Casein Micelles As Nanovehicles of Interesting Molecules for Food and Pharmaceutical ApplicationsSome examples

Casein Micelles As Nanovehicles of Interesting Molecules for Food and Pharmaceutical ApplicationsSome examples. 5.journées scientifiques de l'agro-alimentair

Transfection with fluorinated lipoplexes based on fluorinated analogues of DOTMA, DMRIE and DPPES

AbstractFluorinated double-chain (poly)cationic lipids (one or both of these chains being ended by a highly fluorinated tail) which are close analogues of DOTMA, DMRIE or DPPES were designed as synthetic vectors for gene delivery. For N/P ratios (N=number of amine functions of the lipid; P=number of DNA phosphates) from 0.8 to 5, these fluorinated cationic lipids condensed DNA, with or without the use of DOPE, to form fluorinated lipoplexes. No specific cell toxicity was evidenced for these new fluorinated lipoplexes. The efficiency of some of the fluorinated lipoplexes to transfect lung epithelial A549 cells was comparable to that of the first generation of fluorinated lipoplexes made from fluorinated analogues of DOGS (Transfectam) [Bioconjug. Chem. 12 (2001) 114]. These results, combined with the higher in vivo transfection potential found for fluorinated lipoplexes than for conventional lipoplexes or PEI polyplexes [J. Gene Med. 3 (2001) 109], confirm that fluorinated lipoplexes are very promising gene transfer systems

Structure development of soft cheese curd

Structure development of soft cheese curd. 26 ème congrès international de laiteri

Composition of raw cow milk and artisanal yoghurt collected in Maroua (Cameroon)

The composition of milk is of most importance to the dairy industry and human health. This study was conducted to provide data on the composition of raw cow milk and artisanal yoghurt collected in Maroua (Cameroon). Milk and yoghurt samples were collected from 11 breeding sites and 12 producers in the city of Maroua, respectively. The following parameters were determined: pH, dry matter, ash, fat, lactose, total protein, non-casein nitrogen (NCN), non-protein nitrogen (NPN), true protein, whey protein, casein, amino acid composition, α-lactalbumin, β-lactoglobulin, αS1-casein, αS2-casein, β- casein, κ-casein and mineral composition. The results showed that, the composition of the milk and yoghurt varied from one sample to another. The chemical composition of some of the milk and yoghurt studied differed from the corresponding samples in previous studies. For example the mean pH of the raw cow milk (6.25) and artisanal yoghurt (3.84) were lower. The mean NPN levels of the cow milk and yoghurt (0.21g/100g) were higher. The mean fat content of milk (4.48 g/100 g) was higher. The protein fraction was lower in yoghurt while Fe, Cu and Mn levels were lower in both cow milk and yoghurt. The data reported in this paper would be helpful in dairy technology and public health.Key words: Composition, cow milk, artisanal yoghurt, Maroua, Cameroon

Stability of casein micelles cross-linked with genipin: a physicochemical study as a function of pH

Chemical or enzymatic cross-linking of casein micelles (CMs) increases their stability against dissociating agents. In this paper, a comparative study of stability between native CMs and CMs cross-linked with genipin (CMs-GP) as a function of pH is described. Stability to temperature and ethanol were investigated in the pH range 2.0-7.0. The size and the charge ($\zeta$-potential) of the particles were determined by dynamic light scattering. Native CMs precipitated below pH 5.5, CMs-GP precipitated from pH 3.5 to 4.5, whereas no precipitation was observed at pH 2.0-3.0 or pH 4.5-7.0. The isoelectric point of CMs-GP was determined to be pH 3.7. Highest stability against heat and ethanol was observed for CMs-GP at pH 2, where visible coagulation was determined only after 800 s at 140 $^\circ$C or 87.5% (v/v) of ethanol. These results confirmed the hypothesis that cross-linking by GP increased the stability of CMs.Comment: 5 pages, 2 figures, International Dairy Journal, 201

Nanofiltration of lactic acid whey: A process to improve the dryability and the quality of powder

Nanofiltration of lactic acid whey: A process to improve the dryability and the quality of powder. 6. European Drying Conference: EuroDrying 201

Adjuvant Formulations Designed to Improve Swine Vaccine Stability: Application to PCV2 Vaccines

AbstractPorcine circovirus associated diseases (PCVADs) are economically important diseases of domestic pigs caused by porcine circovirus type 2 (PCV2). PCV2 vaccination is usually performed with adjuvanted inactivated formulations and is necessary to control PCVADs and subclinical PCV2 related body weight losses in pig farming. An important issue with PCV2 vaccine formulation is that PCV2 antigenic media often have properties which destabilize vaccine formulations. Vaccine adjuvants are a key parameter in modern vaccination closely linked to galenic properties of vaccine formulations, and galenic stability is necessary to insure efficacy stability during vaccine shelf life. Here we show that especially designed formulations based on MontanideTM ISA 11R VG (Oil in water) and MontanideTM ESSAI Gel R (polymer) adjuvants are able to resist to very destabilizing antigenic media and conditions while keeping safety parameters and efficacy at requested levels

Microstructure and chemical composition of camel and cow milk powders’ surface

This study aimed at investigating the chemical composition and microstructure of spray dried camel and cowmilk powders' surfaces with two different milk-fat contents (1 and 20g 100 g−1). The SEM (Scanning ElectronMicroscopy) micrographs showed that spherical particles with a ‘brain’-type surface for both milk powders wereproduced. The surface roughness (Ra) of whole (WDMP) and skimmed (SDMP) camel milk powders(Ra=7.6 ± 0.4 nm and 5.6 ± 0.7 nm, respectively) were significantly lower as compared with the partiallyskimmed (PSCMP) and skimmed (SCMP) cow milk powders. The XPS (X-ray Photoelectron Spectroscopy)analysis highlighted that the surface of skimmed camel milk powders contained twice the lactose amount(17.7 ± 0.8%) as compared to cow milk powders (8.7 ± 0.4%). Furthermore, both milk powders showed theoverexposure of proteins and fats at their surfaces regardless of the fat content. The CLSM (Confocal LaserScattering Microscopy) micrographs highlighted that most of the camel milk fat globules were encapsulated bythe proteins near the powder surface. Camel milk fat behavior during particle formation was attributed to theirlower size distribution and their higher crystallization temperature

The surface properties of milk fat globules govern their interactions with the caseins: Role of homogenization and pH probed by AFM force spectroscopy

The surface of milk fat globules consists of a biological membrane rich in polar lipids and glycoproteins. However, high shear stress applied upon homogenization disrupts the membrane and leads to the adsorption of casein micelles, as the major protein fraction of milk. These changes in the interface properties could affect the interactions between native or homogenized milk fat globules and the surrounding protein matrix, at neutral pH and upon acidification. In this study, macroscale rheometry, microscopic observations, nanoscale AFM-based force spectroscopy and physico-chemical analysis were combined to examine the interfacial composition and structure of milk fat globules and to evaluate their interactions with casein micelles. We showed that the surface properties of milk fat globules (biological membrane vs. caseins) and pH govern their interactions with casein micelles. The adhesion between individual fat globules and casein micelles was higher upon homogenization, especially at acid pH where the work of adhesion increased from 3.3 x 10-18 to 14 x 10-18 J for native and homogenized fat globules, respectively. Consequently, casein-coated homogenized fat globules yield stiffer milk acid gels. These findings cast light on the importance of colloidal particle’s surface properties and pH on their connectivity with the surrounding matrix, which modulates the bulk microstructure and rheological properties with potential functional consequences, such as milk lipid digestion