Food Intake Biomarkers for Increasing the Efficiency of Dietary Pattern Assessment through the Use of Metabolomics: Unforeseen Research Requirements for Addressing Current Gaps

Current research on nutritional sciences depends upon the precise measurement of food intake. Despite being the most widely used dietary measurement tools, self-reported surveys are not exempt from already recognized limitations.(1, 2) Low dietary assessment accuracy contributes to the inconsistency of results already observed in many instances when trying to understand the connections between diet and healthiness or disease risk, thereby weakening their potential translation to clinical and public health applications.(1) The drawbacks of conventional instruments have encouraged research on food intake biomarkers (FIBs) as a complementary or alternative measure of dietary intake, being one of the cornerstones of nutritional epidemiology.(1) FIBs are those food compounds or food-derived metabolites that allow for recent or average intakes of specific food groups, foods, or food components to be objectively and accurately measured in a biological specimen.(3) They are assumed to be a more accurate measurement of dietary exposure than self-reported consumption because they cover the bioavailability of dietary compounds and allow for the drawbacks of composition tables, portion estimation, and subjectivity, among other things, to be handled. However, there are still some gaps that have to be addressed for such biomarkers to reach their full potential for the community. These are related to their specificity, interindividual variation, validation, and quantification. These aspects will be outlined in the following paragraphs

Functional characterization of khadi yeasts isolates for selection of starter cultures

4openInternationalInternational coauthor/editorYeasts play an important role in spontaneous fermentation of traditional alcoholic beverages. Our previous study revealed that a mixed-consortia of both Saccharomyces and non-Saccharomyces yeasts were responsible for fermentation of khadi, a popular, non-standardized traditional beverage with an immense potential for commercialization in Botswana. Functional characterization of isolated fermenting yeasts from mixed consortia is an indispensable step towards the selection of potential starter cultures for commercialization of khadi. In this study, we report the characterization of 13 khadi isolates for the presence of brewing-relevant phenotypes such as their fermentative capacity, ability to utilize a range of carbon sources and their ability to withstand brewing-associated stresses, as a principal step towards selection of starter cultures. Khadi isolates such as Saccharomyces cerevisiae, Saccharomycodes ludwigii and Candida ethanolica showed good brewing credentials but Lachancea fermentati emerged as the isolate with the best brewing attributes with a potential as a starter culture. However, we were then prompted to investigate the potential of L. fermentati to influence the fruity aromatic flavor, characteristic of khadi. The aroma components of 18 khadi samples were extracted using headspace solid phase micro-extraction (HS-SPME) and identified using a GC-MS. We detected esters as the majority of volatile compounds in khadi, typical of the aromatic signature of both khadi and L. fermentati associated fermentations. This work shows that L. fermentati has potential for commercial production of khadi.openMotlhanka, K.; Lebani, K.; Garcia Aloy, M.; Zhou, N.Motlhanka, K.; Lebani, K.; Garcia Aloy, M.; Zhou, N

High resolution mass spectrometric analysis of secoiridoids and metabolites as biomarkers of acute olive oil intake - an approach to study inter-individual variability in humans

SCOPE: Phenolic compounds are minor components of extra virgin olive oil (EVOO). Secoiridoids are the major components contributing to the phenolic content of EVOO. {Silva, 2015 #95}Information is lacking regarding their potential as biomarkers for EVOO intake. METHODS AND RESULTS: Healthy volunteers (n = 9) ingested 50 mL of EVOO in a single dose containing 322 mg/kg total phenolic content (caffeic acid equivalents) and 6 mg/20g hydroxytyrosol and its derivatives. Plasma was collected before (0h) and at 0.5, 1, 2, 4 and 6h after ingestion. Urine samples were collected prior to ingestion (0h) and at 0-4, 4-8, 8-15 and 15-24h. Samples were analysed by UPLC coupled with an Exactive Orbitrap MS. Partial Least Squares Discriminant Analysis with Orthogonal Signal Correction was applied to screen for metabolites that allowed samples discrimination. Plasma biomarkers and urine biomarkers were selected although individual variability was observed among volunteers. Results are in accordance with in vitro experiments performed (in vitro digestion and hepatic microsomal activity assays). CONCLUSIONS: Plasma (elenolic acid + H2 ; p-HPEA-EA + H2 + glucuronide) and urinary (3,4-DHPEA-EA, 3,4-DHPEA-EA + H2 +glucuronide, methyl 3,4-DHPEA-EA + H2 +glucuronide) secoiridoid compounds were selected as biomarkers to monitor EVOO intake showing good predictive ability according to multivariate analysis

Comparative metabolitefingerprinting of legumes using LC-MS-baseduntargeted metabolomics

Legumes are a well-known source of phytochemicals and are commonly believed to have similar composition between different genera. To date, there are no studies evaluating changes in legumes to discover those compounds that help to discriminate for food quality and authenticity. The aim of this work was to characterize and make a comparative analysis of the composition of bioactive compounds between Cicer arietinum L. (chickpea), Lens culinaris L. (lentil) and Phaseolus vulgaris L. (white bean) through an LC-MS-Orbitrap metabolomic approach to establish which compounds discriminate between the three studied legumes. Untargeted metabolomic analysis was carried out by LC-MS-Orbitrap from extracts of freeze-dried legumes prepared from pre-cooked canned legumes. The metabolomic data treatment and statistical analysis were realized by using MAIT R's package, and final identification and characterization was done using MSn experiments. Fold-change evaluation was made through Metaboanalyst 4.0. Results showed 43 identified and characterized compounds displaying differences between the three legumes. Polyphenols, mainly flavonol and flavanol compounds, were the main group with 30 identified compounds, followed by α-galactosides (n = 5). Fatty acyls, prenol lipids, a nucleoside and organic compounds were also characterized. The fold-change analysis showed flavanols as the wider class of discriminative compounds of lentils compared to the other legumes; prenol lipids and eucomic acids were the most discriminative compounds of beans versus other legumes and several phenolic acids (such as primeveroside salycilic), kaempferol derivatives, coumesterol and α-galactosides were the most discriminative compounds of chickpeas. This study highlights the applicability of metabolomics for evaluating which are the characteristic compounds of the different legumes. In addition, it describes the future application of metabolomics as tool for the quality control of foods and authentication of different kinds of legumes

Grape lipidomics: an extensive profiling thorough UHPLC–MS/MS method

8openInternationalItalian coauthor/editorLipids play many essential roles in living organisms, which accounts for the great diversity of these amphiphilic molecules within the individual lipid classes, while their composition depends on intrinsic and extrinsic factors. Recent developments in mass spectrometric methods have significantly contributed to the widespread application of the liquid chromatography-mass spectrometry (LC–MS) approach to the analysis of plant lipids. However, only a few investigators have studied the extensive composition of grape lipids. The present work describes the development of an ultrahigh performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) method that includes 8098 MRM; the method has been validated using a reference sample of grapes at maturity with a successful analysis and semi-quantification of 412 compounds. The aforementioned method was subsequently applied also to the analysis of the lipid profile variation during the Ribolla Gialla cv. grape maturation process. The partial least squares (PLS) regression model fitted to our experimental data showed that a higher proportion of certain glycerophospholipids (i.e., glycerophosphoethanolamines, PE and glycerophosphoglycerols, PG) and of some hydrolysates from those groups (i.e., lyso-glycerophosphocholines, LPC and lyso-glycerophosphoethanolamines, LPE) can be positively associated with the increasing °Brix rate, while a negative association was found for ceramides (CER) and galactolipids digalactosyldiacylglycerols (DGDG). The validated method has proven to be robust and informative for profiling grape lipids, with the possibility of application to other studies and matrices.openMasuero, Domenico; Škrab, Domen; Chitarrini, Giulia; Garcia-Aloy, Mar; Franceschi, Pietro; Sivilotti, Paolo; Guella, Graziano; Vrhovsek, UrskaMasuero, D.; Škrab, D.; Chitarrini, G.; Garcia-Aloy, M.; Franceschi, P.; Sivilotti, P.; Guella, G.; Vrhovsek, U

Exploratory analysis of commercial olive-based dietary supplements using untargeted and targeted metabolomics

8openInternationalItalian coauthor/editorThe market of olive-based dietary supplements (OBDS) is composed of a broad range of natural extracts claiming different health effects and often sold without a clear statement on their chemical composition. The aim of this survey was to characterize the chemical profiles of 14 commercially available OBDS. As many as 378 compounds were tentatively annotated in the analyzed samples. Although for most of metabolites the annotation at level I was prevented due to the lack of the analytical standard, the spectra obtained from high-resolution tandem mass spectrometry (MS/MS) measurements were very informative, allowing annotation of dozens of metabolites at level II or III. A targeted method allowed the quantification of 26 selected compounds. A large qualitative and quantitative variability was observed. The products obtained from buds by glyceric maceration were those with the lowest concentrations of all the quantified elements. The dose of 5 mg of hydroxytyrosol, corresponding to the European Food Safety Authority (EFSA) health claim, was only reached by four products, all of them originating from the olive fruit or the leaves. If we also take into consideration oleuropein, two additional products provide this daily amount. This work demonstrates the high complexity and diversity in the composition of OBDSopenGarcia Aloy, M.; Groff, N.; Masuero, D.; Nisi, M.; Franco, A.; Battelini, F.; Vrhovsek, U.; Mattivi, F.Garcia Aloy, M.; Groff, N.; Masuero, D.; Nisi, M.; Franco, A.; Battelini, F.; Vrhovsek, U.; Mattivi, F

Phytochemicals in Legumes: A Qualitative Reviewed Analysis

Legumes are an excellent source of nutrients and phytochemicals. They have been recognized for their contributions to health, sustainability, and the economy. Although legumes comprise several species and varieties, little is known about the differences in their phytochemical composition and the magnitude of these. Therefore, the aim of this review is to describe and compare the qualitative profile of phytochemicals contained in legumes and identified through LC-MS and GC-MS methods. Among the 478 phytochemicals reported in 52 varieties of legumes, phenolic compounds were by far the most frequently described (n = 405, 85%). Metabolomics data analysis tools were used to visualize the qualitative differences, showing beans to be the most widely analyzed legumes and those with the highest number of discriminant phytochemicals (n = 180, 38%). A Venn diagram showed that lentils, beans, soybeans, and chickpeas shared only 7% of their compounds. This work highlighted the huge chemical diversity among legumes and identified the need for further research in this field and the use of metabolomics as a promising tool to achieve it

Biomarkers of cereal food intake

Background/objectives: Cereal foods are major contributors to the daily energy, protein, and dietary fiber intake all over the world. The role of cereals in human health is dependent on whether they are consumed as refined or whole grain and on cereal species. To unravel the underlying mechanisms of health effects attributed to specific cereal foods and to provide more precise dietary advice, there is a need for improved dietary assessment of whole-grain intake. Dietary biomarkers of specific cereals, different fractions or cereal-containing foods could offer such a possibility. The aim of this review was to summarize the current status on biomarkers of different cereals, fractions, and specific cereal foods. Subjects and methods: A literature review was conducted and putative biomarkers of different cereals and pseudo-cereals (wheat, oats, rye, barley, rice, and quinoa) as well as for different grain fractions (whole grain, refined grain, bran) and foods were summarized and discussed. Results: Several putative biomarkers have been suggested for different cereals, due to their unique presence in these grains. Among the biomarkers, odd-numbered alkylresorcinols are the most well-studied and -evaluated biomarkers and reflect whole-grain wheat and rye intake. Even-numbered alkylresorcinols have been suggested to reflect quinoa intake. Recent studies have also highlighted the potential of avenanthramides and avenacosides as specific biomarkers of oat intake, and a set of biomarkers have been suggested to reflect rice bran intake. However, there are yet no specific biomarkers of refined grains. Most biomarker candidates remain to be evaluated in controlled interventions and free-living populations before applied as biomarkers of intake in food and health studies. Conclusion: Several putative biomarkers of different cereals have been suggested and should be validated in human studies using recently developed food intake biomarker validation criteria. Keywords: Alkylresorcinols; Avenacosides; Avenanthramides; Benzoxazinoids; Biomarkers; Cereals; Cinnamic acids; Phenolic acids; Whole grain

Food intake biomarkers for berries and grapes

Grapes and berries are two types of widely consumed fruits characterized by a high content in different phytochemicals. However, their accurate dietary assessment is particularly arduous, because of the already wide recognized bias associated with self-reporting methods, combined with the large range of species and cultivars and the fact that these fruits are popularly consumed not only in fresh and frozen forms but also as processed and derived products, including dried and canned fruits, beverages, jams, and jellies. Reporting precise type and/or quantity of grape and berries in FFQ or diaries can obviously be affected by errors. Recently, biomarkers of food intake (BFIs) rose as a promising tool to provide accurate information indicating consumption of certain food items. Protocols for performing systematic reviews in this field, as well as for assessing the validity of candidate BFIs have been developed within the Food Biomarker Alliance (FoodBAll) Project. This paper aims to evaluate the putative BIFs for blueberries, strawberries, raspberries, blackberries, cranberries, blackcurrant, and grapes. Candidate BFIs for grapes were resveratrol metabolites and tartaric acid. The metabolites considered as putative BFI for berries consumption were mostly anthocyanins derivatives together with several metabolites of ellagitannins and some aroma compounds. However, identification of BFIs for single berry types encountered more difficulties. In the absence of highly specific metabolites reported to date, we suggested some multi-metabolite panels that may be further investigated as putative biomarkers for some berry fruits

Food intake biomarkers for apple, pear, and stone fruit

Fruit is a key component of a healthy diet. However, it is still not clear whether some classes of fruit may be more beneficial than others and whether all individuals whatever their age, gender, health status, genotype, or gut microbiota composition respond in the same way to fruit consumption. Such questions require further observational and intervention studies in which the intake of a specific fruit can be precisely assessed at the population and individual levels. Within the Food Biomarker Alliance Project (FoodBAll Project) under the Joint Programming Initiative 'A Healthy Diet for a Healthy Life', an ambitious action was undertaken aiming at reviewing existent literature in a systematic way to identify validated and promising biomarkers of intake for all major food groups, including fruits. This paper belongs to a series of reviews following the same BFIRev protocol and is focusing on biomarkers of pome and stone fruit intake. Selected candidate biomarkers extracted from the literature search went through a validation process specifically developed for food intake biomarkers