Determination of droplet size distributions in emulsions by pulsed field gradient NMR

Mooren, M.M.W.; Gribnau, M. C. M.; Voorbach, M.A.

doi:10.1016/b978-044481499-9/50007-x

Cited by 5 publications

(4 citation statements)

References 15 publications

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“…This method was released at the beginning of this year. Typical samples of interest are mayonnaise and dressings as well as other oil-in-water emulsions [19][20].…”

Section: The Oil Droplet Size Distribution Applicationmentioning

confidence: 99%

Quality control with time-domain NMR

Todt

Burk

Guthausen

et al. 2001

Eur. J. Lipid Sci. Technol.

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“…This method was released at the beginning of this year. Typical samples of interest are mayonnaise and dressings as well as other oil-in-water emulsions [19][20].…”

Section: The Oil Droplet Size Distribution Applicationmentioning

confidence: 99%

Quality control with time-domain NMR

Todt

Burk

Guthausen

et al. 2001

Eur. J. Lipid Sci. Technol.

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“…2 However, NMR is still considered an expert technique, whereas the rapid pace of product development requires understanding and/or control of food structures at the laboratory bench/kitchen table or manufacturing plant. In recent decades, low-cost and easy-to-handle benchtop NMR systems 3 have been developed which can determine phase-compositional 4 and microstructural 5 parameters of food materials. These systems operate at low field, typically 0.47 T (20 MHz for 1 H), and this poses intrinsic limitations on sensitivity and resolution.…”

Section: Introductionmentioning

confidence: 99%

Scope of droplet size measurements in food emulsions by pulsed field gradient NMR at low field

Duynhoven

Goudappel

Dalen

et al. 2002

Magnetic Reson in Chemistry

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Low-field NMR instrumentation offers a user-friendly and cost-effective means for assessment of water and oil droplet size measurements in food emulsions. Examples are given of major food application areas, and these are supported with validation data in terms of precision and equivalence to other methods. The NMR method gives the same results as other techniques, such as microscopy, laser diffraction and electric sensing, but with similar or better precision. NMR distinguishes itself by a simple and non-perturbing sample preparation procedure (in addition to the aforementioned advantages). For reliable results, the NMR parameters should be properly chosen and adjusted. A survey is given of experimental NMR parameters than can have an impact on the performance of water and oil droplet size determination. Copyright  2002 John Wiley & Sons, Ltd. KEYWORDS: NMR;1 H NMR; droplets; emulsion; foods; laser diffraction; microscopy INTRODUCTIONIn food research, the pressure to bring products faster to the market has become stronger, and the systems under investigation are becoming ever more complex both in structure and in chemical composition. 1 NMR spectroscopy has become an indispensable technique that can relate meso-and microstructural parameters to consumer-related features, such as shelf-life and mouthfeel.2 However, NMR is still considered an expert technique, whereas the rapid pace of product development requires understanding and/or control of food structures at the laboratory bench/kitchen table or manufacturing plant. In recent decades, low-cost and easy-to-handle benchtop NMR systems 3 have been developed which can determine phase-compositional 4 and microstructural 5 parameters of food materials. These systems operate at low field, typically 0.47 T (20 MHz for 1 H), and this poses intrinsic limitations on sensitivity and resolution. Nevertheless, these systems have gained a considerable position in food industry laboratories, with applications ranging from research and development to process and product control.The classical NMR application in the microstructural domain is the assessment of water droplet size distributions in food emulsions.6 -8 These methods are being used to explain and predict physical and microbiological stability of water-in-oil food emulsions, 9 such as margarines and low-calorie spreads. A more recent development is the assessment of oil droplet size distributions in oil-in-water systems.10 These systems also are fairly abundant as Ł Correspondence to: J. P. M. van Duynhoven, Unilever R&D Vlaardingen, Olivier van Noortlaan 120, 3133 AT Vlaardingen, The Netherlands. E-mail: john-van.duynhoven@unilever.com mayonnaises, cheese, dressings, spreads, etc. 11 Both the water and oil droplet size distribution measurements are based on the restricted diffusion of the liquid inside a droplet, a phenomenon that can be described analytically. The droplet size determination by low-field NMR has several significant advantages over other, and perhaps more obvious, methods. A summary of the typical ch...

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“…The commonly used methods for the determination of the water droplet size distribution in fat spreads are microscopy, nuclear magnetic resonance spectroscopy, NMR (van den Enden et al , 1990; Balinov et al , 1994; Mooren et al , 1995), laser diffraction, e.g. Helos & Malvern (Barth, 1984), and electric sensing, e.g.…”

Section: Introductionmentioning

confidence: 99%

Determination of the water droplet size distribution of fat spreads using confocal scanning laser microscopy

Dalen

2002

Journal of Microscopy

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SummaryKnowledge of the water droplet size distribution of fat spreads is necessary for the development and production of high quality microbiological safe products. Fat spreads are water-inoil emulsions. The water droplet size distribution can be determined by confocal scanning laser microscopy (CSLM) after staining the fat with Nile Red. The profiles of the nonfluorescent water droplets in the 2D images are identified and measured using image analysis. The 'true' water droplet size distribution is calculated from the distribution of the measured profile diameters using a Wicksell transformation of lognormal distributions. The influence of the fluorescent staining and CSLM parameters on the information were studied. The CSLM method was tested on fat spreads with a fat content ranging from 40% to 80%. The results were compared with those obtained by nuclear magnetic resonance spectroscopy (NMR). The distribution parameters [volume weighed geometric mean diameter ( D 3,3 ) and the standard deviation ( σ ) of the logarithm of the droplet diameter] calculated for 80% fat spreads are in good agreement with those obtained by NMR (within ± 7% relative). Small differences were found for 65% fat spreads and large differences were identified for 40% fat spreads. The precision for the determination of the D 3,3 value by CSLM is worse than that of NMR, even when three images were used to calculate this parameter [3-11% and 1-6% relative standard deviation (RSD), respectively]. The precision for the determination of exp( σ ) by CSLM is comparable or better than that of NMR (1-5% and 3-6% RSD, respectively). CSLM proved to be a reliable method for the determination of the water droplet size distribution of margarines (80% fat). The advantage of CSLM compared to NMR is that visual information is given about the water droplet size distribution in the sample.

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Determination of droplet size distributions in emulsions by pulsed field gradient NMR

Cited by 5 publications

References 15 publications

Quality control with time-domain NMR

Quality control with time-domain NMR

Scope of droplet size measurements in food emulsions by pulsed field gradient NMR at low field

Determination of the water droplet size distribution of fat spreads using confocal scanning laser microscopy

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