APPROACHES TO EXTEND SHELF-LIFE, MINIMIZE WATER LOSS, CHILLING INJURY AND STORAGE DISEASES IN SUMMER SQUASH (Cucurbita pepo L.)
Loading...
Date
2015
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
DIVISION OF FOOD SCIENCE & POST HARVEST TECHNOLOGY ICAR-INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI –
Abstract
Summer squash is an important vegetable of Cucurbitaceae family and it is highly
perishable due to excessive loss of moisture, severe chilling injury and proneness to
postharvest diseases mainly caused by gray mould and bacterial soft rot during
storage. With this background the present study was carried out to minimize above
said postharvest problems of water loss, chilling injury and postharvest decay
through the application of suitable surface coating material, anti chilling compound
and post harvest disease controlling microbes. For minimizing the excessive water
loss during handling and storage, gum arabic (5, 10 and 15%) and fruwash were
applied on freshly harvested fruit. Prior giving the coating treatment freshly
harvested fruit were subjected to hot water dip treatment (38 ºC) for 30 minutes.
Treated fruits were stored at 8 ±2 ºC and 85-90% RH and various physico-chemical
parameters were recorded at three days interval during storage. Under this
experiment 10% gum arabic as a coating material proved to be the best in
minimizing water loss (more than 50%), respiration rate (more than 50%) and
maintaining higher fruit firmness (7.55 N).
Under the chilling injury minimizing experiment, fruits were treated with
salicylic acid (1.0– 1.5 mM) and sodium nitroprusside (1.0– 1.25 mM) followed by
cold storage at 5 ±2 ºC. Among the tested anti chilling molecules, salicylic acid
@1.0 mM proved the best in minimizing chilling injury score (0.74), PLW (11.73%),
retaining higher level of phenolics (420.75 µg/g) and proline (333.87 µg/g ) during
storage.
In order to achieve higher shelf-life of summer squash fruit during storage
ozone treatment (0.2, 0.4 and 0.6 ppm) was given through dissolving ozone in
distilled water. Freshly harvested fruit were dipped in ozonated water for 10 minute
followed by storage, for collection of data on physico-chemical and microbiological
parameters. Ozonated water concentration @ 0.4 ppm retained the best physical traits
like fruit firmness (5.84 N) and lower PLW (15.06%), although higher concentration
of ozonated water (0.6 ppm) effectively controlled decay incidence (10.83%),
bacterial count (3.92 log cfu/g) and yeast-mould count (3.65 log cfu/g).
For controlling postharvest diseases Debaryomyces hansenii, Pseudomonas
fluorescens and Bacillus subtilis bio agents were used. Among the tested bio-control
agents, Debaryomyces hansenii proved the best in terms of minimizing decay
incidence (13.50%), firmness loss (5.93 N) and weight loss (11.78%) by virtue of
higher antagonistic activities against gray mould disease. Pseudomonas fluorescens
was found to be the best in controlling bacterial soft rot by minimizing lesion
diameter (26.67 mm), maximizing zone inhibition (4.33 cm2
) and minimizing fruit
weight loss (13.54 %) at the end of storage period of 12 days.
Description
t-9378
Keywords
APPROACHES TO EXTEND SHELF-LIFE, MINIMIZE WATER LOSS, CHILLING INJURY AND STORAGE DISEASES IN SUMMER SQUASH (Cucurbita pepo L.)