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vol. 13, nr. 1 (2009)
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Rheological properties of foams prepared for drying
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Agata Marzec, Ewa Jakubczyk
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Department of Food Engineering and Process Management, Faculty of Food Sciences, SGGW, ul. Nowoursynowska 159C, 02-776 Warszawa |
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vol. 13 (2009), nr. 1,
pp. 185-194
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abstract:
The objectives of this work were to assess the effect of concentration of foaming agents and whipping time of apple pulp foam on their rheological properties. Foams were prepared by adding albumin and/or methylcellulose and whipping at different times (1-18 min). The rheological properties were investigated by squeezing flow test based on compression of a specimen between two parallel Teflon plates. It was found that the concentration of albumin from 0.5 to 7% resulted in moderate decrease of flow index. The albumin foam (2% w/w) was the most stable from among all investigated materials. An effect of whipping time on flow index was observed; the material after 1 minute of whipping showed the highest resistance to flow. The apparent stress obtained after 60 and 100 s of relaxation decreased with increased whipping times. The investigated foams demonstrated pseudoplastic flow during compression.
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keywords:
foams, albumin, rheological properties, density
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original in:
Polish
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