Articles
Quality improvement of degreened oranges and mandarins by reducing the postharvest exposure to ethylene
Article number
1458_48
Pages
363 – 370
Language
English
Abstract
Early-season citrus fruit cultivated in the Mediterranean area are often subjected to degreening treatment, including the application of exogenous ethylene, when they have reached the minimum standards of internal maturity, while their peel is still green.
However, the postharvest use of ethylene has been associated with fruit disorders, such as calyx drop, pitting, and brown spots on the peel, as well as alterations in taste and aroma.
The aim of the present work was to evaluate the effect of a 24-h low-temperature storage prior to the degreening process (DP) on reducing the fruit’s exposure time to ethylene. ‘Navel’ oranges and ‘Clementine’ mandarins were harvested with peel colour index -4.3 and 0.55, respectively, while both had reached total soluble solids/titratable acidity (TSS/TA) values >7.5/1. After harvest, the fruits were divided into two groups; the fruits of the first group were subjected to degreening treatment under commercial conditions for 72 h (oranges) and 48 h (mandarins), respectively.
Fruit from the second group was stored at 4°C for 24 h before DP and, therefore, was subjected to a reduced exposure time to ethylene (by 24 h). Changes in peel colour (assessed by L*, a*, b*, h°, C*, and CI) and main quality parameters (such as TSS, TA, pH, and % juice) were evaluated after postharvest treatments and during cold storage at 8°C for oranges and at 12°C for mandarins, for up to a month. ‘Navel’ oranges subjected to 24 h cold storage followed by reduced time DP developed similar peel colour to fruit subjected to commercial degreening, and no differences between the two treatments were observed during storage.
Regarding ‘Clementine’ mandarins, fruit subjected to the commercial degreening process had higher CI values compared to fruit of all other treatments.
However, ‘Clementines’ exposed to 4°C for 24 h and then to commercial DP showed higher CI values at the beginning of storage than controls.
However, the postharvest use of ethylene has been associated with fruit disorders, such as calyx drop, pitting, and brown spots on the peel, as well as alterations in taste and aroma.
The aim of the present work was to evaluate the effect of a 24-h low-temperature storage prior to the degreening process (DP) on reducing the fruit’s exposure time to ethylene. ‘Navel’ oranges and ‘Clementine’ mandarins were harvested with peel colour index -4.3 and 0.55, respectively, while both had reached total soluble solids/titratable acidity (TSS/TA) values >7.5/1. After harvest, the fruits were divided into two groups; the fruits of the first group were subjected to degreening treatment under commercial conditions for 72 h (oranges) and 48 h (mandarins), respectively.
Fruit from the second group was stored at 4°C for 24 h before DP and, therefore, was subjected to a reduced exposure time to ethylene (by 24 h). Changes in peel colour (assessed by L*, a*, b*, h°, C*, and CI) and main quality parameters (such as TSS, TA, pH, and % juice) were evaluated after postharvest treatments and during cold storage at 8°C for oranges and at 12°C for mandarins, for up to a month. ‘Navel’ oranges subjected to 24 h cold storage followed by reduced time DP developed similar peel colour to fruit subjected to commercial degreening, and no differences between the two treatments were observed during storage.
Regarding ‘Clementine’ mandarins, fruit subjected to the commercial degreening process had higher CI values compared to fruit of all other treatments.
However, ‘Clementines’ exposed to 4°C for 24 h and then to commercial DP showed higher CI values at the beginning of storage than controls.
Authors
A. Velliou, M. Kafkaletou, M.V. Christopoulos, I. Lycoskoufis, A. Spyropoulos, E. Tsantili
Keywords
oranges, mandarins, ethylene exposure, cold storage
Online Articles (67)