Agriculture Reference
In-Depth Information
Table 13.3.
Total plate count and yeast and mold count of fresh-cut cantaloupes prepared
from hot-water-treated fruit
TPC
Yeast and Mold
Storage
Time (Day)
20 ° C
Water
Chlorine
76 ° C
Water
20 ° C
Water
Chlorine
76 ° C
Water
0
2.0
±
0.7
2.4
±
0.7
2.4
±
1.0
1.5
±
0.4
1.8
±
0.2
1.4
±
0.5
1
2.9 ± 0.7
3.1 ± 0.9
3.1 ± 1.0
2.2 ± 0.9
2.1 ± 0.8
1.9 ± 0.8
6
3.8
±
0.8
3.6
±
0.7
2.7
±
1.3
2.6
±
0.6
2.2
±
0.8
1.8
±
1.0
8
4.1
±
0.9
4.2
±
1.3
3.4
±
0.6
2.5
±
0.5
2.3
±
0.8
2.1
±
1.1
10
4.7 ± 1.2
4.7 ± 1.7
2.9 ± 1.1
3.0 ± 0.8
2.8 ± 1.0
2.0 ± 1.0
13
5.6 ± 1.8
5.3 ± 1.5
3.2 ± 0.5
2.8 ± 0.9
2.4 ± 1.1
1.6 ± 0.9
16
5.9 ± 1.9
6.0 ± 1.9
3.4 ± 0.5
2.8 ± 0.7
2.6 ± 0.9
2.0 ± 0.8
20
6.7 ± 1.9
6.3 ± 1.9
4.4 ± 1.7
3.4 ± 0.8
2.8 ± 1.1
1.8 ± 1.2
LSD
1.5
2.0
1.1
0.8
1.0
1.0
Data represent the means ± standard deviations (n = 9).
Whole cantaloupes were submerged into 10 ° C water for 20 min, 20 ppm chlorine at 10 ° C for 20 min, or
76 °C water for 3 min (Fan and others 2008). Pieces prepared from whole cantaloupe were stored in clam-
shell containers at 4 ° C.
Apples
Hot water (80 or 95 °C) treatment of whole apples for 15 sec reduced
E. coli
O157 : H7
by more than 5 log CFU/g (Fleischman and others 2001). The treated apples were used
to produce cider. Heat damage to the apple skin did not negatively affect quality of
the apple cider. The effi cacy of H
2
O
2
solutions at different concentrations and tem-
peratures in decontaminating apples inoculated with foodborne pathogens was also
investigated (Sapers and others 2002; Sapers and Sites 2003). Apples inoculated with
a nonpathogenic
E. coli
ATCC 25922 and
E. coli
O157 : H7 were washed with 1%
H
2
O
2
at 20, 40 or 50 °C for up to 30 min. Population reductions approaching 3 log were
obtained with all treatments. Comparable reductions were obtained with apples inocu-
lated directly with 3 strains of
E. coli
O157 : H7 associated with cider outbreaks.
Venkitanarayanan and others (2002) spot-inoculated apples with
E. coli
O157 : H7,
Salmonella
Enteritidis, and
L. monocytogenes
near the stem end and treated the inocu-
lated fruit in 1.5% lactic acid plus 1.5% hydrogen peroxide solutions for 15 min at
40 °C. The treatment reduced bacterial pathogens on fruits by more than 5.0 log CFU
per fruit, whereas washing in water decreased the pathogens by only 1.5 to 2.0 log CFU
per fruit. The sensory and qualitative characteristics of apples treated with the chemi-
cal wash were not adversely affected by the treatment.
Oranges
Oranges inoculated with
E. coli
ATCC 25922 were immersed into hot water (80 °C)
for 1 or 2 min (Pao and others 2001). Greater than 5-log reductions in the population
of
E. coli
were achieved in the juice processed from the hot-water-treated fruit in
comparison to the
E. coli
level detected in the juice directly prepared from inoculated
fruit. Hot-water treatment can be used to pasteurize whole oranges for the further
processing of juice or fresh-cut oranges. However, it is unclear whether the treatment
