Schematic diagram of post-harvest handling

The fruit should be harvested carefully and arranged in a basket with the wrappers still intact. It is then carried to the collection centre and arranged horizontally in a special plastic baskets or corrugated paper boxes. It is not necessary to remove the wrappers because they will protect the fruits from damage due to bruises. The fruit is graded according to size, colour and quality at the packing centre. Grading is important especially if the fruits are to be exported. The grades used in Malaysia as major exporting, are as follows:

The colour indices of starfruit used in Malaysia are as follows: -

•  The whole fruit is dark green.

•  The fruit turns light green

•  The fruit is more green than yellow

•  The fruit is yellowish green

•  The fruit turns to greenish yellow

•  The whole fruit turns yellow

•  The whole fruit turns orange

Starfruit Colour Indices

It should be noted that, every box filled with fruits cannot contain more than 10 percent of off-sized fruits.

The uniformity of fruit maturity stage also has to be given close attention. Each box should have one the following labels:

The fruit are cleaned with a brush to remove any scale insects, dirt or foreign matter. This is necessary because during bagging in the field, remains of the calyx may be left at the stem end.

The remains may carry latent diseases which later cause rotting during storage. It is advisable to remove the fruit stalk and calyx to prevent the development of fungi at the stem end.

The Starfruit has to be freshly packed within 24 hours after harvest. Immediate packing is important to maintain quality and good fruit form. At the same time the fruit colour is maintained and does not changed very much when marketed. The fruits are individually wrapped with PP or HLDP film, tissue paper or polystyrene net. The wrapped fruits are then packed in corrugated fibreboard cartons of size 450 mm x 325 mm x 280 mm. Each carton has four ventilation holes of 32 mm diameter at each of the longer sides and a ventilation hole of 75 mm x 40 mm which also serves as a handle, at each of the shorter sides. The inside of the carton is cushioned with materials such as rolled and crumpled paper. The fruit are arranged with the stem ends facing down. Two layers are arranged in a carton with 70 fruit per carton. The net weight is 14 kg. Each layer is separated by cushioning material which protects the fruit during handling and transportation.

A smaller corrugated fibreboard box with internal dimension of 315 mm x 270 mm x 155 mm is suitable for packing a smaller number of fruit. The number of fruit per carton is either 15, 18, 20, 24, 28, 30 or 32. The carton with either 15,18 or 20 is more common. The carton can contain 15 large fruit, 18 medium fruit or 20 small fruit. The net weight of each carton is 3.5 kg. The inner walls and the top and bottom of the carton are lined with a sponge layer of 13 mm thickness to protect the fruit.

Each carton is labelled with the type of fruit, name and address of the company, number of fruit and net weight. The carton may be one piece or a telescopic type. The telescopic type is preferred for retail sale. The fruit are distributed locally for sale or exported by air or sea.

Boxes of fruits are stored in a cold room between 5-10 °C, ready for export. Lower temperatures may induce chilling injury depending on cultivar, ripeness stage, temperature and duration of storage. The optimum relative humidity in the storage facility is 90-95%; a lower humidity results in more severe symptoms of rib browning. Fruit can be stored for about 28 days in these conditions.

For long distance transportation which requires 5 weeks, a temperature between 5-10 °C is suitable. Fruit of Colour Index 1 are not suitable for storage at 5-10 °C for more than 5 weeks because of chilling injury.

Diseases do not develop in the fruit if they are stored within the recommended storage periods.

Chilling injury: Symptoms include surface pitting [pits are either small (<1 mm), deep and dark brown or large (1-2 mm), superficial, and light brown] and rib-edge browning. These symptoms have been reported in some starfruit cultivars after 2 weeks at 0°C or 6 weeks at 5°C followed by 2 days at 20°C.

Irradiation (250 Gy), cold treatment (12 days, 1°C) and heat treatments (fruit centre to about 49°C) have potential to destroy insects that are quarantine concerns in importing countries. These treatments can occasionally lead to some skin discolouration, dehydration and pitting. Hot water treatments can reduce shelf-life. Cold treatment can result in injury occurring to some fruit allowing rapid senescence and decay. Harvesting more mature fruit, based on peel colour, will result in reduced development of peel disorders that cause consumer rejection in the marketplace. Subjecting starfruit to ethylene treatment prior to cold treatment will not eliminate peel disorders, but growers should not expose mature green peel fruit to ethylene treatment or cold treatment. When quarantine treatment is required, the best results for maintaining quality fruit are achievable by harvesting fruit with 25% yellow peel and cold treating without exposure to ethylene.