The ripening of bananas is a process that needs to take place in accurately controlled conditions to ensure synchronization of all the metabolic processes that are involved with ripening so that the best quality product can be made available to the consumer. Optimal ripening requires the correct ambient room temperature and relative humidity, adequate ventilation and ethylene treatment. Banana ripening occurs at temperatures between 16º-18ºC, with 95% humidity and constant ventilation. Ripening is triggered when the bananas are exposed to ethylene for 24 hours. Fruit that ripens in ideal circumstances has a bright yellow colour, firm soft pulp and strong peel, are sweet tasting and have a pungent aroma. The conditions in the store and ripening rooms, especially temperature, are not always regulated to the optimum and subtropical fruits such as bananas are injured at temperatures below 12ºC. Phase transitions in the membranes, from a liquid-crystalline to a solid gel-like phase, are responsible for chilling injury. Chilling injury delays ripening, but does not noticeably influence the eating quality of the fruit. The bananas are still sweet with a firm soft pulp and strong peel. The aroma production is however reduced by the cold and undesirable colour changes occur. The chilling injured bananas are dull greyyellow in colour with brown or black spots on the peel. The peel sometimes becomes completely brown or black. The quality of the bananas is potentially influenced by this colour change since the consumer judges the fruit on visual appearance. Controlled atmosphere storage and modified atmosphere packaging reduce chilling injury and extends the life of the fruit due to delayed ripening. Chilling injured fruit consequently has less brown or black spots and sometimes even an improved yellow colour. A better quality product can be supplied to the consumer and the temperature control in the storeroom does not need to be 100% accurate. The advantages of these techniques are attributed to the modified atmospheres, namely reduced oxygen and increased carbon dioxide concentrations which influence respiration, ethylene synthesis and action. / Prof. C.S. Whitehead

"November 2002" Includes bibliographyical references (leaves 150-172)

"November 2002" / Includes bibliographyical references (leaves 150-172) / xvii, 172, [53] leaves : ill. (chiefly col.), plates (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 2002

Seasonal variations had a great influence on the ripening patterns of banana fruit. Normal ripening was enhanced or delayed by the effect of the maturing season on the fruit. Fruit maturing in summer (harvested in autumn) showed an increase in the rate of ripening, while fruit harvested in winter and spring showed a decrease in the rate of ripening. The banana fruit are sensitive to temperatures outside of their acclimated range. Due to ineffective storage and faulty handling procedures, cold and heat stress is a universal problem in bananas. Large amounts of fruit are lost due to heat and cold stress. Chilling injury occurs when bananas experience or are stored at temperatures below 13C, for a few hours to a few days. Temperatures slightly above 30C may cause extensive heat damage. The three main mechanisms suggested for the prevention of chilling and heat injury are the synthesis of small heat shock proteins, changes in the saturation of fatty acids of the membranes and suppression of the ethylene production and respiration rates. The prevention of cold and heat stress is investigated by monitoring the effect of short-term heat treatment and treatment with ethylene inhibitors on the ripening of the fruit. To determine changes in ripening the following eight ripening parameters are monitored: Yellowing, firmness of the pulp, sugar concentration, starch content, ethylene synthesis, respiration rate, rate of moisture loss and ion leakage. It was found that 1-methylcyclopropene (1-MCP) alleviates the symptoms of heat injury up to a point, but the symptoms of chilling injury were not affected. The effects of the three temperatures investigated: 35°C, 40°C and 45°C for different times. A short pre-heat treatment of 35˚C for 20 minutes proved successful to delay the ripening of the banana fruit, but did not protect the fruit against heat or chilling injury. The results of this study clearly indicate that both chilling and heat injury involve the action of ethylene and suggested that longer exposures to 1-MCP may be effective in preventing both types of injury. / Prof. C.S. Whitehead

Title page, summary and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / "This study examined how the efficacy of 1-MCP varies throughout the year; the effect of concentration, duration and timing of ethylene application; the effect of hand position on the bunch; the timing of 1-MCP application in relation to ripening and harvest time; and the effect of ripening storage temperatures and chilling storage .. The findings of this study allow 1-MCP to be used in a more commercially reliable manner" -- from Abstract. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1256621 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2006

Title page, summary and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / "This study examined how the efficacy of 1-MCP varies throughout the year; the effect of concentration, duration and timing of ethylene application; the effect of hand position on the bunch; the timing of 1-MCP application in relation to ripening and harvest time; and the effect of ripening storage temperatures and chilling storage .. The findings of this study allow 1-MCP to be used in a more commercially reliable manner" -- from Abstract. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1256621 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2006

Title page, summary and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / "This study examined how the efficacy of 1-MCP varies throughout the year; the effect of concentration, duration and timing of ethylene application; the effect of hand position on the bunch; the timing of 1-MCP application in relation to ripening and harvest time; and the effect of ripening storage temperatures and chilling storage .. The findings of this study allow 1-MCP to be used in a more commercially reliable manner" -- from Abstract. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1256621 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2006