Author Topic: Sous vide: recognition of dangers of high-heat cooking?  (Read 5504 times)

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Offline PaleoPhil

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Sous vide: recognition of dangers of high-heat cooking?
« on: December 14, 2009, 04:35:40 am »
Dr. Eades invented a cooker that uses the low-and-slow "sous vide" method of cooking (http://www.proteinpower.com/drmike/food-porn/diy-sous-vide/).

I also recall reading Dr. Cordain advocate a low-and-slow method of cooking, though I can't find the reference.

I don't recall them getting into the details much of what the health reasons for this style of cooking would be, but perhaps they recognize that high-heat cooking produces toxic Maillard products and consider it a concern?
>"When some one eats an Epi paleo Rx template and follows the rules of circadian biology they get plenty of starches when they are available three out of the four seasons." -Jack Kruse, MD
>"I recommend 20 percent of calories from carbs, depending on the size of the person" -Ron Rosedale, MD (in other words, NOT zero carbs) http://preview.tinyurl.com/6ogtan
>Finding a diet you can tolerate is not the same as fixing what's wrong. -Tim Steele
Beware of problems from chronic Very Low Carb

Offline invisible

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #1 on: December 14, 2009, 10:14:17 am »
Seems that it's more about making the meat tender, since recommends to 'sear' the outside which makes it just like a roast dinner.

When I was eating alot of cooked meat I thought it would be healthier to cook with water than dry heat. I would boil beef steaks for 10 - 20 seconds or steam chicken and lamb to cooked completely through with some green vegetables and herbs. I thought it tasted fine without needing to being browned.

Offline PaleoPhil

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #2 on: December 14, 2009, 10:29:04 am »
Granted, it's nothing like we would do and obviously I'm not recommending it, but it's interesting how some prominent experts are starting to show a concern about high-heat cooking. With sous vide, the food is cooked at a much lower temperature than avg. He only says to sear it very briefly at the end and he shows a cross section of the meat showing pink throughout the rest, whereas grilled or baked meat tends to be pink in the middle only, if that. I've even ordered "rare" steak at a restaurant only to find that just the middle was pink, though at least it was juicy. Someone else ordered medium rare and it was tan to brown throughout.

The question it raises is, if Maillard products and nutrient loss are no concern, as some of the critics of raw eating have claimed, then why use low-and-slow cooking methods? It seems to be a partial acknowledgment that there's some wisdom in what we're doing. My guess is that they would argue that low-and-slow is low enough and going all the way down to raw is unnecessary.
>"When some one eats an Epi paleo Rx template and follows the rules of circadian biology they get plenty of starches when they are available three out of the four seasons." -Jack Kruse, MD
>"I recommend 20 percent of calories from carbs, depending on the size of the person" -Ron Rosedale, MD (in other words, NOT zero carbs) http://preview.tinyurl.com/6ogtan
>Finding a diet you can tolerate is not the same as fixing what's wrong. -Tim Steele
Beware of problems from chronic Very Low Carb

Online TylerDurden

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #3 on: December 14, 2009, 05:52:25 pm »
I know, they've tried(Eades in particular) to claim that heat-created toxins are not a big deal. But I guess the multitude of studies damning cooked-meat-consumption has caused them to be more wary so that they now only claim that lightly-cooked meats are OK.
"During the last campaign I knew what was happening. You know, they mocked me for my foreign policy and they laughed at my monetary policy. No more. No more.
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Offline PaleoPhil

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #4 on: December 15, 2009, 08:02:32 am »
Well, they haven't made that specific claim, AFAIK. They so far have promoted the sous vide solely for taste reasons. I couldn't find anything on health benefits, though the Eades probably adopted sous vide cooking in part to get the health benefits of emulating the Paleolithic style of low-and-slow cooking.

I think that if you're going to cook, then low-and-slow is indeed the way to go, but I'm a bit concerned about the anaerobic aspect of sous vide. The Eades are intelligent people who know not to store cooked food in a vacuum for lengthy periods, but will all their customers be so knowledgeable? After all, some Inuits have died from storing raw food in airtight plasticware that became infected with botulism. I hope the Eades made sure there are prominent warnings in the instructions and have good insurance and wish them luck. They've probably moved further in our direction as a result of this than all but a handful of meat-eating gurus. I just wish it was an aerobic cooker, like some kind of improved crockpot or something.

From the Eades' Sous Vide Website:
Quote
"Q: At what temperature do you cook foods sous vide?

A: The concept of sous vide is to cook the food at the same temperature you wish it to be served; most dishes should cook between 120°–190° Fahrenheit (48.9°–87.8° Celcius). The key to sous vide is maintaining the same water temperature throughout the entire cooking process, as a difference of only one degree can change appearance, flavor and texture."

Quote
Sous Vide Moves From Avant-Garde to the Countertop
Published: December 8, 2009
http://www.nytimes.com/2009/12/09/dining/09sous.html?pagewanted=2&_r=3

By traditional methods, the steak has to be blasted with heat from the outside, anywhere from 350 degrees (normal oven temperature) to 800 degrees (the grill at Peter Luger’s). As the heat transfer takes place, the meat changes: proteins coagulate, fibers contract, collagens loosen, liquid evaporates. By the time the center is a rosy 135 degrees, the surrounding flesh is dried out.

“About 45 percent of a rare beef loin cooked by normal methods is technically overcooked,” said Chris Young, the culinary research manager at Intellectual Ventures in Seattle....

But sous vide also carries an edge of risk, because vacuum sealing creates an anaerobic environment that can silently breed toxins like the bacteria that cause botulism.

[Although this is not a problem] for home cooks who serve their sous-vide handiwork as soon as it is cooked.

This guy totally doesn't get it:
Quote
“As long as the food is cooked to the usual safe temperatures, this system seems fine,” said Elliott Marcus, the chief of food safety for the city health department...."
NO, it's not "cooked to the usual safe temperatures," silly. That's the whole point of the sous vide: low-and-slow.

Quote
DIY sous vide
http://www.proteinpower.com/drmike/food-porn/diy-sous-vide/

mreades, 2. December 2009, 10:08

@Anders

Botulism isn’t really a worry as long as you are removing the food from the bag and consuming it after cooking. The bacterium that produces the botulism toxin can grow only in anaerobic conditions, which are really difficult to achieve with vacuum sealing devices, so you don’t have to worry about it. And it takes a while to develop, which you don’t provide if you eat the food after cooking.

Too bad Dr. Eades didn't reply to this comment:
Quote
Sylvie O., 3. December 2009, 8:33

Dear Dr Mike,

Are you at all familiar with the work of Dr Jean Seignalet ?

http://seignaletdiet.wordpress.com/diet-basis/

He contended that food should never be cooked beyond 110C as it creates what he called Maillard molecules, which he believed were harmful for humans. The diet he recommended (ancestral, no grains, no dairy) was apparently used successfully for people suffering from auto-immune diseases.

If you care to look into that, I think it would be interesting for a lot of people to see that as the topic of a future blog post.

One device I'd be interested in is a crock pot that cooks at temps above the "warm" setting and below 40C, so that I could melt things more efficiently while still not cooking them.
« Last Edit: December 15, 2009, 08:25:03 am by PaleoPhil »
>"When some one eats an Epi paleo Rx template and follows the rules of circadian biology they get plenty of starches when they are available three out of the four seasons." -Jack Kruse, MD
>"I recommend 20 percent of calories from carbs, depending on the size of the person" -Ron Rosedale, MD (in other words, NOT zero carbs) http://preview.tinyurl.com/6ogtan
>Finding a diet you can tolerate is not the same as fixing what's wrong. -Tim Steele
Beware of problems from chronic Very Low Carb

Offline van

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #5 on: December 15, 2009, 10:57:46 am »
  HI,  you can hook up a reostat, like what's used with dimming lights to your slow cooker.  Not very difficult, just spice and rehook some wires with caps.  YOu can buy them at any hardware store.  I did it when I used to make yogurt.  You just play around with the settings with the cooker filled with water to you get the right temp.  Usually overnight per attempt. 

Offline PaleoPhil

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #6 on: December 15, 2009, 11:17:34 am »
Thanks, though I don't want to cook anything in water, I just want to melt suet and other fats below 40C.
>"When some one eats an Epi paleo Rx template and follows the rules of circadian biology they get plenty of starches when they are available three out of the four seasons." -Jack Kruse, MD
>"I recommend 20 percent of calories from carbs, depending on the size of the person" -Ron Rosedale, MD (in other words, NOT zero carbs) http://preview.tinyurl.com/6ogtan
>Finding a diet you can tolerate is not the same as fixing what's wrong. -Tim Steele
Beware of problems from chronic Very Low Carb

Online TylerDurden

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #7 on: December 15, 2009, 06:06:39 pm »
Actually, Cordain has already spoken out about the dangers of heat-created toxins, directly as a result of all those anti-cooked-meat studies out there. Eades has mentioned it in passing, and is highly selective in mentioning such studies(ie only mentioning the tiny, tiny minority of studies which dismiss AGEs etc.)

What I find refreshing is that the number of anti-cooked meat studies is so huge now that even Wrangham had to very grudgingly acknowledge their existence though he laughably claimed that humans were adapted to them.
"During the last campaign I knew what was happening. You know, they mocked me for my foreign policy and they laughed at my monetary policy. No more. No more.
" Ron Paul.

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #8 on: December 15, 2009, 06:23:35 pm »
Where did Seignalet get that arbitrary figure of 110C for the creation of Maillard molecules? I suspect the figure is much lower, given that enzymes(which are proteins) already start being affected c.40C and destroyed at 47C and upwards.
« Last Edit: December 15, 2009, 06:29:23 pm by TylerDurden »
"During the last campaign I knew what was happening. You know, they mocked me for my foreign policy and they laughed at my monetary policy. No more. No more.
" Ron Paul.

alphagruis

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #9 on: December 15, 2009, 09:25:27 pm »
Where did Seignalet get that arbitrary figure of 110C for the creation of Maillard molecules? I suspect the figure is much lower, given that enzymes(which are proteins) already start being affected c.40C and destroyed at 47C and upwards.

Let's recall a little bit physics or chemistry.

Denaturation of proteins or enzymes takes places at fairly low temperatures indeed, for instance 50 °C (but also sometimes obviously at much higher temperatures in bacteria capable to live in deep see boiling water niches !). Denaturation of proteins means a change in configuration and structure in 3-dimensional space of a macromolecule, i.e. a big molecule made here of a long string of typically hundreds of aminoacids. This prevents the protein as an enzyme to remain active in the organism's biochemistry but does not render it toxic by itself if one eats it. In this respect it is important to become aware of the fact that all proteins are denaturated in the acid stomacal environment upon digestion and/or hydrolysis. Toxicity is brought about only when the aminoacids themselves are damaged or reacted with other molecules by heat and this needs usually markedly higher temperatures than 50°C. Notice that otherwise a simple fever would wreak havoc in the organism's biochemistry.

Formation of Maillard molecules or other culinary toxins similarly needs higher temperatures to take place in sizable or harmful quantities. This is because, as aminoacid destruction or damage or racemization, these chemical reactions are non-enzymatic thermally activated reactions that are very slow at body temperature but become very rapid about 100°C or higher.

 To give just an idea of the reaction rates involved typically:

While in given quantity of a food we get for instance 1 molecule of a typical Maillard product formed per second when left at 15°C, there are 40000 of them formed per second at 90°C and 10 millions of them formed per second at 180°C. That's thermal activation...In other words one gets about 70000 times (10^7 x 30 / (60 x 24 x 3) more AGE's after cooking 30 minutes at 180°C  than when left raw at 15°C for 3 days.  

Since from a darwinian point of view we had ample time to adapt to it, one may imagine that we are capable to deal easily with the tiny amount of AGE's produced in food left at room temperature even after several hours or days or months. Yet with 70000 times more and 2 meals a day for several tens of years our detoxination mechanisms might well be progressively overwhelmed and the organism more and more poisened. This is obviously in line with the fact that the health problems of civilized "cooked" people usually appear and increase upon aging only.

So, to come back to Seignalet, from a technical point of view 110°C is certainly not a limit with no heat generated toxin formation below. There are just one or two orders of magnitude less than at 180°C. Best adaptation of our or other species is for no heating at all. AFAIK Seignalet knew that of course but just told his patients that the lesser evil for those of them unable to eat their meat or fish raw was to cook it at temperature below 110°C.  



« Last Edit: December 15, 2009, 09:36:55 pm by alphagruis »

Online TylerDurden

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #10 on: December 16, 2009, 02:39:00 am »
Fevers, AFAIK, only go a few degrees above body-temperature(isn't somewhere between 40C-42C the maximum, before the person starts dying?). And the few studies done on foods boiled at 100C do show quite a number of AGEs(though nowhere near as much as with fried foods, of course).

I do agree that the human body can get rid of microscopic traces of AGEs each day, but, IMO, that is only useful on a mostly-raw diet where there's no constant intake of AGEs.
"During the last campaign I knew what was happening. You know, they mocked me for my foreign policy and they laughed at my monetary policy. No more. No more.
" Ron Paul.

alphagruis

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Re: Sous vide: recognition of dangers of high-heat cooking?
« Reply #11 on: December 16, 2009, 03:15:16 am »
Fevers, AFAIK, only go a few degrees above body-temperature(isn't somewhere between 40C-42C the maximum, before the person starts dying?).

Well I agree. I mentioned fevers just to point out that our enzymes still seem to work quite well about 40°C, a temperature not so rarely observed with fevers.    
« Last Edit: December 16, 2009, 03:23:19 am by alphagruis »

 

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