Identifcation of yeasts from raw milk and selection for some specific antioxidant properties

Eleven different species of yeasts isolated from raw milk, such as Issatchenkia orientalis , Pichia fermentans , Rhodotorula mucilaginosa and Yarrowia lipolytica were identified using an integrated approach, including phenotypic and genotypic methods and the API 20C AUX system. Eleven selected strains which tolerated low pH levels, gastric juice and bile salt were further analysed for the presence of functional traits useful for probiotic application as antioxidants. The ability to scavenge DPPH (2, 2-diphenyl-1-picrylhydrazyl) and inhibit linoleic acid peroxidation indicated that P. fermentans BY5 and HJ15 may be promising candidate strains for use as probiotics with antioxidant activity.     

Synthesis and Anti-Proliferative Activity of Novel Quinolin-8-ol Derivatives

Through the coupling of substituted benzaldehydes with 8-hydroxy 5-amino methyl quinoline scaffold, a series of new derivatives has been synthesized. In vitro growth inhibitory effects on cancer cell line model have been evaluated. Discussion on the chemical reactivity of these new polycyclic aromatic analogs to generate alkylating species led to the hypothesis that the presence of an imine moiety impedes the formation of quinone methide intermediate and consequently abolishes in part their antiproliferative activity.     

Mechanisms of Syneresis in Rennet Curd without Mechanical Treatment

An original method for syneresis evaluation was developed, based on image analysis which enabled direct monitoring of curd shrinkage. Image analysis was employed in combination with the customary tracer method to follow the effects of cutting on curd syneresis. The two methods were then utilized to study curd syneresis in the presence of ethanol, a solvent less polar than water. Curd syneresis was reduced in the presence of diluted ethanol which led to the hypothesis that the mechanism which causes rennet curd to synerese probably relates to changes in protein conformation, essentially due to hydrophobic bonding.     

Application d'une méthodologie expérimentale à l'étude du diagramme ternaire d'un gel

Nous avons montré sur l'exemple d'un gel, mélange de trois constituants (C12–C15 Alcohols Benzoate, Cyclomethicone et Ethylene Vinyl Acetate Copolymer) qu'il est possible d'optimiser une formulation en un nombre preécis d'essais en faisant appel à une stratégic expérimentale optimale. Le gel avait déjàétéétudié par Chang,¹ mais par approches successives.
Nous avons utlisé les matrices d'expériences développées dans le cas des mélanges par Scheffe sous le nom de 'reseaux-simplex'. Prévoyant des intéractions de 2éme ordre entre les constituants nous avons retenu le modéle appelé'cubique réduit'. Cette approche permet l'exploration systémique de tout le domaine.
Les réponses étudiées sont la compatibilité (gel homogène ou non), la consistance, la blancheur et le coût. Le meilleur gel étant celui qui se rapproche le plus de la vaseline.
A partir des résultats, nous avons tracé des courbes d'isoréponse en blancheur, consistance et coût. La superposition des diagrammes conduit à la détermination d'une zone où les réponses sont optimales.
En ajoutant la réponse supplémentaire: 'facilité d'étalement sur la peau'on arrive au meilleur gel avec un nombre réduit d'essais.
La même méthode s'appliquerait à des mélanges de plus de trois constituants.
Study of a ternary diagram gel according to a methodology of experimental research     

Water and Glycerol as Plasticizers Affect Mechanical and Water Vapor Barrier Properties of an Edible Wheat Gluten Film

Glycerol improved film extensibility but reduced film puncture strength, elasticity, and water vapor barrier properties. The plasticizing effect of water was highly temperature dependent. During hydration of gluten film, a sharp decrease in puncture strength, elasticity, and an increase of extensibility and water vapor transmission rate were observed at 5, 30 and 50°C for respective water contents of 30 (0,8 a_w,), 15 (0,7 a_w) and 5% (0,4 a_w). This was related to disruptive water-polymer hydrogen bonding and glass-to-rubber transition.     

Principles of swell measurement by SAR with application to ERS-1 observations off the Mauritanian coast

This paper addresses the imaging of swell waves by Synthetic Aperture Radar ( SAR). We give the principles for the determination of swell parameters from image data. Wave height determination is based on a simple method derived from the quasi-linear version of the wave imaging model of Hasselmann and Hasselmann. The influence of wind waves on wave height determination is discussed. Results on coastal swell events observed by ERS-1 off the Banc d' Arguin ( Mauritania) are presented. These results are compared, generally favourably, with estimates from the wave prediction model of Meteo-france and from a model of swell propagation in finite depth water. However, in intermediate to shallow water, SAR wave length estimates were found to be greater than the theoretical values obtained without currents. The results are discussed in terms of swell-current interaction phenomena. A general conclusion of the study is that satellite SAR can be considered as a quasi-operational instrument for swell monitoring at low to moderate wind speeds. Also, we point out that SAR imagery can henceforth be envisaged for physical studies on swell propagation in the coastal zone.     

Edible Wheat Gluten Films: Influence of the Main Process Variables on Film Properties using Response Surface Methodology

An edible wheat gluten film was developed and effects of gluten concentration, ethanol concentration (ET) and pH of the film-forming solution on various film properties were evaluated using Response Surface Methodology. pH and ethanol concentration had strong interactive effects on film opacity, water solubility and water vapor permeability. A simultaneous variation of ethanol concentration and pH between 32.5% ET, pH 4 and 45% ET, pH 2 resulted in homogeneous and transparent film with relatively low water solubility. The lowest water vapor permeability would be expected with 20% ethanol concentration and pH 6. Mechanical properties were mainly affected by gluten concentration and pH. The most resistant film was obtained at high gluten concentration (12.5%) and pH 5.     

Edible composite films of wheat gluten and lipids: water vapour permeability and other physical properties

Edible composite films comprised of wheat gluten as the structural matrix and various concentrations of different lipids as the moisture barrier component were tested for water vapour permeability, dispersion in water, opacity and mechanical properties. the effects of lipids on the functional properties of gluten-based composite films depended on the lipid characteristics and on the interactions between the lipid and the protein structural matrix. Beeswax, a solid and highly hydrophobic lipid, was the most effective lipid for improving moisture barrier properties of films; but these films were opaque, weak and disintegrated easily in water. Combining wheat gluten proteins with a diacetyl tartaric ester of monoglycerides reduced water vapour permeability, increased strength and maintained transparency.     

利用高分辨辉光放电质谱技术对难熔金属材料进行痕量元素定量和深度剖面分析

直接采样的高分辨辉光放电质谱(GDMS)是当今高纯固体常规分析中可用的高灵敏度分析方法之一。这种多元素分析技术通常用于主量化学成分的定量分析、监测元素质量分数随微米级深度(深度分布)的变化,或用于对多种固体和镀层上肉眼可见体积的高灵敏度的分布研究,包括纯金属、高温合金、陶瓷或其中陶瓷金属。由于GDMS的检测几乎涵盖了所有方法,因此在监测痕量级的多元素含量方面是最具成本优势的。另外,它使对在包含绝缘层和(或)镀层及两者化合物的平面上的高灵敏度的含量深度分布分析成为可能。本文着重介绍直流辉光质谱技术用于监测痕量至超含量元素分析技术目前的进展以及直接采样分析实践中应当采用的策略。