96-1 |
The effects of gamma-radiation vs. heat on the quality of papayas |
J. H. MOY1, X. Bian, W. Q. Pang, and O. Kawabata4. (1) Dept. of Molecular Biosciences & Biosystems Engineering, Univ. of Hawaii, 1920 Edmondson Rd., Honolulu, HI 96822, (2) Dept. of Plant & Environmental Protection Sciences, Univ. of Hawaii, Honolulu, HI 96822 Hawaiian papayas for exports are either irradiated or vapor heat-treated for disinfestation. Quality retention is part of the efficacy test. Data on gamma-irradiated papayas are available, but none on vapor heat-treated. A side-by-side comparison will give fruit packers an informed choice of treatment method. Data would answer claims by anti-food irradiation activists that irradiation destroys nutrients. It would also provide facts to irradiation proponents frequently confronted with question on quality. Our objective was to determine and compare nutrient and sensory quality of four cultivars of Hawaii-grown papayas treated by gamma-radiation or vapor heat. Papayas from experimental and commercial orchards were irradiated at 0.25 to 0.90 kGy at the Hawaii Research Irradiator, or heated with 90-100% R.H. air for 4 hrs to a core temperature of 47.2 deg C at a commercial facility. Treated fruits and control were stored at 10 and 21 deg C, then analyzed from day-1 to day-5 for nutrient, texture, and sensory quality. Data were statistically analyzed. Nutrient and sensory quality of two traditional (Kapoho, Sunset) and two transgenic cultivars (UH Rainbow, UH SunUp) were well retained after disinfestation treatment by either irradiation or vapor heat. Some differences in nutrient contents and flavor were found among cultivars. Heat-treated papayas averaged 75.5 and irradiated averaged 77.0 mg of vitamin C/100 g pulp. Heat-treated papayas averaged 0.30 vs. 0.33 mg total carotenoids/100 g pulp for irradiated. Both were not significantly different, with six replicates per cultivars. Results show papaya quality were retained by both treatments, indicating process efficacy. It gives fruit packers a choice of treatment methods, and rebuts anti-food irradiation groups' claims of nutrient destruction by irradiation.
Session 96, Fruit & Vegetable Products
|