Debittering of corn gluten hydrolysate with active carbon

Corn gluten hydrolysates were treated with active carbons to remove the bitterness. After treatment with active carbons, the ACE (angiotensin-converting enzyme) inhibitory activity decreased in the order of active clay, Junsei (fine and granule) and Koent CPG (67.2, 65.4 and 64.9% respectively) in TP 10K. In addition, that of PP 10K treated with Junsei (fine and granule) and active clay decreased to 75.6, 72.2 and 74.7% respectively. In PP 10K, Koent PWA and active clay effectively reduced the bitterness. PP 10K treated with Koent PWA and active clay was reported to taste as trace of bitterness to slightly bitter. TP 10K treated with Koent RC and CPG tasted as trace of bitterness to slightly bitter, and that treated with Koent PWA and Junsei (granule) tasted as slightly bitter to bitter. After treatment with active carbons, the amounts of T-N (total nitrogen) in PP 10K and TP 10K reduced from 148 and 135 mg to 136-42 and 134-108 mg respectively. Before treatment with active carbons, PP 10K and TP 10K consisted of peptides with APLs (average peptide lengths) 14.4 and 12.8 respectively. After Junsei (fine) treatment, the APLs of PP 10K and TP 10K were 16.9 and 16.2 respectively. After treatment with the other active carbons, the APLs of PP 10K and TP 10K were 14.4-2.78 and 14.4-3.5 respectively. Before treatment with active carbons, the surface hydrophobicities of PP 10K and TP 10K were 38 and 29.9 respectively. However, after treatment with active carbons, the surface hydrophobicities of PP 10K and TP 10K were reduced, except for PP 10K treated with active clay. In PP 10K, treatments with Koent PWA and active clay markedly reduced the surface hydrophobicity from 38 to 13.3 and 14.2 respectively. The surface hydrophobicity of TP 10K treated with Koent RC and CPG was markedly reduced from 29.9 to 9.9 and 11.1 respectively. (C) 2000 Society of Chemical Industry.