BLBS102-c38 BLBS102-Simpson March 21, 2012 14:17 Trim: 276mm X 219mm Printer Name: Yet to Come
38 Thermal Processing Principles 739Table 38.9.fh/UVersusgRelationships Whenz= 18 ◦F for Stumbo Method (1973)Values of g Whenjof Cooling Curve isfh/U 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.000.20 4.09–05 4.42–05 4.76–05 5.09–05 5.43–05 5.76–05 6.10–05 6.44–05 6.77–05
0.30 2.01–03 2.14–03 2.27–03 2.40–03 2.53–03 2.66–03 2.79–03 2.93–03 3.06–03
0.40 1.33–02 1.43–02 1.52–02 1.62–02 1.71–02 1.80–02 1.90–02 1.99–02 2.09–02
0.50 4.11–02 4.42–02 4.74–02 5.06–02 5.38–02 5.70–02 6.02–02 6.34–02 6.65–02
0.60 8.70–02 9.43–02 1.02–01 1.09–01 1.16–01 1.23–01 1.31–01 1.38–01 1.45–01
0.70 0.150 0.163 0.176 0.189 0.202 0.215 0.228 0.241 0.255
0.80 0.226 0.246 0.267 0.287 0.308 0.328 0.349 0.369 0.390
0.90 0.313 0.342 0.371 0.400 0.429 0.458 0.487 0.516 0.545
1.00 0.408 0.447 0.485 0.523 0.561 0.600 0.638 0.676 0.715
2.00 1.53 1.66 1.80 1.93 2.07 2.21 2.34 2.48 2.61
3.00 2.63 2.84 3.05 3.26 3.47 3.68 3.89 4.10 4.31
4.00 3.61 3.87 4.14 4.41 4.68 4.94 5.21 5.48 5.75
5.00 4.44 4.76 5.08 5.40 5.71 6.03 6.35 6.67 6.99
6.00 5.15 5.52 5.88 6.25 6.61 6.98 7.34 7.71 8.07
7.00 5.77 6.18 6.59 7.00 7.41 7.82 8.23 8.64 9.05
8.00 6.29 6.75 7.20 7.66 8.11 8.56 9.02 9.47 9.93
9.00 6.76 7.26 7.75 8.25 8.74 9.24 9.74 10.23 10.73
10.00 7.17 7.71 8.24 8.78 9.32 9.86 10.39 10.93 11.47
15.00 8.73 9.44 10.16 10.88 11.59 12.31 13.02 13.74 14.45
20.00 9.83 10.69 11.55 12.40 13.26 14.11 14.97 15.82 16.68
25.00 10.7 11.7 12.7 13.6 14.6 15.6 16.5 17.5 18.4
30.00 11.5 12.5 13.6 14.6 15.7 16.8 17.8 18.9 19.9
35.00 12.1 13.3 14.4 15.5 16.7 17.8 18.9 20.0 21.2
40.00 12.8 13.9 15.1 16.3 17.5 18.7 19.9 21.1 22.3
45.00 13.3 14.6 15.8 17.0 18.3 19.5 20.8 22.0 23.2
50.00 13.8 15.1 16.4 17.7 19.0 20.3 21.6 22.8 24.1
60.00 14.8 16.1 17.5 18.9 20.2 21.6 22.9 24.3 25.7
70.00 15.6 17.0 18.4 19.9 21.3 22.7 24.1 25.6 27.0
80.00 16.3 17.8 19.3 20.8 22.2 23.7 25.2 26.7 28.1
90.00 17.0 18.5 20.1 21.6 23.1 24.6 26.1 27.6 29.2
100.00 17.6 19.2 20.8 22.3 23.9 25.4 27.0 28.5 30.1
150.00 20.1 21.8 23.5 25.2 26.8 28.5 30.2 31.9 33.6
200.00 21.7 23.5 25.3 27.1 28.9 30.7 32.5 34.3 36.2
250.00 22.9 24.8 26.7 28.6 30.5 32.4 34.3 36.2 38.1
300.00 23.8 25.8 27.8 29.8 31.8 33.7 35.7 37.7 39.7
350.00 24.5 26.6 28.6 30.7 32.8 34.9 37.0 39.0 41.1
400.00 25.1 27.2 29.4 31.5 33.7 35.9 38.0 40.2 42.3
450.00 25.6 27.8 30.0 32.3 34.5 36.7 38.9 41.2 43.4
500.00 26.0 28.3 30.6 32.9 35.2 37.5 39.8 42.1 44.4
600.00 26.8 29.2 31.6 34.0 36.4 38.8 41.2 43.6 46.0
700.00 27.5 30.0 32.5 35.0 37.5 39.9 42.4 44.9 47.4
800.00 28.1 30.7 33.3 35.8 38.4 40.9 43.5 46.0 48.6
900.00 28.7 31.3 34.0 36.6 39.2 41.8 44.4 47.0 49.7
999.99 29.3 31.9 34.6 37.3 39.9 42.6 45.3 47.9 50.6- Also, the Stumbo method accommodates different values
ofzand can be used for not only cold-point values but also
for integrated lethality computations. The use of this yield
more accurate process times (Smith and Tung 1982).
Typical calculations of process time and process lethality us-
ing Stumbo method are illustrated in Tables 38.10 and 38.11.QUALITY OPTIMIZATION
The effect of the thermal sterilization process on quality and
nutrient retention of food has been of major concern for food
processors since the invention of canning. During sterilization
of foods, heat has two simultaneous effects: sterilization and
cooking. Therefore, it is necessary to optimize between these