Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2009
Publication Date: 5/1/2010
Citation: Wang, S.Y., Chen, C., Yin, J. 2010. Effect of allyl isothiocyanate on antioxidants and fruit decay of blueberries. Food Chemistry. 120:199-204. Interpretive Summary: Blueberries are highly perishable, susceptible to rapid spoilage and have short market shelf-life. We treated blueberries with a natural plant product, allyl isothiocyanate (AITC), and evaluated its efficacy to reduce spoilage of blueberry fruit. We found that AITC effectively retarded decay in blueberries. AITC treated blueberries maintained higher amounts of sugars, but lower levels of acids and antioxidants. This information is useful to consumers, growers, and the blueberry industry.
Technical Abstract: The effect of allyl isothiocyanate (AITC) on flavonoids, radical scavenging capacity, fruit decay and quality of blueberries (Vaccinium corymbosum L. cv. Duke) was evaluated. Results from this study showed that AITC was effective in retarding blueberry decay during storage at 10 'C. AITC treatment resulted in maintenance of higher amounts of sugars and lower organic acids in fruit. However, AITC treatment decreased the contents of total phenolics and anthocyanins, and reduced antioxidant enzyme activities and the nonenzyme antioxidant components, ascorbate (AsA) and glutathione (GSH). Compared with control, AITC-treated berries had lower scavenging capacities for the oxygen radical absorbance capacity (ORAC) assay, hydroxyl radicals(•OH) and for the 2, 2-Di (4-tert-octylphenyl) -1-picrylhydrazyl (DPPH*) assay, but promoted the accumulation of H2O2 radicals. The free radical scavenging properties of blueberry fruit with or without AITC treatment were also evaluated by electron spin resonance (ESR). Results of the ESR measurements confirmed that free radical scavenging capacities against •OH, DPPH• and O2•- were lower in treated fruit than in control. AITC treatments also reduced the amount of phenolic acids (chlorogenic acid, myricetin 3- arabinoside, quercetin 3-galactoside, quercetin 3-arabinoside, and kaempferol 3-glucoside) and anthocyanins (delphinidin 3-galactoside, delphinidon 3-glucoside, delphinidin 3-arabinoside, petunidin 3-galactoside, petunidin 3-glucoside, petunidin 3-arabinoside, malvidin 3-galactoside, and malvidin 3-arabinoside) during storage at 10 'C. The results from this study indicate that AITC does not enhance antioxidant properties or the scavenging of constitutive reactive oxygen species (ROS), but paradoxically generates additional amounts of ROS which can then inhibit the growth and proliferation of microbial cells, thereby reducing decay in fruit tissue.