35 research outputs found

    Encapsulated proanthocyanidins as novel ingredients

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    Proanthocyanidins (OPC) are polyphenolic compounds, derivatives of flavan-3-ol flavonoids. They are abundant in grape seeds and skins, and contribute to most of the polyphenols in red wine. Proanthocyanidins from grape seed have been reported to show various health as well as technological properties. Aim of the study was to investigate the coating efficiency of maltodextrin (MD) in different molecular ratios with arabic gum (AG) on encapsulation of phenolic compounds extracted from grape pomace. The present study was planned to examine the contributions of MD, AG and OPC to the structural architecture of encapsulated OPC by means of scanning electron microscopy (SEM), their encapsulation efficiency and their functionality (antioxidant activity and bioavailability) by spectrophotometric assays and mass spectrometry analysis (MALDI-TOF-MS). The effect of encapsulated OPC on in vitro polyphenol digestibility was also evaluated according to the Infogest protocol. Encapsulated products were obtained by a mild ultrasonication method in controlled conditions based on the phenomenon of acoustic cavitation, and then freeze-dried. The content of coating material had significant (p>0.05) impact on particle morphology of spray-dried suspensions. SEM analysis of samples of AG/MD and AG/MD/OPC were similar and exhibited cracks and sharp edges, but samples with OPC showed a more enclosed structure. Total and Surface phenolic content of microcapsules showed the best encapsulation efficiency for samples with 4% of AG and 12% of MD. MALDI-TOF-MS characterization of encapsulated samples showed integrity of OPC components in the microcapsules with no changes with respect to original OPC. The in vitro digestion experiments showed also that composition and functionality of encapsulated OPC were better preserved along gastrointestinal digestion process. In conclusion, OPC microcapsules could be utilized both as nutraceuticals and additives in various food application

    Physical properties and antimicrobial activity of bioactive film based on whey protein and Lactobacillus curvatus 54M16 producer of bacteriocins

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    The objective of the work was to study the viability and antimicrobial activity of bacteriocin-producing lactic acid bacteria (LAB) incorporated into whey protein/inulin/gelatine (WP) edible films in presence or absence of nutrient (modified MRS broth). Moreover, the role of the cell on the film structure and properties has been investigated. The results of the work showed that WP-based films were able to ensure a high viability of the bacteriocin-producing strain L. curvatus 54M16 during 28 days of storage at 4 �C. The addition of nutrient in the film matrix slightly affected the viability of the cells, but it was critical for the antimicrobial activity of the films. Films in presence of nutrient showed a good antimicrobial activity against L. innocua C6 as in vitro system as on cooked ham. The presence of LAB has a significant effect on the structure of the film: it reduced the viscosity of the film forming solution and improved the elasticity and the percentage of elongation. Whereas, no effect was observed for water vapour transmission rate and solubility. Thus, WP-based films in presence of modified MRS broth can be used as effective delivery and carrier systems for lactic acid bacteria to develop bioactive edible film or coating with antimicrobial properties

    Interferon-α Improves Phosphoantigen-Induced Vγ9Vδ2 T-Cells Interferon-γ Production during Chronic HCV Infection

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    In chronic HCV infection, treatment failure and defective host immune response highly demand improved therapy strategies. Vγ9Vδ2 T-cells may inhibit HCV replication in vitro through IFN-γ release after Phosphoantigen (PhAg) stimulation. The aim of our work was to analyze Vγ9Vδ2 T-cell functionality during chronic HCV infection, studying the role of IFN-α on their function capability. IFN-γ production by Vγ9Vδ2 T-cells was analyzed in vitro in 24 HCV-infected patients and 35 healthy donors (HD) after PhAg stimulation with or without IFN-α. The effect of in vivo PhAg/IFN-α administration on plasma IFN-γ levels was analyzed in M. fascicularis monkeys. A quantitative analysis of IFN-γ mRNA level and stability in Vγ9Vδ2 T-cells was also evaluated. During chronic HCV infection, Vγ9Vδ2 T-cells showed an effector/activated phenotype and were significantly impaired in IFN-γ production. Interestingly, IFN-α was able to improve their IFN-γ response to PhAg both in vitro in HD and HCV-infected patients, and in vivo in Macaca fascicularis primates. Finally, IFN-α increased IFN-γ-mRNA transcription and stability in PhAg-activated Vγ9Vδ2 T-cells. Altogether our results show a functional impairment of Vγ9Vδ2 T-cells during chronic HCV infection that can be partially restored by using IFN-α. A study aimed to evaluate the antiviral impact of PhAg/IFN-α combination may provide new insight in designing possible combined strategies to improve HCV infection treatment outcome

    Potential antidiabetic effect of muffins formulated with different protein hydrolysates: Role of bioactive peptides formed during digestion

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    This study aimed to evaluate whether the reformulation of a conventional muffin (CM) by incorporating hydrolysates of casein, soybean protein, pea protein, and rice protein at two concentrations as wheat flour replacement, affected the glycemic index (GI) and the release of bioactive peptides (BAPs) during the digestion in vitro.Compared to CM, muffins with hydrolyzed pea and rice proteins lowered GI by 15% and 5%, respectively, without a significant dose-dependent effect; moreover, during digestion they delivered BAPs, including some amylase-inhibitors. Conversely, the muffins incorporating casein hydrolysate at high concentration showed the highest GI and delivered highest amount of opioid and DPPIV-inhibitor BAPs. Soy protein hydrolysates did not significantly affect the GI or BAPs released.Findings suggested that reformulating a muffin with protein hydrolysates, besides a reduced GI, as in the case of pea and rice protein hydrolysates, may provide further biological effects through the release of BAPs during the digestion

    GLI EFFETTI DELL'INTRODUZIONE DI SITI DI INVERSIONE DELLA POLARITA' SULLA STRUTTURA QUADRUPLEX DEL DNA (TGGGT)4

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    GLI EFFETTI DELL'INTRODUZIONE DI SITI DI INVERSIONE DELLA POLARITA' SULLA STRUTTURA QUADRUPLEX DEL DNA (TGGGT)
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