Search results for " polysaccharide"

Influence of solvent-free reticulation treatment on edible film properties based on chitosan and gelatin, containing or not natural antioxidants : ph…

2015

This thesis aims to develop an edible packaging made of a mixture of chitosan and gelatin (beef or fish), to better understand the influence of the electron beam irradiation and of the incorporation of natural antioxidants on the physico-chemical and functional properties of the films. A study of the effect of irradiation on antioxidants release kinetics in a simple liquid medium was studied for validation. A preliminary study first showed that the densification of the film-forming solution and the gel during drying does not depend on the thickness or concentration or time and suggests a Fickian diffusion of water in the matrix. The permeability to water vapor increases linearly with film t…

Algae and their extracts in medical treatment

2018

Scientific efforts undertaken in recent decades have undoubtedly proven that algae are an inestimable and, what is more, important renewable source of hundreds of chemical compounds characterized by a wide spectrum of biological activity. Polysaccharides, phenolic compounds and their derivatives, pigments, proteins, lipids, and fatty acids are the substances that can be isolated from seaweeds, possessing antimicrobial, antiviral, antifungal, antilipidemic, antitumor, antidiabetic, anticoagulant, antioxidant, and antiallergic properties, which can be successfully utilized for human needs. The majority of attention has been focused on marine polysaccharides and their application in medicine a…

Water-soluble polysaccharides from Opuntia stricta Haw. fruit peels: Recovery, identification and evaluation of their antioxidant activities

2015

Abstract Opuntia stricta Haw. is considered as one of the most common cactus plant growing in Tunisia. Extracting valuable compounds from its fruit peel, considered as by-product, is drawing more and more attention, making it on the verge of commercialization. Water-soluble polysaccharides were extracted from Opuntia stricta Haw. peels, and their chemical composition assessed using thin layer chromatography. The antioxidant activities of the extracted polysaccharides were assessed using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, total antioxidant activity and reducing power capacity. The extraction yield of water-soluble polysaccharides was 7.53±0.86%. The chemical comp…

Membrane oligo- and polysialic acids

2011

AbstractPolysialic acid (polySia) and oligosialic acid (oligoSia) chains are linear polysaccharides composed of sialic acid monomers. The majority of biological poly/oligoSia chains are bound to membranes. There is a large diversity of membrane poly/oligoSia in terms of chain length, occurrence, biological function, and the mode of membrane attachment. Poly/oligoSia can be anchored to a membrane via a phospholipid (polySia in bacteria), a glycosphingolipid (oligoSia in gangliosides), an integral membrane glycoprotein, or a glycoprotein attached to a membrane via glycosylphosphatidylinositol. In eukaryotic cells, the attachment of a poly/oligoSia chain to the membrane anchor is usually throu…

Radiation-tailored xyloglucan-doxorubicin nanoparticles for cancer therapy

2022

Polysaccharides are long chains of monosaccharides linked by glycosidic bonds. They are widely utilized in biomedical applications, for tissue engineering and wound management, and as excipients of pharmaceutical formulations. In cancer therapy, the development of nanoscale drug delivery systems aims at addressing issues related to the low efficacy of chemotherapeutics and protein drugs due to poor solubility and stability, and to off-target effects that severely affect patients’ body conditions. Biocompatibility, availability of functional groups, amenability of chemical derivatisation and multifunctional conjugation with drugs and targeting ligands make polysaccharide nanoparticles intere…

Gamma irradiation of xyloglucans and hydroxypropyl cellulose in dry and humid solid state to tune molecular weight distribution

2022

The shell matrix of the freshwater mussel Unio pictorum (Paleoheterodonta, Unionoida). Involvement of acidic polysaccharides from glycoproteins in na…

2007

13 pages; International audience; Among molluscs, the shell biomineralization process is controlled by a set of extracellular macromolecular components secreted by the calcifying mantle. In spite of several studies, these components are mainly known in bivalves from only few members of pteriomorph groups. In the present case, we investigated the biochemical properties of the aragonitic shell of the freshwater bivalve Unio pictorum (Paleoheterodonta, Unionoida). Analysis of the amino acid composition reveals a high amount of glycine, aspartate and alanine in the acid-soluble extract, whereas the acid-insoluble one is rich in alanine and glycine. Monosaccharidic analysis indicates that the in…

Fresh-Cut Mangoes: How to Increase Shelf Life by Using Neem Oil Edible Coating

2022

The mango is the most widely cultivated tropical fruit. Fresh-cut mango is very useful, but it is very perishable. The purpose of this study was to highlight the effects of neem oil on fresh-cut mango fruits kept for 9 days at 4 ± 1 °C and 80 ± 5% relative humidity. The neem plant (Azadirachta indica) has numerous antioxidant and antibacterial properties. Despite this, very few studies have been carried out on neem oil added to edible coatings (EC) to retard ripening processes. Two formulations were tested: EC1 (hydroxypropyl methylcellulose + CaCl2) and EC2 (hydroxypropyl methylcellulose + CaCl2 + neem oil), both compared with an untreated sample (control). Physicochemica…

Innovative and Applied Research in Biology: Proceedings, Vol. 2

2020

The collection contains SCIENTIFIC articles on the topics of the LU 78 conference reports. The main focus is on innovative and applied research in biology and interdisciplinary fields.

Incidence de la clarification des moûts de raisin sur les fermentescibilltés alcoolique et malolactique

1993

<p style="text-align: justify;">Des essais de débourbage en vinification en blanc, réalisés de 1988 à 1992, mettent en évidence le rôle important joué par la teneur en macromolécules solubles dans le moût de raisin. Les moûts de faible turbidité conduisent en effet à des fermentations alcooliques lentes en relation avec de faibles populations levuriennes. Il est également confirmé que la libération de polysaccharides exocellulaires par les levures au cours de la fermentation alcoolique est d'autant plus élevée que le moût de départ a été fortement appauvri en colloïdes de raisin. Par contre, ce sont dans les lots les plus clarifiés que l'on observe la meilleure fermentescibilité malol…