Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2005
Publication Date: 4/9/2010
Citation: Zheng, Y., Wang, C.Y., Wang, S.Y., Zheng, W. 2010. Effect Of superatmospheric oxygen on anthocyanins, phenolics and antioxidant activity of blueberries and strawberries. Acta Horticulturae. 857:475-482. Interpretive Summary: Increasing evidence has shown that diets rich in fruits and vegetables may reduce the risk of some types of cancer and other chronic diseases. One factor contributing to health benefits of fresh produce is the abundance of chemicals called antioxidants. However, information is lacking on the changes in antioxidants in fresh produce after harvest. We also do not yet know how to maintain or increase levels after produce is harvested. Antioxidant content can decline rapidly after harvest due to mishandling. We treated blueberry and strawberry fruits with high concentrations of oxygen immediately after harvest and found that high oxygen not only could maintain antioxidant levels in blueberries and strawberries, but oxygen concentrations higher than 60% could also lead to increases in total anthocyanins and other helpful chemicals in the fruit. In addition, high oxygen atmospheres also retarded decay of berry fruits during storage. Therefore, it is possible that the health benefits as well as shelf-life of these berry fruits can be improved by postharvest exposure to high oxygen atmospheres. This information will be useful to the berry industry and beneficial to the consumers.
Technical Abstract: The effects of superatmospheric oxygen levels on anthocyanins, phenolics, antioxidant activity and fruit quality of blueberries (Vaccinium corymbosum L.) and strawberries (Fragaria x ananassa Duch.) during storage at 5oC were investigated. High oxygen treatment increased the levels of total anthocyanins, total phenolics as well as several individual flavonoid compounds during the first 21 days of storage for blueberries and first 7 days of storage for strawberries. Antioxidant activity, measured as oxygen radical absorbance capacity or ORAC, also increased in these fruits during the same period after exposure of the fruit to superatmospheric oxygen concentrations. However, these effects diminished with prolonged storage duration. No significant differences in total anthocyanins, total phenolics, ORAC values or individual flavonoid compounds were observed between high oxygen and air-treated fruit during the later part of storage. Little differences were also found in titratable acidity, total soluble solids or surface color among the fruits treated with various concentrations of oxygen throughout the storage period. These results suggest that high oxygen treatments may improve the antioxidant activities of blueberry and strawberry fruits during the initial stage of storage.