Agriculture Reference
In-Depth Information
market potential. One possible reason is that segments of
peeled citrus fruits are delicate as compared to other com-
monly marketed fresh-cut fruits (e.g., apple and pineapple);
moreover, the typical equipment used for other sliced and
diced fresh-cut products is not suitable for citrus fruits,
which would require a greater amount of manual labor.
Del Valle et al. (2009) studied the feasibility of de-
veloping a ready-to-eat mandarin segments product. Af-
ter manual processing, mandarin segments were stored in
controlled atmosphere environments at 3
◦
C. The results
observed for different freshness indicators, especially the
accumulation of acetaldehyde and ethanol and the sensory
test scores, indicated that an atmosphere with low CO
2
(3%)
is suitable for minimally processed mandarin segments. A
mathematical model which considered the respiration rate
and the gas mass transfer through plastic films was used to
make a preselection of suitable packages; it showed that,
due to the high respiration rate of mandarin segments, it is
necessary to use microperforated plastic films to design the
modified atmosphere package (MAP). The sensory quality
results showed that the optimum equilibrium modified at-
mosphere packaging (EMAP) for mandarin segments was
19.8% O
2
and 1.2% CO
2
(del Valle et al., 2009).
The retention of antioxidant activity in minimally pro-
cessed mandarin segments was investigated by Piga et al.
(2002). Fruits of uniform size and maturity were washed
in chlorinated water, dried, and processed into segments
that were sealed into trays under films with different gas
permeabilities (polyolefinic or polypropylenic films) for up
to 12 days at 4
◦
C. Ascorbic acid content, total phenols,
antioxidant activity, and redox potential were monitored
during storage, and in-package CO
2
and O
2
evolution was
checked at preselected intervals (Table 22.5). The changes
in antioxidant properties of minimally processed man-
darins were not wholly related to the fate of ascorbic acid.
Table 22.4.
Effect of color enhancement
(degreening) treatments on the chlorophyll and
carotenoid concentration of California-grown
'Nules Clementine' mandarin.
Chlorophyll
Carotenoid
Treatment
(μg/g, dry wt)
(μg/g, dry wt)
Untreated; T4
1
77.4
87.2
Untreated; T5
2
76.3
100.1
Ethylene-degreening
3
; T4
4.4
179.9
Ethylene-degreening; T5
10.5
183.4
Cold shock
4
; T4
4.6
159.5
Cold shock; T5
15.6
203.2
1
T4, yellow/orange strongly dominant with patches of
green;
2
T5, yellow/orange becoming dominant over green;
3
ethylene degreening treatment (2
μ
l/liter) was applied for
72 hours at 23
◦
C and 95% RH;
4
fruit were cold shocked at
0
◦
C for 30 min and then transferred to a 4
◦
C cold room
for 6 hours to complete the cold shock treatment;
thereafter, fruit were incubated at 19
◦
C for 72 hours.
Source: Barry and van Wyk (2006).
shelf life that is sufficient to make its distribution feasible
within the region of its consumption (Vasconellos, 2000;
Laurila and Ahvenainen, 2002). Fresh-cut produce is one
of the fastest growing segments of the food industry in the
United States. The demand for these ready-to-eat, freshlike,
and convenient products has been growing at a much faster
rate than any other segment of the industry and is expected
to grow as more and more fresh-cut products become avail-
able, especially from tropical and subtropical fruits.
Citrus group fruits, including tangerines, mandarins, and
clementines, have not been exploited for their fresh-cut
Table 22.5.
Influence of film wrapping on O
2
and CO
2
concentration within trays of minimally
processed 'Avana' mandarins during 4
◦
Cstorage.
CO
2
(%)
O
2
(%)
Storage
Film A (polyolefinic)
Film B (polypropylenic)
Film A (polyolefinic)
Film B (polypropylenic)
4 day
3.78
6.24
18.12
15.97
8 day
4.12
7.24
17.01
15.04
12 day
4.31
8.82
16.82
13.34
O
2
permeability: 3,400 ml/m
2
day bar (Film A) and 87 ml/m
2
day bar (Film B). CO
2
permeability: 8,500 ml/m
2
day bar
(Film A) and 592 ml/m
2
day bar (Film B).
Source: Adapted from (Piga et al., 2002).
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