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The Caco-2 cellular permeability of phenolic aqueous extracts from blackcurrant press cake (BC), Norway spruce bark (NS), scots pine bark (SP), and sea buckthorn leaves (SB) was evaluated by combining high-resolution mass spectrometry and atomic force microscopy. Besides, Caco-2 and HepG2 cells allowed the study of intracellular oxidative stress assessed in both apical and basolateral domains. Overall, BC and NS showed the highest total phenolic contents, 4.38 and 3.76 µg/mL, respectively. Multivariate statistics discriminated NS and BC from SP and SB extracts because of their phenolic profile. Polyphenols were classified as highly permeable, thus suggesting their potentially high bioavailability through the gastrointestinal tract. All the phenolic subclasses showed efflux ratio values < 1, except for BC flavonols, flavan-3-ols, and stilbenes. Regarding cellular damage, NS and BC extracts, when acting on the basolateral cellular side, caused epithelial leakage and morphological shape cell damage on Caco-2 cells associated with ROS production., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Sizeable scientific evidence indicates the health benefits related to phenolic compounds and dietary fiber. Various phenolic compounds-rich foods or ingredients are also rich in dietary fiber, and these two health components may interrelate via noncovalent (reversible) and covalent (mostly irreversible) interactions. Notwithstanding, these interactions are responsible for the carrier effect ascribed to fiber toward the digestive system and can modulate the bioaccessibility of phenolics, thus shaping health-promoting effects in vivo. On this basis, the present review focuses on the nature, occurrence, and implications of the interactions between phenolics and food components. Covalent and noncovalent interactions are presented, their occurrence discussed, and the effect of food processing introduced. Once reaching the large intestine, fiber-bound phenolics undergo an intense transformation by the microbial community therein, encompassing reactions such as deglycosylation, dehydroxylation, α- and β-oxidation, dehydrogenation, demethylation, decarboxylation, C-ring fission, and cleavage to lower molecular weight phenolics. Comparatively less information is still available on the consequences on gut microbiota. So far, the very most of the information on the ability of bound phenolics to modulate gut microbiota relates to in vitro models and single strains in culture medium. Despite offering promising information, such models provide limited information about the effect on gut microbes, and future research is deemed in this field., (© 2022 The Authors. Comprehensive Reviews in Food Science and Food Safety published by Wiley Periodicals LLC on behalf of Institute of Food Technologists.)

Plant cell cultures from cloudberry (CL), lingonberry (LI), stone berry (ST), arctic bramble (AB), and strawberry (SB) were studied in terms of their polyphenol and carotenoid composition, antioxidant activity, antihemolytic activity and cytotoxicity effects on cancerous cells. High-resolution mass spectrometry data showed that LI, presented the highest antioxidant activity, contained the highest contents of flavones, phenolic acids, lignans, and total carotenoids, while CL, ST and SB presented the opposite behavior. AB and SB presented the lowest FRAP and CUPRAC values, while AB and CL presented the lowest reducing power. SB presented the lowest antioxidant activity measured by single electron transfer assays and the lowest content of lignans, phenolic acids, and flavones. CL and LI decreased the viability of in vitro mammary gland adenocarcinoma while only LI decreased the viability of in vitro lung carcinoma and showed protective effects of human erythrocytes against mechanical hemolysis., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In this work the (poly)-phenolic profile of Moringa oleifera leaves was comprehensively investigated through untargeted metabolomics, following a homogenizer-assisted extraction (HAE) using three solvent systems, i.e. methanol (HAE-1), methanol-water 50:50 v/v (HAE-2) and ethyl acetate (HAE-3). This approach allowed to putatively annotate 291 compounds, recording mainly flavonoids and phenolic acids. Thereafter, antioxidant capacity, antimicrobial activity and enzyme inhibition were assayed in the different extracts. HAE-1 extract showed the highest total phenolic content (31.84 mg/g), followed by HAE-2 (26.95 mg/g) and HAE-3 (14.71 mg/g). In addition, HAE-1 and HAE-2 extracts exhibited an expressive activity against Bacillus cereus and Listeria innocua. The HAE-2 leaf extract was characterized by the highest DPPH and ABTS values (being 49.55 and 45.26 mgTE/g), while ferric reducing antioxidant power was found to be higher in HAE-1 (58.26 mgTE/g). Finally, the enzyme inhibitory effects of M. oleifera leaf extracts were investigated against five enzymes, namely acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, α-amylase and α-glucosidase. All of the tested extracts exhibited inhibitory effects on AChE and BChE with a higher activity for HAE-3 and HAE-1, whilst HAE-1 showed the higher impact on tyrosinase, glucosidase and amylase activities. Taken together, these findings suggest that M. oleifera leaf extracts are a good source of bioactive polyphenols with a potential use in food and pharma industries., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Untargeted metabolomics was used in this study to discriminate the phenolic fingerprints of six Syzygium species. This approach resulted in the annotation of 441 compounds that belong to different phenolic classes, such as flavonoids, lignans, stilbenes, tyrosols, alkylphenols, and phenolic acids. Multivariate data analysis unraveled the main differences between the studied species. S. paniculatum and S. aqueum were the richest sources in terms of phenolic compounds, cumulatively amounting to 355.3 and 266.4 mg/g dry matter, respectively. Nevertheless, S. jambos showed reduced amounts of phenolics, when compared with other species. The biological activity of Syzygium leaf extracts was assessed on MCF-7 breast adenocarcinoma and MDA-MB-231 breast cancer cell lines. Potent estrogenic activity was detected using the SRB assay on MCF-7. This activity may be ascribable to the presence of phenolic compounds miming phytoestrogens such as lignans, stilbenes, and isoflavonoids in the investigated Syzygium extracts. By examining the biological effect of Syzygium extracts against MDA-MB-231 cell lines, the Syzygium gratum leaf extract exhibited the strongest inhibition, with IC 50  = 19.4 µg/mL, followed by S. paniculatum (IC 50  = 50.9 µg/mL). However, the Syzygium gratum leaf extract showed a potent cytotoxic effect on normal human skin fibroblasts, HSF (IC 50  = 1.24 µg/mL), assuming a nonselective cytotoxic effect. On the other hand, other studied Syzygium leaves proved as safe nutraceuticals (IC 50  ≥ 100 µg/mL) on HSF cell lines. Our study suggested a possible implication of Syzygium malaccense and Syzygium aqueum leaves as potential estrogenic candidates in relation to their health-promoting phenolic constituents., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

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., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Tomato is one of the most important agricultural crops and it is characterized by a wide bioactive compound profile. However, little information is reported on its comprehensive polyphenol profile. In this work, 13 commercial tomato cultivars for industrial transformation were screened by ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS) for both free and bound phenolic profiles. Thereafter, the in vitro antioxidant activity of each cultivar was assessed by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance activity (ORAC) assays. Multivariate statistics, i.e. orthogonal projection to latent structures discriminant analysis (OPLS-DA), were then used to model samples according to their distinct phenolic signatures, thus providing compounds that better discriminated between the distributions of the cultivars that were considered., Results: More than 350 phenolic compounds could be identified across the samples that were considered: flavonoids (such as flavones and flavanols), hydroxycinnamic acids, lignans, and lower-molecular-weight phenolics were the most frequently observed classes of phenolics in tomato berries. Anthocyanins were the most abundant class among bound phenolics (being highest in the Leader F1 and Defender F1 cultivars), followed by tyrosols (mainly in Heinz cultivars). However, flavones and hydroxybenzoic acids were the most represented discriminant phenolics in the bound fraction., Conclusions: Untargeted metabolomics allowed significant differences in phenolic composition to be outlined across the tomato cultivars that were analyzed. Such differences were particularly evident regarding the free-to-bound phenolic ratio, hence allowing differences in the bioaccessibility of phenolics to be postulated. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

In this work, quinoa and buckwheat cooked seeds were fermented by two autochthonous strains of lactic acid bacteria isolated from the corresponding seeds, namely Lactobacillus paracasei A1 2.6 and Pediococcus pentosaceus GS·B, with lactic acid chemically acidified seeds as control. The impact of cooking and fermentation on the comprehensive phenolic profile of quinoa and buckwheat seeds was evaluated through untargeted ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS). Samples were analyzed also for in vitro antioxidant capacity (as FRAP and ORAC assays) and total phenolic content (TPC). The in vitro spectrophotometric assays highlighted that the microbial fermentation was more efficient in increasing (p < .05) the TPC and in vitro antioxidant potential in quinoa cooked seeds. However, an increase (p < .05) in TPC and ORAC radical scavenging was observed in both pseudocereals after the different cooking processes (i.e., boiling or toasting). The untargeted phenolic profiling depicted the comprehensive phenolic composition in these matrices. Raw seeds of both pseudocereals possessed a similar phenolic content (4.4 g kg -1 equivalents; considering free and bound fractions). Besides, the metabolomics-based approach showed that all treatments (i.e., cooking and fermentation) induced the release of specific classes, namely phenolic acids and tyrosols. The PLS-DA multivariate approach identified in flavonoids the best markers allowing to discriminate the different treatments considered (i.e., cooking, chemical acidification and microbial fermentation). These findings support the use of cooking and microbial fermentation to ensure the health-promoting properties of non-wheat grains, such as buckwheat and quinoa., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The interest in gluten-free (GF) products increases together with the increase in gluten-sensitive people. However, GF foods might have decreased nutritional quality as compared to the gluten containing counterparts. In this work, an investigation of the phenolic and antioxidant profile in 18 GF flours belonging to legumes, cereals and pseudocereals was achieved. Significant differences could be observed across samples. Total phenolic content was highest in violet rice flours, whereas total anthocyanins were highest in violet, nerone, and black rice flours. FRAP and ORAC antioxidant activities were correlated to phenolic contents and found to be higher in violet rice flours. Metabolomics highlighted a wide diversity in phenolics, with flavonoids (197 compounds ascribable to anthocyanins, flavones, flavanones, isoflavonoids, flavonols, and flavanols), phenolic acids (74 compounds belonging to hydroxycinnamics, hydroxybenzoics, and hydroxyphenylacetics), and tyrosol derivatives the most represented. Finally, OPLS-DA multivariate statistics outlined flavonoids, furofurans and phenolic acids as the most discriminant phenolics., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The impact of different extraction methods, namely maceration, homogenizer-assisted extraction, rapid solid-liquid dynamic extraction, microwave-assisted extraction and ultrasound-assisted extraction, on polyphenols of Moringa oleifera leaves was studied. The phenolic composition of alcoholic (methanol 100%) and hydroalcoholic (methanol/water 50:50, v/v) extracts was compared by using an untargeted metabolomics-based profiling approach followed by multivariate statistics. With this aim, ultra-high-pressure liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometry was used to profile phenolic compounds under the different extraction conditions. Besides, the in vitro antioxidant activities of Moringa leaves were also investigated as ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). The metabolomic approach allowed to putatively annotate 262 phenolic compounds. In particular, glycosidic forms of quercetin (i.e., quercetin 3-O-galactoside, quercetin 3-O-glucoside, and quercetin 4'-O-glucoside) were the most represented compounds among flavonoids. Furthermore, protocatechuic acid was found to be the most abundant hydroxybenzaldheyde derivative, while the isomeric forms of hydroxybenzoic acid characterized the phenolic acids class. Overall, the extractions in methanol 100% were found to be the most effective for phenolic compounds recovering, when compared with those in methanol/water (50:50, v/v). Homogenizer-assisted extraction of M. oleifera leaves using 100% methanol allowed extracting the highest amounts of polyphenols (35.19 mg/g) and produced the highest oxygen radical absorbance capacity (536.27 μmol Trolox Equivalents/g). The supervised orthogonal projection to latent structures discriminant analysis identified phenolic acids as the phenolic class mostly affected by the different extraction technologies. These findings demonstrate that each extraction method promoted the recovery of specific phenolic subclasses with different efficiencies., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The antioxidant and antimicrobial effects of guarana seed extracts (GSE) added to pork patties were evaluated for 18 days storage at 2 ± 1 °C. Five treatments were prepared: i) without natural antioxidant [control (negative control)], ii) with BHT at 200 mg/kg (positive control), and iii) with three different concentrations: 250  mg/kg (guarana seed low dose-GSL), 500  mg/kg (guarana seed medium dose-GSM) and 1000  mg/kg (guarana seed high dose-GSH) of guarana extracts, respectively. The pH, instrumental colour (CIE L*, a*, b*), total viable counts (TVC), Pseudomonas spp. counts and lactic acid bacteria (LAB) counts, 2-thiobarbituric acid reactive substances (TBARS) and carbonyl content were determined after 0, 7, 11, 15 and 18 days of storage period. The in vitro antioxidant activity together with the phenolic profile of GSE was also studied. Microbial analysis showed that GSE had no antimicrobial activity on pork patties. The untargeted UHPLC-ESI-QTOF approach confirmed the wide phenolic composition of GSE able to explain the antioxidant power (28.2 g/kg of phenolic equivalents). Low doses (GSL) of GSE were able to preserve the values of colour parameters, obtaining higher L*, a* and b* values during storage, which is reflected in the lowest colour differences during storage (ΔE* 0-18  = 4.56). TBARS and carbonyls values in GSE added samples were lower than control and BHT ones. GSL and GSM provided better results than the synthetic antioxidant (0.08 and 0.07 vs 0.18 mg MDA/kg; 2.47 and 3.13 vs 3.23 nmol/mg, for GSL and GSM vs BHT, respectively). These findings show that GSE are very effective against colour deterioration, lipid and protein oxidation in pork patties and possessing the potential to be used as natural antioxidants., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A bioaccessibility study of polyphenols after in vitro simulated large intestine fermentation was carried out on edible nuts. Raw nuts were also analysed for total phenolic content and antioxidant potential, considering both bound and free phenolics. The highest phenolic content was found in walnuts, followed by pistachios extracts (596.9 and 410.1 mg gallic acid equivalents 100 g -1 , respectively). Consistently, the total antioxidant capacity was highest in walnuts (3689.7 μM trolox equivalents 100 g -1 ) followed by peanuts and pistachios (3169.6 and 2990.1 μM trolox equivalents 100 g -1 , respectively). Data showed high correlations between total phenolics and both antioxidant activities. The metabolomics-based phenolic profile depicted during in vitro fermentation showed a degradation of higher-molecular-weight phenolics over 48 hours of faecal fermentation, with a concurrent increase in low-molecular-weight compounds (hydroxybenzoic and hydroxycinnamic acids, alkylphenols, and tyrosols). Our findings indicate that nuts deliver polyphenols into the colon, with bioaccessibility values not negligible for alkylphenols, tyrosols and phenolic acids., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The comprehensive phenolic fingerprint of Calligonum azel Maire plant fractions, collected from the Tunisian Desert, have been assessed for the first time as a source of natural antioxidants. Total phenolic content (TPC), Trolox Equivalent Antioxidant Capacity (TEAC) in scavenging DPPH, ABTS + and Ferric Reducing Antioxidant Power (FRAP) were determined. C. azel Maire showed a relevant content in phenolic compounds, which are related to the antioxidant activity. The flowers presented the highest antioxidant capacity against DPPH free radicals, while the leaves showed the highest scavenging capacity against ABTS. As for the FRAP assay, results showed that the roots had the highest ferric reducing antioxidant power. Methanol extracts of the four organs were screened by ultra high performance liquid chromatography coupled to quadruple time of flight mass spectrometry and the identified phenolics were further quantified. Flavones and flavanols were the most abundant phenolic compounds identified, and were quantitatively measured as luteolin and catechin equivalents. Although the phenolic profile was diverse between the four organs, the obtained results showed that Calligonum azel Maire is an excellent source of various natural antioxidants with high radical scavenging capacities, which could be used in food preservation. Further studies on the isolation of such compounds appear to be of high interest., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Cooking by boiling dry pasta could have varying degrees of influence on nutritional and functional components. In the present study, its effect on total phenolic content and antioxidant capacity, as well as on the comprehensive profile of free and bound phenolics, was investigated in six commercial gluten-free (GF) pasta products. Overall, the heat treatment caused a significant reduction (P<0.01) of the total phenolic content as well as FRAP reducing power and ORAC radical scavenging, with significant differences among the pasta samples considered. The highest values were recorded in free phenolic fraction remaining in black rice (41mggallic acid equivalents100g -1 and 25mmolTrolox Equivalents100g -1 ) and quinoa (24mggallic acid equivalents100g -1 and 14mmolTrolox Equivalents100g -1 ) cooked GF pasta. Significant correlations (P<0.01) could be found between total phenolics and both the antioxidant capacity assays performed. UHPLC-ESI/QTOF-MS mass profiling allowed confirming the spectrophotometric results, while identifying the amount of free and bound fractions. Among phenolic classes, lignans exhibited the highest decrease during the cooking process, followed by stilbenes and flavonoids. However, phenolic acids and other phenolics showed the highest stability. Furthermore, cooking by boiling strongly lowered the bound-to-free ratio of phenolic compounds, by an averaged factor ranging from 14-folds for flavonoids to 5-folds for other classes of phenolics., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The characterization of phenolic fingerprints in common gluten-free flours is still scarce. Total phenolic and anthocyanin contents, antioxidant capacity and the entire phenolic profile were investigated for extracts from chickpea, sorghum, quinoa, black rice, lentil, amaranth, brown rice, oat and white rice flours, using soft wheat flour as a comparison. The highest phenolic content was found in black rice, followed by quinoa extracts (147.9 and 87.2mg gallic acid equivalents 100g -1 , respectively). Consistently, antioxidant capacity was highest in black rice and quinoa flours (34mmol trolox equivalents 100g -1 ), while anthocyanins were highest in black rice flour. Data showed a high correlation between phenolic content and both reducing and scavenging activities, with Pearson's coefficient of 0.90 and 0.91, respectively. Although the entire phenolic profile was diverse and differed among flours, these represent a valuable source of health-promoting compounds, mainly belonging to flavonoids, phenolic acids and lignans., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The fate of phenolic compounds, along with short-chain fatty acids (SCFAs) production kinetics, was evaluated on six different commercial gluten-free (GF) pasta samples varying in ingredient compositions, focussing on the in vitro faecal fermentation after the gastrointestinal digestion. A general reduction of both total phenolics and reducing power was observed in all samples, together with a substantial change in phenolic profile over 24h of faecal fermentation, with differences among GF pasta samples. Flavonoids, hydroxycinnamics and lignans degraded over time, with a concurrent increase in low-molecular-weight phenolic acids (hydroxybenzoic acids), alkylphenols, hydroxybenzoketones and tyrosols. Interestingly, discriminant analysis also identified several alkyl derivatives of resorcinol as markers of the changes in phenolic profile during in vitro fermentation. Furthermore, degradation pathways of phenolics by intestinal microbiota have been proposed. Considering the total SCFAs and butyrate production during the in vitro fermentation, different fermentation kinetics were observed among GF pasta post-hydrolysis residues., (Copyright © 2017 Elsevier Ltd. All rights reserved.)