I shouldn't pose as a dairy expert, but will share a few things I have learned.
The word "casein" has the same root as "cheese" and was coined to describe the proteins in cheese. In the presence of calcium and magnesium, casein is quite insoluble in water. It can be dissolved by overwhelming the calcium with sodium hydroxide, to form sodium caseinate, which is somewhat water soluble and forms a very viscous solution - or perhaps more of a water dispersion.
Lactose is a sugar, water soluble, which can be split into two other sugars called galactose and glucose. I am not aware of research into whether it's the lactose per se or the galactose formed from it that causes problems for lactose intolerant individuals. Maybe that's a source of some of the baffling contradictions that seem to haunt the subject of LI.
Whey is the liquid drained from cheese curds after they are formed. Whey is mostly water and contains the dissolved lactose as well as some relatively soluble proteins. If it were possible to completely remove and rinse all the whey from the cheese curds, they should be quite free of lactose. Of course, this doesn't quite happen. Apparently, aging converts some of the remaining lactose. (To galactose or what???).
The bottom line is, casein may contain a low level of lactose, depending on degree of purification. Highly purified sodium caseinate will have very low levels, less than 1%.
Whey is extremely cheap because it is an unwanted byproduct of cheesemaking and used to be a major water pollutant in dairy areas. That is why whey powder is used in so many food formulations. Whey proteins can also be separated to some extent from the lactose. The early "whey protein concentrates" had more lactose than protein. They are somewhat purer now.
Don Maxwell
Date: Sun, 19 Sep 1999 21:01:44 -0400
Don Marcotte wrote:
>So, is it basically that the industrial processes don't
totally remove whey proteins (and lactose) when
they try to isolate casein, or does casein contain lactose?<
Yes, sorta, to the former, and no to the latter, Don.
Lactose is an entirely separate component of milk
from the proteins. It is dissolved in the liquid portion
of milk (which is simply water).
Because everything else is also dissolved (or technically
in colloidal suspension) in the liquid, processors have to work
hard to make sure they separate out all the lactose.
A cheese curd starts out liquid and traps some water,
including lactose, inside the curd. Aging almost
literally squeezes the water and lactose out.
Industrial processing is more sophisticated, but
the principle is the same.
It can be done, and I believe that processors in general
are doing a better job than in the past.
Best,
Date: Mon, 20 Sep 1999 00:05:17 -0400
Steve Carper -- Thanks for the info. However, to make sure I completely
understand, the lactose is not in the so-called whey proteins? It is
basically in suspension in the liquid? So when I see "whey" on an
ingredient list, I don't have to worry? Hmmmm. I have an allergic reaction
to things with lactose in it but not casein, e.g., Veggie Slices,
apparently. I read somewhere that the whey proteins contained lactose so
I've stayed away from anything with whey in it, e.g., some margarines. I
have done significanlty better as a result. However, allergic reactions
should be provoked by proteins, you would think. I may not have found the
magic answer yet. I'm more knowledgeable but even more confused. Didn't
someone say "a little knowledge is dangerous"?
Don M
Date: Mon, 20 Sep 1999 09:15:57 -0500
Think of the 'little miss muffit' ....eating her curds and Whey.
Curds and whey together are like cottage cheese. The lumps are Curds
(Cheese, Casein), and the whey is Liquid=likely Lactose, or think of
it as Whey=Water.
So there's a small amount of lactose in the casein part (otherwise it
would be hard). But there's much more chance of lactose in the whey,
unless the manufacturer chose to purify it.
Date: Mon, 20 Sep 1999 15:34:05 -0400
Juliann -- Thanks for the nursery rhyme remedial course
I'll have to continue with my research in this area. And I thought I had it
all worked out. It made sense but wasn't good science!
Don
Date: Mon, 20 Sep 1999 18:25:49 -0400
Don Maxwell wrote:
It's the lactose, Don. There are literally hundreds of
articles in the medical literature on this over the last
forty years. One session on MEDLINE will lead you to
as many of them as needed. Galactose bothers no one
except for the extremely tiny percentage of people with
galactosemia - and they already know who they are, I
assure you. For the rest of us galactose is converted to
glucose within 45 minutes.
And which LI contradictions are you referring to?
>The bottom line is, casein may contain a low level
of lactose, depending on degree of purification.
Highly purified sodium caseinate will have
very low levels, less than 1%.<
The highest reported level I have ever seen for
lactose in casein is 2%, but that was an isolated
report. There is no reason to believe that most
commercially processed casein has anywhere
near that amount. And sodium caseinate will have
proportionally much less than that, effectively zero
for anyone with LI.
Steve Carper
Steve Carper's Lactose Intolerance Clearinghouse
End of NO-MILK Digest - 19 Sep 1999 to 20 Sep 1999 (#1999-180)
From: Steve Carper
Subject: Re: Milk ingredients
Steve Carper
From: Don Marcotte
Subject: Re: Milk ingredients
From: Juliann Seebauer
Subject: Re: Milk ingredients
From: Don Marcotte
Subject: Re: Milk ingredients
From: Steve Carper
Subject: Re: does casein contain lactose?
>I am not aware of research into whether it's the
lactose per se or the galactose formed from it that
causes problems for lactose intolerant individuals.
Maybe that's a source of some of the baffling
contradictions that seem to haunt the subject of LI.<
author of Milk Is Not for Every Body: Living with LI
http://ourworld.compuserve.com/homepages/stevecarper
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