|Chanjirakul, Korakot - KASETSART UNIV, THAILAND|
|Siriphanich, Jingtair - KASETSART UNIV, THAILAND|
Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: March 30, 2005
Publication Date: July 1, 2005
Citation: Wang, C.Y., Chanjirakul, K., Wang, S.Y., Siriphanich, J. 2005. Effect of natural products on decay and antioxidant activities of fresh-cut papayas. Hortscience. 40(4):1004 Technical Abstract: The effect of naturally occurring volatile compounds on decay and antioxidant activities in fresh-cut papayas (Carica papaya L.) was studied. Exposure to methyl jasmonate (MJ), methyl salicylate (MS) or allyl isothiocyanate (AITC) substantially delayed the onset and reduced the severity of decay during and after storage at 5 degree centgrade. Treatment with tea tree oil (TTO) or ethyl alcohol (ETOH) was also effective in retarding decay, but to a lesser extent. No beneficial effect was obtained with the use of vinegar vapor. MJ and MS increased oxygen radical absorbance capacity and elevated the activities of several antioxidant enzymes, including glutathione reductase, glutathione peroxidase, guaiacol peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and superoxide dismutase. The nonenzyme components in the ascorbate-glutathione cycle were also increased by MJ and MS treatments, including ascorbate and glutathione. It is possible that MJ and MS treatments enhanced the antioxidant system and increased the resistance of tissue to decay. However, while AITC also suppressed the development of decay in papaya slices, it had little effect on antioxidant levels and antioxidant enzyme activities. Apparently, AITC exerted its effect through different mechanisms. Studies are in progress to determine if AITC inhibits decay directly via its antimicrobial properties.