Abstract
Studies reported here were undertaken to determine the feasibility of producing for human food a protein isolate from rice bran. Various extractants and conditions were evaluated for effectiveness in solubilizing and recovering the protein of the defatted rice bran. As the result of the evaluation, the following isolation process was determined to be very effective: (1) The defatted rice bran is stirred with 20 times volumes of 0.05% NaOH for 2 hrs. at 37°C. (2) The solubilized protein is recovered from alkaline extracts by isoelectric precipitation at pH 4.5 to 5.0. (3) The precipitated protein is soaked with 85% ethanol for 1hr. at room temperature and freeze-dried.
The above process yielded an odorless protein isolate of a very light-gray color and 94 to 99% protein (dry basis) which has excellent essential amino acid pattern and high digestibility. About 30 to 40% of total crude protein in defatted bran is recovered as the protein isolate.
