Cherimoya

Cherimoya (Atemoya & Sweetsop)

MATURITY & QUALITY

Maturity Indices

Change in skin color from dark-green to light-green or greenish-yellow is the primary maturity index for cherimoya (Annona cherimola), atemoya (Annona cherimoya X A. squamosa), sweetsop (Annona squamosa), and custard apple (Annona reticulata). Other indicators include appearance of cream color between segments on the skin and increased surface smoothness of the separate fruit carpels.

Quality Indices

• Fruit size, color, absence of defects and decay, firmness (annona fruits are relatively soft fruits and must be handled with care to minimize bruising).
• Cherimoya, atemoya and sweetsop have high concentrations of sugars (14-15% when ripe) and moderate acidity (0.4-0.7% when ripe). They are good sources of vitamin C (45-60mg/100g) and potassium (250-500mg/100g edible portion).

TEMPERATURE & CONTROLLED ATMOSPHERE (CA)

Optimum Temperature

8-12°C (46-54°F) depending on cultivar, ripeness stage, and duration.

Optimum Relative Humidity

90-95%

Rates of Respiration

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

Annona fruits are climacteric fruits. High levels of ethylene (up to 100-300 µl /kg·hr, depending on cultivar) are produced during ripening at 20°C (68°F).

Responses to Ethylene

Exposure to ethylene (100ppm for 1-2 days) accelerates ripening of mature-green cherimoya and other annona fruits; they can ripen in about 5 days if kept at 15°C (59°F) to 20°C (68°F).

Ethylene removal can be helpful in retarding ripening of mature-green fruits.

Responses to Controlled Atmospheres (CA)

• The optimum CA storage atmospheres range from 3-5% O₂ and 5-10% CO₂ Benefits include delayed ripening, lower respiration and ethylene production rates, and firmness retention.
• Cherimoyas can be kept for up to 6 weeks at 10°C (50°F) in 5% O₂, then ripened with good flavor at 20°C (68°F).
• Exposure to<1% O₂ and/or >15% CO₂ can result in development of off-flavors and uneven ripening.