Hojicha - Does roasting affect antioxidant content?

[ReturnofMike]

Hello there.

I have a co-worker who has started drinking green tea for health reasons, specifically the antioxidants. He has tried some of my green tea samples from Adagio but he does not like the grassy vegetable flavor that some have. So I thought he might like to try hojicha.

I brought my new sample tin of hojicha into work and told him that it was roasted and had a much different taste. The first thing he asked was if it still had the antioxidant properties of other green tea, and I didn't know the answer. It seems plausible to me that roasting over a fire could be changing the tea leaves in the same way as oxidizing would.

Would roasting green tea remove the antioxidants? Can I tell him that Hojicha is just as good for him as the "grassy" greens?

-The hojicha is excellent, by the way. Thank you.

[Marlene]

Does roasting affect the anti-oxident levels? My response, Who cares? lol

[ReturnofMike]

Does roasting affect the anti-oxident levels? My response, Who cares? lol

That's pretty much what I was thinking. If it tastes good, I'll drink it. But this fellow is only concerned with health benefits (I worry he may actually have a serious ailment that he is concerned about) . He probably wont care how good it tastes unless he thinks it's as healthy as the bitter bag greens he has been drinking. He thinks hojicha probably doesn't count as "green" anymore and is missing out!

[illium]

The short answer is that the differences are minimal.

HoJiCha is still a green tea.

The only difference is that after the normal production method of green tea, hojicha is put through an additional roasting process, where the leaves are roasted over charcoal.

There are some differences, most notably the loss of Vitamin C, which reduces to about a third (or less) than what's in a normal green tea. Vitamin C is one of the common anti-oxidants found in green tea.

However one of the most significant chemicals (and the one unique to green tea) is catechin. This is the chemical contained in the tannins of green tea, which are also, unfortunately, responsible for the bitter, astringent taste associated with those teas.

Hojicha has less tannins than Sencha or Matcha, but only by a small amount. So, while it is somewhat less healthful than it's more bitter tasting cousins, it is still quite healthy and worth drinking. There wouldn't be a major change in health benefits by choosing this tea over one of the other varieties.

For some more info:
Hs an overview flow chart of the Japanese tea processing methods, and the naming conventions that correspond:
http://www.greentealovers.com/greenteac ... essing.htm

A very thorough explanation of the various chemical properties in tea, as they relate to health. At the very bottom of this page is a comparison chart of the different types of tea, by thier vitamin/anti-oxidant contents:
http://greentealovers.com/greenteahealt ... m#catechin

Hope that helps,
Troy

[ReturnofMike]

Thank you very much for the response, Troy. Very comprehensive, just the information I was looking for.

Now, to enjoy a tasty cup of hojicha, no matter what sorts of curatives it contains!

[AlexZorach]

The short answer is that the differences are minimal.

This does not fit with what I've read. Be careful what you read online...there are lots of claims about health effects of teas that have been made without any research or reference to rigorous science. Fortunately, this has been studied scientifically, so there's no need to be in the dark. See here:

http://ddr.nal.usda.gov/handle/10113/1807

Page C556 lists a table with a chemical analysis of various teas; hojicha is listed as #57 here. The amount of both catechins (the antioxidants in all tea, esp. in green tea) in hojicha are actually much less than in most other kinds of teas...in fact, hojicha had the least total catechins of all teas tested (except for herbal teas not containing the tea plant).

However...this is not true of all catechins. Gallocatechin gallate (GCG) is actually higher in hojicha than in a number of green or black teas, however. Also, the caffeine content is much less, which might be desireable for some people.

Keep in mind, however, that they only tested a single brand...is it representative? I don't know. It could be that that particular brand (yamamotoyama) doesn't have as many catechins as other brands. Note that in the table there's also a huge amount of variation between different types of black tea. Presumably, if they tested different types of hojicha, they might find a lot of diversity too.

It's notable, however, that in the text of the article, the authors actually remark that hojicha has a very different chemical profile from the other teas. One last thing to consider is that there may be beneficial chemicals in hojicha that have not been discovered yet, because it hasn't been studied very much.

[AlexZorach]

By the way, for what it's worth, I was drinking hojicha while reading and replying to this thread.

[Ed]

Yeah, there's no way you can roast the &%@* out of bancha and expect to get all the same nutritional benefits of fresh green tea. The caffeine is not completely eliminated either. I drank two pots of houjicha and that was enough to feel the caffeine. I personally didn't care for houjicha the first couple of times I tried it, but recently Den's threw a houji genmaicha sample in with my order and it was delicious! I ordered 4 packages of it. I like to drink it with meals.

But if you want EGCG, drink sencha!