Storage of guava under short term modified atmosphere conditions
Loading...
Date
2007
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
The fruits of guava from winter season crop were harvested at green
matured stage, packed in corrugated fiber boxes (control) and in sealed 300
gauge LDPE bags to create various MA conditions viz., MA (air), 100%
vacuum, 50% vacuum, 75% N2 + 25% air ( 5-6% O2). The fruits were kept in
these respective MA conditions for 2, 4, 6 and 8 days, and after these
differential periods, were unpacked and stored similar to control. Fruits
under all the treatments were stored at room temperature (20+2oC; 63+3%
RH) for 12 days and sampled at every alternate day for various physiological
and biochemical parameters.
It was observed that packing guava fruits in sealed poly bags brought
down O2 concentration inside the bags to 0.1 % and elevated CO2
concentration to > 50% within two days of storage. The PLW of the fruits was
reduced drastically by all MA treatments. All the MA conditions were equally
effective except that higher PLW was observed in fruits subjected to MA (air)
for 2 days. The ripening of fruits was reduced by all MA conditions, most
effective being the 100 % vacuum treatment. More the duration of MA, more
is the reduction in ripening. MA conditions did not show any decay loss up to
8th day of storage but develop brown patches on the top and bottom surface
at later storage periods. The incidence of such patches was least in 100%
vacuum packed fruits.
There decrease in flesh firmness of the fruits was rapid and progressive
in control fruits but there was slower decrease in firmness of fruits under
various MA conditions. Under longer durations of storage ( > 2 days) in 100%
vacuum and MA (air), the fruits became excessively hard. The acidity of the
fruits was higher in MA than control, maximum being observed for fruits
exposed to 100% vacuum followed by MA (air), while it was minimum in 75%
nitrogen. The increasing duration of exposure to MA resulted in higher acidity
of the fruits. There was higher retention of ascorbic acid during storage in
fruits exposed to various MA conditions, however, no consistent trend was
observed in the magnitude of retention of ascorbic acid during storage under
various MA conditions.
There was increase in ethanol and acetic acid contents of the fruits
under MA conditions and during storage. Longer the duration of MA, more is
the accumulation of ethanol and acetic acid. Based on the results obtained in
the present investigation, different MA conditions effectively reduced PLW,
decay loss, ripening and softening of fruits during storage. However, excessive
hardening, reduced TSS and development of off-flavour due to accumulation
of acetic acid and ethanol in the fruits exposed to MA conditions, particularly
the longer durations, and under 100% vacuum and MA (air) conditions, the
organoleptic quality of the stored fruits was low and unacceptable. Hence,
these treatments can not be regarded as effective treatments to enhance the
shelf life of guava fruits. However, the fruits exposed to short duration of 2
days under these MA conditions showed enhanced shelf life by about 4 days
over control showing shelf life of 8 days at room temperature.
Description
Keywords
Acetic acid, Ethanol, Firmness, guava, modified atmosphere, Organoleptic quality, Shelf life