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Emulsion Droplet Size Determination

Quality attributes of food emulsions, such as appearance, stability, and rheology, are strongly influenced by the size of the droplets that they contain (Friberg and Larsson, 1997 McClements, 1999). For example, the creaming stability of an emulsion decreases as droplet size increases. Analytical techniques that provide quantitative information about droplet size are therefore required to aid in the development and production of high-quality emulsion-based food products. A variety of analytical techniques have been developed to measure droplet size, e.g., laser diffraction, electrical pulse counting, sedimentation techniques, and ultrasonic spectrometry (McClements, 1999). These techniques are used for fundamental research, product development, and quality assurance. This unit focuses on the two most commonly used techniques in the food industry, laser diffraction and electrical pulse counting. [Pg.581]

LASER DIFFRACTION DETERMINATION OF DROPLET SIZE DISTRIBUTION [Pg.581]

In the near future, an ISO standard for the installation and validation of laser diffraction units will be published. [Pg.582]

Calibration standard containing particles of known diameter (see recipe) Laser-diffraction instrument designed for particle size analysis (e.g., Mastersizer, Malvern Instruments) [Pg.582]

Turn on the laser diffraction instrument and allow it to warm up for 30 min before taking measurements. [Pg.582]


The responses chosen all relate to important foam properties. We believed that yi, the emulsion droplet size, determines y2, the cell size in the resultant foam, and we wished to determine whether this is true over this range of formulations. The foam pore size ys should determine the wetting rate y7, so these responses could be correlated, and yg, the BET surface area, should be related to these as well. The density y and density uniformity ys are critical to target performance as described above, and ys, the compressive modulus, is an important measure of the mechanical properties of the foam. [Pg.78]

D3.3 Emulsion Droplet Size Determination Basic Protocol 1 Laser Diffraction Determination of Droplet Size D3.3.1... [Pg.565]

Electrical pulse counting, emulsion droplet size determination, 581, 583-584, 586-588... [Pg.759]

Ultrasonic methods infrared scanning for emulsion stability determination, 597-598 spectrometry, emulsion droplet size determination, 581 velocimetry, to measure fat, 572 Ultraviolet (UV). see also Spectrophotometry protein analysis, CD, 219-243 protein concentrations by... [Pg.767]

Particle Size Measurement. The best way to evaluate an emulsion s stability is probably to measure its particle size distribution. A number of methods are available for droplet size determination (see Sec. VIII.A). Optical microscopy, although a time-consuming technique, is a direct way of measuring droplets larger than 1 pm. Nowadays, laser lightscattering, diffraction, and transmission methods are becoming popular for routine determination of particle size [151, 152],... [Pg.273]

McClements DJ. Principles of ultrasonic droplet size determination in emulsions. Langmuir 1996 12 3454-3461. [Pg.202]

Figure 1. Effect of Binary Mixture Surfactant Concentration and Self-Emulsification Temperature on Emulsion Droplet Size for the Miglyol 812-Tagat TO System as Determined by Laser Diffraction. Bars Represent Standard Errors. Figure 1. Effect of Binary Mixture Surfactant Concentration and Self-Emulsification Temperature on Emulsion Droplet Size for the Miglyol 812-Tagat TO System as Determined by Laser Diffraction. Bars Represent Standard Errors.
Emulsion droplet size and composition determined particle sizes and compositions. The amorphous powders (spherical with diameters less than I pm) became crystalline upon calcination... [Pg.183]

Coupland, J.N. and McClements, D J. 2001. Droplet size determination in food emulsions Comparison of ultrasonic and light scattering methods. J. Food Eng. 50(2), 117-120. [Pg.257]

Much of the work in this area has been done in emulsions having a droplet size of more than 1 pm, and the application of submicron (nano) emulsions in encapsulation of oils and flavors is relatively new in the literature. Some works have been carried out to determine the influence of submicron emulsions produced by different emulsification methods on encapsulation efficiency and to investigate the encapsulated powder properties after SD for different emulsion droplet sizes and surfactants. The process has been referred to as nanoparticle encapsulation since a core material in nanosize range is encapsulated into a matrix of micron-sized powder particles (Jafari et al., 2008). This area of research is developing. Some patents were filed in the past describing microemulsion formulations applied to flavor protection (Chung et al., 1994 Chmiel et al., 1997) and applications in flavored carbonated beverages (Wolf and Havekotte, 1989). However, there is no clear evidence on how submicron or nanoemulsions can improve the encapsulation efficiency and stability of food flavors and oils into spray-dried powders. [Pg.670]

Sensing zone techniques have been applied to oil-in-water emulsions, although they cannot distinguish between dispersed droplets and solid particles [6]. Unless an emulsion sample contains no particles, or is very well characterized, the results can be difficult to interpret. For both suspensions and emulsions, conductometric size determination is limited to diameters above about 0.6 pm [6, 51]. [Pg.44]

The obvious application of the method is to determine emulsion droplet sizes. The NMR sizing method, which was apparently first suggested by Tanner in Ref. 24, has been applied to a number of different emulsions ranging from cheese to crude-oil emulsions (25-31). [Pg.101]

To illustrate the method and discuss its acciuacy we will use as an example some results for margarines (low-calorie spreads) (21). This system highlights some of the definite advantages of using the NMR method to determine emulsion droplet sizes, since other nonperturbing methods hardly exist for these systems. [Pg.284]

Emulsion droplet sizes in the range from 1 to 50 jim can be measured with rather modest gradient strengths of about 1 T/m. Note that the size determination rests on measuring the molecular motion of the dispersed phase, so the method cannot be applied to dispersed phases with low molecular mobility. In practice, oils with self-diffusion coefficients above 10 m s is required for sizing of OAV emulsions. Of course, W/0 emulsions with most conceivable continuous media can be sized. [Pg.285]

Higashi and coworkers [44-47] used SPG membrane emulsification to prepare W/O/W emulsions for arterial injection chemotherapy of liver cancer. By means of sonication, they produced a sub-micron W/O emulsion in which aqueous droplets containing epirubicin, a water-soluble anticancer drug, are dispersed in iodized poppy seed oil (IPSO), which selectively deposits itself on the cancerous tumor. They then used the SPG membrane to produce quasi-monodisperse IPSO droplets with diameters of 30.1 5.1 pm (CV aa 16.9%) or 70.0 6.7 pm (CV 9.6%) in order to encapsulate the aqueous phase containing the anticancer agent. Finally, they used the W/O/W emulsions for clinical apphcations and reported that the IPSO droplet size determines the anticancer effect... [Pg.855]

The formation of IL/O microemulsions in mixtures of [bmim][BFJ (IL) and cyclohexane, stabilized by the nonionic surfactant, TX-lOO has been proved [30]. Three-component mixtures could form IL/O microemulsions of well-defined droplet size determined by fixing the water content (mole ratio of IL to TX-lOO) [30,48,49]. An upper critical point (T) was observed in the mixture [([bmim][BFJ/ TX-lOO)-I-cyclohexane] with fixed water content (mole ratio of [bmim][BFJ to TX-lOO) [50]. The mixture separated into two microemulsion phases of different composition but with the same composition below as occurred in other systems [48]. The microemulsion system, [bmim][BF ]/TX-100 +cyclohexane, could be regarded as a pseudobinary mixture of [bmim][BF ]/TX-100 IL droplets dispersed in the cyclohexane continuous phase. Therefore, the phase behavior could be depicted in a two-dimensional diagram with concentration of droplets along the abscissa and temperature along the ordinate. A coexistence curve of temperature (T) against a concentration variable, such as volume fraction ( ), could then be drawn in the same way as it was done for pseudobinary mixtures in AOT/water/decane micro-emulsions [48]. [Pg.367]

Abstract In this contribution we suggest that nuclear magnetic resonance constitutes a promising technique for studying essential features of emulsions. The background of the method is discussed, and it is emphasized that the method determines the mean-squared displacements of molecules over distances of order 10 m. It is pointed out that such distances correspond to typical emulsion droplet sizes. As a consequence, the method, when applied to emulsions, yields information on droplet sizes and the presence of diffusional barriers. To exemplify this, two... [Pg.45]

We start by summarizing the pulsed field gradient method and then describe two relevant topics the first deals with droplet size determination of emulsions and the second deals with the characterization of concentrated emulsions. The former is a well-developed area, which has been used for a long time not only by the present author, while the latter constitutes a novel field for the application of the method. We present some (very) preliminary data from such a system. [Pg.46]

The electrical charge of emulsion droplets was determined via zeta-potential measurement by electrophoretic light scattering. The oil droplet size of the emulsions was analysed by static light scattering after dilution of the emulsion to the required optical density or, in the case of spray-dried particles, after dissolution of an aliquot of the microcapsules. Microencapsulation efficiency was calculated from total oil content in the formulation and the gravimetric determination of the oil extracted from the microcapsules with petrol ether [62]. [Pg.60]

McClements, D. J., Principles of Ultrasonic Droplet Size Determination in Emulsions, Langmuir, 19%, 12, 3454-3461. [Pg.54]


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