Abstract:
The influence of modified atmosphere packaging (MAP) and storage temperature on the
postharvest quality characteristics and biochemical properties of green chilli peppers
(Capsicum sps. cvs Legon 18 and KA2) was investigated. Packaging films; Low Density
Polyethylene (LDPE) 35fim non-perforated and perforated, Polypropylene(PP) 80um non perforated
and perforated (twenty perforations were made on each perforated bag using a pin
of diameter 0.14 mm) and LDPE micro-perforated 31.75p.m were tested at three storage
temperatures of 4.3C°, 10°C and 26-34°C (ambient). Fruits were stored for four weeks at
low temperatures (4.3°C and 10°C) in a 2 x 5 factorial treatment combinations in completely
randomized design with three replications and nine days in ambient temperature (26-34°C)
in completely randomized design with three replications. Data on weight loss, firmness, fruit
green colour retention and incidences of chilling injury and decay were collected and
subjected to statistical analysis. Biochemical analysis of the MAP-stored fe^ fsrfo f^ an g e s in
titratable acidity, soluble solids, ascorbic acid, total carotenoids and fffcjfen phenolicVSentents
were also assessed quantitatively before and after storage. Packagin^r(M A P )j^ 3 lte d in
reduced weight loss at all the temperatures (4.3°C, 10°C and 26 -34 °C) compared to
unpackaged pepper fruits stored at the respective temperatures. Fruit weight loss was
significantly lower in the film-packed fruits stored atlO°C than at 4.3°C. Firmness was fairly
maintained in the film-packed fruits at all the storage temperatures than unpacked fruits.
Green colour retention o f the fruits was significantly higher in packaged fruits held at 4.3°C
and 10°C than the control. Chilli peppers stored in the packaging films at 10°C, showed
significantly lower chilling injuries compared to those at 4.3°C storage temperature with KA2
fruits being less susceptible than Legon 18. Packaged fruits did not present fruit decay at low
temperature storage (4.3°C and 10°C), however, the combination of film packaging and
storage under ambient temperature (26-34°C) had significantly high incidence of fruit decay
particularly in the Legon 18 fruits. Changes in biochemical components were observed in
chilli peppers after MAP storage at both low and ambient storage temperatures. This study
showed that postharvest treatments involving a combination of MAP and optimum storage
temperature (10°C) is beneficial in maintaining the quality and in effect extending the
marketable/shelf-life o f fresh green chilli pepper fruits.