Cooked potato

Thybo AK, Molgaard JP and Kidmose U (2002) Effect of different organic growing conditions on quality of cooked potatoes . Journal of the Science of Food and Agriculture, 82, 12-18. 

Ancient chuno production produced the first dehydrated potatoes, but for a modem context we need to move forward to the end of the 18th century. The first European reference (Burton, 1989) to dried potato was by Parmentier in France in 1781 in the form of biscuits made from boiled potatoes for use by sailors. He also discussed methods of drying cooked potatoes in forms to be reconstituted by the addition of boiling water. Although the first US patent for dehydrating mashed potatoes was granted to Edwards in 1845 (Eskew, 1959), it was in wartime in industrialized countries in the 20th century that dehydration was widely practiced. Dehydrated potatoes provided combatant troops with a food that was less bulky than fresh potatoes and easier... 

The bulk of potato tubers is made up of parenchyma cells that have thin, non-lignified, primary cell walls (Reeve et al., 1971 Bush et al, 1999, 2001 Parker et al., 2001). Unless stated to the contrary, potato cell walls refers to parenchyma cell walls. These walls and their component polysaccharides are important for a number of reasons they form part of the total intake of dietary fiber, influence the texture of cooked potato tubers and form much of the waste pulp that is produced in large amounts by the potato starch industry when starch is isolated. The pulp is usually used as cattle feed, but potentially could be processed in a variety of ways to increase its value (Mayer, 1998). For example, the whole cell-wall residues could be used as afood ingredient to alter food texture and to increase its dietary-fiber content, or cell-wall polysaccharides could be extracted and used in a similar way or for various industrial applications (Turquois et al., 1999 Dufresne et al, 2000 Harris and Smith, 2006 Kaack et al., 2006). 

Jarvis, M. C., Duncan, H. J. (1992). The textural analysis of cooked potato. 1. Physical principles of the separate measurement of softness and dryness. Potato Research, 35, 83-91. 

De Swert, L. F. A., Cadot, R, Ceuppens, J. L. (2007). Diagnosis and natural course of allergy to cooked potatoes in children. Allergy, 62,750-757. 

Figure 7.3a-c Effect of LTB on the engineering stress in potato samples, (a) Engineering stress in blanched potato samples, (b) Engineering stress in blanched-and-cooked potato samples, (c) Engineering stress in blanched-frozen-and-cooked potato samples. 

Stationary point for PME activity was not calculated because of the low percentage of explained variability of the model. However, from the shape of the plots it seems reasonable to assume the existence of a relationship between the increase in PME activity and firmer texture (Figure 7.15), suggesting that the changes in the composition of the cell wall caused by the PME activity contribute to the firmness of frozen cooked potatoes (cv. Kennebec). 

Alvarez, M. D., Canet, W. (1998h). Rheological characterization of fresh and cooked potato tissues (cv. Monalisa). Z. Lebensm. Unters. Forsch. A., 207, 55-65. 

Downey, G. (2003). Effects of cryoprotectant mixtures on physical properties of frozen and thawed pureed cooked potatoes some introductory studies. Int. J. Food Sci. TechnoL, 38, 857-868. 

Van Dijk, C., Fisher, M., Beekhuizen, J. G., Boeriu, C., Stolle-Smiths, T. (2002). Texture of cooked potatoes (Solanum tuberosum). 3. Preheating and the consequences for the texture and cell wall chemistry. J. Agric. Food Chem., 50, 5098-5106. 

Texture has a number of component attributes, and some of them can be assessed by mechanical means. The texture or firmness of cooked potatoes is evaluated by subjecting each sample to a compression test using a universal testing machine equipped with a load cell. Cooked potato cylinders are compressed in a single-cycle compression-decompression test. Uniaxial compression is measured with an Instron machine with a lOON load cell. Measurements are performed on hot potato cylinders (depth 12 mm, height 10 mm) from 15 potatoes immediately after cooking, at a deformation rate of 20 mm/min. Stress and strain at fracture are calculated by the Instron series IX version 7.40 software and means of 15 repetitions are calculated. 

Sloughing or disintegration of potatoes during cooking is a major attribute of texture that can be measured directly. In these tests the potato sample is cooked and sieved, and the mass of the remaining cooked potato tissue on the sieve is recorded (see for example Hejlova et al., 2006). 

A good (70%) prediction of sensory texture attributes of cooked potatoes has been obtained with nuclear magnetic resonance imaging, however, not all sensory attributes of texture are... 

Sensory evaluation of cooked potato quality is based on appearance and mouthfeel scored by trained or untrained evaluators using some form of hedonic scale on which the assessor records the perceived value of the attribute, typically on a nine-point scale, from extreme like to extreme dislike. 

Thybo, A. K., Bechmann, I. E., Martens, M., Engelsen, S. B. (2000). Prediction of sensory texture of cooked potatoes using uniaxial compression, near infrared spectroscopy and low field H NMR spectroscopy. Lebensmittel-Wissenschaft und-Technologie, 33, 103-111. 

Thybo, A. K., Szczypihski, P. M., Karlsson, A. H., Donstrup, A., Stodkilde-Jorgensen, H. S., Andersen, H. J. (2004). Prediction of sensory texture quality attributes of cooked potatoes by NMR-imaging (MRI) of raw potatoes in combination with different image analysis methods. Journal of Eood Engineering, 61, 91-100. 

Figure 9.1 The effect of cooking time on compressive force of cooked potatoes.

A detailed method to perform texture profile analysis (TPA) on raw and cooked potatoes has been described by Kaur et al. (2007). The raw or cooked cylindrical pieces are prepared as described... 

Figure 9.4 A typical texture profile analysis force-time curve for cooked potato. (Source Singh et al., 2008).

Table 9.3 Texture profile analysis parameters of cooked potatoes from different cultivars... 

Textural and Rheological Characteristics of Raw and Cooked Potatoes 257 Table 9.4 Pearson correlation coefficients for rheological and selected textural properties... 

Figure 9.5 A typical stress relaxation curve of cooked potatoes. (Source Kauretal., 2002).

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