Adding citrus juices or vitamin C to green tea may raise its antioxidant goodness, a new study suggests.

The antioxidants in question are called catechins, believed to be responsible for some of green tea's reported health benefits, such as reducing the risk of cancer, heart attack and stroke.

"Although these results are preliminary, I think it's encouraging that a big part of the puzzle comes down to simple chemistry," lead author Mario Ferruzzi, assistant professor of food science at Purdue University in West Lafayette, Ind., said in a prepared statement.

Using a laboratory model that simulates digestion in the stomach and small intestine, Ferruzzi tested green tea with a number of additives, including juices and creamers.

He found that citrus juice increased recoverable (absorbable) catechin levels by more than five times, while vitamin C (ascorbic acid) boosted recoverable levels of the two most abundant catechins by six and 13 times.

The findings were published in the journal Molecular Nutrition and Food Research.

Citrus juices and vitamin C may interact with catechins to prevent degradation in the intestines, Ferruzzi said.

"If you want more out of your green tea, add some citrus juices to your cup after brewing or pick a ready-to-drink product formulated with ascorbic acid," he suggested.

Ferruzzi is currently conducting a study examining whether citrus juices and vitamin C increase catechin absorption in lab animals.

一项新的研究表明，在绿茶中加入柑橘类果汁或维生素C可提高其抗氧化作用。

被研究的抗氧化剂名为儿茶素，被认为是绿茶中对身体有益的物质，如减少患癌症、心脏病和中风的风险。

"虽然这些成果都是初步的，但大部份的疑惑都被简单的化学作用所解开，我认为这很令人鼓舞，"此研究的主笔人马里奥费鲁齐，执教于印第安纳州西拉斐特市普渡大学的助理教授在一份准备好的声明中说。

费鲁齐用实验模型来模拟胃和小肠消化功能，向绿茶中放一些添加剂如果汁和奶盖来测试绿茶。

他发现，柑橘汁将可恢复（可吸收的）儿茶素水平提高了5倍还多，同时维生素C（抗坏血酸）将其中两种含量最多的儿茶素中的可恢复水平提高了6倍和13倍。

调查结果刊登在杂志分子营养与食品研究上。

柑橘类果汁和维生素C也可与儿茶素相互作用以防止肠子的退化，费鲁齐说。

他建议，"如果你想从绿茶获得更多好处，，在泡好的茶中加上一些柑橘类果汁，或挑选一种加抗坏血酸的即饮产品" 。

费鲁齐目前正在从事一项研究，在实验室动物身上研究柑橘类果汁和维生素C是否能增加儿茶素的吸收水平。