Modeling Botrytis cinerea growth…
Table 2—Colony growth rate (), lag time (), time needed of shelf-life will be greater, though the spores will have to germi-
for the Botrytis cinerea colony to reach 3 mm (ts), esti-
nate and the colony has to acquire the enough size to be seen (3
mm), and the model will not be so over-conservative that it will
conduce to reduction of benefits to the producer with no justified
reason.
In contrast, Hertog and others (1999) report shelf-life esti-
mates, based on evidence of B. cinerea, of between 19 h and 36 h
for strawberries packed and stored at 18 °C. Depending on the
number of strawberries initially affected, these authors report a
value substantially lower than that calculated using our model
mated from data obtained by Agar and others (1990).
-
1
%
CO2
(h )
(h)
ts (h)
0
1.073
0.746
0.578
0.529
0.486
0.413
0.106
0.000
0.000
0.000
10.092
21.240
33.856
63.300
3.78
5.13
6.49
15.67
27.31
40.99
91.00
1
1
2
2
3
4
0
5
0
5
0
0
for 0% CO that is the shorter shelf-life, or 96 h (Table 1).
2
Conclusion
HIS STUDY SIMULATES THE CONDITIONS IN WHICH BOTRYTIS MAY
T
appear in a product such as the strawberry, by means of
eters, determined when colonies reached a dia of 3 mm, were 96
spores, which is a more realistic view than studying mycelium
growth. Hence, this model enables us (a) to know that, in order to
inhibit fungal development, the product should be kept in an
h, 156 h, and 240 h for 0%, 10%, and 20% CO , respectively. Linear
2
regression of the data enabled the theoretical product shelf-life
to be determined, according to the possible growth of this fun-
enriched atmosphere with more than 20% CO content; and (b)
to estimate shelf-life in function of CO content of the packed, as
the time taken for any colonies to become visible, thus giving rise
to immediate rejection by consumers.
2
gus, with CO contents of between 0 and 20% and using the fol-
2
2
lowing equation:
ts (h) = 7.2* (%CO ) + 92
r2 = 0.99
2
References
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Figure 1—Mathematical fit of Botrytis cinerea colony di-
ameter growth at different CO concentrations.
2
1
906 JOURNAL OF FOOD SCIENCE—Vol. 67, Nr. 5, 2002