443 research outputs found

    Recovery of Oligomeric Proanthocyanidins and Other Phenolic Compounds with Established Bioactivity from Grape Seed By-Products

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    Grape seeds are a copious part of the grape pomace produced by wine and juice industry and they represent an interesting source of phenolic compounds. Proanthocyanidins (PAs) are the main class of grape seed phenols and are important dietary supplements for their well-known beneficial properties. In this study enriched extracts obtained from Chardonnay and Pignoletto grape seeds were characterized for their proanthocyanidins and other minor phenolic compounds content and composition. Seed PAs were fractionated using Sephadex LH-20, using different ethanol aqueous solutions as mobile phase and analysed by normal phase HPLC-FLD-ESI-MS. Monomers, oligomers up to dodecamers and polymers were recorded in all samples. For both cultivars, the extracts showed a high content in PAs. The determination of other phenolic compounds was carried out using a HPLC-QqQ-ESI-MS and Chardonnay samples reported a greater content compared to Pignoletto samples. Contrary to PAs fraction, extracts obtained with ethanol/water 50/50 (v/v) presented a significant higher phenolic content than the others.This project was supported by University of Granada (project PPJI2017.16)

    Effect of Different Egg Products on Lipid Oxidation of Biscuits

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    Egg products are one of the main ingredients used in bakery industries, and they contain cholesterol. Cholesterol su ers several chemical changes during the food processes, allowing some potentially toxic compounds called cholesterol oxidized products (COPs). Thus, the aim of this work was to study the evolution of lipid oxidation from eggs to egg products, and to evaluate the influence of egg products on COPs formation in biscuits formulated with them. The results confirmed that spray-drying technology improves the cholesterol oxidation 2.6 times compared to pasteurized eggs. Biscuit samples showed a COPs content that is strictly related to the egg products used. Samples formulated with spray-dried eggs noticed lower amounts of COPs compared to those formulated with pasteurized eggs. It is important to stress that COPs composition was di erent between the two samples, underlining that the kinetic of COPs formation is dependent on the type of egg products.Spanish Ministry of Economy and Competitiveness (MINECO) RYC-2015-1879

    CaCu3Ti4O12 single crystals: insights on growth and nanoscopic investigation

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    The combination of scanning impedance microscopy and conductive atomic force microscopy was applied to single crystals of the perovskite-type oxide CaCu3Ti4O12 (CCTO) in order to provide a local dielectric characterization on ingot sections. Both techniques clearly showed dielectric heterogeneities due to the presence of inclusions within crystals grown in different laboratories. Despite macroscopic characterizations, such as Laue diffraction, gave no indications for the presence of inclusions within the crystals, the discovery of dielectric heterogeneities prompted a careful structural analysis, which revealed the presence of crystalline CaTiO3 (CTO) precipitates. Thus, the scanning probe investigation provided the evidence for the electrical homogeneity within the CCTO crystal and the presence of internal barriers due to the CCTO/CTO interfaces

    Primary intra and extradural solitary fibrous tumor/hemangiopericytoma of thoracic spine with paravertebral intrathoracic spread: Case report and review of the literature

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    Solitary fibrous tumors/hemangiopericytomas (SFTs/HPCs), constitute 1% of all CNS tumors. Spinal SFTs/HPCs are extremely rare. To date, few retrospective studies and case reports of primary spinal SFTs/HPCs have been published in the literature. We report clinical and radiological presentation, surgical treatment, and post-operative outcome at three years follow-up of a rare case of primary spinal intra and extradural SFT/HPC of thoracic spine with dumbbell shaped paravertebral intrathoracic spread and multidirectional erosion of the bone. A 73-year-old female presented with progressive lower limbs weakness and hypoesthesia below the rib cage. MRI showed an irregular isointense T5-T7 dumbbell shaped tumor. Tumor resection was successfully carried out through posterior and antero-lateral approach. Histological examination showed a grade II SFT/HPC. No local recurrence nor systemic metastases were observed at three years follow-up. A literature review has been performed to describe epidemiology, radiographic features, treatment, recurrence rate and mean disease-free survival of primary spinal SFTs/HPCs. No radiographic pathognomonic findings have been reported for these tumors. Differential diagnosis must be made with meningioma, schwannoma, chordoma, aggressive hemangioma, metastases, angiosarcoma. Surgical resection is the first choice of treatment, and total resection should be attempted whenever possible in all cases. Postsurgical radiotherapy does not change significantly recurrence rate after GTR, nonetheless it increases mean disease-free survival, especially in patients with extradural SFTs/HPCs. After subtotal resection, adjuvant radiotherapy is necessary to reduce progression of disease. The efficacy of chemotherapy has yet to be determined. Pathological degree and total surgical resection are the most important predictive factors of recurrence

    Scanning Probe Microscopy on heterogeneous CaCu3Ti4O12 thin films

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    The conductive atomic force microscopy provided a local characterization of the dielectric heterogeneities in CaCu3Ti4O12 (CCTO) thin films deposited by MOCVD on IrO2 bottom electrode. In particular, both techniques have been employed to clarify the role of the inter- and sub-granular features in terms of conductive and insulating regions. The microstructure and the dielectric properties of CCTO thin films have been studied and the evidence of internal barriers in CCTO thin films has been provided. The role of internal barriers and the possible explanation for the extrinsic origin of the giant dielectric response in CCTO has been evaluated

    Assessment of Lipid Quality in Commercial Omega-3 Supplements Sold in the French Market

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    Supplementation of omega-3 fatty acids is considered a valuable strategy to supply the low intake of these fatty acids. Thus, the safety of the supplements is an important milestone. Because of that, we analyzed 20 unflavored supplements sold in the French market for fatty acid and triglyceride composition, for EPA and DHA, and for tocol content, as well as for oxidative status. This study found that only 2.5% of the supplements did not meet their label claims for omega-3 content. TAG analysis showed high variability among the triglyceride distribution, and the same trend was also noticed for the tocol content; in fact, a high variability of the distribution of the six tocols (four tocopherols and two tocotrienols) was found among the samples. Of the tested products, all of them complied with peroxide value, p-anisidine value, and Totox values established by the Global Organization for EPA and DHA Omega-3s (GOED) and were not oxidized

    Use of Sieving as a Valuable Technology to Produce Enriched Buckwheat Flours: A Preliminary Study

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    Fractionation processes based on physical separation are a good strategy to produce enriched cereal flours. Therefore, the aim of this work is to evaluate the suitability of sieving of buckwheat flours to produce protein and phenolic (especially rutin) enriched fractions. Because of that, dehulled whole buckwheat flour (GSTQ) was sieved obtaining fractions with a particle size of 215 um, 160 um, 85 um, and 45 um (GS215, GS160, GS85, and GS45). For that purpose, the determination of protein, ash, and total starch content and free and bound phenolic compounds was carried out. The highest content of total phenolic compounds was obtained in GS215 (3118.84 mg kg-1 d.w.), followed by GS160 (2499.11 mg kg-1 d.w.), GS85 (989.46 mg kg-1 d.w.), GSTQ (983.15 mg kg-1 d.w.), and GS45 (481.31 mg kg-1 d.w.). Therefore, the phenolic content decreased with the particle size decrease from 215 um to 45 um. Besides, there were no significant differences between the total phenolic content in GS85 and GSTQ. The fraction with 215 um reported the highest protein and mineral salt content and presented rutin amounts four times higher than GSTQ

    Distribution of Free and Bound Phenolic Compounds in Buckwheat Milling Fractions

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    Buckwheat is a rich source of phenolic compounds that have shown to possess beneficial effect to reduce some diseases due to their antioxidant power. Phenolic compounds are present in the free and in the bound form to the cell wall that are concentrated mainly in the outer layer (hull and bran). Hull is removed before the milling of buckwheat to obtain flours. In order to evaluate the phenolic composition in dehulled buckwheat milling fractions, it was carried out a determination of free and bound phenolic compounds in dehulled whole buckwheat flour, light flour, bran flour, and middling flour by high-performance liquid chromatography-mass spectrometry (HPLC–MS). The most abundant free phenolic compounds were rutin and epiafzelchin–epicatechin-O-dimethylgallate, whereas the most abundant bound phenolic compounds were catechin and epicatechin in all buckwheat flours. Besides, the highest content of free phenolic compounds was obtained in bran flour (1249.49 mg/kg d.w.), whereas the greatest bound phenolic content was in middling (704.47 mg/kg d.w.) and bran flours (689.81 mg/kg d.w.). Thus, middling and bran flours are naturally enriched flours in phenolic compounds that could be used to develop functional foods

    Optimization of Sonotrode Ultrasonic-Assisted Extraction of Proanthocyanidins from Brewers’ Spent Grains

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    Brewing spent grains (BSGs) are the main by-product from breweries and they are rich of proanthocyanidins, among other phenolic compounds. However, literature on these compounds in BSGs is scarce. Thus, this research focuses on the establishment of ultrasound-assisted extraction of proanthocyanidin compounds in brewing spent grains using a sonotrode. To set the sonotrode extraction up, response surface methodology (RSM) was used to study the effects of three factors, namely, solvent composition, time of extraction, and ultrasound power. Qualitative and quantitative analyses of proanthocyanidin compounds were performed using HPLC coupled to fluorometric and mass spectrometer detectors. The highest content of proanthocyanidins was obtained using 80/20 acetone/water (v/v), 55 min, and 400W. The established method allows the extraction of 1.01 mg/g dry weight (d.w.) of pronthocyanidins from BSGs; this value is more than two times higher than conventional extraction.This project was supported by the University of Granada (project PPJI2017.16)

    Molecular interactions, characterization and photoactivity of Chlorophyll a/chitosan/2-HP-β-cyclodextrin composite films as functional and active surfaces for ROS production

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    Novel photosensitizing film based on the natural hybrid polymer Chitosan/2-hydroxy-propyl-β-Cyclodextrin (CH/CD) is synthesized introducing Chlorophyll a (CH/CD/Chla) as a photoactive agent for possible application in antimicrobial photodynamic therapy (PDT). The polymer absorbs visible light, in turn able to generate reactive oxygen species (ROS) and, therefore it can be used as environmental friendly and biodegradable polymeric photosensitizer (PS). The modified film is characterized by means of different spectroscopic, calorimetric, diffraction techniques and microscopic imaging methods including time-resolved absorption spectroscopy. UV–Vis, FTIR-ATR and X-ray Photoelectron Spectroscopy (XPS) analyses suggest that Chla shows a strong affinity toward Chitosan introducing interactions with amino groups present on the polymer chains. Nanosecond laser flash photolysis technique provides evidence for the population of the excited triplet state of Chla. Photogeneration of singlet oxygen is demonstrated by both direct detection by using infrared luminescence spectroscopy and chemical methods based on the use of suitable traps. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Differential Scanning Calorimetry (DSC) analyses confirm also the occurrence of structural changes both on the film surface and within the film layer induced by the insertion of the pigment. Moreover, X-ray Diffraction data (XRD) shows the existence of an amorphous phase for the chitosan films in all the compared conditions
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