Prestorage Temperature and Ultra-low Oxygen Treatments Affect Incidence of Physiological Disorders in Organic ‘Granny Smith’ Apples

Abstract

The physiological disorders superficial scald, bitter pit, and lenticel blotch pit severely compromise the commercial value of 'Granny Smith' apples. A number of chemical treatments are available to alleviate these disorders but they are unacceptable in the expanding organic market. The objective of this research was to study the effectiveness of prestorage treatments-delayed cooling and elevated temperature under ultra-low oxygen (ULO) atmospheres-as organic-friendly strategies to control these disorders. 'Granny Smith' apples were exposed to four different treatments: 1) conditioning temperature treatments (CTemp): 10 days at 3 8C or 30 days at 3 8C or 10 days at 20 8C, in air; 2) the same conditioning temperature treatments combined with an ultra-low oxygen (ULO) conditioning treatment of 0.2-0.5 kPa O 2 and <0.5 kPa CO 2 ; 3) 1-methylcyclopropene (1-MCP) treatment as a commercial control; and 4) untreated control fruit. After the prestorage treatment, fruit were stored for 90 or 150 days at 0 8C, and then held poststorage for 8 days at 20 8C before quality analysis. A combination treatment of temperature conditioning and ULO for 30 days at 3 8C achieved the best control of superficial scald, bitter pit, and lenticel blotch pit. The use of ULO with CTemp for 10 days at 20 8C offered the same control but induced high concentrations of ethanol and acetaldehyde that affected the organoleptic acceptability of the fruit and reduced its commercial value. The use of 1-MCP offered 100% control of superficial scald but bitter pit and lenticel blotch pit disorder incidences were similar or higher than in the control fruit. All ULO conditioning treatments resulted in high ethanol and acetaldehyde concentrations during the first 90 days of storage, but fruit exposed to ULO conditioning treatment for 30 days at 3 8C showed similar organoleptic acceptability to control fruit after 150 days. Therefore, ULO conditioning is a potentially useful treatment for the organic apple industry.

Ultra-Low Oxygen and Preconditioning Storage Regulate Ethylene Synthesis to Prevent Corky Disorders in ‘Fuji’ Apple

“…However, the incidence was almost entirely alleviated in ULO-treated fruit (0.3–0.5 kPa O 2 ) during the delayed period of storage. These results confirm previous reports ( Pesis et al, 2010 ; Val et al, 2010 ; Zoffoli et al, 2018 ) where combination of low O 2 with high temperature or high temperature alone alleviates these disorders. Although the ULO conditioning treatment was applied for a short period of time, the effectiveness extended 75 days at 0°C after the ULO treatment.…”

“…In order to obtain the desired partial oxygen (0.3–0.5 kPa O 2 ) and CO 2 (<0.5 kPa) pressure, initial air (21 kPa) was replaced with 100 kPa N 2 , dispensed from a nitrogen cylinder (Indura S.A., Santiago, Chile). The oxygen partial pressure was adjusted manually following the methodology described by Zoffoli et al (2018) , by flushing with nitrogen (to lower it) or with air (to raise it). Gas monitoring, O 2 , and CO 2 were performed using a portable MAP Test Gas Analyzer 4000 (Hitech Instruments Ltd., Luton, United Kingdom).…”

“…Similar results using a short anaerobic period before storage at 0°C alleviated bitter pit and superficial scald in ‘Granny Smith’ and ‘Golden Reinders’ apples ( Val et al, 2010 ). The results showed that the initial ULO treatments reduced the ethylene production, conjugated trienols, and respiration rate of the fruit ( Pesis et al, 2010 ; Val et al, 2010 ; Zoffoli et al, 2018 ).…”

“…However, positive physiological effects can also be achieved in the fruit. Studies, carried out on ‘Granny Smith’ apples, demonstrated a reduction in oxidative-related disorder (superficial scald), bitter pit, and lenticel blotch pit, using a combination of 30 days delayed storage at 3°C under ULO partial pressure (0.3–0.5 kPa) after 150 days of storage at 0°C ( Zoffoli et al, 2018 ). Similar results using a short anaerobic period before storage at 0°C alleviated bitter pit and superficial scald in ‘Granny Smith’ and ‘Golden Reinders’ apples ( Val et al, 2010 ).…”

Strategies to Preserve Postharvest Quality of Horticultural Crops and Superficial Scald Control: From Diphenylamine Antioxidant Usage to More Recent Approaches

“…Zoffoli et al [97] tested different pre-storage treatments in conserving 'Granny Smith' apples commercial value. The use of temperature conditioning (10 d at 3 • C) and ultra-low oxygen 0.2-0.5 kPa achieved the best control of fruit hazards, compared to 1-MCP treatment.…”