No abstract

No abstract

No abstract

No abstract

We report the preparation and characterization of multilayer coated droplets in an emulsion. Stability and control of mass transport across the interface are the key issues for such coated microdroplets. Shelf life of cosmetic, pharmaceutical, and food formulations can be improved by increasing stability. Moreover, such emulsions have potential applications in drug delivery and storage. A primary oil-in-water emulsion with caseinate as an emulsifier was prepared. On the basis of attractive electrostatic interactions, polyelectrolytes with opposite charges were added layer by layer. The oil droplets (particle size around 10 microm) were successively coated with casein, pectin, whey proteins, pectin, whey proteins, and pectin. Laser diffraction spectroscopy, particle charge measurements, and confocal laser scanning microscopy were applied to characterize the multilayer droplets. The complementary results indicate that the inner layers merge and the packing density of the interface increases. AFM-induced mechanical compression of single oil droplets coated with casein and pectin is monitored by an inverted optical microscope, and simultaneously AFM force curves are recorded. Thus, the deformation of the droplet is reflected by its lateral expansion and the force curve. Force volume imaging is applied to probe the lateral distribution of mechanical properties of the droplet.

No abstract

A diet with a high glycemic index (GI) is associated with an elevated risk for obesity or type 2 diabetes. We investigated the GI of a newly-developed fiber enriched cookie and characterized the microstructure of ingredients used. In a study with 26 non-diabetic healthy volunteers it was shown that the fiber enriched cookie has a GI of 58.9 in relation to white bread as reference. Using a conversion factor of 1.4, the GI of the fiber enriched cookie in relation to a glucose-solution is 42.0 and can be classified as a low-GI food. Postprandial insulin concentration was significantly lower after consumption of fiber enriched cookies compared to white bread. Glucose release after in vitro digestion was significantly lower from fiber enriched cookies compared to other cookies tested. In addition to its high percentage of fiber, the cookies' low GI can be attributed to the limited gelatinization potential of the starch granules found in the ingredients used. Using confocal laser scanning microscopy it is shown that starch granule surface area of whole grain barley flour, spelt flour and oat flakes bears cluster-shaped protein-NSPS complexes that preferentially absorb water in conditions of water shortage and thereby prevent starch gelatinization.

No abstract