lycopene

I've been lurking, but the question/comments about lycopene was one I couldn't pass up. Your right Neil, lycopene is the major pigment in tomatoes. And yes Linda, lycopene is also in red chilies. It is also in watermelon and reddish cast of apricots. Lycopene is relatively easy to identify since it is the only red pigment that is fat soluble. It also does not change colors with changes in pH.

The anthocyanins in addition to being water or alcohol soluble are also pH sensitive. If you add a little vinegar, you can shift the color towards red. A little baking soda will shift to blue - and you can go back and forth. Doing this with shredded red cabbage results in very interesting colors.

A relative rare pigment in food is betanin (red beets, red chard veins, prickly pear fruit). I know it occurs in some flowers but have not hear any of you mention it in iris. It also is water soluble, but when treated with a base, the color goes rusty brown-red instead of blue.

Anthoxanthins get overlooked because they are white to cream or pale yellow. They are water soluble and pH sensitive. The addition of soda can shift the color to yellow and helps one see if they are present. (They are also the reason for the recommendation to cook cauliflower with a pinch of cream of tartar so that the pH is shifted to the acid side and the cauliflower ends up nice and white.)

Charlotte, zone 4

=====USU=====USU=====USU=====USU======USU====USU==
Charlotte P. Brennand, EMail: Foodsafe@cc.usu.edu
Food Safety Extension Specialist or CharlotB@ext.usu.edu Dept. of Nutr. & Food Sci. Utah State Univ. Voice 435 797-2116
Logan, UT 84322-8700 FAX 435 797-2379 =====USU=====USU=====USU=====USU======USU====USU==


ate: Mon, 11 Oct 2004 13:24:43 -0400
From: "Neil A Mogensen" <neilm@charter.net>
Subject: [iris] HYB: color of Lycopene

Unless I am mistaken, that orange-red stuff that is the last part of a
spaghetti sauce to get cleaned off in a ring in the kettle is Lycopene in the
raw, pure form.  Same goes for the plates or pasta bowls in tomato-containing
pasta sauces.  The stuff is resistant to water, but sure does finally come off
with strong soap.  It emulsifies then gets flushed.

Iris beard colors redder than the Lycopene residue mentioned above are
modified by the presence, I suspect, of anthocyanins.

Chuck, your extraction comments have been very helpful!  They provide good
means of distinguishing the pigments.

Neil Mogensen z 7 western NC mountains.

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Date: Mon, 11 Oct 2004 14:33:16 -0400
From: Linda Mann <lmann@volfirst.net>
Subject: [iris] Re: HYB: tttt

Hmm... probably the same orange-red color of oriental hot oil sauce, oil
that has had hot peppers soaked it it.  That stuff also has sort of a
pinkish tint to it, I think.

I guess I could soak a tomato in some oil and find out for myself.
Thanks Neil.

Neil said:
<Unless I am mistaken, that orange-red stuff that is the last part of a
                   spaghetti sauce to get cleaned off in a ring in the
kettle is Lycopene in the
                   raw, pure form.  Same goes for the plates or pasta
bowls in tomato-containing
                   pasta sauces.  The stuff is resistant to water, but
sure does finally come off
                   with strong soap.  It emulsifies then gets flushed.>

- --
Linda Mann east Tennessee USA zone 7/8
East Tennessee Iris Society <http://www.korrnet.org/etis>
American Iris Society web site <http://www.irises.org>
talk archives: <http://www.hort.net/lists/iris-talk/>
photos archives: <http://www.hort.net/lists/iris-photos/>
online R&I <http://www.irisregister.com>

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