General
Summer pears are characterized by high respiration rates, sensitivity to breaks in the cold chain, and a consumer preference for a sweet, soft, juicy product. If best practice guidelines are not followed meticulously, serious defects such as internal browning, unsightly chafe marks, and over-ripeness may occur. Because cooling is crucial in the handling chain, planning for sufficient cooling capacity is vital, especially during periods of loadshedding.
1. Cultivars
- Flamingo
- Rosemarie
- Cheeky
- Bon Rouge
- Williams Bon Chretien
- Early Bon Chretien
- Celina
2. Harvest Maturity
- Firmness is the main maturity indicator for pears. Use DALRRD’s regulation as a guideline.
- Add 0.9 kg (2 pounds) to the minimum firmness to lower the risk of overmature fruit entering the packhouse.
- Use discretion to start harvesting; pears close to the maximum of the “firmness window” are very susceptible to developing rub marks during handling.
- Ensure compliance with your market’s TSS (Total Soluble Solids) requirements.
3. Harvest
- Avoid harvesting fruit with high turgidity after rain.
- Avoid harvesting during periods of high ambient temperature as far as possible.
- Cover bins with wet blankets during transport from the orchard to the bin off-loading area.
- All fruit should be transported from the orchard to the packhouse (cold store) on the same day.
- Insert thermocouples to measure the core temperature of bins during the cooldown period.
4. Fruit Receiving
- Measure the temperature of incoming fruit.
- If fruit are packed wet – do not drench at fruit receiving.
- If fruit are packed dry – drench at fruit receiving:
- Chlorine drench at 100 ppm.
- Test chlorine concentration every 200 bins to ensure effective treatment.
5. Fruit Cooling Before Packing
- Room set point: -1.0 °C DAT.
- Stick to your room’s designed cooling capacity.
- If the capacity is 200 bins per day, do not load 300; rather, put the last 100 in another room.
- Keep loadshedding in mind, as it will negatively affect your cooling capacity.
- Keep fruit in the cold room for 48 hours before packing.
- Measure fruit temperature to ensure it has been cooled to below 0 °C.
- The next day’s fruit must be kept in a separate room.
6. Packing
- Only use the specially designed SuperVent carton for summer pears.
- Do not change packaging (bags/cartons) without proper trials to test the impact on quality.
- Fruit with a temperature above +2.0 °C should not be packed.
- When packing wet, maintain a chlorine concentration of 100 ppm.
- Generally, pack in 20-micron bags.
- Temperature after packing, palletizing, and inspection should be kept below 12 °C.
- Timeous inspection by PPECB should help maintain the cold chain.
7. Re-cooling
- Forced air cooling (FAC) after packing is non-negotiable.
- FAC at -2.0 °C. After 24 hours, rotate pallets in tunnels 180 degrees (inside wall to outside).
- Final fruit temperature of -0.5 °C should be reached within 48 hours after packing.
8. Load Out
- Load pallets directly from cold room/tunnel into the shipping container—do not let them stand outside.
- Load out temperatures must not exceed +1.5 °C.
- Container temperature set point: -0.5 to -1.5 °C.
- Thicker bag = lower set point
- Thinner bag = warmer set point
- 37-micron bag ideally at -1.0 °C
- DP1: -1.0 °C (summer pears in bags only)
Carry at -1 °C for the full duration of the voyage. Closed vents. - DP2: -1.5 °C (summer pears in bags only)
Carry at -1 °C for the full duration of the voyage. Closed vents. - D05: -0.5 °C (summer pears without bags)
Carry at -0.5 °C for the full duration of the voyage. Closed vents.
9. Transport
- With high ambient temperatures during the early months of the year, gensets should be used when travel time to the port terminal exceeds 1 hour. This is one hour less than PPECB’s Time Temperature Tolerance (TTT) regulations for deciduous fruit, but due to the sensitivity of summer pears to breaks in the cold chain (especially January to March), this guideline is necessary.
- Note that a genset adds about 1 ton to the vehicle mass, and problems may occur at weighbridges with axle mass limitations.
(PPECB HP22 Carrying Temperature Regime Codes of Perishable Produce)