Kaki, Diospyros kaki / Ebenaceae
Postharvest Atmosphere Management
Persimmons must be stored at temperatures around 0ºC. Below 2ºC the fruit freezes. The levels of moisture must be kept high, between 90 and 95%. Ethylene is used to eliminate astringency, but it produces an excessive softening of the produce, complicating their marketing. If the air is enriched with 80% of carbon dioxide for 24 hours at 20ºC, we remove the astringency while the firmness is maintained.
Kakis have a positive response to controlled atmosphere. The suitable conditions to use it are 3-5% of oxygen levels, levels of 5-8% of carbon dioxide and an atmosphere free of ethylene. Under these conditions and with optimum temperatures and levels of moisture, kakis may last up to 3 or 5 months.
Distribution
Persimmons are very fragile fruit, so their transport must be extremely careful. The temperature must be as low as possible and the ventilation must be such as to reduce the levels of ethylene. The loads must not be a mix of substances that produce this gas. During distribution, the temperature and ventilation must also be taken into account.
Postharvest Problems
Among the problems that persimmons may undergo during their storage there are damages caused by ethylene, chilling injuries and damages caused by low levels of oxygen and high levels of carbon dioxide.
Damages caused by ethylene: if the concentration of this gas is high, it causes a premature aging of the fruit, leading to the softening and loss of quality.
Chilling injuries: the non-astringent varieties such as "Fuyu’ are very sensitive to temperatures between 5 and 15ºC, and they may show browning and softening of the pulp. These problems worsen with ethylene.
If persimmons are subject to environment with levels of oxygen below 3% for more than a month, they may have problems in maturation and loss of taste.
Levels of carbon dioxide over 10% for more than a month may cause pulp browning and taste loss.