Creaming measurement

R. Chanamai, N. Herrmann, D. J. McClements 2000, (Probing floe structure by ultrasonic spectroscopy, viscom-etry, and creaming measurements), Langmuir 16, 5884. 

The meltdown test (or melt resistance) of ice cream measures its ability to resist melting when exposed to warm temperatures for a... 

Microcapsules are used in several film coatings other than carbonless paper. Encapsulated Hquid crystal formulations coated on polyester film are used to produce a variety of display products including thermometers. Polyester film coated with capsules loaded with leuco dyes analogous to those used in carbonless copy paper is used as a means of measuring line and force pressures (79). Encapsulated deodorants that release their core contents as a function of moisture developed because of sweating represent another commercial appHcation. Microcapsules are incorporated in several cosmetic creams, powders, and cleansing products (80). 

The methylene blue and resazurin reduction methods indirectly measure bacterial densities in milk and cream in terms of the time interval required, after starting incubation, for a dye—milk mixture to change color (methylene blue, from blue to white resazurin, from blue through purple and mauve to... 

Here the TEWL-value measurements showed that Kujalnik peloids and magnesium pelobischofite complex salutary potentize each other in their mixtures and provide the effective preservation of acidic mantle of the skin. Besides, the pelobischofite addition to the cosmetic cream compositions results in the effective coverlet moistening. Also, the pelobischofite addition provides the decrease of the negative surfactants effect on the skin health. The TWL parameter value is less by half, the water balance of the skin is normalized and the wrinkled skin becomes smoothed out and velvety. 

Fig. 4.1.11 Calculated and measured pressure-drop data in a multi-rate primary drainage experiment on the Texas Cream limestone sample (Reprinted with permission for [34]).

In terms of measuring emulsion microstructure, ultrasonics is complementary to NMRI in that it is sensitive to droplet flocculation [54], which is the aggregation of droplets into clusters, or floes, without the occurrence of droplet fusion, or coalescence, as described earlier. Flocculation is an emulsion destabilization mechanism because it disrupts the uniform dispersion of discrete droplets. Furthermore, flocculation promotes creaming in the emulsion, as large clusters of droplets separate rapidly from the continuous phase, and also promotes coalescence, because droplets inside the clusters are in close contact for long periods of time. Ideally, a full characterization of an emulsion would include NMRI measurements of droplet size distributions, which only depend on the interior dimensions of the droplets and therefore are independent of flocculation, and also ultrasonic spectroscopy, which can characterize flocculation properties. 

Studies of flow-induced coalescence are possible with the methods described here. Effects of flow conditions and emulsion properties, such as shear rate, initial droplet size, viscosity and type of surfactant can be investigated in detail. Recently developed, fast (3-10 s) [82, 83] PFG NMR methods of measuring droplet size distributions have provided nearly real-time droplet distribution curves during evolving flows such as emulsification [83], Studies of other destabilization mechanisms in emulsions such as creaming and flocculation can also be performed. 

Intranasal S. aureus increases the risk of S. aureus exit-site infections, tunnel infections, peritonitis, and subsequent catheter loss.49 Several measures have been used to decrease the risk of peritonitis caused by S. aureus, including mupirocin cream applied daily around the exit site, intranasal mupirocin cream twice daily for 5 days each month, or rifampin 300 mg orally twice daily for 5 days, repeated every 3 months.49 Mupirocin use is preferred over rifampin to prevent the development of resistance to rifampin, although mupirocin resistance has also been reported.49 Other measures that have been used to decrease both S. aureus and P. aeruginosa infections include gentamicin cream applied twice daily and ciprofloxacin otic solution applied daily to the exit site.49... 

M Bury, J Gerhards, W Erni, A Stamm. Application of a new method based on conductivity measurements to determine the creaming stability of O/W emulsions. Int Pharm 124(2) 183 194, 1995. 

Procedure Separately inject equal volumes (about 1 pL) of the Assay preparation and the Standard preparation into the chromatograph, record the chromatograms, and measure the peak responses. Calculate the quantity, in mg, of miconazole nitrate (C18H14CI4N2O HNO3) in the portion of cream given by the formula ... 

Wrobel et al. [29] described a simple method for the determination miconazole in pharmaceutical creams, based on extraction and second-derivative spectrophotometry. In the presence of sodium lauryl sulfate (0.5%) and sulfuric acid (0.4 mol/L), the miconazole and internal standard (methylene blue) were extracted to 100 pL of methylene chloride. The organic phase was evaporated in the nitrogen stream and the dry residue was dissolved in methanol (1.5 mL). The analytical signal was obtained as the ratio between second-derivative absorbances measured at 236.9 nm... 

Thomas et al. [31] used a colorimetric method for the estimation of miconazole nitrate in creams. The method is based on the ion-pair extraction with bromocresol purple solution and measurement of the solution at 410 nm. 

As we proceed with discussing the various system properties and measurement methods that can be used to investigate water and solids mobility, it is important to keep in mind the influence the complexity of food systems, such as in the ice cream example just discussed, can have on our ability to measure, interpret, understand, and predict food quality, stability, and safety. 

Interpretation/results A GC-isotope ratio MS technique is used on known animal fats and the ancient samples. (In this technique, each peak eluting from the GC is combusted to C02 and its 12C-13C ratio is measured by a mass spectrometer [7].) The 13C ratio of the C-16 0 and C-18 0 fatty acids are plotted. The knowns are concentrated in specific areas on the plot, shown as ellipses in Fig. 21.16. The position of the cream sample points on this pattern recognition plot indicates that the fatty portion of the cream is from ruminant adipose tissue. 

Determination of C02.—Dilute 10 c.c. of the mash to 25 c.c. in a measuring flask and transfer 10 c.c. of the diluted liquid by means of a pipette to a small distilling flask which is directly connected to a nitrometer. To the solution add about 0-2 g. of yeast made into a cream with a little water and then at once displace the air by passing in carbon dioxide from above through a tube which does not dip into the liquid. Close the delivery tube by means of stop-cock or spring clip, fill the nitrometer with water saturated with carbon dioxide, and allow... 

Another experiment was carried out by adjusting the pH of the water and then they were employed for the preparation of the tea infusion. HPLC resulted in the separation of more than 50 components in the broken black tea infusion as demonstrated in Fig. 2.69. Unfortunately, the majority of peaks have not been identified and the chromatographic profiles only indicate the presence of many compounds in the infusions. Some results are presented in Table 2.66. The measurement indicated that theaflavins and tea catechins play a decisive role in the formation of cream particles and tea colour [184],... 

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