Effect of High Hydrostatic Pressure Processing on Microbiological Shelf-Life and Quality of Fruits Pretreated with Ascorbic Acid or SnCl2
Table 3
Evolution of microbiological counts ( CFU/g), firmness, values, and sensory evaluation in HHP-treated at 600 MPa for 5 min at 10°C and untreated (control case) pear pieces in sucrose solution with or without ascorbic acid during storage (5°C). Each data point is an average ± standard deviation from three individual batches.
Time (days)
Time (days)
0
67
122
185
0
67
122
185
P. polymyxa
Firmness
Control
1.2 ± 0.2
2.4 ± 0.2
4.7 ± 0.5
ND
Control
141.0 ± 12.5
70.5 ± 5.0
67.0 ± 8.0
57.0 ± 6.5
1st handling without ascorbic acid
No growth detected (<dl during 185 days)
1st handling without ascorbic acid
75.5 ± 7.5
101.0 ± 8.0
96.0 ± 6.5
92.5 ± 9.5
1st handling with ascorbic acid
No growth detected (<dl during 185 days)
1st handling with ascorbic acid
75.5 ± 7.5
73.5 ± 5.5
78.5 ± 7.5
79.5 ± 7.0
3rd handling without ascorbic acid
No growth detected (<dl during 185 days)
3rd handling without ascorbic acid
100.0 ± 10.5
116.5 ± 6.0
122.5 ± 10.5
116.5 ± 11.5
3rd handling with ascorbic acid
No growth detected (<dl during 185 days)
3rd handling with ascorbic acid
100.0 ± 10.5
107.0 ± 9.5
116.5 ± 11.0
133.0 ± 12.5
Total Viable Counts
value
Control
1.4 ± 0.2
4.3 ± 0.4
6.9 ± 0.7
ND
Control
39.5 ± 3.3
40.1 ± 4.0
38.6 ± 3.0
39.6 ± 2.4
1st handling without ascorbic acid
No growth detected (<dl during 185 days)
1st handling without ascorbic acid
38.8 ± 2.4
38.9 ± 2.6
40.3 ± 2.5
38.4 ± 1.0
1st handling with ascorbic acid
No growth detected (<dl during 185 days)
1st handling with ascorbic acid
37.4 ± 2.5
37.1 ± 3.1
40.0 ± 4.2
34.8 ± 3.7
3rd handling without ascorbic acid
No growth detected (<dl during 185 days)
3rd handling without ascorbic acid
36.9 ± 3.1
36.1 ± 2.4
37.8 ± 1.7
37.4 ± 2.2
3rd handling with ascorbic acid
No growth detected (<dl during 185 days)
3rd handling with ascorbic acid
37.1 ± 1.6
36.9 ± 2.0
34.7 ± 3.2
31.4 ± 2.8
Lactic acid bacteria
Control
<dl
1.2 ± 0.1
2.0 ± 0.4
ND
Control
0.0
1.2
2.0
ND
1st handling without ascorbic acid
No growth detected (<dl during 185 days)
1st handling without ascorbic acid
0.0
0.4
0.5
0.5
1st handling with ascorbic acid
No growth detected (<dl during 185 days)
1st handling with ascorbic acid
0.1
0.3
0.3
0.8
3rd handling without ascorbic acid
No growth detected (<dl during 185 days)
3rd handling without ascorbic acid
0.1
1.4
1.4
1.4
3rd handling with ascorbic acid
No growth detected (<dl during 185 days)
3rd handling with ascorbic acid
0.0
0.8
0.6
0.8
Yeasts
Control
<dl
4.1 ± 0.5
6.3 ± 0.6
ND
Control
10.0
6.4
3.1
ND
1st handling without ascorbic acid
No growth detected (<dl during 185 days)
1st handling without ascorbic acid
10.0
8.0
4.6
5.6
1st handling with ascorbic acid
No growth detected (<dl during 185 days)
1st handling with ascorbic acid
10.0
8.5
8.3
7.9
3rd handling without ascorbic acid
No growth detected (<dl during 185 days)
3rd handling without ascorbic acid
10.0
3.0
4.0
3.5
3rd handling with ascorbic acid
No growth detected (<dl during 185 days)
3rd handling with ascorbic acid
10.0
5.5
5.9
5.8
ND: not determined-spoiled product, dl: detection limit (1 CFU/g); athe taste is the mean value of scores given by 8 panelists-0: good, 1: acceptable, 2: spoiled; bthe total evaluation is the mean value of odor, color, texture, and taste of 8 panelists. -10: very good, 5: acceptable, and 1: totally unacceptable.
