Table 2. Color characteristics of cooked pork sausages containing two different percentages of purple sweet potato combined with nitrite during storage

Items Treatments1) Storage (days)
0 5 10 15 20
L*2) CON 79.20 ± 0.15B 79.04 ± 0.13A 78.69 ± 0.34B 79.01 ± 0.27B 78.70 ± 0.73A
CON1 79.85 ± 0.08A 79.54 ± 0.78A 80.14 ± 0.32A 80.11 ± 0.21A 79.13 ± 1.10A
PP1 75.79 ± 0.24Cb 76.66 ± 0.48Ba 76.38 ± 0.21Cab 76.72 ± 0.19Ca 76.47 ± 0.52Ba
PP2 75.40 ± 0.35C 75.72 ± 0.13C 75.44 ± 0.10D 75.32 ± 0.41D 75.60 ± 0.10B
SP1 75.68 ± 0.15C 76.17 ± 0.05BC 75.80 ± 0.12CD 75.67 ± 0.50D 76.03 ± 0.44B
SP2 72.92 ± 0.38Db 73.87 ± 0.33Da 73.48 ± 0.69Eab 73.15 ± 0.42Eab 73.59 ± 0.18Cab
a* CON 7.08 ± 0.04Cc 7.33 ± 0.12Cb 6.89 ± 0.06Cd 7.65 ± 0.09Ca 7.32 ± 0.07Cb
CON1 2.66 ± 0.15Fa 2.26 ± 0.11Fb 2.02 ± 0.27Fbc 1.69 ± 0.07Fd 1.79 ± 0.19Fcd
PP1 5.14 ± 0.06Ea 4.30 ± 0.29Eb 3.99 ± 0.41Eb 4.26 ± 0.66Eb 3.73 ± 0.25Eb
PP2 5.51 ± 0.10D 5.53 ± 0.22D 4.93 ± 0.31D 5.54 ± 0.68D 5.07 ± 0.55D
SP1 8.49 ± 0.04Bbc 8.59 ± 0.11Bb 8.38 ± 0.13Bc 8.93 ± 0.10Ba 8.47 ± 0.10Bbc
SP2 9.53 ± 0.10A 9.85 ± 0.44A 9.43 ± 0.18A 9.71 ± 0.48A 9.54 ± 0.40A
b* CON 8.19 ± 0.02Bb 8.22 ± 0.05Cb 8.65 ± 0.20Ca 8.07 ± 0.09Cb 8.18 ± 0.04Cb
CON1 10.41 ± 0.10Ac 10.56 ± 0.18Abc 10.83 ± 0.30Ab 11.27 ± 0.04Aa 11.13 ± 0.07Aa
PP1 8.19 ± 0.15Bb 8.94 ± 0.28Bab 9.48 ± 0.44Ba 9.23 ± 0.75Ba 9.58 ± 0.15Ba
PP2 7.82 ± 0.26Cab 7.75 ± 0.38Cb 8.53 ± 0.38Ca 8.22 ± 0.45Cab 8.30 ± 0.48Cab
SP1 6.93 ± 0.11Dab 6.54 ± 0.02Dcd 7.02 ± 0.18Da 6.36 ± 0.15Dd 6.76 ± 0.11Dbc
SP2 5.82 ± 0.32E 5.29 ± 0.42E 5.93 ± 0.10E 5.38 ± 0.23E 5.52 ± 0.51E
W* CON 54.62 ± 0.14Aa 54.38 ± 0.24Ba 52.73 ± 0.47Bb 54.80 ± 0.22Ba 54.16 ± 0.75Ba
CON1 48.63 ± 0.21Ca 47.86 ± 1.31Ea 47.66 ± 0.62Dab 46.29 ± 0.21Dbc 45.74 ± 0.94Ec
PP1 51.22 ± 0.65Ba 49.85 ± 0.43Dab 47.95 ± 1.47Db 49.04 ± 2.21Cab 47.73 ± 0.98Db
PP2 51.93 ± 1.11Bab 52.48 ± 1.22Ca 49.84 ± 1.18Cb 50.67 ± 0.97Cab 50.70 ± 1.42Cab
SP1 54.90 ± 0.48Ac 56.54 ± 0.05Aa 54.75 ± 0.45Ac 56.59 ± 0.10ABa 55.75 ± 0.15ABb
SP2 55.46 ± 0.87Ab 58.01 ± 1.15Aa 55.70 ± 0.83Ab 57.00 ± 1.10Aab 57.03 ± 1.37Aab
Sensory color score3) CON 7.17 ± 0.68ABC 7.14 ± 0.80 7.06 ± 0.62AB 6.75 ± 0.89 6.88 ± 0.99
CON1 6.50 ± 0.32C 6.57 ± 0.53 6.13 ± 0.79C 6.06 ± 0.94 6.13 ± 1.06
PP1 6.67 ± 0.61BC 6.50 ± 0.58 6.38 ± 0.64BC 6.13 ± 0.95 6.06 ± 1.12
PP2 6.58 ± 0.66C 6.50 ± 0.82 6.25 ± 0.93C 6.31 ± 0.75 6.00 ± 1.41
SP1 7.33 ± 0.68AB 7.29 ± 0.49 7.31 ± 0.53A 6.94 ± 0.62 7.13 ± 0.64
SP2 7.67 ± 0.41A 7.07 ± 0.45 7.31 ± 0.70A 7.00 ± 0.65 7.13 ± 0.64
Data represent mean ± SD.
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.
W = L* − 3b*.
Sensory color score were evaluated based on a 9-point scale, 0 = extremely dislike and 9 = extremely like.
Means in the same column within the same aging period with different letters are significantly different (p < 0.05).
Means in the same row within the same aging condition with different letters are significantly different (p < 0.05).