Preparation of ultrafiltered rice bran extract and some factors affecting its browning inhibition in potato puree.

Rice bran extract (RBE) was fractionated by using ultrafiltration techniques. The obtained retentate (R) inhibited the browning of potato puree to a similar extent as RBE and more than it's permeate. The R that was incubated at pH 4.0, 5.0, and 6.0 inhibited the browning of potato puree more than R that was incubated at pH 7.0 or 8.0. Potato puree that was treated with heated R at 80 degrees C for 10 min had a browning value similar to that of puree treated with unheated R and lower than those treated with heated R at 40 or 60 degrees C for 10 min.