21 Dec 2005 16:33:32 GMT in article <[email hidden]>
(John Sankey) said:Quoted message said:Quoted message said:Fish canning processes remove a lot of nutrients.
Quoted message said:Not necessarily. Canning process of tuna causes losses of
omega-3s, but other canned fish retain their omega-3s. I think
that canned mackerel, herring and sardines are excellent
choices.
I guess you haven't worked in a North American canning factory,
Matti. Every canned fish I know of starts off being cooked on a
rack so most lipids drip off. Then it's canned, and sterilized at
very high heat in a pressure cooker to ensure that it doesn't
spoil, thus wrecking all heat-sensitive nutrients.
According to what I've read that kind of process is used only for tuna.
And I seriously doubt that it applies to small fish canned as whole such as
sardines. See
Omega-3 | FAQ's
<http://www.omega-3info.com/faqs.htm#10>
An excerpt:
"Is there a high, or even not so high, concentration of
omega-3 in regular tuna? I've heard albacore tuna has a
lot. I eat tuna sandwiches every day, but I'm not sure
that they're albacore tuna. Does it make a difference?
Fresh and frozen tuna are excellent sources of long chain
omega-3 polyunsaturates, supplying around 5% total oil of
which 20% is omega-3. However, during the canning process,
most of the oil and therefore most of the omega-3 is lost.
This is mainly because tuna is cooked before it is canned,
and during the cooking process much of the oil is
separated and lost. The meat that goes in the tin thus has
a low oil content (usually less than 1g per 100g) and a
low omega-3 content (usually less than 0.4g per 100g). It
matters little whether the tuna is albacore or yellowfin
because once it is canned there is little omega-3 left.
Some tuna packers do can raw tuna so that the omega-3
content is higher, but it is usually difficult to
distinguish such products from the others in the
marketplace. Enquire of the producer to be certain. These
comments only apply to tuna. Other canned fish are just as
good as the raw fish as sources of long chain omega-3
polyunsaturates."
Quoted message said:European practice may be different. But here in Canada, frozen
fish is a far better choice.
Depends how it has been packed, because fish fat oxidates even in frozen
fish, unless fish has been packed and frozen airtightly.
--
Matti Narkia
