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Longkong (Lansium domesticum) is a tropical fruit tree distributed throughout South East Asia. The fruit is sweet with a slightly sour taste. At maturity the peel turns yellow and the pulp becomes translucent. At present, the fruit is only exported to neighboring countries. The main problems include peel browning, fruit rot and fruit drop. Our studies revealed that water loss and exposure to ethylene are the two main factors causing peel browning. The fruit is of climacteric type, producing only a limited amount of ethylene. However, at the immature stage, the fruit had a higher rate of ethylene production, resulting in more fruit drop, than the fully colored fruit. Fruit stored below 18°C produce more ethylene than at a higher temperature, resulting in fruit drop and peel browning. A trial shipment of ten days to Shenzhen was successfully conducted with less than 5% fruit drop and fruit rot upon arrival, and less than 20% after transfer to holding temperature for 4 d. It is recommended to harvest the fruit at 13 weeks after full bloom, handle the fruit gently, remove pests hiding in the bunch with an air jet, and dip it in cold fungicide including NAA to minimize fruit rot and fruit drop. During transport the temperature should be set at 18°C. KMnO4 was found to be ineffective in removing ethylene in the container. Hence, a ventilation rate of at least two container volumes h-1 was recommended.

Postharvest fruit abscission from the rachis (fruit drop) is a major problem in longkong. Recent reports showed that 1-MCP or NAA could reduce fruit drop, indicating ethylene involvement in the longkong fruit abscission process. Fungicides were found to give good fungal control and reduce fruit drop in longkong. This suggests that postharvest abscission in longkong is due to ethylene production induced by fungal growth on the fruit. An experiment was conducted by dipping longkong in fungicide solutions with different modes of action, i.e., carbendazim, prochloraz, mancozeb and difenoconazole at 1000 mg L-1 for 3 min, then stored at 25±1°C. It was found that fruit rot was reduced in proportion to the rate of ethylene production and the degree of fruit abscission. When ethylene production was determined in apple and wax gourd tissues, which had been dipped in 500 mg L-1 of all four fungicide solutions for 1 min, it was found that only prochloraz effectively reduced ethylene production in both tissues. The results suggested that the cause of longkong abscission is ethylene simultaneously produced by fungi grown on the fruit and by the fruit induced by the fungal growth. Hence, it is suggested that to prevent longkong fruit abscission pre- and postharvest fungal control is indispensable.

Longkong fruit drop was visually checked at two different positions: between the peduncle and the calyx (separation zone 1; SZ1), and between the calyx and the fruit (separation zone 2; SZ2). After color break, 10 weeks after full bloom (WAFB), the breaking strength (BS) at SZ1 only slightly decreased, while BS at SZ2 declined considerably and continued to decrease until the fully ripe stage at 15 WAFB. Fruit drop at SZ1 was induced by exposure of the fruit to ethylene, while at SZ2 separation required an external force exerted on the fruit. This study reports the change in polygalacturonase (PG) and β-glucanase activities at the two positions during fruit coloration and exposure to ethylene and 1-methylcyclopropene (1-MCP) after harvesting at 13 WAFB. The results indicate that at both positions, PG and β-glucanase activities were stable during fruit coloration, indicating that changes in PG and β-glucanase activities were not responsible for the separation zones weakening at this stage. After harvest, in the non-treated, control fruit, β-glucanase activity in SZ1 increased slightly but PG activity was stable. When longkong fruit were exposed to ethylene both PG and β-glucanase activities increased. In contrast, PG and β-glucanase activities decreased after exposure to 1-MCP. In SZ2, PG and β-glucanase activities increased with or without exposure to ethylene; after 1-MCP treatment, PG and β-glucanase activities were lower than the control. These data indicate that both enzymes participate in the cell separation process at both positions in response to ethylene, but other enzymes are also involved. It is postulated that the differential enzyme activities at the two positions, at different stages, provide a benefit to the survival of the plant depending on environmental conditions.

Trimmed young coconuts wrapped with PVC film have a short storage life. Current commercial shipments are carried out at 3-6°C without visual chilling symptoms. Experiments were conducted to study chemical composition and postharvest features of intact and trimmed fruit wrapped with PVC film and stored at 4 and 25°C. After 3 weeks at 25°C, coconut water had a slight off-flavor score while at 4°C a strong off-flavor score was observed. Similar findings were found in the coconut kernel but the scores were higher. Trimmed fruit had a much higher respiration and ethylene production rate than intact fruit. At 4°C, the coconut water had about 100-300 nl L-1 dissolved O2, but at 25°C, O2 could not be detected. TBA reactive compounds in coconut water at 25°C increased slightly during storage, while at 4°C it was about 50% higher than 25°C after 2 weeks of storage. TBA reactive compounds in the coconut kernel were 3 times higher than in coconut water, but there was no difference between the two storage temperatures. Electrical conductivity in coconut water at 4 and 25°C was similar, while the electrolyte leakage from the kernel at 4°C was 20% higher than at 25°C. The data suggested that 4°C was a suboptimal storage temperature for young coconut.

This study was done to evaluate the postharvest biology and the effect of temperature and application of inhibitor in extending the storage life of Burmese grapes ‘Reinthong’ at yellow and yellow-red maturity stage stored at 25°C. Respiration rate of the yellow-red fruit was 22 mg CO2/kg/h, which was >20% higher than that of yellow fruit. The respiration rates in both stages were stable throughout the 12 days of storage life. Ethylene production at the rate of 1.3 µl C2H4/kg/h in both maturity stages was also found stable and did not change after harvest. Yellow-red fruit were softer than yellow fruit, and softened more when stored longer. Soluble solids in yellow-red fruit were 16.8%, which was >0.4% higher compared to yellow fruit. Titratable acidity was 1.1% in both maturity stages and remained stable throughout storage. The results indicate that Burmese grape is a non-climacteric fruit. The study on the storage of yellow-red fruit at 10, 12, 15 and 25°C showed that the best storage temperature was 15°C with 21 days of storage life. At this temperature, the fruit had little weight loss but the peel turned brown, the fruit rotten, and there was high level of fruit drop. Dipping the fruits in 800 ppm Naphthalene acetic acid (NAA) was found to control fruit drop effectively, while 1-methylcyclopropene (1-MCP) fumigation was not consistently effective.

Internal browning (IB) of pineapples limits the storage life and transportation potential at low temperature. ‘Queen’ and ‘Smooth Cayenne’ pineapples were harvested from various planting locations in Thailand. The total calcium content in nine sample fruits was determined and the remainder stored at 10°C for 21 days. It was found that ‘Queen’ pineapple developed more internal browning after storage than ‘Smooth Cayenne’ pineapple. A relationship was found between the calcium content and IB in one experiment but not in the other. The effect of preharvest and postharvest calcium applications on IB of ‘Queen’ pineapple was also studied. Pineapples sprayed with 1,000 mg L-1 calcium-boron solution combined with 150 kg ha-1 of calcium oxide exhibited a 47.6% internal browning reduction. In a second experiment, the calcium application was not effective in reducing IB. In a postharvest study, calcium application by the immersion of pineapple fruit stems in 0, 1, 2 and 4% calcium chloride solutions at 25°C (80-85% RH) for 18 hours reduced IB by 35, 77 and 79%, respectively. The 2 and 4% calcium chloride solutions caused a dark brown area in the fruit stem, which extended 2.5 cm into the core. Repeated experiments could not confirm the effect of postharvest calcium application on IB reduction. This suggests that calcium content is only one of the factors influencing internal browning in pineapples.

Uneven fruit ripening is often found in 'Mon-Thong' durian. This defect cannot be detected from external appearance and its cause is unknown. It has been suggested that harvesting too early and leaf flushing during fruit growth were perhaps the most probable causes of the problem. To evaluate whether maturity stages were related to uneven fruit ripening, 'Mon-Thong' durians were harvested at 106 and 113 days after anthesis (DAA). The 106 DAA fruits were found to have the higher score of uneven fruit ripening, as well as the higher variation in pulp firmness and soluble solids concentration compared to those harvested at 113 DAA. In addition, to determine whether competition for assimilates between the fruit and other developing parts, such as flushing leaves, was also related to uneven fruit ripening, bearing durian trees were shaded by 50%, using saran nets for 3 weeks during 92-112 DAA. It was found that the fruits from shaded trees, harvested at 113 DAA, had higher uneven fruit ripening characteristics than those from the control trees.

Fruit of three mango cultivars representing severe, moderate and slight chilling injury (CI) susceptibility, were stored at 5°C (chilling temperature) and 13°C (recommended storage temperature) for 0, 7, 14, 21, and 28 days. CI symptoms, hydrogen peroxide content and total antioxidant capacity (TAC) were determined both in the peel and the pulp next to the endocarp. 'Nam Dok Mai' mango developed CI in both the peel and the pulp. 'Chok Anan' developed CI only on the peel. No CI was found in 'Hongsawadee'. Mangoes stored at 5°C developed more CI symptoms on the peel than those stored at 13°C. However CI symptom in the pulp was higher at 13°C than at 5°C. After being transferred to room temperature, ripe mangoes developed more peel browning than unripe mangoes. However, lower CI symptom in the pulp was observed. In the peel, 'Nam Dok Mai' was found to have the highest level of total antioxidant capactiy, while 'Chok Anan' had the highest level of hydrogen peroxide. 'Hongsawadee' had the highest level of TAC in its pulp during cold storage but it was found to be the lowest once the fruit were transferred to room temperature. Despite the difference in chilling injury development among cultivars, tissues and ripening stages, no clear relationship between hydrogen peroxide content or TAC level in the three mango cultivars and chilling iniurv could be established.

Pineapples (Annanus comosus L. Murr.) could easily develop chilling injury symptom during storage at low temperature, depending on maturity, cultivar, temperature and duration of storage. Queen pineapples are known to more sensitive to chilling injury than other groups. Low temperature is believed to cause oxidative stress in plant tissues leading to chilling injury symptoms. Queen and Smooth Cayenne pineapples were stored at 10°C for 3 weeks. Queen pineapples developed slight internal browning after only one week of storage and more than 50% showed moderate symptom after 3 weeks. There was no symptom in Smooth Cayenne after 3 weeks of storage. Hydrogen peroxide content in the flesh of Queen was higher than in Smooth Cayenne before and during storage. Ascorbic acid content was also higher in Queen. Superoxide dismutase activity in Smooth Cayenne was higher at the beginning but declined to about the same level as in Queen. Catalase activity in Queen before storage was three times higher than that in Smooth Cayenne. After one week of storage the activity declined considerably. The higher sensitivity to low temperature in Queen as compare to Smooth Cayenne may be explained by the higher H 2 O 2 content, but further study on other antioxidants and enzymes involved are needed.

Coconut is a wonder fruit which provides the consumer with both a refreshing drink from its water and energy from its kernel. The oil from the mature kernel is used as cooking oil and processed into soap and detergent. The tree itself is known as ‘the tree of life’, since it also provides the locals with shelter and numerous products besides food. The dry kernel or copra was once an important international commodity. After World War II, its importance diminished partly due to the false opinion that coconut oil is an unhealthy food containing high amounts of saturated fat. The result was lower demand and depressed prices. Recently, demand for coconut is reviving, especially for its virgin oil as well as for young fresh fruit, both now recognized as healthy food. This chapter provides insight into postharvest biology and technology of the fruit involving both its water and kernel at both young and mature stages. Hence readers are advised to distinguish between these two parts and stages of the fruit.

The pineapple is the third most important tropical fruit in the world after banana and citrus; the world pineapple production in 2007 was estimated at 21 008 795 tonnes. This chapter discusses various aspects of postharvest biology and technology of pineapple. The chapter is divided into 11 sections covering postharvest physiology, physical and biochemical changes during maturation and ripening, preharvest and postharvest factors affecting quality, physiological disorders, pathological disorders, insect pests and their control, postharvest handling practices, and processing.

Leaf tissues of crisphead lettuce (Lactuca sativa L.) were kept in air or in air enriched with 5% to 20% CO at OC for 2 to 9 days followed by transfer to air or to CO2 2enhanced atmospheres at 20C for 1 day to study the mode of CO2 action on metabolism of organic and amino acids. The 20% treatment caused a decrease in intracellular pH, which alone or, in combination with, other CO2 effects, inhibited succinate dehydrogenase but activated glutamate decarboxylase. This resulted in an accumulation of succinate and γ-aminobutyrate and a reduction in concentrations of malate and glutamate. Elevated CO2 atmospheres did not affect other organic and amino acids. These effects of CO2 were influenced by temperature and concentration/duration of exposure to CO2, while type of tissue (green vs. white) and cultivars of lettuce generally had no influence.