Potato Cultivar Differences Associated with Mealiness

Abstract

Russet Burbank, Norchip, Pontiac, and LaSoda potato cultivars were examined for the parameters mealy and waxy. Russet Burbank was judged dry, hard and particulate, typifying mealiness. Using phase contrast microscopy and scanning electron microscopy, raw mealy cells were determined to be larger and more irregularly shaped than cells from waxy cultivars. Mealy cooked cells were engorged with gelatinized starch, cell walls were more polarized, and cell shapes were better retained after mashing, when compared to waxy cells. NMR-T2 bound water readings from Russet Burbank and Pontiac samples did not differ from each other. Starch granule sizes and shapes varied by cultivar. KeywordsPotato cultivar, texture, starch, microscopy Russet Burbank, Norchip, Pontiac, and LaSoda potato cultivars were examined for the parameters mealy and waxy. Russet Burbank was judged dry, hard and particulate, typifying mealiness. Using phase contrast microscopy and scanning electron microscopy, raw mealy cells were determined to be larger and more irregularly shaped than cells from waxy cultivars. Mealy cooked cells were engorged with gelatinized starch, cell walls were more polarized, and cell shapes were better retained after mashing, when compared to waxy cells. NMR-T2 bound water readings from Russet Burbank and Pontiac samples did not differ from each other. Starch granule sizes and shapes varied by cultivar.

Effect of different organic growing conditions on quality of cooked potatoes

“…The effect of starch content on mealiness and graininess in potatoes is well documented. 12,13,15 CONCLUSION Among the six organic treatments, cattle slurry versus cattle deep litter was found to signi®cantly affect the chemical composition and rheological properties. Compared with deep litter manuring, manuring with slurry decreased dry matter, starch and phytic acid and increased N and rheological properties.…”

Potato Flavor

“…The mealy cultivar Irene was found to have more cell wall material per unit cell surface area than the nonmealy cultivar Nicola. The cell wall and middle lamella were also found to be thicker in the mealy cultivar Russet Burbank than in the waxy cultivar Red Pontiac (McComber et al 1994). The thicker cell walls and middle lamellae, and stronger pectic substances may be more resistant to shearing, resulting in a hard, particulate mouthfeel.…”

“…The proportion of each tuber cell occupied by gelatinized starch influences tuber moistness (Martens and Thybo 2000). Cells that are filled with gelatinized starch are associated with a mealy texture, while those with less starch and more loosely-held water produce a waxy texture (Martens and Thybo 2000;McComber et al 1994). The loosely held water in the latter cell type is released upon chewing, producing a moist mouthfeel.…”

“…Cell wall characteristics can also affect texture Martens and Thybo 2000;McComber et al 1994; van Marle et al 1997b). Pectin methyl esterase activity is important for creating firm tissue during cooking by cross-linking pectin in the middle lamella (Faulks and Griffiths 1983;Thybo and Martens 1999).…”

Exploratory Study of Potato Cultivar Differences in Sensory and Hedonistic Applicability Tests

“…Textural changes are mainly associated with the gelatinization and retrogradation behaviour of starch (Kaur et al 2002) and with enzymatic and non-enzymatic changes in pectin (van Dijk et al 2002). This means that factors, which affect the final texture of tubers significantly, are starch composition and cell wall structures, but also dry matter concentration plays a key role in cooking quality (Freeman et al 1992;McComber et al 1994;van Marle et al 1997;Thybo et al 2000;Thygesen et al 2001). Since dry matter concentration varies significantly as a function of harvest time and between tubers and tuber lots, it will in turn influence the cooking quality (Ochsenbein et al 2008).…”