Investigate rheological, textural properties of emulsions.Commercial hydrocolloids and their mixtures are used in frozen desserts to impart texture and palatability to the final product. They also protect the whipped product against excessive drainage during storage. We do not yet completely understand the mechanism of stabilization by hydrocolloids in foamed emulsions, and a clear understanding of their role is needed to improve product functionality and extend shelf life. With this in mind, Canadian researchers examined the impact of maltodextrin and arabic gum on flow and dynamic properties, glass transition, particle size Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. and distribution, water-holding capacity, and the texture of nondairy non·dair·y adj. Containing no milk or dairy products: nondairy coffee creamer. emulsions--both as a mix and frozen foam. The results of their research could help us to understand more about the functionality of hydrocolloids in frozen desserts. The scientists compared their results to the properties derived from a commercial ice cream mix in both the mix and frozen states. Foamed emulsions also were prepared, and all samples were stored for one week at -20 C before they were examined. The rheological and textural characteristics of mixed and frozen samples were determined using a commercial rheometer rhe·om·e·ter n. An instrument for measuring the flow of viscous liquids, such as blood. and texture analyzer. Glass transition temperatures The glass transition temperature is the temperature below which the physical properties of amorphous materials vary in a manner similar to those of a solid phase (glassy state), and above which amorphous materials behave like liquids (rubbery state). were also measured using commercial differential scanning colorimetry colorimetry Measurement of the intensity of electromagnetic radiation in the visible spectrum transmitted through a solution or transparent solid. It is used to identify and determine the concentrations of substances that absorb light of a specific wavelength or colour . An examination of the flow and dynamic properties of prepared mixes revealed a higher viscosity and flow behavior index for the mix prepared with maltodextrin. All mixes showed pseudoplastic behavior and elastic modulus elastic modulus or elastic constant In materials science and physical metallurgy, any of various numbers that quantify the response of a material to elastic or springy deflection. at a maximum frequency level of 50 rad s-. The apparent viscosity of the mixes was at a minimum shear rate Shear rate is a measure of the rate of shear deformation:  For the simple shear case, it is just a gradient of velocity in a flowing material. of 0.1 s-1, which related to the texture of the frozen foams. The glass transition temperatures of the mix containing matodextrin, arabic gum and commercial ice cream mix were -27.54 C, -30.94 C and -30.41 C, respectively. Further information. Andre Begin, Food Research and Development Centre, Agriculture and AgriFood Canada, Processed Plant Products, 3600 Casavant Blvd. W., Saint-Hyacinthe, QC J2S 8E3, Canada; phone: 450-778-3024; fax: 450-773-8461; email: begina@agr.gc.ca. |
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