2019 ASHS Annual Conference

Some mandarins have characteristics that make it more difficult to successfully store and market them if commercially treated in a conventional manner. In this study a proprietary mandarin variety known to be particularly sensitive to off-flavor development was subjected to a variety of alternative processing methods after harvest to determine if it was possible to improve the postharvest fruit quality in this and other varieties with similar storage problems. In an initial test fruit were washed and sanitized on a commercial packing line and a storage wax (SW, 1% solids) applied. The next day fruit were run over a research packing line and either SW or no wax (NW) applied followed by 3 or 7 weeks of cold storage at 5 °C. After cold storage fruit were again run over a packing line and either SW or pack wax (PW) applied, and the fruit further stored for 1 week at either 5 °C or 20 °C to simulate a marketing period. The nature of the coating prior to cold storage had no impact on fruit quality, whereas fruit coated with SW (1% solids) after initial cold storage had the highest fruit quality, primarily due to there being less off-flavor development. This was particularly true if the fruit were held at 20 °C. Temperature during the marketing period had the greatest overall impact on fruit quality, with fruit maintained at 5 °C having better flavor and lesser levels of decay and water loss, regardless of coating type. In a final test the above experimental format was again utilized except the NW treatment prior to cold storage was deleted and coatings after cold storage consisting of SW containing either 5, 10 or 15% solids. Evaluation after the marketing period indicated that there were no differences in fruit quality due to the variation in solids content in the SW coatings applied after cold storage. As has been noted in our prior work, this study indicated that it is very advantageous to maintain mandarins prone to off-flavor development at low temperatures, such as 5 °C, throughout storage and marketing to preserve flavor quality. If this is not feasible then the use of final coatings more permeable to gas exchange, such as the SW (1% solids) applied in this study, would be beneficial as long as excessive weight loss does not become an issue.