Lubricated squeezing flow of semi-liquid foods

2004 2004

Other formats: Order a copy

Abstract (summary)

The rheological characterization of semi-liquid foods has encountered two major difficulties: (1) the separation of a layer of fluid of different viscosity at the wall of the rheometer (slippage) and (2) the disruption of the internal structure of the specimen when inserted into the equipment.

The increasing utilization of lubricated squeezing flow viscometry in food industry has not only been determined by its relative simplicity but mainly by its ability to overcome the above mentioned problems.

Although the mathematical models to describe the lubricated squeezing flow of fluids have been extensively considered, several aspects and possible applications of this methodology remain unstudied.

Therefore, this research was focused on evaluating the effect of test conditions, especially the displacement rate, on the measured rheological parameters of several semi-liquid food products. A considerable discrepancy was noted between the observed rate effects and those predicted using a pseudoplastic (power law) model. Consequently, a alternative model was proposed and the effect of the deformation rate was described using the following empirical relationship (Fv1− FR)/(Fv2 − FR) = (V1/V2)m.

Since lubricated squeezing flow viscometry barely produces a significant disruption of the sample, it was used to quantify the structural damage caused to a specimen subjected to several disruption mechanisms such as compression and stirring. As expected, compression of the specimen prior to its testing had very little effect on the specimen consistency which supports the view that there was little friction between the Teflon® coated plates and the samples. On the other hand, shearing caused a measurable loss of consistency.

In order to study the recovery of the sample consistency after disruption a rest period was introduced and the rheological parameters of the treated samples were determined. Different levels of recovery were observed for different specimens, however in none of the cases a full recovery of the original consistency was observed in the time span considered (1–3 hours).

Finally, a relation between the instrumental value of consistency obtained using lubricated squeezing flow and sensory perception was estimated. It was established that squeezing flow is more sensitive to textural changes sensory evaluation and that the methodology was appropriate to determine thresholds for sensory detection.

Indexing (details)

Food science
0359: Food science
Identifier / keyword
Biological sciences; Foods; Lubricated; Semiliquid foods; Squeezing flow
Lubricated squeezing flow of semi-liquid foods
Corradini, Maria Gisela
Number of pages
Publication year
Degree date
School code
DAI-B 65/06, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
Peleg, Micha
University of Massachusetts Amherst
University location
United States -- Massachusetts
Source type
Dissertations & Theses
Document type
Dissertation/thesis number
ProQuest document ID
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
Access the complete full text

You can get the full text of this document if it is part of your institution's ProQuest subscription.

Try one of the following:

  • Connect to ProQuest through your library network and search for the document from there.
  • Request the document from your library.
  • Go to the ProQuest login page and enter a ProQuest or My Research username / password.