Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 23, 1997
Publication Date: N/A
Interpretive Summary: Carambola is an important subtropical fruit crop mostly produced in Dade County, Florida. Shipment to western states and some export markets require that carambola are certified free of insect infestation. Cold treatment is an approved treatment, but because carambolas are cold sensitive, injury occurs to some fruit allowing rapid senescence and decay. We found that harvesting more mature fruit, based on peel color, will result in reduced development of peel disorders that cause consumer rejection in the marketplace. Subjecting carambola 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.
Technical Abstract: Carambolas must be treated with an approved insect quarantine procedure such as cold treatment before shipment to certain markets. Condition and quality of mature green peel (MGP) and slight yellow peel (SYP) fruit were determined after they were treated with ethylene, subjected to a cold treatment, and held in storage. Ethylene treated (ETH) fruit were softer compared with non-ETH fruit. MGP fruit were firmer and lost more weight following cold treatment and storage than SYP fruit. Ethylene treatment increased the severity and incidence of peel scald, stem end breakdown (SEB), and fin browning but had no effect on pitting. Cold treatment increased the severity and incidence of scald and pitting, and the severity of SEB. The severity and incidence of peel scald, pitting, SEB, and the severity of fin browning were greater in MGP fruit than SYP fruit at the final evaluation following storage. Ethylene treated fruit had less total soluble solids, higher titratable acidity and pH, and had less preferred flavor and texture compared with non-ETH fruit. We conclude that carambolas should be selected at harvest with a slightly yellow peel (3% to 25% of surface area) instead of a mature green peel and, when cold treatment is required, that fruit not be treated with ethylene. These precautions will lessen the risk of excessive condition and quality deterioration following subsequent storage and/or shipment to distant markets.