Effect of Modified Atmosphere Packaging and Storage Temperature on the Quality of Green Chilli Pepper Fruits

ABSTRACT

The influence o f modified atmosphere packaging (MAP) and storage temperature on the postharvest quality characteristics and biochemical properties o f 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) 80^m nonperforated 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 M AP-stored fe^ fsrfo f^ an g es 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 2 6 -3 4 °^ ^ e m 'p a re d 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 o f 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 o f 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.