Table 5. Protein and amino acid composition of cooked pork sausages containing two different percentages of purple sweet potato combined with nitrite
| Treatments1) |
| CON | CON1 | PP1 | PP2 | SP1 | SP2 |
| Protein | 17.76 ± 0.58 | 17.40 ± 0.16 | 18.09 ± 0.48 | 17.79 ± 0.38 | 18.28 ± 1.14 | 17.99 ± 0.23 |
| Aspartic acid | 9.38 ± 0.12A | 9.22 ± 0.00A | 7.40 ± 0.09B | 6.82 ± 0.93B | 7.50 ± 0.20B | 7.51 ± 0.08B |
| Threonine | 4.65 ± 0.00 | 4.59 ± 0.00 | 4.60 ± 0.06 | 4.65 ± 0.10 | 4.67 ± 0.02 | 4.50 ± 0.01 |
| Serine | 3.87 ± 0.10 | 3.75 ± 0.00 | 4.06 ± 0.18 | 4.07 ± 0.21 | 4.07 ± 0.14 | 4.08 ± 0.18 |
| Glutamic acid | 14.91 ± 0.43B | 14.77 ± 0.00B | 16.00 ± 0.01A | 16.11 ± 0.14A | 15.67 ± 0.30A | 15.59 ± 0.30A |
| Proline | 4.29 ± 0.06 | 4.40 ± 0.00 | 4.43 ± 0.26 | 4.45 ± 0.05 | 4.42 ± 0.28 | 4.58 ± 0.16 |
| Glycine | 4.89 ± 0.25 | 4.81 ± 0.00 | 5.13 ± 0.05 | 4.95 ± 0.11 | 4.97 ± 0.02 | 5.10 ± 0.07 |
| Alanine | 5.86 ± 0.09B | 5.85 ± 0.00B | 6.18 ± 0.06A | 6.25 ± 0.15A | 6.21 ± 0.11A | 6.17 ± 0.03A |
| Cysteine | 1.37 ± 0.11A | 1.20 ± 0.00B | 0.00 ± 0.00D | 0.21 ± 0.00C | 0.00 ± 0.00D | 0.00 ± 0.00D |
| Valine | 5.48 ± 0.05 | 5.54 ± 0.00 | 5.58 ± 0.06 | 5.67 ± 0.16 | 5.73 ± 0.01 | 5.68 ± 0.18 |
| Methionine | 2.40 ± 0.74 | 2.94 ± 0.00 | 2.71 ± 0.02 | 2.59 ± 0.23 | 2.51 ± 0.62 | 2.76 ± 0.19 |
| Isoleucine | 5.08 ± 0.09 | 5.06 ± 0.00 | 5.11 ± 0.07 | 5.24 ± 0.22 | 5.34 ± 0.13 | 5.18 ± 0.18 |
| Leucine | 8.40 ± 0.02 | 8.42 ± 0.00 | 8.50 ± 0.04 | 8.64 ± 0.17 | 8.68 ± 0.06 | 8.61 ± 0.18 |
| Tyrosine | 3.32 ± 0.28 | 3.55 ± 0.00 | 3.51 ± 0.05 | 3.42 ± 0.16 | 3.31 ± 0.23 | 3.55 ± 0.15 |
| Phenylalanine | 4.17 ± 0.01 | 4.19 ± 0.00 | 4.27 ± 0.02 | 4.35 ± 0.10 | 4.29 ± 0.04 | 4.31 ± 0.06 |
| Histidine | 4.85 ± 0.09B | 4.68 ± 0.00C | 5.03 ± 0.08A | 5.12 ± 0.04A | 5.02 ± 0.05A | 4.98 ± 0.08AB |
| Lysine | 9.08 ± 0.02BC | 9.04 ± 0.00C | 9.29 ± 0.04A | 9.32 ± 0.06A | 9.30 ± 0.13A | 9.21 ± 0.01AB |
| Ammonia | 1.53 ± 0.01 | 1.52 ± 0.00 | 1.54 ± 0.12 | 1.58 ± 0.09 | 1.66 ± 0.06 | 1.60 ± 0.01 |
| Arginine | 6.52 ± 0.11B | 6.47 ± 0.00B | 6.72 ± 0.07A | 6.71 ± 0.10A | 6.70 ± 0.00A | 6.63 ± 0.02AB |
| FAA | 14.91 ± 0.43B | 14.77 ± 0.00B | 16.00 ± 0.01A | 16.11 ± 0.14A | 15.67 ± 0.30A | 15.59 ± 0.30A |
| STAA | 19.26 ± 0.45 | 19.00 ± 0.00 | 19.96 ± 0.35 | 19.92 ± 0.15 | 19.91 ± 0.26 | 19.85 ± 0.30 |
| SAA | 3.78 ± 0.84 | 4.14 ± 0.00 | 2.71 ± 0.02 | 2.63 ± 0.00 | 2.51 ± 0.62 | 2.76 ± 0.19 |
| AAA | 7.49 ± 0.26 | 7.73 ± 0.00 | 7.77 ± 0.06 | 7.77 ± 0.06 | 7.60 ± 0.19 | 7.85 ± 0.21 |
| BAA | 31.08 + 0.97 | 32.43 + 0.00 | 32.92 + 0.04 | 33.09 + 0.22 | 32.88 + 0.71 | 33.06 + 0.66 |
| EAA | 50.60 ± 0.68 | 50.93 ± 0.00 | 51.79 ± 0.04 | 52.29 ± 0.70 | 52.20 ± 0.27 | 51.84 ± 0.69 |
| TAA | 100 | 100 | 100 | 100 | 100 | 100 |
Treatments: CON (control), 0.014% sodium nitrite; CON1 (control1), no sodium nitrite and purple-fleshed sweet potato powder combination; PP1 = no sodium nitrite and 0.5% purple-fleshed sweet potato powder; PP2, no sodium nitrite and 1% purple-fleshed sweet potato powder; SP1, 0.011% sodium nitrite and 0.5% purple-fleshed sweet potato powder combination; SP2, 0.011% sodium nitrite and 1% purple-fleshed sweet potato powder combination.
Means in the same column within the same aging period with different letters are significantly different (p < 0.05).
FAA, flavorous amino acid; STAA, sweet taste amino acid; SAA, sulfur-containing amino acid; AAA, aromatic amino acid; BAA, bitter amino acid; EAA, essential amino acid; TAA, total amino acid.