Presenter: Anél Botes
Event: CA Meeting – 5 November 2019
Introduction and Objectives
- Currently, ‘Abate Fetel’ (AF) pears can be stored at 1.5% O₂ and 0.5% CO₂ for 4 months.
- AF is susceptible to soft scald when stored at low oxygen.
- AF is also susceptible to superficial scald.
Objective:
To evaluate the effect of different storage regimes on the quality of ‘Abate Fetel’ pears in order to extend the storage life to possibly 6 months.
Materials and Methods
- Season: 2018
- Production areas: Grabouw and Ceres
- Maturity: Optimum and post-optimum
Treatments
- 1.5% O₂ + 0.5% CO₂ (CA1.5)
- 1.5% O₂ + 0.5% CO₂ + 1-MCP (SF+CA1.5)
- 6% O₂ + 0.5% CO₂ (CA6)
- 6% O₂ + 0.5% CO₂ + 1-MCP (SF+CA6)
- DCA-CF (0.7% O₂) (DCA)
- DCA-CF + 1-MCP (pre-shipment 1-MCP) (DCA+SF)
- RA (Regular Atmosphere)
- RA + 1-MCP (SF+RA)
- Temperature: -0.5°C and 1°C
- Fruit quality evaluation: After 4 and 6 months (+ 6 weeks RA + 7 days at 20°C)
Fruit Quality Parameters
- Total soluble solids (TSS)
- Titratable acidity (TA)
- Firmness (kg)
- Skin colour (scale 1–5)
Sensory Evaluation
- Appearance (1–10)
- Taste (1–10)
- Texture (1–10)
- Off-taste (1–10)
Physiological Disorders
- Superficial scald (%)
- All other internal and external disorders
Results and Discussion
Optimum Abate Fetel from Grabouw Production Area
- After 7-day shelf-life:
- Significant treatment effects observed (Trtx Period P < 0.0001, LSD₅% = 3.91 and 0.35).
- After 6 months + 6 weeks RA + 7 days at -0.5°C:
- Treatments: CA1.5, CA6, RA, SF+CA1.5, SF+CA6, SF+RA, DCA, DCA+SF
Post-Optimum Abate Fetel from Grabouw Production Area
- After 7-day shelf-life:
- Significant treatment effects (Trtx Period P < 0.0001, LSD₅% = 8.01 and 0.30).
- After 6 months + 6 weeks RA + 7 days at -0.5°C:
- Treatments: CA1.5, CA6, RA, SF+CA1.5, SF+CA6, SF+RA, DCA, DCA+SF
Optimum Abate Fetel from Ceres Production Area
- After 7-day shelf-life:
- Significant treatment effects (Trtx Period P < 0.0001, LSD₅% = 5.96 and 0.34).
- After 4 months + 6 weeks RA + 7 days at -0.5°C:
- Treatments: CA1.5, CA6, RA, SF+CA1.5, SF+CA6, SF+RA, DCA, DCA+SF
Post-Optimum Abate Fetel from Ceres Production Area
- After 7-day shelf-life:
- Significant treatment effects (Trtx Period P = 0.0003, LSD₅% = 10.05 and <0.0001, LSD₅% = 0.48).
Conclusions
- Optimum and post-optimum Grabouw and optimum Ceres:
1-MCP + CA was effective to prevent the development of superficial scald and soft scald after 6 months at -0.5°C (not ready-to-eat stage). - Optimum Grabouw and Ceres:
DCA + pre-shipment 1-MCP resulted in no physiological disorders (ready-to-eat). - Store optimum fruit for 4 months:
1-MCP + RA is a cost-effective option.
Acknowledgements
- Funders: ARC and HortgroScience
- Technical assistance: Howard, Viole, and Vanessa