The Phase Transition Analyzer™ and its Applications to the Extrusion Processing of Pet Foods

To read the full-text of this research, you can request a copy directly from the authors.


Thermal processing techniques such as extrusion generate complex chemical and physical changes in ingredients to produce final products with desired characteristics. There are many technical tools that an extrusion technologist can use to enhance his understanding of these changes. The concept of polymer science as it applies to the pet food extrusion process is one such tool that can provide valuable insight. However, measuring the glass and melt transitions of the complex recipes used in pet food production have proven difficult, if not impossible. The Phase Transition Analyzer, a closed-chamber capillary rheometer, may be one useful tool for measuring the "controlling" glass and melt transitions of complex recipes. Information gained from the Phase Transition Analyzer contains the basis for enhancing our understanding of the extrusion process as well as the potential for predictive control of the extrusion system based on raw material properties.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... PTA is a novel technique which was developed by Wenger Manufacturing Inc. (Kansas, USA) in order to assess phase transitions which may occur during extrusion cooking of starch based food materials [13][14][15]. However, this technique can also be used to measure the thermodynamic transitions within a wider range of polymeric powders. ...
... The volume change is measured as an increase in the chamber displacement. Therefore, PTA is a strong complementary technique to the more established methods of DSC and DMTA [13,14]. ...
In this work, the sorption isotherms of xanthan powder obtained under static and dynamic conditions and their fitting with mathematical models were discussed. The transitions within xanthan–water systems have been investigated using a standard material characterization technique – Differential Scanning Calorimetry (DSC) – and two novel techniques – Dynamic Mechanical Thermal Analysis (DMTA) material pocket and Phase Transition Analysis (PTA). It was found that within water–xanthan systems, the onset temperature for the melting of freezable water obtained from DSC method was in agreement with freezable water melting peaks obtained via DMTA material pocket at levels of hydration when the freezable water was present. Also, low-temperature transitions, related to polysaccharide–water interactions, were observed by both techniques within xanthan systems which contained no freezable water. However, the use of the PTA technique was limited to xanthan systems with low water content.
ResearchGate has not been able to resolve any references for this publication.