Microstructural, cooking and textural characteristics of potato (Solanum tuberosum L) tubers in relation to physicochemical and functional properties of their flours

Potato tubers from six different cultivars were freeze-dried, ground into flour and analyzed for thermal, pasting and textural characteristics (using differential scanning calorimetry, Rapid Visco analyzer and Instron universal testing machine, respectively) to study the relationship between flour characteristics and cooked potato mealiness. The potatoes with higher sensory mealiness scores resulted in flours having lower transition and pasting temperatures, higher amylose content, setback, peak and final viscosity. The flour gels from the mealier potatoes also exhibited higher values of textural parameters such as hardness, cohesiveness, chewiness and springiness. The microstructure of the tuber parenchyma (studied using scanning electron microscopy), cooking and sensory characteristics of potatoes were found to be related to the pasting and textural characteristics of their flours. Potato cultivars with lower mealiness scores, loosely packed cell arrangement, with comparatively large-size cells and thinner cell walls showed lower values of textural parameters for both raw and cooked potatoes. This information may prove useful for the selection of potato cultivars with desirable textural and flour-making properties for specific end-uses. (c) 2005 Society of Chemical Industry.