Gas Chromatography/Mass Spectrometry-Based Metabolite Profiling of Nutrients and Antinutrients in Eight Lens and Lupinus Seeds (Fabaceae)

Multidisciplinary approach combining food metabolomics and epidemiology identifies meglutol as an important bioactive metabolite in tempe, an Indonesian fermented food

This study introduces a multidisciplinary approach to investigate bioactive food metabolites often overlooked due to their low concentrations. We integrated an in-house food metabolite library (n = 494), a human metabolite library (n = 891) from epidemiological studies, and metabolite pharmacological databases to screen for food metabolites with potential bioactivity. We identified six potential metabolites, including meglutol (3-hydroxy-3-methylglutarate), an understudied low-density lipoprotein (LDL)-lowering compound. We further focused on meglutol as a case study to showcase the range of characterizations achievable with this approach. Green pea tempe was identified to contain the highest meglutol concentration (21.8 ± 4.6 mg/100 g). Furthermore, we identified a significant cross-sectional association between plasma meglutol (per 1-standard deviation) and lower LDL cholesterol in two Hispanic adult cohorts (n = 1,628) (β [standard error]: -5.5 (1.6) mg/dl, P = 0.0005). These findings highlight how multidisciplinary metabolomics can serve as a systematic tool for discovering and enhancing bioactive metabolites in food, such as meglutol, with potential applications in personalized dietary approaches for disease prevention.

Gas chromatography/mass spectrometry-based metabolite profiling of chia and quinoa seeds in comparison with wheat and oat

INTRODUCTION

With an increasing interest in healthy and affordable cereal intake, efforts are made toward exploiting underutilized cereals with high nutritional values.

OBJECTIVES

The current study aims to explore the metabolome diversity in 14 cultivars of chia and quinoa collected from Germany, Austria, and Egypt, compared with wheat and oat as major cereals.

MATERIAL AND METHODS

The samples were analyzed using gas chromatography-mass spectrometry (GC-MS). Multivariate data analysis (MVA) was employed for sample classification and markers characterization.

RESULTS

A total of 114 metabolites were quantified (sugars, alcohols, organic and amino acids/nitrogenous compounds, fatty acids/esters), but the inorganic and phenolic acids were only identified. Fatty acids were the major class followed by amino acids in quinoa and chia. Chia and oats were richer in sucrose. Quinoa encompassed higher amino acids. Quinoa and chia were rich in essential amino acids. Higher levels of unsaturated fatty acids especially omega 6 and omega 9 were detected in quinoa versus omega 3 in chia compared with oat and wheat, whereas ω6/ω3 fatty acid ratio of chia was the lowest. To the best of our knowledge, this is the first comprehensive metabolite profiling of these pseudo cereals.

CONCLUSION

Quinoa and chia, especially red chia, are more nutritionally valuable compared with oat and wheat because of their compositional profile of free amino acids, organic acids, and essential fatty acids, besides their low ω6/ω3 fatty acid ratio. Such results pose them as inexpensive alternative to animal proteins and encourage their inclusion in infant formulas.

A multiplex metabolomic approach for quality control of Spirulina supplement and its allied microalgae (Amphora & Chlorella) assisted by chemometrics and molecular networking

Microalgae species are of economic importance regarded as "green gold" being rich in bioactive compounds. Spirulina and Chlorella are the most popular microalgal species and are marketed as healthy food supplements. At the same time, Amphora holds potential as a source of healthy lipids and essential fatty acids. Yet, there are considerable variations in their reported chemical composition, and less is known about their compositional differences. A multiplexed metabolomic approach was adopted for the quality control (QC) of Spirulina supplements and to compare its constitutive metabolome to Chlorella and Amphora. The adopted protocol comprised gas chromatography-mass spectrometry (GC-MS), ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UPLC-HRMS/MS), and ultraviolet-visible spectrophotometry (UV/Vis) for mapping their primary and secondary metabolome. Interestingly, UPLC-HRMS/MS analysis delineated the abundance of fatty acids in Amphora versus glycolipids enrichment in Spirulina, and porphyrins were the main pigments identified in Spirulina, with scarce occurrence in Chlorella. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) analysis of GC-MS data set revealed palmitic acid, 3-mannobiose, and glyceryl-glycoside as being most enriched in Spirulina, versus sucrose and leucine in Chlorella and Amphora, respectively. Despite being of low discriminatory potential, UV/Vis OPLS-DA modeling showed that Spirulina was distinguished with the UV absorbances of carotenoids and chlorophyll pigments, as indicated by its OPLS-DA derived S-plot. Our study provides a QC approach for the analysis of the microalgal species and poses alternative spectral and compositional markers for their discrimination.

How does maturity stage affect seeds metabolome via UPLC/MS based molecular networking and chemometrics and in relation to antioxidant effect? A case study in 4 major cereals and legumes

Legumes and cereals as staple food are typically consumed at mature stage, though also consumed at earlier stages. UPLC/MS based molecular networking and chemometrics were employed for the first time to address metabolome composition heterogeneity amongst seeds in the context of their maturity stages. The study included 4 major cereal and leguminous seeds of different species, and cultivars i.e., Triticum aestivum, Hordeum vulgare, Vicia faba and Cicer arietinum. 146 Metabolites from various classes were identified of which several are first time to be reported. Supervised OPLS model of all datasets revealed that sugars and oxylipids were dominant in mature and immature seeds, respectively. DPPH and FRAP assays were assessed for differential secondary metabolites' correlation. Results were attributed to flavonoids, oxylipids, and amino acids/peptides. Mature barley seeds possessed the strongest antioxidant activity among examined seeds. This study provides novel insights on seeds' maturation process in context to holistic metabolic changes.

Nutritional composition and biological activity of narrow-leafed lupins (Lupinus angustifolius L.) hydrolysates and seeds

Lupins are an interesting source of nutrients, part of the Fabaceae family. More specifically, narrow-leafed lupin (Lupinus angustifolius L.) is a legume, largely produced in Australia, which is used both for human food and animal fodder. There is a growing interest in plant proteins-derived products due to benefits for the ecosystem and lower production costs compared to traditional animal sources of protein. This review aimed to summarize major and minor chemical components in Lupinus angustifolius L., and potential health benefits of this plant and product thereof. In particular, the protein fraction of Lupinus and their biological properties are described. L. angustifolius seed and proteins by-products can be used as a valuable source of high value-added compounds for diverse food products with the goal to maximize its economic value.

Tracking Spatial Distribution Alterations of Multiple Endogenous Molecules during Lentil Germination by MALDI Mass Spectrometry Imaging

Exploring the spatial distribution alterations of metabolites during lentil germination is essential to reveal the nutritional value, physiological function, and metabolic pathway in lentils. Hence, an effective matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) method was established for the first time to visualize the spatial localization changes of 53 metabolites in lentils during germination for 12-72 h. The results of MALDI-MSI analysis showed that phosphatidylinositols, phosphatidylethanolamines, phosphatidylglycerols, and phosphatidic acids were mainly located in the cotyledons of lentils throughout the germination process, while triacylglycerols, phosphatidylcholines, diacylglycerols, amino acids, choline, and spermine spread throughout the lentil tissue at the initial stage of germination and gradually presented obvious distribution characteristics in the radicle with increasing germination time. Heat map analysis was used to visualize the correlations between lipid content changes and germination time, which supported the use of germinated lentils as nutraceutical or functional food.

Effect of Maturity Stage on Cereal and Leguminous Seeds' Metabolome as Analyzed Using Gas Chromatography Mass-Spectrometry (GC-MS) and Chemometric Tools

Cereal and leguminous seeds are considered as major generic dietary source of energy, carbohydrates as well as proteins in the Mediterranean diet and are frequently consumed in their immature form in several regions including the Middle East. Hence, the current study aimed to assess metabolites' heterogeneity amongst five major cereal and leguminous seeds of different species, and cultivars, i.e., Triticum aestivum L. (two cultivars), Hordeum vulgare L., Vicia faba L. and Cicer arietinum L., at different maturity stages. Gas chromatography mass-spectrometry (GC-MS) analysis using multivariate data analyses was employed for nutrient profiling and sample segregation assessed using chemometric tools, respectively. A total of 70 peaks belonging to sugars, fatty acids/esters, steroids, amino acids and organic acids were identified including sucrose, melibiose, glucose and fructose as major sugars, with butyl caprylate, hydroxybutanoic acid and malic acid contributing to the discrimination between seed species at different maturity stages. The investigation of total protein content revealed comparable protein levels amongst all examined seeds with the highest level detected at 20.1% w/w in mature fava bean. Results of this study provide a novel insight on cereal and leguminous seeds' metabolomics in the context of their maturity stages for the first time in literature.

An overview of nutritional profiling in foods: Bioanalytical techniques and useful protocols

Maintaining a nutritious diet is essential for humans if they want to live a healthier life. Several food businesses and food safety organizations play a significant role and offer useful ways for improving nutritional quality that assists consumers in making informed selections. Making poor food choices and consuming unhealthy meals are the main causes of non-communicable diseases (NCDs). Nutritional profiling (NP) models are developed to evaluate the nutritional value, calorie content, and the amount of micronutrients and macronutrients contained in a given food accompanied by additional details on the nutritional anomaly provided by published standard nutrients and nutritional databases. To construct an ideal nutritional model that can facilitate food consumption, bioanalytical methods such as chromatography, microscopic techniques, molecular assays, and metabolomics can be applied. With the use of these technologies, one can learn more about the health advantages of nutrition and how to prevent disease. A wider element of NP is also provided by the developing technologies in the area of nutrition research, such as nanotechnology, proteomics, and microarray technology. In this review, we are focusing on the different bioanalytical techniques and the various protocols of NP and their application and refinement of the models. We have evaluated various NP techniques currently used in the food industry for the detection of different components present in food items.

Profiling of Primary Metabolites and Volatile Determinants in Mahlab Cherry (Prunus mahaleb L.) Seeds in the Context of Its Different Varieties and Roasting as Analyzed Using Chemometric Tools

Mahlab cherry (Prunus mahaleb L.) is a plant native to the Mediterranean basin and Eastern Europe, with several health benefits and culinary uses. We explored the compositional heterogeneity in the aroma profile and nutrients of three P. mahaleb seeds in the context of its cultivar type, i.e., white and red, and in response to roasting. A holistic untargeted metabolomics approach was employed for the first time using solid-phase microextraction (SPME-GC-MS) profiles of seed volatiles and primary metabolites coupled with chemometrics. Around 65 peaks belonging to sugars, fatty acids, esters and organic acids were identified by GC-MS. White mahlab from Egypt is rich in fatty acids, e.g., oleic and α-linolenic acids. Some acyl esters, e.g., glycerylmonostearate and n-butylcaprylate, characterized mahlab cultivars from various origins. A total of 135 volatiles were identified, with organic acids and aldehydes the most abundant. Aldehydes were the most discriminatory in seed origin and in accounting for its distinct aroma. Several roasting indices were identified, viz. 1-octanol, γ-caprolactone and isomintlactone. A direct relationship between furans and fatty acids was rationalized by cyclic transformation of the latter into furan derivatives. This study provides the first chemical evidence supporting the nutritional and flavor determinants of mahlab seeds, suggesting novel uses as a functional food.

Antioxidant Phytochemicals in Pulses and their Relation to Human Health: A Review

Pulses are a staple food cultivated since ancient times, which play an important role in the human diet. From a nutritional point of view, pulses are very interesting foods as they are rich in proteins, carbohydrates and dietary fibre. Dietary antioxidants are a complex mixture of hydrophilic and lipophilic compounds usually present in foods of plant origin, including pulses. In the present study, the phytochemical composition of selected pulses (common beans, fava beans, lentils, chickpeas, peas and lupins) has been reviewed in terms of their content of antioxidant compounds. The content of hydrosoluble antioxidants (organic acids, phenolic compounds), liposoluble antioxidants (tocopherols, carotenoids) and other compounds which exert antioxidant properties, such as dietary fibre and minerals (zinc, selenium), has been studied, reporting that pulses are an interesting source of these compounds, which have important health benefits, including a preventing role in cardiovascular diseases, anticarcinogenic or neuroprotective properties. It is important to take into account that pulses are not usually consumed raw, but they must be processed before consumption in order to improve their nutritional quality and their palatability, therefore, the effect of different technological and heat treatments (germination, cooking, boiling, extrusion) on the antioxidant compounds present in pulses has been also reviewed. In this regard, it has been observed that as a consequence of processing, the content of phytochemicals with antioxidant properties is usually decreased, but processed pulses maintain relevant amounts of these compounds, preserving their beneficial health effect.

Impact of lactic acid fermentation on sensory and chemical quality of dairy analogues prepared from lupine (Lupinus angustifolius L.) seeds

Lupine (Lupinus sp.) is a valuable source of plant proteins. There is little knowledge on the impact of food processing on composition and sensory properties of lupine products. In this research, we investigated the impact of fermentation with five starters of lactic acid bacteria on the sensory quality and flavor-active compounds in dairy analogues prepared from sweet lupine (Lupinus angustifolius L.). The sensory qualities of unfermented and fermented products were studied with generic descriptive analysis and affective tests. Acids and sugars were analyzed with GC-FID and volatiles with HS-SPME-GC-MS and GC-O. Fermentation increased sourness and 'vinegar' odor and reduced the 'beany' odor and flavor as well as the unpleasantness of flavor. Formation of volatiles during the fermentation was dependent on the starters. However, all fermentations increased the contents of lactic, acetic, and hexanoic acids, while reducing the contents of hexanal, described as 'grassy' in the unfermented lupine sample.

Sweet and bitter oranges: An updated comparative review of their bioactives, nutrition, food quality, therapeutic merits and biowaste valorization practices

Sweet and bitter oranges are two of the most commercially-important fruit with a total world production of 75.4 Mt, well-recognized for their unique sensory characters in addition to multiple nutritive and therapeutic attributes due to their highly-valued bioactive ingredients. Hence, their differential qualitative/quantitative phytochemical make-ups are presented for better utilization as therapeutic agents. Sweet orange exhibits therapeutic applications as being effective anti-diabetic, anti-obesity, and hypocholesterolemic agents. Whereas, for anti-osteoporotic products and intestinal dysbiosis treatment, bitter orange is more preferred. Moreover, the review recapitulates on different valorization practices of citrus bio-wastes and utilization of their bioactives as therapeutic agents and in functional food industry. Sweet orange waste functions as a fat replacer and preservative to increase food shelf life with better organoleptic attributes than bitter orange. The detailed action mechanism and safety of Citrus bioactives, as well as processing technologies to further improve its effects are posed as future research perspectives.

El-Sayed N, A. El-Toumy S, Abdou Mohamed D, Abdel Aziz Z, Ehrlich A, A. Farag M. Nutrient and Sensory Metabolites Profiling of Averrhoa Carambola L. (Starfruit) in the Context of Its Origin and Ripening Stage by GC/MS and Chemometric Analysis

Averrhoa carambola L. is a tropical tree with edible fruit that grows at different climatic conditions. Despite its nutritive value and reported health benefits, it is a controversial fruit owing to its rich oxalate content. The present study aimed at investigating aroma and nutrient primary metabolites distribution in A. carambola fruits grown in Indonesia, Malaysia (its endemic origin) versus Egypt, and at different ripening stages. Two techniques were employed to assess volatile and non-volatile metabolites including headspace solid-phase micro-extraction (HS-SPME) joined with gas chromatography coupled with mass-spectrometry (GC-MS) and GC-MS post silylation, respectively. Twenty-four volatiles were detected, with esters amounting for the major class of volatiles in Egyptian fruit at ca. 66%, with methyl caproate as the major component, distinguishing it from other origins. In contrast, aldehydes predominated tropically grown fruits with the ether myristicin found exclusively in these. Primary metabolites profiling led to the identification of 117 metabolites viz. sugars, polyols and organic acids. Fructose (38–48%) and glucose (21–25%) predominated sugar compositions in ripe fruits, whereas sorbitol was the major sugar alcohol (2.4–10.5%) in ripe fruits as well. Oxalic acid, an anti-nutrient with potential health risks, was the major organic acid detected in all the studied fruits (1.7–2.7%), except the Malaysian one (0.07%). It increases upon fruit ripening, including considerable amounts of volatile oxalate esters detected via SPME, and which must not be omitted in total oxalate determinations for safety assessments.

Metabolomics reveals impact of seven functional foods on metabolic pathways in a gut microbiota model

•

Metabolomics was employed to assess 7 functional foods impact on gut microbiota.

•

Insights regarding how functional foods alter gut metabolic pathways is presented.

•

Increased GABA production was observed in polyphenol rich functional food.

•

Purine alkaloids served as direct substrate in microbiota metabolism.

Functional food defined as dietary supplements that in addition to their nutritional values, can beneficially modulate body functions becomes more and more popular but the reaction of the intestinal microbiota to it is largely unknown. In order to analyse the impact of functional food on the microbiota itself it is necessary to focus on the physiology of the microbiota, which can be assessed in a whole by untargeted metabolomics. Obtaining a detailed description of the gut microbiota reaction to food ingredients can be a key to understand how these organisms regulate and bioprocess many of these food components. Extracts prepared from seven chief functional foods, namely green tea, black tea, Opuntia ficus-indica (prickly pear, cactus pear), black coffee, green coffee, pomegranate, and sumac were administered to a gut consortium culture encompassing 8 microbes which are resembling, to a large extent, the metabolic activities found in the human gut. Samples were harvested at 0.5 and 24 h post addition of functional food extract and from blank culture in parallel and analysed for its metabolites composition using gas chromatography coupled to mass spectrometry detection (GC-MS). A total of 131 metabolites were identified belonging to organic acids, alcohols, amino acids, fatty acids, inorganic compounds, nitrogenous compounds, nucleic acids, phenolics, steroids and sugars, with amino acids as the most abundant class in cultures. Considering the complexity of such datasets, multivariate data analyses were employed to classify samples and investigate how functional foods influence gut microbiota metabolisms. Results from this study provided a first insights regarding how functional foods alter gut metabolism through either induction or inhibition of certain metabolic pathways, i.e. GABA production in the presence of higher acidity induced by functional food metabolites such as polyphenols. Likewise, functional food metabolites i.e., purine alkaloids acted themselves as direct substrate in microbiota metabolism.

Antiulcer activity of Cyperus alternifolius in relation to its UPLC-MS metabolite fingerprint: A mechanistic study

BACKGROUND

Gastric ulcer is one of the main prevalent gastrointestinal multi-etiological disorders with many associated complications and adverse effects. Our aim was to develop safer antiulcer therapies based on methanol or ethyl acetate extracts of tubers and aerial parts from Cyperus alternifolius.

METHODS

Gastric ulceration was experimentally generated by administration of single oral doses of indomethacin (30 mg/kg) to fasted rats. The animals received methanol or ethyl acetate extracts of C. alternifolius tuber and methanol or ethyl acetate extracts of aerial parts at two dose levels (50 or 100 mg/kg). Ranitidine (50 mg/kg) was used as standard anti-ulcer drug. After 4 h, the ulcer number and the total ulcer score were determined and TNF-α was assessed. Also, pathological and histochemical examination for gastric mucosa were performed. The metabolome heterogeneity of the different extracts was explored using (UPLC-MS) aided by supervised pattern recognition, i.e., orthogonal partial least squares discriminate analysis (OPLS-DA). A second OPLS-DA model was employed to link the UPLC-MS derived metabolome of the different extracts to their antiulcer activity to identify activity mediating metabolites.

RESULTS

The extracts significantly reduced ulcer number, total ulcer score and TNF-α content in the stomach. Methanol or ethyl acetate extracts of tubers were most effective even more than ranitidine. In parallel, the histopathological examination showed an improvement of damaged mucosa. A high PAS reaction was observed in the treated groups indicating a relieve of the mucosal layer. A mechanistic clue of the C. alternifolius antiulcer potential was provided by the identification of its bioactive compounds using OPLS-DA. Both methanol extracts of tubers and aerial parts were more enriched in phenolic acids. The ethyl acetate extract of the aerial part was more abundant in two aldehydes. A mechanism of action was postulated based on their reported actions viz. α-carbonic anhydrase inhibition, anti-inflammatory and analgesic activity by its antioxidant activity and downregulation of several inflammatory mediators.

CONCLUSION

This is the first study to report on the antiulcer activity of C. alternifolius tubers with identification of the key bioactive compounds and the mode of action. Future phytochemical and biological evaluation of the identified bioactive compounds are needed to confirm the plant tubers as safer alternative or adjunct therapy compared to conventional antiulcer drugs.

An Innovative Metabolomic Approach for Golden Rum Classification Combining Ultrahigh-Performance Liquid Chromatography-Orbitrap Mass Spectrometry and Chemometric Strategies

A comprehensive fingerprinting strategy for golden rum classification considering different categories such as fermentation barrel, raw material, and aging is provided, using a metabolomic fingerprinting approach. A nontarget fingerprinting of 30 different rums using liquid chromatography coupled to high-resolution mass spectrometry (Exactive Orbitrap mass analyzer, LC-HRMS) was applied. Principal component analysis (PCA) was used to assess the overall structure of the data and to identify potential outliers. Different chemometric analyses such as partial least-squares discriminant analysis (PLS-DA) were used. A variable importance in projection (VIP) selection method was applied to identify the most significant markers that allow group separation. Compounds related to aging and fermentation processes such as furfural derivates (e.g., hydroxymethylfurfural) and sugars (e.g., glucose, mannitol) were found as the most discriminant compounds (VIP threshold value >1.5). Suitable separation according to selected categories was achieved, and a classification ability of the models of close to 100% was achieved.

Importance of Lupinus albescens in agricultural and food-related areas: A review

The purpose of this review is to assist readers in understanding the importance of Lupinus albescens to nature, farmers, and scientists. L. albescens is mostly found in Argentina, Uruguay, Paraguay, and in "Campanha, Litoral and Missões" regions of State of Rio Grande do Sul (Brazil). Therefore, this review presents information and discussion on this plant that can encourage novel studies in a near future for exploring evermore the biological and physicochemical properties of L. albescens. The plant presents adaptive characteristics of soils with low content of nutrients, being an important plant for the recovering of degraded areas. In the last few years, there was an increase in scientific interest for exploring its chemical composition and biological activities. All plant matrices (i.e., roots, leaves, seeds, and stalks) are rich in antioxidant and antifungal compounds, especially stigmasterol. For example, the extracts obtained from the roots are reported with more than 50 wt% stigmasterol and 25 wt% ergosterol. Furthermore, the extracts present remarkable fungicide effects, especially against Fusarium oxysporum and Fusarium verticillioides.