Table 4. Amino acid composition of extracted oat groat proteins by alkaline extraction and acid precipitation pH conditions

Amino acid (mg/g) pH 13 pH 11 pH 12 pH 13
pH 3.0 pH 4.0 pH 5.0 pH 6.0 pH 7.0 pH 6.0 pH 6.0 pH 6.0
Tyrosine 0.33±0.051)d2) 2.53±0.21b 2.59±0.12b 3.96±0.10a 1.38±0.00c 7.77±0.10a 6.55±0.28b 3.96±0.10c
Glycine 0.70±0.05d 3.51±0.24b 3.22±0.14b 4.85±0.00a 2.12±0.10c 8.90±0.18a 7.45±0.28b 4.85±0.00c
Serine 1.03±0.05e 4.42±0.36b 3.69±0.14c 5.69±0.00a 2.81±0.10d 9.96±0.18a 8.65±0.36b 5.69±0.00c
Alanine 0.79±0.05e 4.00±0.36b 3.57±0.14c 5.41±0.10a 2.41±0.00d 9.79±0.18a 8.47±0.36b 5.41±0.10c
Glutamic acid 3.79±0.23e 19.51±1.52b 17.51±0.58c 26.14±0.26a 11.19±0.34d 48.16±0.80a 41.08±1.47b 26.14±0.26c
Lysine 0.70±0.05e 3.30±0.24b 2.91±0.07c 4.18±0.00a 1.95±0.10d 8.36±0.18a 7.09±0.28b 4.18±0.00c
Leucine 1.45±0.09e 7.09±0.61b 6.28±0.14c 9.42±0.10a 4.13±0.17d 16.96±0.27a 14.53±0.55b 9.42±0.10c
Methionine 0.45±0.00e 1.75±0.12b 1.53±0.00c 2.29±0.10a 1.09±0.10d 3.97±0.10a 3.36±0.28b 2.29±0.10c
Valine 1.18±0.09e 5.05±0.36b 4.59±0.12c 6.74±0.10a 3.04±0.10d 11.45±0.21a 10.09±0.54b 6.74±0.10c
Arginine 1.24±0.05d 6.32±0.56b 5.77±0.20b 8.58±0.10a 3.79±0.17c 15.95±0.27a 13.57±0.45b 8.58±0.10c
Aspartic acid 1.36±0.09e 6.60±0.49b 5.85±0.18c 8.92±0.10a 4.02±0.10d 16.01±0.18a 13.81±0.55b 8.92±0.10c
Isoleucine 0.70±0.05d 3.30±0.24b 3.14±0.07b 4.63±0.10a 2.01±0.10c 8.13±0.10a 7.09±0.28b 4.63±0.10c
Threonine 0.76±0.05e 3.30±0.24b 2.83±0.12c 4.18±0.00a 2.07±0.00d 7.59±0.10a 6.55±0.28b 4.18±0.00c
Phenylalanine 2.76±1.51d 8.84±0.42b 6.64±0.14c 9.75±0.10a 6.02±0.17c 15.07±0.27a 13.69±0.83b 9.75±0.10c
Proline 0.15±0.10d 3.16±0.21b 3.22±0.34b 4.91±0.19a 1.15±0.60c 10.08±0.10a 8.35±0.28b 4.91±0.19c
Histidine 0.55±0.10e 2.32±0.21b 1.96±0.07c 3.01±0.00a 1.43±0.10d 5.16±0.18a 4.50±0.18b 3.01±0.00c
Cysteine 0.02±0.00b 0.08±0.00b 0.12±0.00a 0.17±0.00a 0.03±0.00b 0.36±0.00a 0.18±0.00b 0.17±0.00c
Tryptophan 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00 0.00±0.00
Total essential amino acid 8.55±0.55e 34.95±2.39b 29.88±0.69c 44.20±0.39a 21.74±0.78d 76.69±1.28a 66.91±3.17b 44.20±0.39c
Sum of 18 amino acids 17.96±1.00e 85.07±6.26b 75.42±2.49c 112.8±1.08a 50.64±0.96d 203.7±3.13a 175.0±6.26b 112.8±1.08c
All values are mean±SD (n=3).
Different superscript letters (a-e) in the same row indicate significant differences (p<0.05) by Duncan’s multiple range test.