Objective evaluation of whiteness of cooked rice and rice cakes using a portable spectrophotometer.
The whiteness of cooked rice and rice cakes was evaluated using a portable spectrophotometer with a whiteness index (WI). Also, by using boiled rice for measurement of Mido values by Mido Meter, it was possible to infer the whiteness of cooked rice without rice cooking. In the analysis of varietal differences of cooked rice, 'Tsuyahime', 'Koshihikari' and 'Koshinokaori' showed high whiteness, while 'Satonoyuki' had inferior whiteness. The whiteness of rice cakes made from 'Koyukimochi' and 'Dewanomochi' was higher than the whiteness of those made from 'Himenomochi' and 'Koganemochi'. While there was a significant correlation (r = 0.84) between WI values and whiteness scores of cooked rice by the sensory test, no correlation was detected between the whiteness scores and Mido values, indicating that the values obtained by a spectrophotometer differ from those obtained by a Mido Meter. Thus, a spectrophotometer may be a novel device for measurement of rice eating quality.
Rice Breeding and Crop Science Experiment Station, Yamagata Integrated Agricultural Research Center , 25 Yamanomae, Fujishima, Tsuruoka, Yamagata 999-7601 , Japan ; Graduate School of Agricultural Science, Tohoku University , 1-1 Tsutsumidori-Amamiya, Aoba, Sendai, Miyagi 981-8555 , Japan.
Hajime
H
Goto
Yamagata Integrated Agricultural Research Center , 6060-27 Minorigaoka, Yamagata, Yamagata 990-2372 , Japan.
Noriyuki
N
Asanome
National Institute of Crop Science , 2-1-18 Kannondai, Tsukuba, Ibaraki 305-8518 , Japan.
Keitaro
K
Suzuki
Shonai Area General Branch Administration, Yamagata Prefectural Government , 51 Yamanomae, Fujishima, Tsuruoka, Yamagata 999-7601 , Japan.
Tomoyoshi
T
Sano
Rice Breeding and Crop Science Experiment Station, Yamagata Integrated Agricultural Research Center , 25 Yamanomae, Fujishima, Tsuruoka, Yamagata 999-7601 , Japan.
Hiroshi
H
Saito
Rice Breeding and Crop Science Experiment Station, Yamagata Integrated Agricultural Research Center , 25 Yamanomae, Fujishima, Tsuruoka, Yamagata 999-7601 , Japan.
Yohei
Y
Abe
Rice Breeding and Crop Science Experiment Station, Yamagata Integrated Agricultural Research Center , 25 Yamanomae, Fujishima, Tsuruoka, Yamagata 999-7601 , Japan.
Masaru
M
Chuba
Graduate School of Agricultural Science, Tohoku University , 1-1 Tsutsumidori-Amamiya, Aoba, Sendai, Miyagi 981-8555 , Japan.
Takeshi
T
Nishio
Mido Meter; Oryza sativa L; WI value; color; eating quality; sensory test; whiteness score