Durian

MATURITY & QUALITY

Maturity Indices

The fruit is a large (1.5 to 2.5 kg), spiny capsule that opens into five segments containing seeds covered with a pulpy, edible aril. External color changes with maturation from dull olive-green to light yellowish-green. When mature, the fruit drops to the ground, but it can be carefully harvested before this occurs and ripened in 4 to 6 days. Ease of fruit abscission can be used as a maturity index. Fruit is picked with peduncle attached.

Quality Indices

• Fruit size (weight), shape, color, freedom from defects and decay.
• Internal quality: good color and flavor, fine texture, no wet core or browning.
• The overall smell of the ripe durian has three distinct aromas: one strong and onion like, one delicate and fruity, and one offensive smell (due to hydrogen sulfide and diethyldisulfide).

TEMPERATURE & CONTROLLED ATMOSPHERE (CA)

Optimum Temperature

13-15°C (55-59°F); storage potential is 3-5 weeks (mature unripe durians) or 7-14 days (ripe durians).

Optimum Relative Humidity

90-95%

Rates of Respiration

Vary by cultivar and ripeness stage from 6 to 60 ml CO₂/kg·hr at 13°C (55°F) and from 100 to 250 ml CO₂/kg·hr at 25°C (77°F); climacteric respiratory pattern.

To calculate heat production multiply ml CO₂/kg·hr by 440 to get Btu/ton/day or by 122 to get kcal/metric ton/day.

Rates of Ethylene Production

Vary from 1 to 7°l/kg·hr at 13°C (55°F) and from 6 to 35^ol/kg·hr at 25°C (77°F), depending on cultivar and ripeness stage.

Responses to Ethylene

Ethylene (100ppm) treatment can accelerate ripening and dehiscence of mature but unripe durians and ethylene scrubbing can delay their ripening.

Responses to Controlled Atmospheres (CA)

An atmosphere of 3-5% O₂ and 5-15% CO₂ reduces respiration and ethylene production rates, retards ripening, and extends postharvest-life of durians to 8 weeks (vs. 5 weeks in air) at 14°C (58°F).