Light food systems

The comparison of the light effect on carotenoids in foods is very difficult to carry out because different foods with different isomer compositions are employed at the beginnings of experiments. The presence of large molecules offers some photoprotection to carotenoids in food systems, either by complexation with proteins as found in carrots or acting as a filter to reduce the light incidence. Different storage conditions are often found because different light intensities are used or sometimes they are not even reported and experiments are carried out under air, N2, or in a vacuum. 

Protect the active ingredient from oxidation, light, evaporation, humidity and other substance in the food system. 

Small-angle neutron scattering (SANS) can be applied to food systems to obtain information on intra- and inter-particle structure, on a length scale of typically 10-1000 A. The systems studied are usually disordered, and so only a limited number of parameters can be determined. Some model systems (e.g., certain microemulsions) are characterized by only a limited number of parameters, and so SANS can describe them fully without complementary techniques. Food systems, however, are often disordered, polydisperse and complex. For these systems, SANS is rarely used alone. Instead, it is used to study systems that have already been well characterized by other methods, viz., light scattering, electron microscopy, NMR, fluorescence, etc. SANS data can then be used to test alternative models, or to derive quantitative parameters for an existing qualitative model. 

A major advantage of ciyo-SEM is its ability to accommodate the need to preserve lipid or fatty components within food systems when they are the main subject of study. Kawanari et al [74] used ciyo-SEM in combination with polarized light microscopy to characterize structural differences in butter due to manufacturing differences and their impact on volumetric changes in pastry applications. Such a study would have been very difficult to accomplish via conventional SEM techniques. 

Unlike light-scattering studies, for which dilution is often a prerequisite, ultrasound can measure food properties at concentrations that are technologically relevant. This aspect has obvious benefits for the analysis of inhomogeneous foods such as solidifying fats, dynamically changing dairy food systems, dough, and emulsions. 

Dalgleish D.G., Hallett F.R. 1995. Dynamic light scattering applications to food systems. Food Res. Int. 28, 181-193. 

A third approach, very commonly practiced, has been the study of specific properties in model systems of protein-nonprotein components of different but similar known proteins. The statistical correlation of the results to the behavior of the proteins in food systems throws some light on the effect of particular structural features on this behavior. 

Many benefits are associated with the use of an organic-based stabilizer. They include an environmental friendly nature (no heavy metals, approved for direct contact with food, suitable for drinking water application), outstanding performance (process stability, suppressed crosslinking, wide processing window, no problems with light colored systems), and odor-free. 

Food Systems and Processing 23 Light Polarization Microscopy... 

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