Rheological properties quality attribute

Texture has been recognized as one of the most important quality attributes in dried potatoes which contribute to the consumer acceptance. Texture of potatoes is affected by drying processes and it is strongly associated with composition and stmcture of cells walls (Ramos et al., 2003). As previously stated, water loss is accompanied by loss of internal pressure cellular tissue shrinks and becomes soft. This pressure is known as turgor pressure and plays an important role in the rheological and textural properties of the potato tissue. 

An in vitro release rate can reflect the combined effect of several physical and chemical parameters, including solubility and particle size of the active ingredient and rheological properties of the dosage form. In most cases, in vitro release rate is a useful test to assess product sameness between prechange and postchange products. However, there may be instances where it is not suitable for this purpose. In such cases, other physical and chemical tests to be used as measures of sameness should be proposed and discussed with the Agency. With any test, the metrics and statistical approaches to documentation of sameness in quality attributes should be considered. 

The use of low-calorie fat replacers in foods facilitates reductions in the energy density of the diet. However, since fat confers a number of important quality attributes, it is critical that such foods be highly palatable. When all or part of the fat is replaced, the foods must have comparable rheological and sensory-quality attributes to the original high-fat food. Textural properties are particularly important since fat has a pronounced impact on texture, mouthfeel, and hence eating quality. Therefore, in addition to lowering the calorie density, an acceptable fat substitute must have the appropriate functional properties, such as heat stability, emulsification, aeration, lubricity, spreadability, texture, and mouthfeel (Lukacova and Karovicova, 2003 Silva, 1996). 

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