Postharvest treatments to reduce chilling injury symptoms in stored ...

(QC, Canada) in refrigerated containers maintained at 10 ºC. They were received for the
experiment on January 20, 2003. Fruits were approximately 17 days from harvest at the
start of the experiment. Fruits of uniform size, shape and free of defects were used for the
experiment. The average mass of an individual fruit was 650 g. Three lots of 5 mangoes
were used to assess the quality of the mangoes on their arrival in the laboratory.
Prior to the start of the experiment, the mangoes were randomly divided into four
lots of 60 mangoes. One of the four CI-treatments was then applied to each lot. The first
lot did not receive any CI-treatment and was used as control. The second lots of 60
mangoes were immersed in HW (50 + 2 ºC) for 10 min. A vibrating water bath was used
for this purpose. Mangoes from the third lot were exposed to MJ. A solution of 9:1 ratio
of Ethanol and MJ was prepared and then diluted with water to get final concentration of
10 -4 M. Mangoes were dipped in this solution for 2 min and air dried. Mangoes from the
fourth lot were dipped for 2.5-3.0 min in a solution made of 12 mM DPA in 5 % ethanol
and 0.05 % Tween 20, and air dried.
After receiving their respective CI-treatment, each lot was then divided into four
samples of 15 mangoes each and stored in paper bags for 21 days at either 1, 4, 7 or 10
ºC. At the end of storage, the quality of mangoes was assessed and compared.
3.4.2 Quality assessment
The parameters used to monitor the quality of the mangoes before and after
storage were: skin and flesh color, pH, sugar content, texture, percentage of mass loss and
percentage of good mangoes.
Skin and flesh colors were measured with a Minolta Chromameter Model CR-
300X (Minolta camera Co. ltd., Japan) equipped with a 5 mm diameter measuring area.
Measurements were reported in terms of CIE (Commission Internationale de I’ Eclairage)
L*a*b color space and expressed as L* (whiteness/darkness, ranged from 0 to 100, while
100 being the lightest), a* (redness for positive value and greenness for the negative one)
and b* (yellowness for positive and blueness for negative value) (McGuire, 1992).
Calibration was performed against a standardized white calibration plate according to the
manufacturer specifications.
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