Hot or cold smoking; what preserves food best?

[Lush]

You're spot on about the lack of moisture being the preserving property.

...2. Perhaps it's "hot" smoked in which case it is indeed cooked...

Now don't say "cooking" again please when you mean hot smoking at +/- 72 degrees, that's confusing. Parasites can survive that temp. Almost all fresh salmon do carry Henneguya salminicola. Read (at least) the first and last alinea of the following:

According to Canadian biologist Dorothy Kieser, protozoan parasite Henneguya salminicola is commonly found in the flesh of salmonids. It has been recorded in the field samples of salmon returning to the Queen Charlotte Islands. The fish responds by walling off the parasitic infection into a number of cysts that contain milky fluid. This fluid is an accumulation of a large number of parasites.

Henneguya and other parasites in the myxosporean group have a complex lifecycle where the salmon is one of two hosts. The fish releases the spores after spawning. In the Henneguya case, the spores enter a second host, most likely an invertebrate, in the spawning stream. When juvenile salmon out-migrate to the Pacific Ocean, the second host releases a stage infective to salmon. The parasite is then carried in the salmon until the next spawning cycle. The myxosporean parasite that causes whirling disease in trout, has a similar lifecycle.[19] However, as opposed to whirling disease, the Henneguya infestation does not appear to cause disease in the host salmon — even heavily infected fish tend to return to spawn successfully.
According to Dr. Kieser, a lot of work on Henneguya salminicola was done by scientists at the Pacific Biological Station in Nanaimo in the mid-1980s, in particular, an overview report[20] which states that "the fish that have the longest fresh water residence time as juveniles have the most noticeable infections. Hence in order of prevalence coho are most infected followed by sockeye, chinook, chum and pink." As well, the report says that, at the time the studies were conducted, stocks from the middle and upper reaches of large river systems in British Columbia such as Fraser, Skeena, Nass and from mainland coastal streams in the southern half of B.C. "are more likely to have a low prevalence of infection." The report also states "It should be stressed that Henneguya, economically deleterious though it is, is harmless from the view of public health. It is strictly a fish parasite that cannot live in or affect warm blooded animals, including man".


Sample of pink salmon infected with Henneguya salminicola, caught off the Queen Charlotte Islands, Western Canada in 2009
According to Klaus Schallie, Molluscan Shellfish Program Specialist with the Canadian Food Inspection Agency, "Henneguya salminicola is found in southern B.C. also and in all species of salmon. I have previously examined smoked chum salmon sides that were riddled with cysts and some sockeye runs in Barkley Sound (southern B.C., west coast of Vancouver Island) are noted for their high incidence of infestation."

It sais Henneguya salminicola is not dangerous in humans. Still not sure about other parasites.. It can cause diarrhea I think.

Very good information dogoak thanks

 

[santaman2000]

I still stand by the statement that hot smoking is cooking. Perhaps not to a temp that kills ALL parasites I did say that I'm not sure myself why the smoked salnmon safe to eat, just that that was one theory.

Think about it a minute. When cooking a steak we all have different preferences; rare, medium-rare, medium, medium-well, or well done. Of those choices, only well done will guarantee that ALL parasites are killed, Yet they are ALL cooked. It's no different with smoking temps and fish.

As the article points out though, apparently the only parasite known in salmon is harmless to humans. Maybe. When you read it carefully it states that said parasite were found on smoked salmon, but it doesn't say they were still alive?

 

[British Red]

Okay, heres the deal as I understand it from a person who has studied primitive and modern food preservation techniques - I've not written them up on here yet - but one day I must.

Short answer is neither hot nor cold smoke will do much to eliminate parisites from food. Smoke can impart a mildly antispetic coating to food, but can also contain caricongens. It is certainly not in and of itself a reliable food preserver.

In cold smoking of food the high concentrations of salt / brine have an effect on microorganisms sufficient to kill them - (osmotic effect on the cell membranes of both the host food - almost like mummifying prevent putrefaction) and also drying out the microorganisms. Whether you cold smoke or not after the salt / brine makes a negligable difference frankly other than a mildly antiseptic coating - smoked vs unsmoked bacon is a good example.

In hot smoking it is the heat, not the smoke, that has the effect. Many bacteria will die well below 100C - although not all.

Short answer - smoke does not preserve food in any meaningful way on its own but it does impart flavour. Many things do preserve food (salt, heat also acids, alkalis, sugar, radiation etc.)

 

[Lush]

The only thing is that if you state "they are all cooked" that can give a false sense of security. I wasn't referring to the definition of "cooking". Feel free to use the term "cooking" for smoking any time. We do now understand you very well.

The temp that is needed to get steak well done is 72c. It is safe enough to eat but it doesn't kill all bacteria. A little nuance would be fair, I think.They are brought down to a number that is safe to consume or store. As with fish.

I am not interested in debating you any further in this way. No offence. Please let's return to the question about safety of food.

This is about another parasite that salmon carries: "anisakis". There are other parasites in salmon, trout and other fresh water fish. In Japan salmon was considered dangerous to serve for its higher chance of having parasites than bonito, and it was never eaten raw in Japan, but this was not true for the Ainu culture that lives in Northern Japan. They understood for centuries that freezing the salmon in the snow for a couple days makes it edible without any chance of stomach problems. Recent scientific studies concluded that all parasites linked to sushi can be killed off by freezing it at a temperature of -20 degrees Celsius (-4 degrees Fahrenheit) for 24 hours. Nothing tastes better than a pre-frozen fresh sashimi, but freeze treatment is often used on other fishes used for sashimi and sushi just to be extra safe about parasites. The good news is that most seafood have to be freezed anyways when they are transported. The question to ask is at what temperature and how long.

Anisakiasis is a human parasitic infection of the gastrointestinal tract caused by the consumption of raw or undercooked seafood containing larvae of the nematode Anisakis simplex. The first case of human infection by a member of the family Anisakidae was reported in the Netherlands by Van Thiel, who described the presence of a marine nematode in a patient suffering from acute abdominal pain. [8] It is frequently reported in areas of the world where fish is consumed raw, lightly pickled or salted. The areas of highest prevalence are Scandinavia (from cod livers), Japan (after eating sushi and sashimi), the Netherlands (by eating infected fermented herrings (maatjes)), and along the Pacific coast of South America (from eating ceviche). Fewer than ten cases occur annually in the United States.[9] Development of better diagnostic tools and greater awareness has led to more frequent reporting of anisakiasis.

Within hours after ingestion of infective larvae, violent abdominal pain, nausea, and vomiting may occur. Occasionally, the larvae are regurgitated. If the larvae pass into the bowel, a severe eosinophilic granulomatous response may also occur one to two weeks following infection, causing symptoms mimicking Crohn's disease.
Diagnosis can be made by gastroscopic examination, during which the 2-cm larvae are visually observed and removed, or by histopathologic examination of tissue removed at biopsy or during surgery.
----------------------------------------

I can add that Anisakiasis is/are killed at 60c. So for the question about raw fish or with lemon juice that answers that I guess guys. I did some serious digging which I am sharing with you guys . Learning something every day...

 

[Lush]

Okay, heres the deal as I understand it from a person who has studied primitive and modern food preservation techniques - I've not written them up on here yet - but one day I must.

Short answer is neither hot nor cold smoke will do much to eliminate parisites from food. Smoke can impart a mildly antispetic coating to food, but can also contain caricongens. It is certainly not in and of itself a reliable food preserver.

In cold smoking of food the high concentrations of salt / brine have an effect on microorganisms sufficient to kill them - (osmotic effect on the cell membranes of both the host food - almost like mummifying prevent putrefaction) and also drying out the microorganisms. Whether you cold smoke or not after the salt / brine makes a negligable difference frankly other than a mildly antiseptic coating - smoked vs unsmoked bacon is a good example.

In hot smoking it is the heat, not the smoke, that has the effect. Many bacteria will die well below 100C - although not all.

Short answer - smoke does not preserve food in any meaningful way on its own but it does impart flavour. Many things do preserve food (salt, heat also acids, alkalis, sugar, radiation etc.)

I think that's all true... and drying of course, which also happens during smoking. Which parasites or bacteria die at which temperature is just depending.

 

[British Red]

Drying certainly has an effect - but fish needs to be dried far more than normal "smoked fish" (e.g. kippers etc.) in order for safe preservation to take place - you need to dry it hard - like jerky.

 

[santaman2000]

The only thing is that if you state "they are all cooked" that can give a false sense of security. I wasn't referring to the definition of "cooking". Feel free to use the term "cooking" for smoking any time. We do now understand you very well.

The temp that is needed to get steak well done is 72c. It is safe enough to eat but it doesn't kill all bacteria. A little nuance would be fair, I think.They are brought down to a number that is safe to consume or store. As with fish.

I am not interested in debating you any further in this way. No offence. Please let's return to the question about safety of food.....

Agreed on all three points.

 

[santaman2000]

.....This is about another parasite that salmon carries: "anisakis". There are other parasites in salmon, trout and other fresh water fish. In Japan salmon was considered dangerous to serve for its higher chance of having parasites than bonito, and it was never eaten raw in Japan, but this was not true for the Ainu culture that lives in Northern Japan. They understood for centuries that freezing the salmon in the snow for a couple days makes it edible without any chance of stomach problems. Recent scientific studies concluded that all parasites linked to sushi can be killed off by freezing it at a temperature of -20 degrees Celsius (-4 degrees Fahrenheit) for 24 hours. Nothing tastes better than a pre-frozen fresh sashimi, but freeze treatment is often used on other fishes used for sashimi and sushi just to be extra safe about parasites. The good news is that most seafood have to be freezed anyways when they are transported. The question to ask is at what temperature and how long.....

It's good news IF! If you get your fish from a modern grocery store inland. On the other hand if you catch your own, or if you live near enough the to coast to buy it fresh, then it might still be a concern. Most of the fish (all seafood actually) in my local supermarkets' seafood sections is labeled (by law) as either "frshh never frozen" or "once frozen" (if sold unfrozen by the pound rather than pre-wrapped from the freezer) Also labelled with country of origin and whether it's wild caught or farm raised.

 

[santaman2000]

.....Anisakiasis is a human parasitic infection of the gastrointestinal tract caused by the consumption of raw or undercooked seafood containing larvae of the nematode Anisakis simplex. The first case of human infection by a member of the family Anisakidae was reported in the Netherlands by Van Thiel, who described the presence of a marine nematode in a patient suffering from acute abdominal pain. [8] It is frequently reported in areas of the world where fish is consumed raw, lightly pickled or salted. The areas of highest prevalence are Scandinavia (from cod livers), Japan (after eating sushi and sashimi), the Netherlands (by eating infected fermented herrings (maatjes)), and along the Pacific coast of South America (from eating ceviche). Fewer than ten cases occur annually in the United States....

It'll be interesting to see if this number climbs. Sushi and Sashimi are very popular here and getting more so. Civiche is also growing in popularity here as well.