B. De Cindio

Olive oil and hyperthermal water bigels for cosmetic uses.

Bigels are biphasic systems produced with an organogel (or oleogel) and a hydrogel mixed together at high shear rates. These systems are promising for different uses, among them the formulation of new cosmetic matrices for cosmetic agents delivery is under investigation. In the present paper, a common cosmetic formulation for skin care was enriched with increasing fractions of monoglycerides of fatty acids/olive oil organogels, in order to understand the rheology and the microstructure of these systems. Small amplitude oscillation tests, NMR-self diffusion analysis, contrast phase microscopy and electric conductivity confirmed that the addition of the organogel caused a microstructural change of the starting material, which turned from O/W to a more complex system where, probably, a matrix-in-matrix structure is present at the highest fractions of added organogel.

Influence of Fat Content on Chocolate Rheology

Molten chocolate is a suspension having properties strongly affected by particle characteristics including not only the dispersed particles but also the fat crystals formed during chocolate cooling and solidification. Even though chocolate rheology is extensively studied, mainly viscosity at high temperature was determined and no information on amount and type of fat crystals can be detected in these conditions. However chocolate texture and stability is strongly affected by the presence of specific crystals. In this work a different approach, based on creep test, was proposed to characterize chocolate samples at typical process temperatures (approximately 30 °C). The analysis of compliance, as time function, at short times enable to evaluate a material “elasticity” related to the solid‐like behavior of the material and given by the differential area between the Newtonian and the experimental compliance. Moreover a specific time dependent elasticity was defined as the ratio between the differential area, ...

Pectin: Properties Determination and Uses

Pectin is a high-molecular-weight heteropolysaccharide present in plant cell walls where it contributes to the firmness and structure of the vegetal tissue. Pectin is widely used as food ingredient owing, mainly, to its ability to impart texture and firmness to food products (hydrogels), even though recent interesting uses are also related to other pectin properties, such as interfacial activity. A general overview of pectin and pectin gels is presented, including the most recent experimental techniques used to characterize pectin properties and the texture–structure relationships in pectin hydrogels.

Rheological Study of O/W Concentrated Model Emulsions for Heavy Crude Oil Transportation

Abstract The oil-in-water emulsion is increasing in popularity as a cost-reducing method for “heavy” crude oil transportation. In order to analyze the effect of oil-in-water ratio and emulsifier amount on the viscosity of the final emulsion, concentrated model-emulsion of oil-in-water were rheologically characterized. Two emulsification methods were investigated: batch and “in-flow” in a lab scale plant. Comparison revealed the effect of the emulsifier amount both on the viscosity decay during time and on the final emulsion viscosity. Qualitative microscopy results revealed a rather wide drop size distribution for systems exhibiting a lower viscosity value.

Rheological Influence of Synthetic Zeolite on Cement Pastes

Self Compacting Concrete (SCC) is characterized by specific and particular mechanical properties, often due to the addition of components, able to modify the paste rheology. Concrete properties are strongly affected by characteristics of the fresh cement paste that is the continuous phase dispersing larger aggregates. Therefore, aiming to characterize mechanical properties of final concrete is relevant to know rheological properties of the base cement paste. In this work cement pastes for SCC were prepared by using, as additive, synthetic zeolite 5A in different amounts and they were analyzed by small amplitude oscillations. Experimental results have shown a relationship between dynamic moduli and zeolite content, identifying a proper level of zeolite addition. Moreover samples containing traditional fine additives, such as silica fume and limestone, were prepared and experimental data were compared to those obtained by using zeolite. It was found that zeolite seems to give better properties to cement pas...

Olive Oil Based Emulsions in Frozen Puff Pastry Production

Puff pastry is an interesting food product having different industrial applications. It is obtained by laminating layers of dough and fats, mainly shortenings or margarine, having specific properties which provides required spreading characteristic and able to retain moisture into dough. To obtain these characteristics, pastry shortenings are usually saturated fats, however the current trend in food industry is mainly oriented towards unsatured fats such as olive oil, which are thought to be safer for human health. In the present work, a new product, based on olive oil, was studied as shortening replacer in puff pastry production. To ensure the desired consistency, for the rheological matching between fat and dough, a water‐in‐oil emulsion was produced based on olive oil, emulsifier and a hydrophilic thickener agent able to increase material structure. Obtained materials were characterized by rheological dynamic tests in linear viscoelastic conditions, aiming to setup process and material consistency, and...

Viscoelastic Measurement at Very Low Temperature on Lubricant Systems

Rheological behavior of lubricant base oils is very important especially at low temperature because it can be very helpful in predicting the onset of possible motor failure. It is well known that oils that have passed official standard requirements may nevertheless show failures, depending on some particular conditions to which the engine may be exposed.

Pasta: Manufacture and Composition

The final pasta quality is related to durum grain characteristics, gluten network formation during mixing, and drying conditions. Mixing is the first stage of pasta production during which the durum wheat semolina is added to water in a paddle mixer and then fed into an extrusor, compressed, and extruded through a die. The rheological behavior of dough is mainly related to the gluten development matrix during mixing, and the properties can be measured with different methodologies: dynamic oscillatory measurements, uniaxial extension, etc. Finally, despite that drying is a very common technology, to avoid a final poor quality, excessive stress, and breakage of pasta, the choice between slow and fast processes and then the correct operating conditions are important. This article highlights the important durum and dough characteristics to obtain an optimum structure after mixing; moreover, it describes the more recent experimental methods and the production line, with particular attention to the link between the final quality and process conditions.

Rheological Properties of Food Materials

Food rheology is a science that has the aim to measure and interpret mechanical and flow behavior of these materials. There are two approaches diversifying and unifying, the first one is more empirical and is based mainly on industrial experience, whereas the second one stand on more solid theory, mainly taken from polymer science. Empirical instruments useful for industries are illustrated. Fundamental rheometry is described. Flow curve, creep compliance, and dynamic moduli are presented as a tool for food characterization. The network theory in terms of both relaxation spectrum and weak gel is discussed referring to specific example of food.

The Effect of Waxes Addition on Rheological Properties of O/W Concentrated Model Emulsions

Abstract As heavy oil contains different impurities that increase the viscosity, pipeline transportation becomes economically disadvantageous. Oil-in-water emulsification, adopted as a cost reduction transportation technique, may take advantage of the presence of natural components of heavy crudes, asphaltenes, and resins as emulsifiers and waxes as stabilizers, decreasing the viscosity with respect to the pure-oil one. This article aims at investigating the effect of waxes addition on the viscosity of model oil-in-water emulsions produced in bench-scale, using two different emulsification techniques. Results showed that paraffin accelerates the emulsification completion during an in-flow test and also emulsion viscosity was lowered by waxes addition.