76C-30 |
Effect of light on ripening of Mexican plums stored in refrigerated, sealed containers |
M. MATA1, E. Montalvo1, B. Tovar1, and H. S. Garcia2. (1) Lab. de Investigación en Alimentos, Instituto Tecnológico de Tepic, Av. Tecnologico # 2595, Tepic, Nay., 63175, Mexico, (2) UNIDA, Instituto Tecnologico de Veracruz, M.A. de Quevedo # 2779, Col. Formando Hogar, Veracruz, Ver., 91897, Mexico The Mexican yellow plum is cultivated in tropical and subtropical areas. A respiratory climacteric peak has been reported on the 5th day of ripening at 26 °C, and displays chilling injury if stored at 6 °C. Alternative preservation methods of the fresh produce are worth considering. In the present work we report the effect of light on composition and physiology of plums stored at 16 °C in air or gas-tight containers. Mexican yellow plums (Spondias sp.) were harvested from a local orchard at physiological maturity with an average diameter of 3.5 cm. Three treatments were established: light, no light and alternate light/darkness. Half of fruits from each treatment were placed in open containers and half in gas-tight plastic boxes. Respiration rate (RR), Oxygen consumption (OC), ethylene production rate (EPR) and CO2 accumulation (CA) were measured by GC. Additionally, pH values, titratable acidity and soluble solids and sugars by HPLC were also monitored. Respiration climacteric peak was found on day 9 and highest ethylene production on day 7. Oxygen consumption remained stable for all treatments. CO2 accumulated in samples handled with light and alternating light/darkness, but showed little change in those fruits not exposed to light, which was consistent with the trend displayed by the Oxygen for these samples. Highest sucrose and glucose concentrations were noted at day 9 and then decreased, while fructose remained unchanged and followed a similar trend than soluble solids. In general, fruits stored under light had greater sugar content than those maintained in the dark. The latter also showed decreased respiration rates and ethylene production rates as well as CO2 accumulation, whereas light induced sugar synthesis but acidity remained elevated. Light and storage in sealed containers exert and important effect on the physiology of yellow plums and delay ripening to extend shelf life.
Session 76C, Fruit & Vegetable Product: Fresh Fruits and Vegetables
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