We are investigating the factors that influence texture in cooked potatoes and potato products. Texture is a key component of the quality and palatability of potato products. There is a wide natural variation of textural quality within the potato germplasm collections at SCRI and considerable opportunity to breed new varieties with improved textural properties.

The study of texture is generally quantified by measuring the resistance of a product to an applied force, termed rheology. A number of different rheological parameters can provide an evaluation of a range of tuber characteristics such as firmness, hardness, softness, adhesiveness, fracturability etc. These measurements are determined using a QTS Texture Analyser.

Texture is determined by a complex interplay of the architecture of the cellular structure of the tissue (that is, the type and arrangement of different cells) and the ability of the component cells to maintain their shape or resist deformity. Given that the structure of tuber tissue is similar between potato varieties of different textural properties, it is the ability of the cells to resist deformation which is likely to hold the key to controlling texture. The physical strength of cells is largely determined by the structure and composition of the cell walls that surround and attach them to other cells in the tissue.

Therefore, we plan to compare the cell wall composition and structure of a range of varieties of Solanum tuberosum and Solanum phureja which have been found to have different textural properties. Differences in the polysaccharide composition noted will be used to identify candidate genes which may have particular roles in the control or maintenance of textural traits.