EXTRACTION AND FRACTIONATION OF INSOLUBLE FIBER FROM 5 FIBER SOURCES

Commercially processed wheat bran (WB), rice bran (RB), oat fiber (OF) , tomato fiber (TF), and apple fiber (AF) were analyzed for proximate composition, soluble fiber (SF), insoluble fiber (IF) and total dietar y fiber (TDF). IF was further fractionated into four fractions: cellul ose, hemicellulose A and B, and lignin. Protein, IF, and TDF values we re significantly different among the samples. Protein content ranged f rom 4.6% in OF to 24.9% in TF. SF values ranged from 1.5% in OF to 13. 9% in AF. IF values varied from 46.7% in RB to 73.6% in OF. TDF ranged from 51.4% in RB to 75.1% in OF. Hemicellulose A to B ratio was high in all the samples except rice bran. WB had the highest total hemicell ulose (44.0% of TDF) content followed by AF (38.4%), OF (38.3%), TF (3 6.5%), and RB (31.6%). Cellulose was 32.2, 26.6, 24.4, 20.8, and 19.7% of TDF in WB, OF, RB, AF, and TF, respectively. Lignin levels ranged from 5.2% in WB to 21.4% in OF. Copyright (C) 1996 Elsevier Science Lt d