Agriculture Reference
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the storage of sliced mushrooms at 4 ± 1 °C for 13 days. The increase in the shear
force needed was bigger in the control and PVC samples (1,020 N), while there was
less force needed for the shearing of samples stored in PP
1
(890 N) and PP
2
(780 N)
bags. The use of PP
2
bags did not prevent the detection of off-odors, although the
samples had the best appearance scores (no deformation, blotch absence).
A reduction by 2.5 log CFU/g was achieved with the immersion of
Agaricus
bisporus
mushrooms in an aqueous citric acid solution (10 g/L) and subsequent
storage under passive MAP (PVC fi lm used with OTR: 25,000 mL/m
2
day atm.).
Shelf life of samples washed with the citric acid solution and stored under PMAP
was 13 days due to microbial spoilage (Simon et al
2010
).
Mushrooms were stored in plastic containers (creating modifi ed atmosphere con-
ditions) and subjected to temperature fl uctuations (TF) (4 and 14 °C for 2 days
alternatively) during the 12-day storage period. The RH levels were temperature
dependent and with each temperature increase RH dropped rapidly (90 %) and
returning to 100 % when temperature was reaching the initial value. Due to TF,
there was a high ethanol content increase (24.4-fold) in MA packages compared to
ones with stable temperature conditions (1.9-fold) (Tano et al.
2007
).
The effects of vacuum cooling prior to packaging under MAP (5 ± 1 % O
2
/3 ± 1 %
CO
2
initial atmosphere with LDPE fi lm used) or hypobaric conditions (20-30 kPa
total pressure) at 4 ± 1 °C were evaluated by Tao et al. (
2006
). The weight loss was
restrained under MAP whereas it was relatively extensive on mushrooms under HC
(>1 % and 14.78 %, respectively). The membrane permeability of mushrooms under
MAP was 15 %.
VC and AMAP (5 ± 1 % O
2
/3 ± 1 % CO
2
initial atmosphere with LDPE fi lm used)
at 4 ± 1 °C were applied and well defi ned by Tao et al. (
2007
). The activities of
superoxide dismutase, catalase, peroxidase and polyphenol oxidase were positively
affected by vacuum cooling resulting in a 1.2-, 1.2-, 1.1- and 1.1-fold increase,
respectively. Browning was more apparent in control samples than in MA packaged
and VC treated ones (1.5° of browning).
Villaescusa and Gil (
2003
) tested various storage temperatures (0, 4 and 7 °C)
MA conditions [PVC, two microperforated polypropylenes (MPP
1
and MPP
2
) and a
LDPE fi lm were used for storage at 4 °C] and different moisture absorbers (10, 15
and 20 g of sorbitol and 3, 5, 7, and 15 g of silica gel in MPP
2
fi lm) for prolonging
the shelf life of mushrooms. The optimal temperature for mushroom storage was
0 °C since all the quality characteristics remained close to the initial levels (2.0 %
weight loss, 4.2
o
Brix SSC, 6.2 pH and 0.09 g citric acid/100 mL TA).
The use of superatmospheric conditions (50, 70, 80, 90 and 100 % O
2
) for the
preservation of needle mushrooms (PE fi lm, 10 g of bentonite as a moisture absorber
and 8 g of active carbon as a deodorant were used) at 3 °C for 34 days was examined
by Wang et al. (
2011
). Mushrooms under 80 % O
2
had the best appearance scores,
the lowest POD and PPO levels (4.26 and 3.25 U/g, respectively) and the highest
SOD levels (0.73 U/g %) leading to the lowest browning levels and an increased
shelf life.
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