Chilling injury (CI) occurs in most fruits of tropical and subtropical origin if held at temperatures above their freezing point and below 5° to 15°C, depending on the commodity ( Table 3.4 ). This physiological disorder is the most important obstacle to the expansion of trade in tropical fruits in the world market (Siriphanich, 2002) and is the major cause of their typically short postharvest life (7–40 days). CI symptoms become more noticeable upon transfer to higher (non-chilling) temperatures. The most common symptoms are surface and internal discoloration (browning), pitting, water soaked areas, uneven ripening or failure to ripen, off- fl avor development, and accelerated incidence of surface molds and decay (especially organisms not usually found growing on healthy tissue). Ripening is also impaired as a result of exposure to temperatures that cause CI. The ideal control of CI is avoidance of exposure at chilling temperature. Approaches to lessen chilling injury incidence and severity include temperature conditioning, intermittent warming, CA storage, chemical treatments, and growth regulator application (Wang, 1994). These techniques reduce CI by either increasing the tolerance of commodities to chilling temperature or retarding the development of CI symptoms
Subtropical fruits vary in their relative susceptibility to chilling injury among species and cultivars within a species. For example, grapefruit, lemon, lime and pomelo are much more susceptible to chilling injury than orange, kumquat and mandarin. Dates, fi gs, kiwifruits and ‘Hachiya’ persimmons are not sensitive to chilling injury. ‘Fuyu’ persimmons and other subtropical fruits are chillingsensitive. Some tropical fruit are highly sensitive such as banana, breadfruit, jackfruit, mamey, mango, mangosteen, papaya, pineapple, rambutan and soursop, and others are moderately sensitive such as carambola, durian, guava, sugar apples and tamarillo .