Author
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Wang, Shiow |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 10/10/2003 Publication Date: 10/24/2003 Citation: Wang, S.Y. 2003. Cultural management affects phytonutrient content and antioxidant activity in berry fruits. Meeting Abstract. Interpretive Summary: Technical Abstract: People are becoming more aware of the environmental impact on health, and public interest is also increasing on the subject of food quality. Berry fruits contain significant levels of biologically active components that impart health benefits beyond basic nutrition. Berry fruits are a major source of dietary antioxidants, thus making them effective in inhibiting oxidation of human low-density lipoproteins and preventing or alleviating various human diseases caused by oxidative stress. However, no information is available on the effects of environmental factors such as cultural management on phytonutrient content and the scavenging capacity of berry fruits against active oxygen species. We have investigated the effect of cultural system (compost, mulch, pre-harvest application of natural compound and carbon enhancement) on berry plant growth and fruit quality. Compost, as a soil supplement, significantly enhanced content of ascorbic acid, reduced glutathione, and ratios of ascorbic acid/dehydroascorbic acid, and reduced glutathione/oxidized glutathione in fruit of strawberry. The peroxyl radical, as well as the superoxide radical, hydrogen peroxide, hydroxyl radical and singlet oxygen absorbance capacity in strawberries increased significantly with increasing compost use. Plants grown with compost yielded fruits with high levels of phenolics, flavonol, and anthocyanin content. Using different mulch for growing strawberry affected strawberry fruit quality. Fruit from a hill plasticulture (HC) production system had higher flavonoid content and antioxidant capacities compared to the plants grown in a matted row (MR) system. Strawberry fruit from the HC system had significantly higher amounts of p-coumaroylglucose, dihydroflavonol, quercetin 3-glucoside, quercetin 3-glucuronide, kaempferol 3-glucoside, kaempferol 3-glucuronide, cyanidin 3-glucoside, pelargonidin 3-glucoside, pelargonidin 3-rutinoside, cyanidin 3-glucoside-succinate and pelargonidin 3-glucoside-succinate than those from the MR system. Fruits from plants grown in the MR system generally had the lowest content of phenolic acids, flavonols, and anthocyanins. Fruit grown under HC conditions had highest peroxyl radical absorbance capacity. Carbon dioxide is one of the most limiting factors in photosynthesis. CO2 enrichment has been shown to increase plant growth and yield of agricultural crops. Increased CO2 (300 and 600 micromole per mol above ambient) concentrations resulted in increases in antioxidant compounds in strawberries. High anthocyanin and phenolic content were also found in fruit of CO2 treated plants. Growing strawberry plants under CO2 enrichment conditions significantly enhanced fruit flavonoid content. Fruit of strawberry plants grown in the CO2 enrichment conditions also had high oxygen radical absorbance activity against active oxygen radicals. Jasmonic acid and its methyl ester (methyl jasmonate) have been found to occur naturally in a wide range of higher plants. Preharvest treatment of raspberries with methyl jasmonate significantly enhanced the content of flavonoids and the antioxidant capacities in the fruit. In conclusion, the HC system resulted in higher phytonutrient content and antioxidant activities than the MR system in strawberries. Compost supplements in the soil and elevated CO2 also enhanced phytonutrient content and antioxidant activity in strawberries. Preharvest application of methyl jasmonate increased flavonoid content and antioxidant capacities in blackberries and raspberries. |
