Effect of Cultivars and Thermal Processing with Salt Solutions on the Textural Attributes (Hardness, Chewiness and Rate of Softening) of Potatoes (Solanum Tuberosum L.)

Abstract

The change in textural attributes (hardness, chewiness and rate of softening) of three potato cultivars (Russet Burbank, Desiree and Sebago) was investigated. Uniform cylindrical samples (35-mm diameter and 3-mm thick) were prepared and exposed to different thermal processing regimes including; heating at 85°C, 95°C in water and steaming (100.2°C). The effect of salt on these textural attributes was also investigated using different salt concentrations (1.5%, 3% and 6% (w/w) NaCl). After thermal treatments the samples were subjected to texture profile analysis. The instrumental textural attributes were greatly affected by the cultivars and the thermal processing regimes. The change in textural attributes upon steaming was only marginally different compared to that at 95°C in water. Low concentrations of salt (1–3%) were found to accelerate the softening of the texture in these cultivars especially at lower temperatures. The textural attributes were modelled using a two-parameter reaction kinetics model. There was reasonable agreement by the model findings on the textural attributes prepared from all the thermal processing regimes and in presence and absence of (within average absolute error of 1.9–7%). Further, the model indicated that the order of reaction varied from 1.15–2.18 indicating that the changes in textural attributes in these thermal processing regimes followed higher reaction orders.

Keywords:

• Potato cultivars
• Texture
• Hardness
• Chewiness
• Rate of softening
• Thermal processing
• Salt
• Order of reaction