Prickly Pear Factsheet - Dept of Vegetable Crops, UC, Davis
The fruit is a berry, typically weighs 100 to 200 g
Fruit vary considerably in color, size and flavor
need to be harvested near full-ripe
high sugar content (12 to 17% SSC) and low acidity (0.03 to 0.12% TA)
considerable amounts of Vitamin C (200 to 400 µg g-1)
sugar content and sweetness do not increase after harvest
Maturity indices include: fruit size and fullness; changes in peel color; abscission of the small spines or glochids; fruit firmness; and flattening of the floral cavity or receptacle. Peel color is the single most important index for commercial harvest.
Fruit should be cooled to 5 °C (41 °F) to reduce loss of visual appearance (shiny surface) due to water loss.
Cooling may be delayed if fruit undergo a curing treatment
Optimum Storage Conditions:Depending on variety, ripeness stage, and harvest season, fruit can be kept for 2 to 5 weeks at 5 to 8 °C (41 to 46 °F) with 90 to 95% RH. Factors limiting storage-life are decay, dehydration and chilling injury.
Limited research indicates holding cactus pear at 5 °C (41 °F) in 2% O2+ 2 to 5% CO2delays ripening and extends storage-life (Kader, 2000).
chilling sensitive when stored < 5 °C (41 °F), but chilling injury may occur in some varieties < 10 °C (50 °F). Symptoms include pitting, surface bronzing and dark spots on the peel, and increased susceptibility to decay.
Summer-harvested fruit are more chilling sensitive than autumn-harvested fruit (Schirra et al., 1999). Application of calcium chloride, conditioning,and intermittent warming have had variable success in reducing chilling injury.
Prickly pear fruit produce very low amounts of ethylene at about 0.2 µL kg-1 h-1 at 20 °C (68 °F), and are not sensitive to ethylene exposure.
Harvest damage to the peel and stem-end of cactus fruit will lead to attack by numerous pathogens and result in fruit decay. Common postharvest pathogens on cactus fruit are mostly fungi and include Fusariumspp., Alternariaspp, Penicilliumspp, but yeasts and bacteria also cause decay. Hot water dips at 53 to 55 °C (127 to 131 °F) for 5 min and fungicide-containing waxes may reduce surface decay, but are not effective when there is damage tothe stem-ends.
Fruit can be bruised easily by finger compression during harvest, but damage to the stem-end is by far the most serious mechanical injury. Damage at the stem-end can be eliminated by careful harvest (twisting fruit from the stem or cutting fruit with a small piece of stem attached). Fruit harvested with a bit of stem may be packed that way or cured under moderate temperature of 15 to 20 °C (59 to 68 °F) with airflow so the bit of stem dries and falls off before fruit are packed. This prevents damage to the stem end and greatly reduces decay incidence. High-gloss fruit waxes are often used to improve visual appearance and reduce dehydration. This is especiallyimportant if fruit are dry-brushed to remove small tufts of spines or glochids.