Agriculture Reference
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Jiang et al. ( 2010c ) investigated the effect of gamma irradiation (1.0, 1.5 and
2 kGy) on shiitake mushrooms stored under PMAP (BOPP fi lm was used) at 4 °C
for 20 days. Mushrooms irradiated with 1.0 kGy maintained fi rmness, phenolic and
fl avonoid compounds and had a shelf life of 20 days.
Jiang et al. ( 2010d ) investigated the structural changes of the cell wall of shiitake
mushrooms stored under PMAP (LDPE fi lm used with 0, 2 and 4 microholes) at
4 °C for 16 days. The fi lm with 4 microholes proved effective in maintaining fi rm-
ness, reducing losses in protein (46 %) and retarded cellulose increase (35 g/kg DW).
Agaricus bisporus mushrooms were dipped in 2.2-(hydroxynitrosohydrazino)-
bisethanamine (DETANO), a nitric oxide donor (0.5, 1, and 2 mM concentrations)
and subsequently stored under MAP (BOPP fi lm) and stored at 4 °C for 16 days.
Firmness was better maintained with 1 mM DETANO and MAP and the use of
DETANO led to a lower browning incidence. The use of NO combined with MAP
can lead to shelf life extension up to 12 days (Jiang et al. 2011 ).
Enoki mushrooms were packaged under various conditions (full and half vac-
uum with RD-106 polyolefi n for packaging fi lm, half vacuum with cast polypropyl-
ene and polyolefi ns RD-106 and PD-941 for fi lms and RD-106 packages stored at
5, 10 and 15 °C) and stored at 10 °C for 14 days. The higher the degree of vacuum
the lower the weight loss the samples had (1.3, 1.1 and 1 % for air, partial and fully
vacuumized samples). A higher degree of initial vacuum in RD-106 fi lm packages
suppressed stripe elongation (6.5 %) (Kang et al. 2000 ).
Sliced and whole mushrooms were spray-coated with solution of chitosan and
CaCl 2 (2 g per 100 mL) and packaged with a PVC wrap or two polyolefi ns (PD-941
and PD-961) at 12 °C for 6 days. Coated sliced mushrooms exhibited higher
E
than uncoated mushrooms while the use of PD-961 fi lm had the best color results in
terms of L * value. Products coated with chitosan were less mature at the end of the
experiment compared to uncoated ones (Kim et al. 2006 ).
CaCl 2 O 2 (0.4 and 0.8 g/L) treatment and passive (LDPE with 2 or 4 perforations
or PVC) or active atmosphere modifi cation (10 mg/100 mL O 2 /10 mg/100 mL CO 2 )
was tested for the preservation of mushrooms stored at 5 ± 1 °C for 10 days.
Coliforms [6 × 10 6 , 7 × 10 4 and 4 × 10 5 CFU/g for treated LDPE (4 per.) with MAP,
PVC and perforated PVC] and the total plate counts [10 6 , 10 5 and 4 × 10 5 CFU/g for
treated LDPE (4 per.) with MAP, PVC and perforated PVC] of all packaging meth-
ods were lower with the addition of 0.8 g/L CaCl 2 O 2 (Kuyper et al. 1993 ).
Pseudomonas fl uorescens and Candida sake were inoculated into homogenized
mushrooms and stored under different gaseous atmospheres [CO 2 /O 2
(25 %/1 %)-MAP 1 and CO 2 /O 2 (50 %/1 %)-MAP 2 ] at 5 and 10 °C for 18 days. pH
was greatly reduced in MAP 2 storage conditions (5.06 and 5.79 for MAP 2 at 5 and
10 °C, respectively were the lowest pH values). The presence of CO 2 played an
important role in increasing the lag time of Pseudomonas and Candida (Masson
et al. 2002 ).
Figure 1.4 shows that the use of LDPE as a packaging fi lm and treatment with
calcium hypochlorite had a benefi cial effect on retention of pseudomonads . The
combination of hydrogen peroxide and sodium isoascorbate reduced the initial
microbial load but did not have the same effect on the population's growth rate.
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