1,721,196 research outputs found
GLUTEN - FREE FOOD SYSTEM: SCREENING OF POLYPHENOLS AND THEIR BIO ACCESSIBILITY THROUGH IN VITRO GASTROINTESTINAL PROCESSES AND METABOLOMICS - BASED STUDIES
No full textCirca l’1% della popolazione mondiale è colpita da celiachia. I celiaci sono costretti a seguire una dieta priva di glutine e molto spesso quest’ultima risulta essere sbilanciata e/o carente in molti nutrienti. Recentemente, l’uso di matrici alternative al frumento, come pseudocereali, legumi e cultivar di riso pigmentate sta riscuotendo grande interesse a causa del loro elevato quantitativo di composti bioattivi (polifenoli). Quindi, considerando l’importanza attuale dei polifenoli sia nella formulazione tecnologica che nella promozione di aspetti salutistici degli alimenti senza glutine, lo scopo di questa tesi è stata basata su: 1) profilazione dei polifenoli in matrici prive di glutine (farine non di frumento, legumi, pseudocereali e frutta secca) e loro proprietà antiossidanti in vitro; 2) valutazione dell’impatto di trattamenti termici e di fermentazioni microbiche sul profilo fenolico di queste matrici prive di glutine; 3) valutazione del ruolo dei polifenoli come inibitori degli enzimi amilolitici; e 4) valutazione del destino dei polifenoli caratterizzanti alimenti senza glutine durante processi in vitro simulanti digestione gastrointestinale e fermentazione fecale. I polifenoli sono stati analizzati sfruttando tecniche di metabolomica mirata/non-mirata.Around 1% of world population is affected by coeliac disease. Coeliac people are constrained to follow a strict gluten free (GF) diet and very often this latter is unbalanced and lacks in many nutrients. In the last years, the exploitation of alternative crops or underutilized species, such as pseudocereals, legumes and pigmented cereal cultivars, is gaining interest because of their amount and profile of bioactive compounds, such as polyphenols. Therefore, considering the actual importance of polyphenols for both the formulation of GF foods and their health-promoting properties, the current PhD thesis was based on: 1) the profiling of polyphenols in GF raw materials (such as non-wheat flours, legumes, pseudocereals and nuts) and their in vitro antioxidant activities; 2) the evaluation of the impact of different heat treatments and microbial fermentations on the phenolic profile of GF raw materials; 3) the investigation of polyphenols in GF foods as inhibitors of digestive enzymes; and 4) the assessment of the fate of polyphenols characterizing GF foods during simulated in vitro gastrointestinal and fermentation processes. Polyphenols were analysed by means of targeted/untargeted metabolomics-based approaches (i.e., high resolution chromatography and mass spectrometry platforms)
Extending the concept of terroir from grapes to other agricultural commodities: an overview
No full textThe term terroir is widely used in oenology to link geographical
origin and environmental conditions used for grapes training
with the sensorial and hedonistic value of the wine. Overall, this
definition includes the pedo-climatic (such as soil type and
climate) as well as agronomic practices able to affect the
composition of a plant-derived food. This concept is rather
underestimated in matrices other than wine, even though
recent advance in analytics is providing clear evidence that the
organoleptic and nutritional value of foods is strongly affected
by the area of cultivation. This mini review reports the molecular
basis of the effect of terroir on phytochemical profile and
highlights the need to extend this concept from grape to other
crops and food products, thus linking geographical origin and
quality of agricultural commodities
Comparative “phenol-omics” and gene expression analyses in peach (Prunus persica) skin in response to different postharvest UV-B treatments
No full textUltraviolet-B (UV–B) radiation impacts the plant behaviour in many ways, including modifying their secondary metabolism. Although several studies have quantified the UV-B effects on phenolic composition, most of them focused on leaves or investigated a limited amount of phenolics. The present work aimed to investigate the phenolic changes after two postharvest UV-B treatments, 10 and 60 min (1.39 kJ m−2 and 8.33 kJ m−2, respectively), on peach (Prunus persica cv Fairtime) fruit with a non-targeted, whole profiling approach, and targeted gene expression analysis on skin. After both UV-B exposures, peach fruit were harvested at 24 and 36 h for “phenol-omics” analysis, while additional 6 h and 12 h recovery times were used for gene expression analysis. Our results revealed that both UV-B exposures resulted in a decrease of several phenolic compounds, such as anthocyanins, after 24 h from the exposure. In contrast, the expression of the UV-B signalling components, the phenylpropanoid biosynthesis genes and their transcriptional regulators increased 6 h after the treatment, mostly with a UV-B-dose dependent behaviour, preceding an accumulation of most phenolics in both the UV-B treatments at 36 h compared to 24 h. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) revealed that flavonoids, particularly anthocyanins, were the main phenolic subclasses accumulated after UV-B exposure
Phenolic fingerprint allows discriminating processed tomato products and tracing different processing sites
No full textTomatoes are important in human nutrition, as they are a source of carotenoids and phenolic compounds. However, transformation processes may alter the nutritional value of foods, decreasing the concentration of health-promoting compounds. This work aimed to explore the effects of industrial transformation on processed tomatoes (crushed pulp, puree and paste), as well as the effect of the different pre-processing technologies, rather than different manufacturing sites, in producing tomato paste. Results demonstrate that phenolics profiling can distinguish between different processed products as well as different paste pre-treatments (namely cold, warm and hot break), even though the latter underwent a final thermal treatment at > 100 °C. Analogously, the different processing sites could be discriminated thanks to their characteristic phenolic fingerprint. The greatest differences identified were between conjugated forms of flavonoids, phenylpropanoids and lignans. The latter were the most labile phenolics, followed by flavonoids and then phenylpropanoids. Results provide evidence for the potential of phenolic fingerprint to support traceability of transformation processes and to investigate their effect on the nutritional value of processed tomatoes
Untargeted phytochemical profiling and biological activity of small yellow onion (Allium flavum L.) from different regions of Romania
No full textThis study examined the phytochemical profiles (mainly phenolics, carotenoids, and organosulfur compounds) and biological effects of hydroalcoholic extracts of Allium flavum (AF), a species of the Allium genus commonly known as small yellow onion. Unsupervised and supervised statistical approaches revealed clear differences between extracts prepared with samples collected from different areas of Romania. Overall, the AFFF (AF flowers collected from Faget) extract was the best source of polyphenols, also showing the highest antioxidant capacity evaluated through both in vitro DPPH, FRAP, and TEAC anti-radical scavenging assays and cell-based OxHLIA and TBARS assays. All the tested extracts exhibited & alpha;-glucosidase inhibition potential, while only the AFFF extract exhibited anti-lipase inhibitory activity. The phenolic subclasses annotated were positively correlated with the assessed antioxidant and enzyme inhibitory activities. Our findings suggested that A. flavum has bioactive properties worth exploring further, being a potential edible flower with health-promoting implications
Evaluation of different blackcurrant seed ingredients in meatballs by using conventional quality assessment and untargeted metabolomics
No full textBlackcurrants are sources of phenolic compounds, such as anthocyanins, possessing strong antioxidant, antimicrobial and antifungal activity. Therefore, the addition of different blackcurrant pomace ingredients may affect the overall meat quality. The actual chemical profile and bioactivities of blackcurrant pomace ingredients may strongly depend on its preparation; for instance, in our study the highest values of the in vitro antioxidant capacity were determined for blackcurrant seeds after supercritical CO2 extraction. Starting from these background conditions, in this work, we evaluated the ability of three different concentrations (namely 1, 3, and 5% w/w) of blackcurrant (BC) seeds following EtOH/water extraction (BC-AE), before supercritical fluid CO2 extraction (BC-RS), and after supercritical fluid CO2 extraction (BC-ASC) to affect different quality parameters of pork meatballs. These latter were stored considering three different time-points, namely 1, 3 and 6 days at 4 °C packed under modified atmosphere (i.e., 70% N2 and 30% CO2). Untargeted metabolomics allowed to identify several lipid and protein-related oxidation products involved in redox reactions, such as 13-L-hydroperoxylinoleic acid, (12S,13S)-epoxylinolenic acid, 9,10-epoxyoctadecenoic acid, glutathione, glutathione disulfide, L-carnosine, l-ascorbic acid, and tocotrienols. Besides, multivariate statistics applied on the metabolomics dataset confirmed that the chemical profile of meatballs was an exclusive combination of both BC inclusion levels and type of BC-ingredients considered. Our findings showed that the higher the concentration of BC seed ingredients in meatballs, the lower the cooking loss and the higher the fibre content. Also, all the ingredients significantly affected the colour parameters
Discrimination of Tunisian and Italian extra-virgin olive oils according to their phenolic and sterolic fingerprints
No full textIn the last years, olive oil authentication issues have become topics of prominent importance, not only for consumers, but also for suppliers, retailers, and administrative authorities, and particularly for assurance of public health. In this work, the sterolic and phenolic profile of Tunisian and Italian extra-virgin olive oil (EVOO) samples was depicted using an untargeted UHPLC-ESI/QTOF mass spectrometry approach. Polyphenols and sterols were quantified according to their chemical sub-classes, with high sterols (around 1000 up to 2000 mg/ kg) and tyrosols (on average 420.2 mg/kg) contents detected. The metabolomics data were elaborated by means of multivariate statistics, i.e. unsupervised hierarchical cluster analysis and orthogonal projections to latent structures discriminant analysis (OPLS-DA). This approach allowed identifying the best markers (i.e. hydroxybenzoic acids, cholesterol and stigmasterol derivatives) of the geographical origin able to discriminate Tunisian and Italian EVOO samples, showing the potential of sterolic and phenolic fingerprints for olive oil authenticity evaluations
Cellular assays combined with metabolomics highlight the dual face of phenolics: From high permeability to morphological cell damage
No full textThe 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
Impact of cooking and fermentation by lactic acid bacteria on phenolic profile of quinoa and buckwheat seeds
No full textIn 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-highpressure
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
Impact of Pasture-Based Diets on the Untargeted Metabolomics Profile of Sarda Sheep Milk
No full textIn this work, untargeted metabolomics was used to shed light on the impact of different pasture-based diets on the chemical profile of Sarda sheep milk. The study considered 11 dairy sheep farms located in Sardinia, and milk samples were collected in 4 different periods, namely January, March, May, and July 2019, when all sheep had 58, 98, 138, and 178 days in milk, respectively. The animal diet composition was based on the intake of grazed herbage in natural pasture, hay, and concentrate. Overall, the combination of two comprehensive databases on food, namely the Milk Composition Database and Phenol-Explorer, allowed the putative identification of 406 metabolites, with a significant (p < 0.01) enrichment of several metabolite classes, namely amino acids and peptides, monosaccharides, fatty acids, phenylacetic acids, benzoic acids, cinnamic acids, and flavonoids. The multivariate statistical approach based on supervised orthogonal projections to latent structures (OPLS-DA) allowed us to predict the chemical profile of sheep milk samples as a function of the high vs no fresh herbage intake, while the prediction model was not significant when considering both hay and concentrate intake. Among the discriminant markers of the herbage intake, we found five phenolic metabolites (such as hippuric and coumaric acids), together with lutein and cresol (belonging to carotenoids and their metabolites). Additionally, a high discriminant power was outlined for lipid derivatives followed by sugars, amino acids, and peptides. Finally, a pathway analysis revealed that the herbage intake affected mainly five biochemical pathways in milk, namely galactose metabolism, phenylalanine metabolism, alpha-linolenic acid metabolism, linoleic acid metabolism, and aromatic amino acids involved in protein synthesis (namely tyrosine, phenylalanine, and tryptophan)
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