Effects of heat treatment on oil-binding ability of rice flour.
Heat-treated (120 °C for 120 min) rice flour showed high affinity to oil (oil-binding ability). This oil-binding ability could be observed by shaking the heat-treated rice flour (2.0 g), oil (4.0 mL), and water (20 mL) vigorously in a test tube, and the oil bound to the rice flour sank into the water. To examine the time-dependent levels of the oil-binding ability, rice flour was heat-treated at 120 °C for 10, 20, 40, 60, and 120 min, and the precipitated volume of oil/rice flour complex increased with an increase of the heating time. The oil-binding ability of the rice flour was not affected by the treatments with diethyl ether or boiled chloroform/methanol (2:1) solutions, which suggested no relationship to the oil in the rice flour, but was lost upon alkali (0.2% NaOH solution) or pepsin treatment, which suggested its relationship to the rice proteins.
a Faculty of Home Economics, Laboratory of Food Technology , Kobe Women's University , Kobe , Japan.
Aya
A
Tabara
Mariko
M
Nakagawa
Yuki
Y
Ushijima
Kotaro
K
Matsunaga
Masaharu
M
Seguchi
D001939:Bread / Q000032:analysis; D002725:Chloroform / Q000737:chemistry; D003296:Cooking; D004986:Ether / Q000737:chemistry; D005433:Flour / Q000032:analysis*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D000432:Methanol / Q000737:chemistry; D012275:Oryza / Q000737:chemistry*; D010434:Pepsin A / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry; D014867:Water / Q000737:chemistry*
D010938:Plant Oils; D014867:Water; D004986:Ether; D012972:Sodium Hydroxide; D002725:Chloroform; D010434:Pepsin A; D000432:Methanol
heat treatment; hydrophobicity; oil-binding ability; rice flour; rice flour proteins