1. Fruit Maturity and Packaging
- Flesh firmness must be between 7.0 and 5.0 kg (optimum: 6.5 kg), measured with a penetrometer fitted with an 11 mm plunger.
- Fruit maturity must be uniform.
- No plums below a minimum flesh firmness of 5.0 kg are permissible in the consignment.
- Skin colour must not exceed plate 6 on colour chart PL19 for Songold plums.
- Minimum average TSS (Total Soluble Solids) is 12.5%.
- Plums can be packed in standard cartons, punnets, or thrift bags prior to or after SmartFreshSM application.
- In standard cartons, perforated grape bags (54 x 2 mm perforations) or perforated plum wrappers can be used. Perforated grape bags must only be used on SmartFreshSM treated Songold plums.
- Plum wrappers, rather than bags, are preferred for fruit with a high decay potential.
2. Re-inspection
- According to the Agricultural Product Standards Act, 1990 (Act No 119 of 1990), the re-inspection period for Songold plums treated with SmartFreshSM is after 35 days.
3. SmartFreshSM Application Procedure and Handling
3.1 Shipping Container or Room Application (for shipping after warming period at 7.5°C)
- Plums must be packed and placed under cooling at –0.5°C within 24 hours after harvest. Follow standard norms for cooling Songold plums.
- SmartFreshSM application must be conducted after plums have been cooled to –0.5°C, but within a maximum of 7 days after harvest.
- The temperature set point in the cold room and shipping container must be –0.5°C. The container must be available for 24 hours to facilitate the SmartFreshSM application.
- SmartFreshSM application duration: 16–24 hours.
- After SmartFreshSM application, raise the temperature to 7.5°C for 14–18 days (room or container). Monitor flesh firmness during this period; re-cool to –0.5°C if firmness drops below 4.5 kg.
- After the period at 7.5°C, re-cool plums to –0.5°C using forced-air cooling and store/ship at –0.5°C (PD1). Maximum storage period from harvest is 56 days (excluding shelf life).
- Since SmartFreshSM treated plums may be stored for extended durations, pre- and post-harvest decay prevention strategies should be strictly followed.
- Plums can be ripened at 18°C prior to marketing if required.
3.2 Shipping Container Application (with warming cycle conducted in container during shipping)
- Plums must be packed and placed under cooling at –0.5°C within 24 hours after harvest. Follow standard norms for cooling Songold plums.
- SmartFreshSM application must be conducted after plums have been cooled to –0.5°C, but within a maximum of 7 days after harvest.
- The temperature set point of the shipping container must be –0.5°C. The container must be available for 24 hours to facilitate the SmartFreshSM application.
- SmartFreshSM application duration: 16–24 hours.
- After SmartFreshSM application, raise the temperature in the container to 7.5°C for 14 days. After 14 days, lower the container temperature again to –0.5°C.
- Store the fruit at –0.5°C for the remainder of the cold storage period.
3.3 Bin Application in CA Rooms (for plums held in South Africa for up to 3 weeks prior to packing and shipping)
- Ensure the SmartFreshSM application room is air-tight.
- No bins with overripe or insect-damaged fruit should be in the treatment room (damaged/overripe fruit will produce ethylene and compromise the treatment).
- Clean and sanitise the room before use.
- Plums must be placed under cooling at –0.5°C immediately after harvest. Ensure fruit in the centre of bins is also effectively cooled.
- SmartFreshSM application must be conducted after plums have been cooled to –0.5°C, but within a maximum of 5 days after harvest.
- SmartFreshSM application duration: 16–24 hours.
- Ensure the room is well vented after application to prevent CO₂ build-up.
- After treatment, raise the temperature to 7.5°C for 14–18 days, depending on maturity.
- Check the maturity and general quality of the plums regularly prior to packing.
- Pack fruit immediately if flesh firmness declines to 5.0 kg or below.
- Pack fruit immediately after the period at 7.5°C. Bins that cannot be packed immediately must be placed at –0.5°C.
- After packing, force-air cool plums to –0.5°C and store/ship at –0.5°C.
- Maximum storage period from harvest is 56 days (excluding shelf life).
- Since SmartFreshSM treated plums may be stored for extended durations, decay prevention strategies should be strictly followed.
- Plums can be ripened at 18°C prior to marketing if required.
4. SmartFreshSM Efficacy Samples
- Two extra representative cartons of plums must be made available to ExperiCo prior to SmartFreshSM application.
- One carton will be treated with SmartFreshSM in the commercial application, and the other will be used as an untreated control.
- The extra cartons will be used to determine the efficacy of the SmartFreshSM treatment.
- While every effort will be made to inform packhouses/exporters of abnormal ripening if it occurs, it remains the responsibility of the packhouse/exporter to monitor fruit ripening progression in the supply chain and to make decisions required to achieve optimal quality. This applies particularly to monitoring the maturity of plums in cases where the warming cycle is conducted locally.