TABLE 2
Evolution of different parameters* during frozen storage of Wels catfish fillets that were pretreated under different conditions**
Frozen Storage Time
(months)
1
3
6
pH
BC
x 6.73 b
(0.09)
y 6.40 a
(0.02)
y 6.55 ab
(0.14)
AA
z 6.27 a
(0.02)
y 6.40 b
(0.04)
y 6.47 b
(0.13)
CA
y 6.37 c
(0.06)
z 6.28 b
(0.02)
z 6.18 a
(0.05)
Expressible moisture
(g kg-1 flesh muscle)
BC
AA
CA
z 320.9 a
y 405.4
y 391.0
(13.8)
(52.7)
(38.6)
408.9 b
382.6
374.9
(49.2)
(41.2)
(37.2)
y 468.8 c
z 422.0
z 417.3
(11.4)
(21.9)
(26.7)
Heme iron
(μg g-1 flesh muscle)
BC
AA
CA
8.92 b
9.95 b
8.95
(1.22)
(0.71)
(0.68)
z 6.20 a y 9.52 ab
y 9.46
(0.94)
(1.47)
(1.16)
z 6.77 a
y 8.10 a
y 8.85
(0.53)
(0.76)
(1.15)
* Mean values of three independent determinations (n = 3). Standard deviations are indicated in brackets. For each parameter and for each frozen
time (1, 3 and 6 months), mean values preceded by different letters (x, y, z) denote significant differences (p<0.05) among preliminary
treatments. For each parameter and for each previous treatment, mean values followed by different letters (a, b, c) denote significant
differences (p<0.05) as a result of frozen storage time.
** Treatment names: BC (blank control), AA (0.50% ascorbic acid aqueous solution) and CA (0.50% citric acid aqueous solution).
TABLE 3
Evolution of sensory parameters* during frozen storage of Wels catfish fillets that were pretreated under different conditions**
Frozen Storage Time
(months)
1
3
6
BC
A
B
B
Flesh Appearance
AA
CA
A
E
B
B
B
B
BC
E
B
C
Rancid Odour
AA
E
A
B
CA
E
B
B
BC
A
B
B
Flesh Consistency
AA
CA
A
A
B
B
B
B
* Freshness categories: E (excellent), A (good), B (fair) and C (rejectable). All fish were category E for all attributes initially.
** Treatment names as expressed in Table 2.