Pears
Pears are classified as Summer pears and Winter pears.
Key Points for Summer Pears
- Ripening: Summer pears ripen quickly; cooling and maintaining the cold chain is critical.
- Temperature Sensitivity: Extremely sensitive to high temperatures. Cool fruit as fast as possible (within 48 hours) and maintain the cold chain.
- Transport: Preferably use refrigerated trucks. Pulp temperatures may not exceed +0.5°C during loading.
- Freezing Risk: Freezing may occur if core temperatures drop below –1.5°C. Prolonged exposure at these temperatures damages fruit. The Total Soluble Solid (% TSS) content influences the freezing point.
Specific Protocols for Summer Pears
- Varieties: Early Bon Chretien, Beurre Hardy, Bon Chretien, Doyenne du Comice, Bon Rouge, Sempré, Rosemarie, Victoria Blush, Flamingo, Harrow Delight.
- Maturity: Pick strictly according to maturity parameters (see Table 2).
- Fruit Delivery: Within 12 hours of harvest, preferably same day.
- Pre-cooling: Within 48 hours, preferably sooner.
- Packing Period (Bon Chretien):
- Firmness > 8.4 kg: pack within 14 days.
- Firmness < 8.4 kg: pack within 7 days.
- Recooling: To –0.5°C within 96 hours.
- Transport: Preferably in refrigerated trucks. Only fruit adhering to Picking Code 1 (picked early in the window) may be transported by Tautliner trucks for short distances (e.g., Helderberg to harbour, ~50 km). Consider waiting times at the harbour.
- Temperature Protocols:
- DP1: –1.0°C (summer pears in bags only). Carry at –1°C for the full voyage, max +0.5°C.
- D05: –0.5°C (summer pears without bags). Carry at –0.5°C for the full voyage, max +1.5°C.
Storage Parameters for Summer Pears
| Variety | Packaging | Max Storage | CA Gas Mixture | Shelf Life | Inspection STD’s | Optimum Temp |
|---|---|---|---|---|---|---|
| EBC | Poly bag | 3 months | 1.0% O₂ + 0.0% CO₂ | 5 days | 10.0–7.3 kg | –0.5°C |
| BC | Poly bag | 3 months | 1.0% O₂ + 0.0% CO₂ | 5 days | 10.0–7.3 kg | –0.5°C |
| Bon Rouge | Poly bag | 3 months | 1.0% O₂ + 0.0% CO₂ | 5 days | 10.0–7.3 kg | –0.5°C |
| Rosemarie | Poly bag | 3 months | 1.5% O₂ + 1.0% CO₂ | 7 days | 8.2–5.4 kg | –0.5°C |
| Flamingo | Poly bag | 3 months | Not recommended | 7 days | 8.2–6.3 kg | –0.5°C |
| Beurre Hardy | Perforated poly bag | 3 months | 1.5% O₂ + 0.0% CO₂ | 7 days | 6.3–4.1 kg | –0.5°C |
| Doyenne du Comice | Poly bag | 3 months | 1.0% O₂ + 1.0% CO₂ | 7 days | 6.8–3.6 kg | –0.5°C |
Storage Parameters for Winter Pears
| Variety | Packaging | Min Storage | CA Gas Mixture | Shelf Life | Inspection STD’s | Optimum Temp |
|---|---|---|---|---|---|---|
| Forelle | Poly bag | 12 weeks | 1.5% O₂ + 1.0% CO₂ | 10 days | 6.8–4.5 kg | –0.5°C |
| Beurre Bosc | Poly bag | 3 months | 1.5% O₂ + 1.5% CO₂ | 7 days | 8.2–4.5 kg | –0.5°C |
| Packham’s Triumph | Poly bag | 6 months | 1.5% O₂ + 2.5% CO₂ | 7 days | 7.9–5.0 kg | –0.5°C |
Refer to Annexure 3 for detailed CA gas mixtures. With permission from ARC Infruitec-Nietvoorbij.
Apples
Apples are less sensitive to defects from poor cooling than summer pears, but strict cooling protocols are still important for storage potential.
- Sensitive Cultivars: Gala types, Golden Delicious, Braeburn, Red Delicious.
- Cooling: Apples require forced air-cooling.
- Best Practices:
- Do not over-utilise daily cooling capacity.
- Stack bins directly in the path of the air to force air through the fruit.
- Do not stagger or block pack bins; this causes inefficient cooling and high moisture loss.
- Keep doors closed or use plastic/automatic air curtains.
- Use high fan speed for initial cooling; reduce airspeed after room is filled to minimize moisture loss.
- Do not load ethylene-sensitive cultivars (e.g., Royal Gala) with high ethylene producers (e.g., some summer pears).
- Take care with reloading times after packing, especially for Class 1 and Class 2 fruit.
Storage Parameters for Apples
| Cultivar | Packaging | Max Storage | CA Gas Mixture | Shelf Life | Inspection STD’s | Optimum Temp |
|---|---|---|---|---|---|---|
| Gala types | n/a | 3 months | 1.5% O₂ + 1.5% CO₂ | 7 days | Min 5.9 kg | –0.5°C |
| Golden Delicious | Poly bag | 6 months | 1.5% O₂ + 2.5% CO₂ | 7 days | Min 6.8 kg | –0.5°C |
| Red Delicious | n/a | 6 months | 1.5% O₂ + 2.5% CO₂ | 7 days | Min 6.4 kg | –0.5°C |
| Braeburn | n/a | 6 months | 1.5% O₂ + 1.5% CO₂ | 7 days | Min 6.4 kg | –0.5°C |
| Fuji types | n/a | 6 months | 1.5% O₂ + 1.5% CO₂ | 7 days | Min 5.4 kg | –0.5°C |
| Granny Smith | n/a | 6 months | 1.5% O₂ + 1.0% CO₂ | 7 days | Min 5.9 kg | 0.0–1.0°C |
| Cripps Pink | n/a | 6 months | 1.5% O₂ + 1.0% CO₂ | 7 days | Min 6.3 kg, >10% red | –0.5°C |
| Cripps Red | n/a | 6 months | 1.5% O₂ + 2.5% CO₂ | 7 days | Min 6.3 kg | –0.5°C |
| Pink Lady® | n/a | 4 months | 1.5% O₂ + 1.0% CO₂ | 7 days | Min 7.0 kg, >40% red, TSS 13% | –0.5°C |
| Sundowner® | n/a | 6 months | 1.5% O₂ + 2.5% CO₂ | 7 days | Min 30% starch breakdown | –0.5°C |
Refer to Annexure 3 for detailed CA gas mixtures. With permission from ARC Infruitec-Nietvoorbij.
Defects After Poor Cooling
- Over-ripe fruit (low firmness)
- Wilted fruit, especially pears
- Yellowing (Bon Chretien, Royal Gala, Golden Delicious)
- Bitter pit (Golden Delicious, Braeburn)
- Reduced storage potential and shelf-life
- Mealiness (Red Delicious types)
- Greasiness (Granny Smith, Cripps’ Pink/Pink Lady®) linked to over-maturity
Preventing Bruising of Apples and Pears
Bruising can occur due to:
- Rough handling
- High turgidity
- Cultivar bruise potential (e.g., Golden Delicious is more prone)
Types of Bruises
- Pressure bruise: Caused by prolonged pressure, e.g., tightly packed fruit or firm gripping.
- Velocity/impact bruise: Caused by fruit hitting each other or machinery, especially during packing and transport. Pears like Doyenne du Comice are particularly prone.
Prevention Measures
- Train pickers and orchard sorters.
- Prepare farm roads before harvest, especially after rain.
- Prepare bin trailers (correct tyre pressure: 1.5–1.8 kPa for sandy conditions).
- Avoid driving too fast.
- Use bin liners where applicable.
- Do not pick during or directly after rain.
- Pickers should have short nails and not wear jewellery.
- Empty picking bags onto a thick (10 mm) sponge mat to minimize bruising.
- Regularly check the pack line (e.g., with an “electronic apple”) to identify bruise risks.