Seo Park Y.,Mokpo National University |
Polovka M.,Food Research Institute |
Ham K.-S.,Mokpo National University |
Park Y.-K.,Mokpo National University |
And 5 more authors.
Journal of AOAC International | Year: 2016
Organic, semiorganic, and conventional "Hayward" kiwifruits, treated with ethylene for 24 h and stored during 10 days, were assessed by UV spectrometry, fluorometry, and chemometrical analysis for changes in selected characteristics of quality (firmness, dry matter and soluble solid contents, pH, and acidity) and bioactivity (concentration of polyphenols via Folin-Ciocalteu and p-hydroxybenzoic acid assays). All of the monitored qualitative parameters and characteristics related to bioactivity were affected either by cultivation practices or by ethylene treatment and storage. Results obtained, supported by statistical evaluation (Friedman twoway ANOVA) and chemometric analysis, clearly proved that the most significant impact on the majority of the evaluated parameters of quality and bioactivity of "Hayward" kiwifruit had the ethylene treatment followed by the cultivation practices and the postharvest storage. Total concentration of polyphenols expressed via p-hydroxybenzoic acid assay exhibited the most significant sensitivity to all three evaluated parameters, reaching a 16.5% increase for fresh organic compared to a conventional control sample. As a result of postharvest storage coupled with ethylene treatment, the difference increased to 26.3%. Three-dimensional fluorescence showed differences in the position of the main peaks and their fluorescence intensity for conventional, semiorganic, and organic kiwifruits in comparison with ethylene nontreated samples.
Boonkorn P.,Chiang Mai University |
Boonkorn P.,Postharvest Technology Research Institute |
Gemma H.,University of Tsukuba |
Sugaya S.,University of Tsukuba |
And 5 more authors.
Postharvest Biology and Technology | Year: 2012
The effects of gaseous ozone on the growth of green mold (Penicillium digitatum) and the activity of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase) in the peel of artificially inoculated tangerine (Citrus reticulata Blanco cv. Sai Nam Pung) fruit were examined. Ozone (200μLL -1) was applied for 0 (control), 2, 4 or 6h to inoculated tangerine fruit. Exposing fruit to ozone for 4 and 6h delayed disease incidence and reduced severity. Scanning electron microscopy confirmed that exposing fruit to ozone for 4 and 6h reduced growth of fungi on the fruit peel. The activities of superoxide dismutase, catalase and ascorbate peroxidase were increased after ozone fumigation and remained significantly higher than those of the control fruit through three days of storage at 25°C. Throughout the experiment, fruit qualities in all treatments were not affected by ozone exposure and no phytotoxicity occurred in fruit exposed to high doses of ozone. © 2011 Elsevier B.V.
Hassarangsee S.,Postharvest Technology Research Institute |
Chantara S.,Chiang Mai University |
Whangchai K.,Postharvest Technology Research Institute |
Whangchai K.,Chiang Mai University |
And 2 more authors.
Acta Horticulturae | Year: 2015
The reduction of Ethion, a frequently used pesticide in tangerine production was carried out by titanium dioxide (TiO2) photocatalysis with different concentrations (5, 10, 20, 40 and 60 mg ml-1) and exposure times (0, 15, 30, 45 and 60 min) under a UV lamp. To evaluate the oxidation potential by TiO2 photocatalysis effects, iodine liberation from the reaction was measured. Iodine yield, which increased with increasing concentration and reaction time, was highest at 60 mg ml-1 of TiO2 and longest at 60-min exposure time. TiO2 photocatalysis at the highest concentration was the most effective (60%) at reducing Ethion concentration with the highest rate of degradation occurring within the first 15 min (60%). When treated for alonger exposure time, the reduction of Ethion became insignificant.