Articles
Dynamic controlled atmosphere – chlorophyll fluorescence (DCA-CF) and controlled atmosphere (CA) for long-term storage of ‘Cripps Pink’ apples with special reference to internal browning
Article number
1456_8
Pages
57 – 66
Language
English
Abstract
Dynamic control atmosphere – chlorophyll fluorescence (DCA-CF) technology has been shown to reduce superficial scald in ‘Granny Smith’ apples.
As both internal browning (IB) and superficial scald are forms of oxidative browning this study hypothesized that storing fruit at lower O2 in DCA-CF could result in lower IB in ‘Cripps Pink’ apples compared to controlled atmosphere (CA) storage. ‘Cripps Pink’ apples were harvested in the 2021 season from two apple production regions in South Africa.
Fruit harvested from Ceres (Western Cape) had an optimum starch breakdown of 28%, and fruit harvested from the Langkloof (Eastern Cape) had post-optimum starch breakdown of 60% prior to low-oxygen storage.
After treatment with 1-Methylcyclopropene (1-MCP), fruit were stored under DCA-CF (O2≈0.4 kPa; CO2<0.5 kPa) or CA (O2 1.5 kPa; CO2 0.5 kPa). The fruit were step-down cooled (3°C for 30 d, 2°C for 30 d) before being stored at 1°C for 7 months.
Fruit were then stored for 6 weeks in regular air (RA) at 1°C to simulate the shipping period, followed by 7 d shelf-life conditions in RA at 20°C. IB incidence and type were assessed after each storage period.
Marginal differences in IB incidence were found between DCA-CF and CA storage treatments.
Fruit harvested at optimum maturity generally had lower IB than fruit harvested at post-optimum maturity, regardless of storage method.
Principal component analysis (PCA) showed that maturity before storage had a greater influence on IB development than storage treatment.
These findings highlight the critical role of harvest and before storage maturity in mitigating IB in ‘Cripps Pink’ apples.
Since the harvest maturities were sampled from orchards in different production regions, statistical comparisons could not be made.
Future studies should verify findings by harvesting fruit at both optimum and post-optimum maturity from the same orchard to account for these variances.
As both internal browning (IB) and superficial scald are forms of oxidative browning this study hypothesized that storing fruit at lower O2 in DCA-CF could result in lower IB in ‘Cripps Pink’ apples compared to controlled atmosphere (CA) storage. ‘Cripps Pink’ apples were harvested in the 2021 season from two apple production regions in South Africa.
Fruit harvested from Ceres (Western Cape) had an optimum starch breakdown of 28%, and fruit harvested from the Langkloof (Eastern Cape) had post-optimum starch breakdown of 60% prior to low-oxygen storage.
After treatment with 1-Methylcyclopropene (1-MCP), fruit were stored under DCA-CF (O2≈0.4 kPa; CO2<0.5 kPa) or CA (O2 1.5 kPa; CO2 0.5 kPa). The fruit were step-down cooled (3°C for 30 d, 2°C for 30 d) before being stored at 1°C for 7 months.
Fruit were then stored for 6 weeks in regular air (RA) at 1°C to simulate the shipping period, followed by 7 d shelf-life conditions in RA at 20°C. IB incidence and type were assessed after each storage period.
Marginal differences in IB incidence were found between DCA-CF and CA storage treatments.
Fruit harvested at optimum maturity generally had lower IB than fruit harvested at post-optimum maturity, regardless of storage method.
Principal component analysis (PCA) showed that maturity before storage had a greater influence on IB development than storage treatment.
These findings highlight the critical role of harvest and before storage maturity in mitigating IB in ‘Cripps Pink’ apples.
Since the harvest maturities were sampled from orchards in different production regions, statistical comparisons could not be made.
Future studies should verify findings by harvesting fruit at both optimum and post-optimum maturity from the same orchard to account for these variances.
Authors
D. Ramos, I. de Jong, M. Jooste, I.J. Crouch, E.M. Crouch
Keywords
1-methylcyclopropene (1-MCP), combination browning, diffuse browning, Malus domestica, maturity, radial browning, step-down cooling
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