Rheological properties of ice cream emulsion prepared from lipase-catalyzed transesterified palm kernel olein:anhydrous milk fat mixture
The effect of different fat sources used in the preparation of ice cream emulsions was investigated. Anhydrous milk fat (AMF), a mixture of unmodified palm kernel olein (PKO) and AMF (70:30, w/w) and enzyme-transesterified PKO:AMF (70:30, w/w) mixture were used in the preparation of the emulsions. T...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2001
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| Online Access: | http://psasir.upm.edu.my/id/eprint/115552/ http://psasir.upm.edu.my/id/eprint/115552/1/115552.pdf |
| Summary: | The effect of different fat sources used in the preparation of ice cream emulsions was investigated. Anhydrous milk fat (AMF), a mixture of unmodified palm kernel olein (PKO) and AMF (70:30, w/w) and enzyme-transesterified PKO:AMF (70:30, w/w) mixture were used in the preparation of the emulsions. Transesterification was catalyzed by mycelium-bound lipase from Rhizomucor miehei. Rheological and viscoelastic properties measured were the creep compliance, controlled-stress steady state flow and frequency sweep profiles. Results indicate that emulsion prepared using transesterified PKO:AMF (TE-PKO:AMF) exhibited a different rheological behavior from that of AMF alone, and the unmodified PKO:AMF (70:30) blend. Frequency sweep profiles showed that the G = values of both AMF and TE-PKO:AMF emulsions were higher than their G at values, indicating that these emulsions were dominated by the elastic component over all frequencies measured. On the other hand, the PKO:AMF emulsion was dominated by viscous components at low frequency. A plot of viscosity versus log shear rate illustrated that the ice cream emulsion made from TE-PKO:AMF was more viscous than those of unmodified PKO:AMF and AMF. The lower creep compliance showed a stronger emulsion in the TE-PKO:AMF than that of the unmodified PKO:AMF. Since high viscosity and greater strength are some of the desired properties in ice cream emulsion, this suggests that transesterification of PKO:AMF (70:30, w/w) can be used to produce a fat that is suitable for use in the preparation of ice cream emulsions. |
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