Detecting temperature breaks in the initial stages of the citrus export cold chain: A case study

Background: Fruit is an important export commodity for South Africa and accounts for 35% of its agricultural exports. South Africa is the second largest citrus exporter in the world, behind Spain. Maintaining the postharvest cold chain is key to ensuring that fruit quality meets export standards. Objectives: The main objectives of this research were to investigate the frequency, location, magnitude and duration of temperature deviations in the South African leg of the clementine and navel orange cold chain. Method: Temperature trials were conducted on two consignments of clementines and two consignments of navels. Each consignment contained 36 iButtons (R), of which 18 measured pulp temperature and 18 measured ambient temperature. Data were successfully retrieved from 130 of the 144 iButtons (R). Results: This research identified areas where the temperature went outside the prescribed range along the South African portion of the export cold chain of navel oranges and clementines from Citrusdal, South Africa to the Port of Newark, United States of America. Conclusion: The temperature incidents identified could result in a breach of the cold sterilisation (steri) protocols and quality defects. Recommendations were made to address these deficiencies to improve the South African citrus industry's global competitiveness. Contribution: This research allowed the citrus industry to investigate and adjust current cold chain practices to improve the integrity of the entire export cold chain, potentially resulting in a higher quality product and increased revenue.