Abstract
Properties of mashed potatoes prepared from potatoes with high and low specific gravity were investigated. The numbers of bound cells and broken cells were greater in the low specific gravity samples than in the high specific gravity samples during a cooling off process in post-steaming. As the temperature falls in post-steaming soluble starch increased and pectin decreased, and this tendency was more remarkable for the low specific gravity samples. When the potato cells were separated with a hydrochloric acid solution (pH 1.3) and sodium hydroxide solution (pH 12.0) treatment, the cells in the high specific gravity potatoes were separated completely, but the separating ratio in the low specific gravity potatoes was about 70%. Pectin solubility by this treatment was greater in the low specific gravity potatoes than in the high specific gravity ones. The swelling temperature of the separated cells measured with photopastegraphy was 61°C for the high specific gravity potato and 66°C for the low specific gravity one.
