Metabolomic fingerprinting of saffron by LC/MS: novel authenticity markers

Characterization of Exosome-like Nanoparticles from Saffron Tepals and Their Immunostimulatory Activity

Plant exosomes exhibit high stability and easy absorption, and have emerged as promising bioactive tools due to their potential health benefits and biomedical applications. Saffron tepals contain abundant metabolites with potential therapeutic properties and were used for exosome extraction by ultracentrifugation and gradient purification. The exosomes showed an average particle size of 151.5 ± 79.6 nm and exhibited a spherical morphology. Five well-conserved miRNAs-miR157, miR166, miR168, miR396, and miR398-were identified in the exosomes, which are involved in the coordination of growth and physiological plant responses with endogenous and environmental abiotic and biotic signals, and their potential targets in mammals are upregulated in specific cancer types and associated with inflammation. Proteome analysis revealed an enrichment of proteasome proteins, ribosomal proteins, and proteins involved in the cytoskeleton, transport across the membrane (ABC transporters), and vesicle trafficking (RAB GTPases, TM9SF and Coatomer subunits). Metabolite analyses showed mainly anthocyanins. The exosomes have selective stimulatory activity on macrophages, increasing the expression of surface molecules (CD80 and CD86), and cytokines (IL-1β, IL-6, and TNF-α), but not the levels of IL-10. Overall, these results indicated that saffron flowers are an effective and abundant source of exosomes as new nanomedicines for human health.

Authentication of edible herbal materials and food products using mass spectrometry based metabolites and inorganic constituents

Medicinal food homologous (MFH) substances not only provide nutrition but also serve as a traditional means to overcome many health issues. Authentication of these products verifies their efficacity and assures consumers of a genuine product. In this review paper, we focus the determination of MFH authenticity including geographical identification and adulteration detection using mass spectrometry (liquid and gas chromatography) based metabolites and inorganic constituents (muti-elements and stable isotopes). The application of these techniques to determine product identification characteristics combined with chemometrics are discussed, along with the limitations of these techniques. Multi-elements, stable isotopes, and metabolite analysis are shown to provide an effective combination of techniques to resolve the origin of various MFH products. Most organic compounds from MFH products are identified using chromatographic separation techniques (HPLC, GC) combined with different detection methods. Chemometric analysis of organic and inorganic fingerprints offers a robust method to detect and classify mislabeled and suspected fraudulent samples of different MFH products.

Drying of Saffron Petals as a Critical Step for the Stabilization of This Floral Residue Prior to Extraction of Bioactive Compounds

Saffron petals represent floral biomass generally wasted due to rapid deterioration. Previous characterization studies have revealed the presence of bioactive compounds in petals, such as flavonols and anthocyanins. Petal stabilization is a challenge for the efficient isolation of these compounds. This research evaluated three different drying techniques before the solid-liquid extraction of bioactive compounds: oven-drying (40 and 60 °C), lyophilization, and vacuum evaporation (25 and 50 °C). The characterization of the extracts allowed the annotation of 22 metabolites with a quantitative predominance of anthocyanins and derivatives of kaempferol and quercetin. Oven-drying at 60 °C was the most suitable approach for extracting minor compounds, such as crocins and safranal, at concentrations below 1 mg/g dry weight. Vacuum evaporation (50 °C) and lyophilization were the most recommended strategies for efficiently isolating flavonoids. Therefore, drying saffron petals is crucial to ensure the efficient extraction of bioactive compounds.

Distribution of Main Bioactive Compounds from Saffron Species as a Function of Infusion Temperature and Time in an Oil/Water System

Most research on saffron has focused on its composition and beneficial effects, while the culinary perspective to enhance its gastronomic potential remains unexplored. This study aims to define the transfer of the main compounds responsible for color, flavor, and aromatic properties, evaluating three critical variables: temperature (60 °C, 80 °C and 100 °C), infusion time (ranging from 10 to 30 min), and the composition of the medium (water, oil, and water/oil). Samples were analyzed using the LC-QTOF MS/MS and ISO 3632-1:2011 methods. The major compounds were crocins, including trans-crocin and picrocrocin. Among the flavonoids, kaempferol 3-O-sophoroside stands out. Regarding extraction conditions, crocins, glycoside flavonoids, and picrocrocin were enhanced in water, the former in 100% water and at low temperatures, while picrocrocin proved to be the most stable compound with extraction favored at high temperatures. The variable with the greatest incidence of picrocrocin isolation seemed to be the concentration of water since water/oil compositions reported higher concentrations. Safranal and kaempferol were enriched in the oil phase and at lower temperatures. This study provides a chemical interpretation for the appropriate gastronomic use of saffron according to its versatility. Finally, the determination of safranal using the ISO method did not correlate with that obtained using chromatography.

Phytochemical Elucidation and Effect of Maesa indica (Roxb.) Sweet on Alleviation of Potassium Dichromate-Induced Pulmonary Damage in Rats

Maesa indica (Roxb.) Sweet is one of the well-known traditionally-used Indian plants. This plant is rich in secondary metabolites like phenolic acids, flavonoids, alkaloids, glycosides, saponins, and carbohydrates. It contains numerous therapeutically active compounds like palmitic acid, chrysophanol, glyceryl palmitate, stigmasterol, β-sitosterol, dodecane, maesaquinone, quercetin 3-rhaminoside, rutin, chlorogenic acid, catechin, quercetin, nitrendipine, 2,3-dihydroxypropyl octadeca-9,12-dienoate, kiritiquinon, and β-thujone. The Maesa indica plant has been reported to have many biological properties including antidiabetic, anticancer, anti-angiogenic, anti-leishmanial, antioxidant, radical scavenging, antibacterial, antiviral, and anti-coronavirus effects. One purpose of the current study was to investigate the leaves' metabolome via Triple-Time-of-Flight-Liquid-Chromatography-Mass Spectrometry (T-TOF LC/MS/MS) to identify the chemical constituents of the Maesa indica ethanolic extract (ME). Another purpose of this study was to explore the protective effect of ME against potassium dichromate (PD)-induced pulmonary damage in rats. Rats were assigned randomly into four experimental groups. Two different doses of the plant extract, (25 and 50 mg/kg), were administered orally for seven consecutive days before PD instillation injection. Results of our study revealed that ME enhanced cellular redox status as it decreased lipid peroxidation marker, MDA and elevated reduced glutathione (GSH). In addition, ME upregulated the cytoprotective signaling pathway PI3K/AKT. Moreover, ME administration ameliorated histopathological anomalies induced by PD. Several identified metabolites, such as chlorogenic acid, quercetin, apigenin, kaempferol, luteolin, and rutin, had previously indicated lung-protective effects, possibly through an antioxidant effect and inhibition of oxidative stress and inflammatory mediators. In conclusion, our results indicated that ME possesses lung-protective effects, which may be the result of its antioxidant and anti-inflammatory properties.

An overview of analytical methods employed for quality assessment of Crocus sativus (saffron)

This paper reviews qualitative and quantitative analytical methodologies used for the appraisal of saffron quality, as the most expensive spice. Due to the chemical diversity of biologically active compounds of the Crocus genus, analytical methods with different features are required for their complete analysis. However, screening of the main components, such as carotenoids and flavonoids, appears to be sufficient for quality control, a more precise examination needs evaluation of minor compounds, including anthocyanins and fatty acids. High-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), ultraviolet-visible spectroscopy (UV), nuclear magnetic resonance spectroscopy (NMR), and thin-layer chromatography (TLC), are elementary and applicable methods in quality control analysis, whereas HPLC provides metabolite fingerprint and monitoring multi-compound instances at preparative and analytical levels. Combination approaches like metabolomics using different methods could classify saffron types, identify its adulterations, contaminants and provide a comprehensive metabolite map for quality control of selected compounds.

The Identification and Cytotoxic Evaluation of Nutmeg (Myristica fragrans Houtt.) and Its Substituents

The aril and seed of nutmeg, Myristica fragrans Houtt. (Myristicaceae), hold significant value in various industries globally. Our preliminary research found two morphological variations: a globose shape and an oval shape. Due to these different characteristics, the safety of consumers is of primary concern. Thus, authentication and comparative pharmacological and toxicity analyses are necessary. In this study, pharmacognostic and advanced phytochemical analyses, DNA barcoding, cytotoxicity, and the anti-nitric oxide production of commercial Thai nutmeg were examined. Via morphologic examinations and TLC fingerprinting, all the sampled aril and seed were categorized into globose and oval-shaped groups. The results of HPLC, GC-MS, and LC-MS/MS experiments revealed distinct differences between these groups. The DNA barcoding of the trnH-psbA region using the BLAST method and neighbor-joining tree analyses confirmed the globose nutmeg as M. fragrans and the oval-shaped variant as M. argentea. A comparison was then carried out between the potential toxicity and anti-inflammatory capabilities of M. fragrans and M. argentea. Cytotoxicity tests on HaCaT, 3T3-L1, Caco-2, HEK293, and RAW264.7 were performed using both methanolic extracts and volatile oil from the arils and seeds of both species. This study concludes that blending or substituting these two species maintains their therapeutic integrity without posing safety concerns.

A Combined Gas and Liquid Chromatographic Approach for Quality Evaluation of Saffron-Based Food Supplements

Considering the interest in the bioactive properties of saffron (Crocus sativus L.), as well as its limited production and high price, saffron-based food supplements (SFS) are highly susceptible to adulteration. However, their complex composition and the wide variety of potential fraudulent practices make the comprehensive assessment of SFS quality a challenging task that has been scarcely addressed. To that aim, a new multianalytical strategy based on gas chromatography coupled to mass spectrometry (GC-MS) and liquid chromatography with diode array detection coupled to mass spectrometry (HPLC-DAD-MS) was developed and validated in order to detect different frauds affecting SFS. Dried saffron stigmas and a commercial standardized saffron extract (affron®) were selected as reference samples (RS) to obtain an authenticity profile, which was further used to evaluate the quality of 17 SFS. Up to 17 crocins and crocetins, 5 kaempferol glycosides, picrocrocin (determined for the first time by GC-MS), safranal, furanone and isophorone-related compounds were determined in RS. Safranal and crocins were identified in all SFS except for one sample. However, discrepancies with the content declared were detected in 65% of the cases. Moreover, this multianalytical methodology also allowed identifying undeclared additives and the non-declared addition of vegetable sources other than saffron.

Natural complex substances: From molecules to the molecular complexes. Analytical and technological advances for their definition and differentiation from the corresponding synthetic substances

Natural complex substances (NCSs) are a heterogeneous family of substances that are notably used as ingredients in several products classified as food supplements, medical devices, cosmetics and traditional medicines, according to the correspondent regulatory framework. The compositions of NCSs vary widely and hundreds to thousands of compounds can be present at the same time. A key concept is that NCSs are much more than the simple sum of the compounds that constitute them, in fact some emerging phenomena are the result of the supramolecular interaction of the constituents of the system. Therefore, close attention should be paid to produce and characterize these systems. Today many natural compounds are produced by chemical synthesis and are intentionally added to NCSs, or to formulated natural products, to enhance their properties, lowering their production costs. Market analysis shows a tendency of people to use products made with NCSs and, currently, products made with ingredients of natural origin only are not conveniently distinguishable from those containing compounds of synthetic origin. Furthermore, the uncertainty of the current European regulatory framework does not allow consumers to correctly differentiate and identify products containing only ingredients of natural origin. The high demand for specific and effective NCSs and their high-cost offer on the market, create the conditions to economically motivated sophistications, characterized by the addition of a cheap material to a more expensive one, just to increase profit. This type of practice can concern both the addition of less valuable natural materials and the addition of pure artificial compounds with the same structure as those naturally present. In this scenario, it becomes essential for producers of natural products to have advanced analytical techniques to evaluate the effective naturalness of NCSs. In fact, synthetically obtained compounds are not identical to their naturally occurring counterparts, due to the isotopic composition or chirality, as well as the presence of different trace metabolites (since pure substances in nature do not exist). For this reason, in this review, the main analytical tests that can be performed to differentiate natural compounds from their synthetic counterparts will be highlighted and the main analytical technologies will be described. At the same time, the main fingerprint techniques useful for characterizing the complexity of the NCSs, also allowing their identification and quali-quantitative evaluation, will be described. Furthermore, NCSs can be produced through different manufacturing processes, not all of which are on the same level of quality. In this review the most suitable technologies for green processes that operate according to physical extraction principles will be presented, as according to the authors they are the ones that come closest to creating more life-cycle compatible NCSs and that are well suited to the European green deal, a strategy with the aim of transforming the EU into a sustainable and resource-efficient society by 2050.

Complete chemical characterization of Crocus sativus via LC-HRMS: Does trimming affect the chemical content of saffron?

Saffron, a spice derived from Crocus sativus, which in Iran is subjected to different trimming, is known for its beneficial health effects and high market value. Authentication studies related to geographical origin and adulterants presence mainly exist in literature, however fraud due to trimming has not been reported. In the current research, chemical characterization of six saffron trims, namely Sargol, Negin, Pushal, Bunch, Style, and Powder, was accomplished through suspect and non-target screening employing LC-QToF-MS in both electrospray ionization modes. The samples were extracted using methanol:water (50:50,v:v) and 62 compounds were identified, including amino acids, vitamins, flavonoids, phenolics, carotenoids, cyclohexenones. A clear discrimination among the red trims (Pushal, Sargol and Negin), as well as between Style and Bunch using Multivariate Chemometrics techniques was achieved. Proline and isophorone were highlighted as authenticity markers. Finally, the effect of three harvesting year on the most contributing compounds for trimming discrimination has been evaluated.

Detection of Markers in Green Beans and Roasted Beans of Kalosi-Enrekang Arabica Coffee with Different Postharvest Processing Using LC-MS/MS

Our study is aimed at evaluating the effect of postharvest processing (natural, honey, and fully washed) on the compounds profile in green beans and roasted beans of Kalosi-Enrekang Arabica coffee and determining the marker compounds for each process. These beans were extracted using boiling water, and the extract was analyzed using LC-MS/MS. The results of this work confirmed the significant impact of postharvest processing on compounds in the coffee beans, and each process has a marker compound. Green beans by natural processing have 3 marker compounds, honey processing has 6 marker compounds, and fully washed processing has 2 marker compounds. Meanwhile, roasted beans by natural processing have 4 marker compounds, honey processing has 5 marker compounds, and fully washed processing has 7 marker compounds. In addition, our research identified caffeoyl tyrosine in green beans from natural and honey processing, which was previously only identified in Robusta coffee. These marker compounds can differentiate postharvest processing (natural, honey, and fully washed). These results can also help understand the effect of postharvest processing on the chemical composition of green and roasted beans.

Detection of Saffron’s Main Bioactive Compounds and Their Relationship with Commercial Quality

This review aims to evaluate the state of saffron’s main bioactive compounds and their relationship with its commercial quality. Saffron is the commercial name for the dried red stigmas of the Crocus sativus L. flower. It owes its sensory and functional properties mainly to the presence of its carotenoid derivatives, synthesized throughout flowering and also during the whole production process. These compounds include crocin, crocetin, picrocrocin, and safranal, which are bioactive metabolites. Saffron’s commercial value is determined according to the ISO/TS3632 standard that determines their main apocatotenoids. Other techniques such as chromatography (gas and liquid) are used to detect the apocarotenoids. This, together with the determination of spectral fingerprinting or chemo typing are essential for saffron identification. The determination of the specific chemical markers coupled with chemometric methods favors the discrimination of adulterated samples, possible plants, or adulterating compounds and even the concentrations at which these are obtained. Chemical characterization and concentration of various compounds could be affected by saffron’s geographical origin and harvest/postharvest characteristics. The large number of chemical compounds found in the by-products (flower parts) of saffron (catechin, quercetin, delphinidin, etc.) make it an interesting aromatic spice as a colorant, antioxidant, and source of phytochemicals, which can also bring additional economic value to the most expensive aromatic species in the world.

Comprehensive characterization of ingredients in Crocus sativus L. from different origins based on the combination of targeted and nontargeted strategies

As a valuable medicinal and edible plant, Crocus sativus L. has had wide applications since ancient times. Herein, a comprehensive approach for characterization of constituents in saffron was established based on the combination of targeted and non-targeted strategies. A targeted UPLC-ESI/MSⁿ strategy was applied for in-depth identification of crocins, and a non-targeted UPLC-ESI/MS² approach characterized other components. This integration strategy was used to analyze ingredients in 21 batches of saffrons from 6 origins. Forty-seven crocins belonging to 8 types were identified including 32 new crocins. Among them, 6 new compounds with specific structures were reported for the first time, i.e. trans-6(G, 2G), trans-4(GT, g), trans-3(GT), cis-3(GT), methyl ester-trans-2(G) and methyl ester-cis-2(G). Besides, 91 non-crocin components were identified including 43 new compounds. Based on systematic investigation of crocins and non-crocins, we found that crocins were the critical components to distinguish saffrons from different origins, especially between domestic and foreign samples.

Understanding saffron biology using omics- and bioinformatics tools: stepping towards a better Crocus phenome

Saffron is a unique plant in many aspects, and its cellular processes are regulated at multiple levels. The genetic makeup in the form of eight chromosome triplets (2n = 3x = 24) with a haploid genetic content (genome size) of 3.45 Gbp is decoded into different types of RNA by transcription. The RNA then translates into peptides and functional proteins, sometimes involving post-translational modifications too. The interactions of the genome, transcriptome, proteome and other regulatory molecules ultimately result in the complex set of primary and secondary metabolites of saffron metabolome. These complex interactions manifest in the form of a set of traits 'phenome' peculiar to saffron. The phenome responds to the environmental changes occurring in and around saffron and modify its response in respect of growth, development, disease response, stigma quality, apocarotenoid biosynthesis, and other processes. Understanding these complex relations between different yet interconnected biological activities is quite challenging in saffron where classical genetics has a very limited role owing to its sterility, and the absence of a whole-genome sequence. Omics-based technologies are immensely helpful in overcoming these limitations and developing a better understanding of saffron biology. In addition to creating a comprehensive picture of the molecular mechanisms involved in apocarotenoid synthesis, stigma biogenesis, corm activity, and flower development, omics-technologies will ultimately lead to the engineering of saffron plants with improved phenome.

Intraperitoneal Lavage with Crocus sativus Prevents Postoperative-Induced Peritoneal Adhesion in a Rat Model: Evidence from Animal and Cellular Studies

Postoperative peritoneal adhesions are considered the major complication following abdominal surgeries. The primary clinical complications of peritoneal adhesion are intestinal obstruction, infertility, pelvic pain, and postoperative mortality. In this study, regarding the anti-inflammatory and antioxidant activities of Crocus sativus, we aimed to evaluate the effects of Crocus sativus on the prevention of postsurgical-induced peritoneal adhesion. Male Wistar-Albino rats were used to investigate the preventive effects of C. sativus extract (0.5%, 0.25% and 0.125% w/v) against postsurgical-induced peritoneal adhesion compared to pirfenidone (PFD, 7.5% w/v). We also investigated the protective effects of PFD (100 μg/ml) and C. sativus extract (100, 200, and 400 μg/ml) in TGF-β1-induced fibrotic macrophage polarization. The levels of cell proliferation and oxidative, antioxidative, inflammatory and anti-inflammatory, fibrosis, and angiogenesis biomarkers were evaluated both in vivo and in vitro models. C. sativus extract ameliorates postoperational-induced peritoneal adhesion development by attenuating oxidative stress [malondialdehyde (MDA)]; inflammatory mediators [interleukin- (IL-) 6, tumour necrosis factor- (TNF-) α, and prostaglandin E₂ (PGE₂)]; fibrosis [transforming growth factor- (TGF-) β1, IL-4, and plasminogen activator inhibitor (PAI)]; and angiogenesis [vascular endothelial growth factor (VEGF)] markers, while propagating antioxidant [glutathione (GSH)], anti-inflammatory (IL-10), and fibrinolytic [tissue plasminogen activator (tPA)] markers and tPA/PAI ratio. In a cellular model, we revealed that the extract, without any toxicity, regulated the levels of cell proliferation and inflammatory (TNF-α), angiogenesis (VEGF), anti-inflammatory (IL-10), M1 [inducible nitric oxide synthase (iNOS)] and M2 [arginase-1 (Arg 1)] biomarkers, and iNOS/Arg-1 ratio towards antifibrotic M1 phenotype of macrophage, in a concentration-dependent manner. Taken together, the current study indicated that C. sativus reduces peritoneal adhesion formation by modulating the macrophage polarization from M2 towards M1 cells.

Quantitative Determination and Characterization of a Kashmir Saffron (Crocus sativus L.)-Based Botanical Supplement Using Single-Laboratory Validation Study by HPLC-PDA with LC-MS/MS and HPTLC Investigations

Food ingredients hold a higher nutritional value as a botanical supplement playing a vital role in modifying and maintaining the physiological conditions that improve human health benefits. The Kashmir saffron (Crocus sativus L; KCS) obtained from dried stigmas is known for its aroma precursors and apocarotenoid derivatives, imparting a wide range of medicinal values and therapeutic benefits. In the present study, a simultaneous determination of apocarotenoids and flavonoids in stigma-based botanical supplements was carried out using analytical investigations. The high-performance thin-layer chromatography-based qualitative analysis of the raw material (stigmas, stamens, and tepals) and stigma extract has been carried out to identify apocarotenoids and flavonoids. The rapid HPLC-PDA method for the simultaneous quantification of KCS apocarotenoids was robust, precise (<5.0%), linear (R 2 > 0.99), and accurate (80-110%) as per the single-laboratory validation data. Furthermore, the combined-expanded uncertainty (95%; K = 2) was calculated and found as 0.0035-0.007% (<5.0%) as per the EURACHEM guide for this HPLC analysis. Additionally, an untargeted identification of 36 compounds in the botanical supplement was based on the elution order, UV-vis spectra, mass fragmentation pattern, and standards by ESI-MS/MS analysis with comprehensive chromatographic fingerprinting. Thus, these analytical approaches enable a composite profile of the stigma-based extract as a potential supplement for human health benefits.

Integration of Untargeted and Pseudotargeted Metabolomics for Authentication of Three Shrimp Species Using UHPLC-Q-Orbitrap

In this work, an untargeted and pseudotargeted metabolomics combination approach was used for authentication of three shrimp species (Litopenaeus vanmamei, Penaeus japonicus, and Penaeus monodon). The monophasic extraction-based untargeted metabolomics approach enabled comprehensive-coverage and high-throughput analysis of shrimp tissue and revealed 26 potential markers. The pseudotargeted metabolomics approach confirmed 21 markers (including 9 key markers), which realized at least putative identification. The 21 confirmed markers, as well as 9 key markers, were used to develop PLS-DA models, correctly classifying 60/60 testing samples. Furthermore, DD-SIMCA and PLS-DA models were integrated based on the 9 key markers, with 59/60 and 20/20 samples of the species that were involved and uninvolved in model training correctly classified. The results demonstrated the potential of this untargeted and pseudotargeted metabolomics combination approach for shrimp species authentication.

Authentication of saffron spice accessions from its common substitutes via a multiplex approach of UV/VIS fingerprints and UPLC/MS using molecular networking and chemometrics

Saffron is a spice revered for its unique flavor and health attributes often subjected to fraudulence. In this study, molecular networking as a visualization tool for UPLC/MS dataset of saffron and its common substitutes i.e. safflower and calendula (n = 21) was employed for determining genuineness of saffron and detecting its common substitutes i.e. safflower and calendula. Saffron was abundant in flavonol-O-glycosides and crocetin esters versus richness of flavanones/chalcones glycosides in safflower and cinnamates/terpenes in calendula. OPLS-DA identified differences in UPLC/MS profiles of different saffron accessions where oxo-hydroxy-undecenoic acid-O-hexoside was posed as saffron authentication marker and aided in discrimination between Spanish saffron of high quality from its inferior grade i.e. Iranian saffron along with crocetin di-O-gentiobiosyl ester and kaempferol-O-sophoroside. Kaempferol-O-neohesperidoside and N,N,N,-p-coumaroyl spermidine were characteristic safflower metabolites, whereas, calendulaglycoside C and di-O-caffeoyl quinic acid were unique to calendula. UV/VIS fingerprint spectral regions of picrocrocin (230-260 nm) and crocin derivatives (400-470 nm) were posed as being discriminatory of saffron authenticity and suggestive it can replace UPLC/MS in saffrom quality determination.

LC-ESI-QTOF-MS/MS Profiling and Antioxidant Activity of Phenolics from Custard Apple Fruit and By-Products

Custard apple is an edible fruit grown in tropical and subtropical regions. Due to its abundant nutrient content and perceived health benefits, it is a popular food for consumption and is utilized as a medicinal aid. Although some published research had provided the phenolic compound of custard apple, the comprehensive phenolic profiling of Australian grown custard apple is limited. Hence, this research aimed to evaluate the phenolic content and antioxidant potential by various phenolic content and antioxidant assays, followed by characterization and quantification of the phenolic profile using LC-ESI-QTOF-MS/MS and HPLC-PDA. African Pride peel had the highest value in TPC (61.69 ± 1.48 mg GAE/g), TFC (0.42 ± 0.01 mg QE/g) and TTC (43.25 ± 6.70 mg CE/g), followed by Pink’s Mammoth peel (19.37 ± 1.48 mg GAE/g for TPC, 0.27 ± 0.03 mg QE/g for TFC and 10.25 ± 1.13 mg CE/g for TTC). African Pride peel also exhibited the highest antioxidant potential for TAC (43.41 ± 1.66 mg AAE/g), FRAP (3.60 ± 0.14 mg AAE/g) and ABTS (127.67 ± 4.60 mg AAE/g), whereas Pink’s Mammoth peel had the highest DPPH (16.09 ± 0.34 mg AAE/g), RPA (5.32 ± 0.14 mg AAE/g), •OH-RSA (1.23 ± 0.25 mg AAE/g) and FICA (3.17 ± 0.18 mg EDTA/g). LC-ESI-QTOF-MS/MS experiment successfully characterized 85 phenolic compounds in total, encompassing phenolic acids (20), flavonoids (42), stilbenes (4), lignans (6) and other polyphenols (13) in all three parts (pulp, peel and seeds) of custard apple. The phenolic compounds in different portions of custard apples were quantified by HPLC-PDA, and it was shown that African Pride peel had higher concentrations of the most abundant phenolics. This is the first study to provide the comprehensive phenolic profile of Australian grown custard apples, and the results highlight that each part of custard apple can be a rich source of phenolics for the utilization of custard apple fruit and waste in the food, animal feeding and nutraceutical industries.

Comprehensive Profiling of Most Widely Used Spices for Their Phenolic Compounds through LC-ESI-QTOF-MS2 and Their Antioxidant Potential

Spices have long been used to improve food flavor, due to their appealing fragrance and sensory attributes. Nowadays, spices-based bioactives, particularly phenolic compounds, have gained attention due to their wide range of significant effects in biological systems. The present study was conducted to characterize the 12 widely used spices (allspice, black cardamom, black cumin, black pepper, cardamom, cinnamon, clove, cumin, fennel, nutmeg, star-anise, and turmeric) for their phenolics with the liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS2), polyphenols estimation, and their antioxidant potential. Total phenolics, total flavonoids, and total tannin content and their antioxidant activities were estimated in all spices. Clove and allspice had the highest value of total polyphenol content (215.14 and 40.49 mg gallic acid equivalent (GAE) per g of sample), while clove and turmeric had the highest total flavonoids (5.59 mg quercetin equivalent (QE) per g of sample) and total tannin contents (23.58 mg catechin equivalent (CE) per g of sample), respectively. On the other hand, black cumin and black pepper had the highest phosphomolybdate activity (15.61 and 15.43 mg ascorbic acid equivalent (AAE) per g of sample), while clove was almost identified with highest free radical scavenging capacity. A positive correlation was observed among phenolic compounds and antioxidant activities. In this quest, a total of 79 phenolic compounds were tentatively characterized by using LC-ESI-QTOF-MS2 including 26 phenolic acids, 33 flavonoids, 16 other polyphenols, and 4 lignans. The high-performance liquid chromatography coupled with photodiode array detector (HPLC-PDA) quantification of phenolic compounds exhibited higher phenolic acids. These results provided us some valuable information that spices have powerful antioxidant potential that can be further used in human food and animal feed as a supplement for different health promoting applications.

Characterization of Phenolics in Rejected Kiwifruit and Their Antioxidant Potential

Kiwifruit hold significant nutritional value and are a good source of antioxidants due to their diverse range of bioactive compounds. Kiwifruit waste is generated throughout the food supply chain, particularly during transportation and storage. Kiwifruit rejected from the retail market due to unfavorable appearance still possess potential economic value as kiwifruit are abundant in phenolic compounds. The present work studied the phenolic profile and antioxidant potential of rejected kiwifruit, including SunGold (Actinidia chinensis), Hayward (Actinidia deliciosa), and round organic Hayward (Actinidia deliciosa). Regarding phenolics estimation, SunGold possessed the highest TPC (0.72 ± 0.01 mg GAE/g), while Hayward exhibited the highest TFC (0.05 ± 0.09 mg QE/g). In antioxidant assays, SunGold showed the highest antioxidant activities in DPPH (0.31 ± 0.35 mg AAE/g), FRAP (0.48 ± 0.04 mg AAE/g), ABTS (0.69 ± 0.07 mg AAE/g), •OH-RSA (0.07 ± 0.03 mg AAE/g) assays, and FICA (0.19 ± 0.07 mg EDTA/g), whereas Hayward showed the highest RPA (0.09 ± 0.02 mg AAE/g) and TAC (0.57 ± 0.04 mg AAE/g). Separation and characterization of phenolics were conducted using LC-ESI-QTOF-MS/MS. A total of 97 phenolics were tentatively characterized from rejected SunGold (71 phenolics), Hayward (55 phenolics), and round organic Hayward (9 phenolics). Hydroxycinnamic acids and flavonols were the most common phenolics characterized in the three samples. The quantitative analysis was conducted by HPLC-PDA and found that chlorogenic acid (23.98 ± 0.95 mg/g), catechin (23.24 ± 1.16 mg/g), and quercetin (24.59 ± 1.23 mg/g) were the most abundant phenolics present in the rejected kiwifruit samples. The notable presence of phenolic compounds and their corresponding antioxidant capacities indicate the potential value of rescuing rejected kiwifruit for further utilization and commercial exploitation.

Phenolic Profiling of Five Different Australian Grown Apples

Apples (Malus domestica) are one of the most widely grown and consumed fruits in the world that contain abundant phenolic compounds that possess remarkable antioxidant potential. The current study characterised phenolic compounds from five different varieties of Australian grown apples (Royal Gala, Pink Lady, Red Delicious, Fuji and Smitten) using LC-ESI-QTOF-MS/MS and quantified through HPLC-PDA. The phenolic content and antioxidant potential were determined using various assays. Red Delicious had the highest total phenolic (121.78 ± 3.45 mg/g fw) and total flavonoid content (101.23 ± 3.75 mg/g fw) among the five apple samples. In LC-ESI-QTOF-MS/MS analysis, a total of 97 different phenolic compounds were characterised in five apple samples, including Royal Gala (37), Pink Lady (54), Red Delicious (17), Fuji (67) and Smitten (46). In the HPLC quantification, phenolic acid (chlorogenic acid, 15.69 ± 0.09 mg/g fw) and flavonoid (quercetin, 18.96 ± 0.08 mg/g fw) were most abundant in Royal Gala. The obtained results highlight the importance of Australian apple varieties as a rich source of functional compounds with potential bioactivity.

A Comparative Investigation on Phenolic Composition, Characterization and Antioxidant Potentials of Five Different Australian Grown Pear Varieties

Pear (Pyrus communis L.) is widely spread throughout the temperate regions of the world, such as China, America and Australia. This fruit is popular among consumers due to its excellent taste and perceived health benefits. Various bioactive compounds, which contribute to these health benefits, have been detected in the pear fruits, including a range of phenolic compounds. Five Australian grown pear varieties, which include Packham’s Triumph, Josephine de Malines, Beurre Bosc, Winter Nelis and Rico were selected for this study to examine the phenolic compounds in pears. Beurre Bosc exhibited the highest total polyphenol content (TPC) (3.14 ± 0.02 mg GAE/g), total tannin content (TTC) (1.43 ± 0.04 mg CE/g) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) (5.72 ± 0.11 mg AAE/g), while the Josephine de Malines variety was high in total flavonoid content (TFC) (1.53 ± 0.09 mg QE/g), ferric reducing antioxidant power (FRAP) (4.37 ± 0.04 mg AAE/g), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (4.44 ± 0.01 mg AAE/g) and total antioxidant capacity (TAC) (5.29 ± 0.09 mg AAE/g). The liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) data indicate that a total of 73 phenolic compounds were detected in Beurre Bosc (37 compounds), Josephine de Malines (34), Rico (22), Packham’s Triumph (15) and Winter Nelis (9), respectively. From HPLC-PDA quantification, the Beurre Bosc pear variety showed significantly higher in phenolic acids (chlorogenic acid; 17.58 ± 0.88 mg/g) and while flavonoids were significantly higher in Josephine de Malines (catechin; 17.45 ± 1.39 mg/g), as compared to other pear varieties. The analyses suggest that the Australian grown pears might contain an ideal source of phenolic compounds which benefit human health. The information provided by the present work can serve as practical supporting data for the use of pears in the nutraceutical, pharmaceutical and food industries.

Comprehensive chemotaxonomic analysis of saffron crocus tepal and stamen samples, as raw materials with potential antidepressant activity

Saffron crocus (Crocus sativus L.) has been widely grown in Iran. Its stigma is considered as the most valuable spice for which several pharmacological activities have been reported in preclinical and clinical studies, the antidepressant effect being the most thoroughly studied and confirmed. This plant part contains several characteristic secondary metabolites, including the carotenoids crocetin and crocin, and the monoterpenoid glucoside picrocrocin, and safranal. Since only the stigma is utilized industrially, huge amount of saffron crocus by-product remains unused. Recently, the number of papers dealing with the chemical and pharmacological analysis of saffron is increasing; however, there are no systematic studies on the chemical variability of the major by-products. In the present study, we harvested saffron crocus flowers from 40 different locations of Iran. The tepals and stamens were separated and subjected to qualitative and quantitative analysis by HPLC-DAD. The presence and amount of seven marker compounds, including crocin, crocetin, picrocrocin, safranal, kaempferol-3-O-sophoroside, kaempferol-3-O-glucoside, and quercetin-3-O-sophoroside were determined. The analytical method was validated for filter compatibility, stability, suitability, accuracy, precision, intermediate precision, and repeatability. Tepal and stamen samples contained three flavonol glycosides. The main constituent of the tepals was kaempferol-3-O-sophoroside (62.19-99.48 mg/g). In the stamen, the amount of flavonoids was lower than in the tepal. The amount of kaempferol-3-O-glucoside, as the most abundant compound, ranged between 1.72-7.44 mg/g. Crocin, crocetin, picrocrocin, and safranal were not detected in any of the analysed samples. Our results point out that saffron crocus by-products, particularly tepals might be considered as rich sources of flavonol glucosides. The data presented here can be useful in setting quality standards for plant parts of C. sativus that are currently considered as by-products of saffron production.

Untargeted HILIC-MS-Based Metabolomics Approach to Evaluate Coffee Roasting Process: Contributing to an Integrated Metabolomics Multiplatform

An untargeted metabolomics strategy using hydrophilic interaction chromatography-mass spectrometry (HILIC-MS) was developed in this work enabling the study of the coffee roasting process. Green coffee beans and coffee beans submitted to three different roasting degrees (light, medium, and strong) were analyzed. Chromatographic separation was carried out using water containing 10 mM ammonium formate with 0.2 % formic acid (mobile phase A) and acetonitrile containing 10 mM ammonium formate with 0.2 % formic acid (mobile phase B). A total of 93 molecular features were considered from which 31 were chosen as the most statistically significant using variable in the projection values. 13 metabolites were tentatively identified as potential biomarkers of the coffee roasting process using this metabolomic platform. Results obtained in this work were complementary to those achieved using orthogonal techniques such as reversed-phase liquid chromatography-mass spectrometry (RPLC-MS) and capillary electrophoresis-mass spectrometry (CE-MS) since only one metabolite was found to be common between HILIC-MS and RPLC-MS platforms (caffeoylshikimic acid isomer) and other between HILIC-MS and CE-MS platforms (choline). On the basis of these results, an untargeted metabolomics multiplatform is proposed in this work based on the integration of the three orthogonal techniques as a powerful tool to expand the coverage of the roasted coffee metabolome.

Development of a high-performance liquid chromatography with tandem mass spectrometry method for identifying common adulterant content in saffron (Crocus sativus L.)

Objectives

This study aimed to develop an efficient and reliable method for estimating common adulterants in saffron by detecting their characteristic components to warrant its efficacy and regular use as a highly valuable medicinal herb.

Methods

A selective and sensitive high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) method was developed to estimate the common adulterants in saffron from corn stigma, chrysanthemum and safflower through the simultaneous determination of specific constituents including allantoin, chlorogenic acid (ChA) and hydroxysafflor yellow A (HSYA). Peak identification of each target compound was confirmed from product ions obtained using multiple reaction monitoring triggered enhanced product ions mass chromatogram. Method validation in terms of linearity, sensitivity, reproducibility, accuracy and stability was systematically performed according to official guidelines.

Key findings

Satisfactory separation of the three components was achieved on a C18 column (4.6 × 250 mm, 5 μm) with methanol–acetonitrile–ammonium acetate (3.0 mm) as the mobile phase at gradient elution. The identification of these specific constituents was accomplished using the multiple reaction monitoring mode in combination with enhanced product ion supplementary confirmation. The established method was validated in terms of linearity, sensitivity, reproducibility, accuracy and recovery, which were found satisfactory for sensitive detection of the three target compounds.

Conclusions

By detecting the specific constituents allantoin, ChA and HSYA in one run, the adulterants of corn stigma, chrysanthemum and safflower can be effectively identified and estimated in saffron. This is the first report on developing a simple, sensitive and operational method for the identification and estimation of common adulterants of saffron, that was forwarded for broaden application.

Identification of phenolic markers for saffron authenticity and origin: An untargeted metabolomics approach

Saffron is a high-quality and expensive spice being widely subjected to adulteration. An UHPLC-ESI/QTOF-MS metabolomic-based approach was therefore used to investigate the discrimination potential between adulterated (added with different percentage of other parts of the flower) and authentic saffron, as well as to trace its geographical origin. Both unsupervised (hierarchical clustering) and supervised OPLS-DA multivariate statistics allowed discriminating authentic saffron from styles added of other floral components, as well as PDO (Protected Designation of Origin) vs non PDO saffron samples according to their chemical fingerprints. The proposed markers were then validated through ROC curves. Anthocyanins and glycosidic flavonols were the best markers of the styles' adulteration. However, other flavonoids (mainly free flavonols and flavones), together with protocatechuic aldehyde and isomeric forms of hydroxybenzoic acid, were also validated as markers for the discrimination of PDO vs non PDO saffron samples. This work outlines the potential of untargeted metabolomics based on UHPLC-ESI/QTOF mass spectrometry for saffron authenticity and traceability.

Metabolic profile analysis of free amino acids in experimental autoimmune uveoretinitis rat plasma

AIM

To determine the differences of amino acid (AA) levels in experimental autoimmune uveoretinitis (EAU).

METHODS

AA analysis of the plasma samples in EAU rats induced by interphotoreceptor retinoid-binding protein emulsion were performed with high performance liquid chromatography (HPLC) and phenylisothiocyanate (PITC) pre-column derivation methods were performed. Using partial least squares discriminant analysis (PLS-DA), the potential biomarkers were identified in EAU rat plasma, and the metabolic pathways related to EAU were further analyzed.

RESULTS

The method results showed that linear (r≥0.9957), intra-day reproducible [relative standard deviation (RSD)=0.04%-1.33%], inter-day reproducible (RSD=0.06%-2.07%), repeatability (RSD=0.03%-0.89%), stability (RSD=0.05%-2.48%) and recovery (RSD=1.98%-4.39%), with detection limits of 0.853-11.4 ng/mL. The metabolic profile in EAU rats was different from that in the control groups five AAs concentrations were increased and nine AAs were reduced. Moreover, five metabolic pathways were related to the development of EAU.

CONCLUSION

The developed method is a simple, rapid and convenient for determination of AAs in EAU rat plasma, and these findings will provide a comprehensive insight on the metabolic profiling of the pathological changes in EAU.

Metabolomic Approach for the Authentication of Berry Fruit Juice by Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry Coupled to Chemometrics

Berry fruit juice, which is represented by blueberry and cranberry juice, has become increasingly popular due to its reported nutritional and health benefits. However, in markets, adulteration of berry fruit juice with cheaper substitutes is frequent. In the present study, a metabolomic approach for authentication of berry fruit juices by liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was established. The global characterization of the berry fruit metabolome by information dependent acquisition directed LC-MS/MS coupled to a peak mining workflow by isotope pattern matching was reported. Targeted metabolomics analysis of known juice biomarkers, such as flavonoids, anthocyanins, etc. exhibited a good separation of berry fruit juices from adulterant juices. Moreover, untargeted metabolomics analysis was carried out and subjected to chemometrics analysis. Discrimination of blueberry juice, cranberry juice, and its adulterant apple juice and grape juice was obtained by principal component analysis-discriminant analysis. Eighteen characteristic markers discriminating berry fruit juice and its adulterants were selected by comparison of marker abundances in different juice samples. Identification of characteristic markers was accomplished by elemental formula prediction and online database searches based on accurate MS information. These results suggested that the combination of untargeted and targeted metabolomics approach has great potential for authentication of berry fruit juice.

UHPLC Analysis of Saffron (Crocus sativus L.): Optimization of Separation Using Chemometrics and Detection of Minor Crocetin Esters

Ultra-high performance liquid chromatography (UHPLC) coupled with diode array detection (DAD) was applied to improve separation and detection of mono- and bis-glucosyl esters of crocetin (crocins), the main red-colored constituents of saffron (Crocus sativus L.), and other polar components. Response surface methodology (RSM) was used to optimise the chromatographic resolution on the Kinetex C18 (Phenomenex) column taking into account of the combined effect of the column temperature, the eluent flow rate and the slope of a linear eluent concentration gradient. A three-level full-factorial design of experiments was adopted to identify suitable combinations of the above factors. The influence of the separation conditions on the resolutions of 22 adjacent peaks was simultaneously modelled by a multi-layer artificial neural network (ANN) in which a bit string representation was used to identify the target analytes. The chromatogram collected under the optimal separation conditions revealed a higher number of crocetin esters than those already characterised by means of mass-spectrometry data and usually detected by HPLC. Ultra-high performance liquid chromatography analyses carried out on the novel Luna Omega Polar C18 (Phenomenex) column confirmed the large number of crocetin derivatives. Further work is in progress to acquire mass-spectrometry data and to clarify the chemical structure to the newly found saffron components.

MS-Based Analytical Techniques: Advances in Spray-Based Methods and EI-LC-MS Applications

Mass spectrometry is the most powerful technique for the detection and identification of organic compounds. It can provide molecular weight information and a wealth of structural details that give a unique fingerprint for each analyte. Due to these characteristics, mass spectrometry-based analytical methods are showing an increasing interest in the scientific community, especially in food safety, environmental, and forensic investigation areas where the simultaneous detection of targeted and nontargeted compounds represents a key factor. In addition, safety risks can be identified at the early stage through online and real-time analytical methodologies. In this context, several efforts have been made to achieve analytical instrumentation able to perform real-time analysis in the native environment of samples and to generate highly informative spectra. This review article provides a survey of some instrumental innovations and their applications with particular attention to spray-based MS methods and food analysis issues. The survey will attempt to cover the state of the art from 2012 up to 2017.

Semi-synthesis and HPLC analysis of (bacterio)chlorophyllides possessing a propionic acid residue at the C17-position

Various chlorophyll and bacteriochlorophyll derivatives possessing a magnesium or zinc atom at the central position and a free carboxylic acid group at the C17[Formula: see text]-position, also known as (bacterio)chlorophyllides, were synthesized through a combination of organic synthesis techniques and enzymatic steps. The semi-synthetic (bacterio)chlorophyllides were purified and analyzed using reversed-phase high-performance liquid chromatography with UV-vis spectroscopy and mass spectrometry. These free propionic acid-containing chlorophyllous pigments can be useful research materials for the study of (bacterio)chlorophyll metabolisms.

Plant Metabolomics: Maximizing Metabolome Coverage by Optimizing Mobile Phase Additives for Nontargeted Mass Spectrometry in Positive and Negative Electrospray Ionization Mode

Nontargeted screening methods with ultrahigh-performance liquid chromatography-electrospray ionization/quadrupole-time-of-flight mass spectrometry have been extensively applied to plant metabolomics to very diverse scientific issues in plant metabolomics. In this study, different mobile phase additives were tested in order to improve the electrospray ionization process and to detect as many metabolites as possible with high peak intensities in positive and negative ionization mode. Influences of modifiers were examined for nonpolar and polar compounds, as optimal conditions are not always the same. By combining different additives, metabolite coverage could be significantly increased. The best results for polar metabolites in positive ionization mode were achieved by using 0.1% acetic acid and 0.1% formic acid in negative ionization mode. For measurements of nonpolar metabolites in positive ionization mode, the application of 10 mmol/L ammonium formate led to the best findings, while the use of 0.02% acetic acid was more appropriate in negative ionization mode.

Geographical identification of saffron (Crocus sativus L.) by linear discriminant analysis applied to the UV-visible spectra of aqueous extracts

We attempted geographical classification of saffron using UV-visible spectroscopy, conventionally adopted for quality grading according to the ISO Normative 3632. We investigated 81 saffron samples produced in L'Aquila, Città della Pieve, Cascia, and Sardinia (Italy) and commercial products purchased in various supermarkets. Exploratory principal component analysis applied to the UV-vis spectra of saffron aqueous extracts revealed a clear differentiation of the samples belonging to different quality categories, but a poor separation according to the geographical origin of the spices. On the other hand, linear discriminant analysis based on 8 selected absorbance values, concentrated near 279, 305 and 328nm, allowed a good distinction of the spices coming from different sites. Under severe validation conditions (30% and 50% of saffron samples in the evaluation set), correct predictions were 85 and 83%, respectively.

Targeted and untargeted mass spectrometric approaches in discrimination between Myrtus communis cultivars from Sardinia region

In the present study, the discrimination of phytochemical content of Myrtus communis berries from different geographical origin and cultivars was explored by Liquid Chromatography-Electrospray Ionization-Fourier Transform-Mass Spectrometry (LC-ESI-FT-MS) metabolic profiling and quantitative analysis. Experiments were carried on myrtle plants grown in an experimental area of Sardinia region, obtained by the germination of seeds taken from berries collected in each part of the region. A preliminary untargeted approach on fruit's extracts was realized by collecting LC-ESI-FT-(Orbitrap)-MS data obtained by operating in negative ion mode and performing principal component analysis with the result of differentiation of samples. In a second step, targeted analysis with a reduced number of variables was realized. A data matrix was obtained by the data fusion of positive and negative ionization LC-ESI-MS results, by using as variables the peak areas of each known compounds. By the observation of principal component analysis, results found that anthocyanins, and mainly derivatives of cyanidin, are the principal marker compounds responsive for the discrimination of samples based on the geographical origin of the seeds. Based on this finding, finally, an LC-diode array detector method was developed, validated and applied for the quantitative analysis of berries' extracts based on 11 commercial standard compounds corresponding to the identified markers. Copyright © 2016 John Wiley & Sons, Ltd.

Geographical classification of Italian saffron (Crocus sativus L.) based on chemical constituents determined by high-performance liquid-chromatography and by using linear discriminant analysis

One hundred and forty-four Italian saffron samples produced in the years from 2009 to 2015 in five distinct areas located in four different regions, Abruzzo (L'Aquila), Tuscany (Florence), Umbria (Cascia and Città della Pieve) and Sardinia, have been analysed by high-performance liquid chromatography with diode array detection. Intensities of the chromatographic peaks attributed to crocins, safranal, picrocrocin and its derivatives and flavonoids were considered as variables in linear discriminant analysis to attempt geographical classification. The results revealed that spices produced at different sites of the Italian territory can be discriminated with good accuracy. The differentiation of saffron cultivated in Sardinia from those produced in Central Italy was mainly attributed to different contents of the most abundant crocins. Good differentiation of spices produced in close sites of Central Italy was also observed, 88% of validation samples being correctly classified; some minor crocins are responsible for such discrimination.