The optimal ripeness stage for processing and marketing fresh-cut mangoes (Mangifera indica ‘Kent’) with best quality and maximum shelf life was determined. The initial ripeness stage selection was based on whole fruit firmness because this quality attribute was more reliable in predicting fresh-cut shelf life than flesh color or soluble solids content (SSC). Overall, the visual quality deteriorated differently and at different rates among ripeness stages. The shelf life, based on subjective visual evaluation, was 10, 7, and 5 days for ripeness stages corresponding to an average flesh firmness of 35, 30, and 25 N, respectively, and was mainly limited by desiccation and development of off-odor for the two firmer ripeness stages or symptoms of edge tissue damage and spoilage for the least firm stage. The slices from fruit with the highest initial firmness remained firmer during storage, had the lowest pH and SSC to titratable acidity (TA) ratio, and had the highest contents of volatile ketones and esters. The softest slices had the highest pH, SSC:TA ratio, and total ascorbic acid (TAA) content, as well as the lowest TA and highest volatile aldehyde and alcohol contents. Intermediate firmness slices had intermediate pH, SSC:TA ratio, color, and TAA content. Also, they had less volatile alcohols and aldehydes than slices from riper fruit but had similar content of esters as slices from the less ripe fruit. Therefore, based on the results from this study, an initial firmness of 30 N is recommended to process mangoes into fresh-cut slices because it assures the best quality and maximum shelf life based on textural, visual, and compositional attributes.
Sharon Dea, Jeffrey K. Brecht, Maria Cecilia do Nascimento Nunes, and Elizabeth A. Baldwin
William Pelletier, Jeffrey K. Brecht, Maria Cecilia do Nascimento Nunes, and Jean-Pierre Émond
Commercial shipments of strawberries (Fragaria ×ananassa) were evaluated from the harvest point to the distribution center (DC). Simulated retail conditions were afterward imposed on the fruit. Commercially harvested ‘San Juan’ strawberries in California were instrumented in the field for temperature and relative humidity (RH) monitoring during handling and distribution. At the cooling facility, five different treatments were imposed on five pallets of strawberries: prompt precooling to a final temperature of 1.7 or 10.0 °C, 4-hour delayed precooling to a final temperature of 1.7 or 10.0 °C, and no precooling. Immediately before being loaded into the trailer, all pallets were wrapped in a modified atmosphere (MA) pallet shrouds. Upon arrival at the DC in Florida, fruit from the same five pallets were exposed to three simulated retail temperatures (0, 6, and 21 °C) for 3 days. Results from this study showed that the refrigerated trailer was unable to maintain the temperature of any of the pallets during transport. In addition, upon arrival at the DC in Florida, strawberries from the partial precooling (cooled to 10.0 °C), 4-hour delayed precooling, and no precooling treatments had higher water loss and lower visual quality compared with fruit that were immediately precooled to a final temperature of 1.7 °C. On the basis of the quality control standards of the cooling facility in California, most of the fruit from the no precooling treatment were considered unacceptable for shipment 1 day after harvest. During simulated retail display, quality of the fruit held at 21 °C was inferior to that of fruit maintained at 0 or 6 °C, particularly that of fruit from the partial and delayed precooling treatments. Strawberries from the prompt precooling to a final temperature of 1.7 °C treatment had acceptable visual quality after simulated retail display for 3 days at 0 °C, whereas visual quality of the fruit from the delayed or partial precooling treatments ranged from slightly poor to poor after the same period of time. The presence of bruises due to mechanical damage shortened the shelf life of the fruit because of accelerated development of decay. Overall, results obtained from this study highlight the importance of prompt precooling and the use of optimum storage temperature (i.e., 0 °C) throughout the distribution chain and during retail display.