in order to corroborate (or not) the equivalence with their conventional counterparts.

Global Foodomics strategy to investigate the health benefits of dietary constituents.

A global methodology, called Foodomics, which allows carrying out a comprehensive evaluation of the health benefits of food ingredients is presented in this work. The new methodology is based on the combination of several analytical platforms and data processing for Transcriptomics, Proteomics and Metabolomics studies, allowing the determination of changes induced by food ingredients at molecular level. Both, the whole methodological development and its potential are presented through the investigation of a case study following a hypothesis-free strategy. Namely, the chemopreventive effect of polyphenols from rosemary was examined on the total gene, protein and metabolite expression in human HT29 colon cancer cells. Conclusions on the bioactivity of polyphenols against colon cancer cells based on the results from each single platform (Transcriptomics, Proteomics or Metabolomics) are compared with the conclusions based on the integration of the whole results from the three platforms, corroborating the interest of using a global integrative strategy as Foodomics. To our knowledge, although many papers and reviews have been published on this topic, this is the first time that Transcriptomics, Proteomics and Metabolomics platforms are put together to study the health benefits from dietary ingredients against colon cancer cells at gene, protein and metabolite level. Advantages, drawbacks and current challenges of this global analytical strategy are discussed in this work. The results from our study provide new insights on the biological mechanisms involved in the cancer risk reduction properties of dietary constituents.

Advances in Nutrigenomics research: Novel and future analytical approaches to investigate the biological activity of natural compounds and food functions

In recent years, nutrition research has moved from classical epidemiology and physiology to molecular biology and genetics. Following this trend, Nutrigenomics has emerged as a novel and multidisciplinary research field in nutritional science that aims to elucidate how diet can influence human health. It is already well known that bioactive food compounds can interact with genes affecting transcription factors, protein expression and metabolite production. The study of these complex interactions requires the development of advanced analytical approaches combined with bioinformatics. Thus, to carry out these studies Transcriptomics, Proteomics and Metabolomics approaches are employed together with an adequate integration of the information that they provide. In this article, an overview of the current methodologies and a thorough revision of the advances in analytical technologies and their possibilities for future developments and applications in the field of Nutrigenomics is provided.

Metabolomics of transgenic maize combining Fourier transform-ion cyclotron resonance-mass spectrometry, capillary electrophoresis-mass spectrometry and pressurized liquid extraction.

In this work, the potential of combining capillary electrophoresis-time-of-flight-mass spectrometry (CE-TOF-MS) and Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) for metabolomics of genetically modified organisms (GMOs) is demonstrated. Thus, six different varieties of maize, three of them transgenic (PR33P66 Bt, Tietar Bt and Aristis Bt) and their corresponding isogenic lines (PR33P66, Tietar and Aristis) grown under the same field conditions, were analyzed. Based on the ultrahigh resolution and remarkable mass accuracy provided by the 12-T FT-ICR-MS it was possible to directly analyze a good number of metabolites whose identity could be proposed based on their specific isotopic pattern. For identification of metabolite isomers, CE-TOF-MS was also used combining the information on nominal mass with electrophoretic mobility corroborating in that way the identity of several new biomarkers. Furthermore, PLE extractions were evaluated in order to establish selective extraction as an additional criterion to obtain useful information in maize metabolomics. Differences in the metabolite levels were found between the three transgenic maize varieties compared with their wild isogenic lines in some specific metabolic pathways. To our knowledge, this is the first time that an approach as the one presented in this work (pressurized liquid extraction+FT-ICR-MS+CE-TOF-MS) is shown for a metabolomic study.

Metabolomics, peptidomics and proteomics applications of capillary electrophoresis-mass spectrometry in Foodomics: A review

In the current post-genomic era, Foodomics has been defined as a discipline that studies food and nutrition through the application of advanced omics approaches. Foodomics involves the use of genomics, transcriptomics, epigenetics, proteomics, peptidomics, and/or metabolomics to investigate food quality, safety, traceability and bioactivity. In this context, capillary electrophoresis-mass spectrometry (CE-MS) has been applied mainly in food proteomics, peptidomics and metabolomics. The aim of this review work is to present an overview of the most recent developments and applications of CE-MS as analytical platform for Foodomics, covering the relevant works published from 2008 to 2012. The review provides also information about the integration of several omics approaches in the new Foodomics field.

Chiral CE-MS.

This review article addresses the developments and applications of capillary electromigration methods coupled on‐line with MS for chiral analysis. The multiple enantiomeric applications of this hyphenated technology are covered including chiral analysis of drugs, food compounds, pesticides, natural metabolites, etc. in different matrices such as plasma, urine, medicines, foods, etc. This work intends to provide an updated overview (including works published till September 2009) on the principal chiral applications carried out by CZE‐MS, CEC‐MS and MEKC‐MS, discussing their main advantages and drawbacks in all their different areas of application as well as their foreseeable development in the not too distant future.

CE/LC-MS multiplatform for broad metabolomic analysis of dietary polyphenols effect on colon cancer cells proliferation

In this study, an analytical multiplatform is presented to carry out a broad metabolomic study on the anti‐proliferative effect of dietary polyphenols on human colon cancer cells. CE, RP/UPLC, and HILIC/UPLC all coupled to TOF MS were combined to achieve a global metabolomic examination of the effect of dietary polyphenols on HT29 colon cancer cells. By the use of a nontargeted metabolomic approach, metabolites showing significant different expression after the polyphenols treatment were identified in colon cancer cells. It was demonstrated that this multianalytical platform provided extensive metabolic information and coverage due to its complementary nature. Differences observed in metabolic profiles from CE‐TOF MS, RP/UPLC‐TOF MS, and HILIC/UPLC‐TOF MS can be mainly assigned to their different separation mechanisms without discarding the influence of the different tools used for data processing. Changes in glutathione metabolism with an enhanced reduced glutathione/oxidized glutathione (GSH/GSSG) ratio were detected in polyphenols‐treated cells. Moreover, significant alterations in polyamines content with important implications in cancer proliferation were observed after the treatment with polyphenols. These results from metabolomics can explain the chemopreventive effect of the tested dietary polyphenols on colon cancer and may be of importance for future prevention and/or treatment of this disease.