|ORNELAS-PAZ, JOSE - Centro De Investigacion En Alimentaction Y Desarollo|
|MEZA, MARIA - Chapman University|
|Obenland, David - Dave|
|RODRIGUEZ, KARINA - Chapman University|
|JAIN, AKANKSHA - Chapman University|
|THORNTON, SHANTAE - Chapman University|
|PRAKASH, ANURADHA - Chapman University|
Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/24/2017
Publication Date: 3/19/2017
Citation: Ornelas-Paz, J., Meza, M., Obenland, D.M., Rodriguez, K., Jain, A., Thornton, S., Prakash, A. 2017. Effect of phytosanitary irradiation on the postharvest quality of Seedless Kishu mandarins (Citrus kinokuni mukakukishu). Food Chemistry. 230:712-720. https://doi.org/10.1016/j.foodchem.2017.02.125.
Interpretive Summary: Mandarins may require a quarantine treatment for the purpose of insect disinfestation prior to export into some foreign markets. Irradiation potentially provides a rapid and effective means to do this but mandarins are more delicate than other types of citrus and the effect of irradiation on mandarin quality has not been well evaluated. In this study ‘Seedless Kishu’ mandarins were treated with gamma irradiation at a variety of doses and stored for three weeks at 6°C and one week at 20°C to simulate commercial handling and marketing practices. Irradiation was found to significantly modify the composition of many compounds involved in the sensory, nutrient, and health-promoting attributes of mandarins. Also, the appearance of the fruit was negatively affected even at the lowest dose that would be needed for a postharvest quarantine treatment. This study indicates that ‘Seedless Kishu’ would not be a good candidate for treatment with irradiation for phytosanitary purposes.
Technical Abstract: ‘Seedless Kishu’ mandarins (Citrus kinokuni mukakukishu) were treated with gamma irradiation at 150, 400, or 1000 Gy and stored for three weeks at 6°C and then for one week at 20°C to simulate commercial handling and marketing. The quality of the fruit was then evaluated following storage using non-irradiated fruit as controls. Irradiation at all doses induced browning of the calyx end with the highest doses of 400, and 1000 Gy promoting fungal infections as well. Irradiation also caused immediate reductions in pulp firmness, vitamin E, individual sugars, and carotenoids, but increased the content of organic acids and phenols. Volatiles were often higher in the irradiated mandarins, with alcohols, aldehydes, and esters being enhanced to the greatest degree. Most of these changes in quality or chemical components were dose dependent and kept the same trend throughout storage. ’Seedless Kishu’ mandarins were found to be very sensitive to irradiation and are not suitable for phytosanitary treatment at the studied doses.