Clear apple juice may be prettier, but cloudy apple juice is probably better for your health. A new study shows that cloudy juice can contain more than five times as much of a health-linked antioxidant as clear juice has.
The color of most apples, other fruits, and vegetables comes from a family of antioxidants called polyphenols. Studies have associated these chemicals with health benefits ranging from a reduced risk of cancer to improved brain functions.
Generally, the stronger the color of the fruit is, the higher the concentration of polyphenols will be. The skin and seeds of an apple are particularly high in these compounds, and the process of making clear apple juice removes this solid matter.
"It is better if you eat whole apples than juices. But for juices, it’s better if you drink this cloudy juice," says the new study’s lead author Jan Oszmianski, who studies fruit and vegetable processing at the Agricultural University of Wroclaw in Poland.
While scientists had widely assumed that cloudy juice (cider) ought to be more healthful, Oszmianski’s study provides a more accurate picture of the difference in antioxidant activity between these two juice types. That’s because the most common way to measure this activity requires a transparent sample. In other words, it only works well with clear juice.
Oszmianski and his colleagues employed a technique called electron paramagnetic resonance (EPR), which can measure the activity of antioxidants in both cloudy and clear juice. The method even accounts for polyphenols bound to solid bits of pulp, which include an especially potent class of polyphenols called procyanidins.
"This is the first time that I’ve seen [anyone] use [EPR] to measure antioxidant activity in plant extracts," says Joshua Lambert, assistant professor of chemical biology at Rutgers University in Piscataway, N.J., who was not involved in the study.
Oszmianski’s team found that procyanidins were between 2.6 and 5.3 times as abundant in cloudy juice as in clear, depending on the variety of apple used. However, amounts of other antioxidants were more nearly equal between the two kinds of juice. Overall, the cloudy juice was 1.5 to 1.8 times as effective an antioxidant as the clear juice. Oszmianski and his colleagues report their results in an upcoming Journal of the Science of Food and Agriculture.