In order to fractionate the rice protein employing paper electrophoresis, 9 subjects of Korean rice and one Indica type, Pin Galw 50 were examine, the results were as follows.
1. Polished rice protein was separated into albumin, globulin, prolamine, and oryzenin. The amount of these fractions was determined by Kjeldahl method showing respectively 0.26%, 0.65%, 0.41%, and 5.01% in average. Albumin was extracted with deionized water, globulin with 10% NaCl, prolamine with 70% ethanol, and oryzenin with 0.05N-NaOH.
2. Albumin was extracted with deionized water and dialyzed by a cellophan tube. The supernatant was submitted to paper electrophoresis using phosphate buffer (pH 7.6, μ 0.18). Albumin was identified as monocomponent in all of 10 varieties under study.
Globulin was extracted and dialyzed to remove the albumin. The precipitates were resolved in 10% saline solution and examined by paper electrophoresis. The globulin consists of two components in phosphate buffer(pH 7.6, μ 0.18) Any subject, regardless the origin, appears to contain globulin Ⅰ and globulin Ⅱ.
Prolamine was extracted with 70% ethanol, dialayzed against deionized water, resolved with ethanol, and analyzed by Paper electrophoresis. It was proved as one component in the 70% alcoholic buffer(pH 9.0, μ=0.0095).
On the contrary, paper electrophoresis with oryzenin demonstrated two or three components in Sorensen´s buffer(pH 13.0, μ 0.11). Yookoo 132, Dungpan 5, Kwansan, and Jaekun contain oryzenin Ⅰ, oryzenin Ⅱ, and oryzenin Ⅲ. On the other hand, Paldal, Jinheung, Sukwang, Eunbangzu, Damakum, and Pin Galw 56 contain only oryzenin Ⅱ, and oryzenin Ⅲ.
On the basis of these analyses a discussion of the differences between the protein fractions of 10 varieties was presented.
3. Globulin Ⅰ varied from 0.22% to 0.46% (aver. 0.35%) in the amount, globulin Ⅱ from 0.21 to 0.44%(aver. 0.32%), oryzenin Ⅰ from 0.17% to 0.44%(aver. 0.3%), oryzenin Ⅱ from 1.59% to 2.88%(aver. 2.23%), and oryzenin Ⅲ from 2.02% to 3.57%(aver. 2.66%).
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