Model Answer
0 min readIntroduction
Post-harvest losses in fruits and vegetables are a significant impediment to food security and economic prosperity in India, estimated to be around 30-40% (Ministry of Food Processing Industries, 2018). These losses occur due to various factors, including inadequate storage, handling, and processing. Among the crucial techniques employed to minimize these losses are curing and degreening, particularly vital for citrus fruits. Curing involves physiological changes induced in fruits to improve their storability, while degreening aims to alter the external appearance to meet market demands. Understanding the distinct roles of these processes is essential for optimizing horticultural supply chains.
Understanding Curing and Degreening
Curing
Curing is a natural process that involves controlled environmental conditions to trigger physiological changes in fruits and vegetables. It primarily occurs in climacteric fruits – those exhibiting a rise in respiration rate after harvest. These changes include the development of a protective rind, reduction in water loss, and accumulation of sugars.
- Role in Loss Reduction: Curing helps extend the shelf life of fruits by strengthening the rind, reducing decay incidence, and improving overall quality. For example, curing onions and potatoes significantly reduces storage losses due to fungal infections.
- Process Details: It involves maintaining specific humidity, temperature, and ventilation for a defined period. For instance, sweet potatoes are cured at 85-90% relative humidity and 29-32°C for 7-14 days.
- Example: Curing of garlic bulbs enhances their storage life from a few weeks to several months, crucial for rural economies.
Degreening
Degreening is a post-harvest treatment primarily applied to citrus fruits like oranges and lemons. It involves removing the green chlorophyll from the fruit's peel, revealing the underlying orange or yellow color that is preferred by consumers. This process does not inherently improve the fruit’s internal quality but enhances its marketability.
- Role in Loss Reduction: Degreening reduces rejection rates and improves consumer acceptance, which indirectly minimizes losses. Fruits rejected due to green color often end up as waste.
- Process Details: Degreening is typically achieved through exposure to ethylene gas (C₂H₄) at controlled temperatures and humidity. The process duration depends on the fruit variety and desired color.
- Challenges: Improper degreening can lead to peel damage and reduced shelf life, negating the benefits. Ethylene is a regulated substance, and its use requires strict adherence to safety protocols.
Comparison and Synergistic Effects
| Feature | Curing | Degreening |
|---|---|---|
| Primary Goal | Improve physiological quality & storability | Enhance external appearance (color) |
| Mechanism | Natural physiological changes | Chemical reaction (ethylene-induced chlorophyll breakdown) |
| Impact on Shelf Life | Extends shelf life significantly | May slightly reduce shelf life if not controlled properly |
| Applicability | Wide range of fruits & vegetables (onions, potatoes, sweet potatoes, garlic) | Primarily citrus fruits |
While curing focuses on internal quality and shelf life, degreening addresses consumer preference. Combining both processes can be beneficial. For example, properly cured citrus fruits can undergo degreening without significant loss of quality, leading to a product that is both durable and visually appealing.
Challenges and Future Directions
- Lack of Awareness: Many farmers are unaware of the benefits of curing and degreening.
- Infrastructure Deficiencies: Adequate infrastructure for controlled environment storage is often lacking, particularly in rural areas.
- Cost: The initial investment in equipment and technology can be a barrier for small farmers.
- Future Directions: Research on natural alternatives to ethylene for degreening and improved curing techniques tailored to specific fruit varieties are crucial.
Conclusion
In conclusion, curing and degreening are vital post-harvest practices for reducing losses and enhancing the marketability of fruits and vegetables. While curing addresses the fruit's internal quality and extends shelf life, degreening caters to consumer preferences. Integrated strategies that combine both practices, along with investments in infrastructure and farmer education, are essential for building a resilient and sustainable horticultural sector in India. The National Horticulture Board plays a key role in promoting these practices.
Answer Length
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