Thursday, September 10, 2009

How Does Pasteurization Affect the Health Benefits of Juice?

I've heard much about the benefits of black currant juice. The juices I find in grocery and health food stores are all pasteurized. What effect does pasteurization have on the health benefits of this or any other juice? Mark N.

Dear Mark,

There's a lot in the news these days about juices providing health benefits. Fruits contain many different substances that we are finding can help protect our cells.

I wouldn't put all my eggs in one basket, so to speak, when choosing a juice for health benefits--they all seem to bring some great properties to the table.

Also, eating the fruit itself, is usually better for several reasons: you're usually getting a more pure form (zero processing), fewer calories, and less concentrated sugar, as well as more fiber when you eat the fruit instead of the juice.

And, as I found out researching your question this morning, it turns out that pasteurization does have an effect on some of the components in juices.

Pasteurizing the fruit is for safety reasons, to keep bacteria from growing. So this has to be considered a health benefit too!
However, I did find some studies that seem to answer your question. One, Biodiversity of Total Phenolics, Antioxidant Capacity, and Juice Quality in Apple Cider Taxa that was submitted to the Journal of Horticulture, Environment and Biotechnology examined the effect pasteurization has on phenols and antioxidants. They found no effect on the phenol content of apple juice after pasteurization, but in fact there was a "significant effect" on the antioxidant activity.

Another study found a significant reduction in carotenoids (namely violaxanthin and lutein) after the pasteurization of Valencia orange juice (Effect of thermal pasteurization and concentration on carotenoid composition of Brazilian Valencia orange juice from Food Chemistry in 2004).

So, it turns out that pasteurization does have an effect on some of the components that are healthy in juices: however, it does outweigh the risk of getting sick from bacteria that can grow in juices that aren't pasteurized.

The bottom line is that it's probably best to eat the fruit when you can, and drink a safer (pasteurized) juice that gives you a bit fewer of the antioxidants and vitamins when the fresh fruit is not available.

No comments:

Post a Comment