Investigate rheological, textural properties of emulsions.
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 and distribution, water-holding capacity, and the texture of nondairy 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 and texture analyzer. Glass transition temperatures were also measured using commercial differential scanning colorimetry.
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 at a maximum frequency level of 50 rad s-. The apparent viscosity of the mixes was at a minimum shear rate 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: email@example.com.
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|Publication:||Emerging Food R&D Report|
|Date:||Feb 1, 2006|
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