Should We Avoid Commercially Roasted Nuts?

cozmik

Here's something interesting I hadn't heard about roasted nuts before.

Roasting nuts at a temperature higher than 170F will cause a breakdown of their fats and the production of free radicals. When nuts roasted at the high temperatures used commercially are consumed, the free radicals they contain can cause lipid peroxidation-the oxidizing of fats in your bloodstream that can trigger tiny injuries in artery walls-a first step in the build up of plaque and cardiovascular disease.

Roasting brings out the flavor of the nuts, and develops their sweetness. It is safe to roast nuts if done at a low temperature-typically a 160-170 degree Fahrenheit oven (at higher temperatures than this, research clearly shows damage to nuts' delicate fats) for 15-20 minutes will do the trick.

http://www.whfoods.com/genpage.php?tname=george&dbid=104

Thoughts?

cozmik

No expert opinions out there?? or 2 cents?

El_Dangeroso

Sounds bang on to me.. although you probably don't want my opinion

This happens to all non-saturated fats at somepoint, which is why sunflower oil, or most vegetable oils, aren't good for frying. I think the highest tolerance is peanut or groundnut oil. I'm not afraid of natural saturated fats so I use organic duck fat and ghee.

rubadub

I get cashews and roast them myself, really nice while still hot, dunno what temp though, my cooker has no numbers. You get raw nuts cheap in the asian shops.

cozmik

neddas wrote: »

Sounds bang on to me.. although you probably don't want my opinion

This happens to all non-saturated fats at somepoint, which is why sunflower oil, or most vegetable oils, aren't good for frying. I think the highest tolerance is peanut or groundnut oil. I'm not afraid of natural saturated fats so I use organic duck fat and ghee.

Thanks for the reply

cozmik

rubadub wrote: »

I get cashews and roast them myself, really nice while still hot, dunno what temp though, my cooker has no numbers. You get raw nuts cheap in the asian shops.

I'm trying to find pistachios but everywhere I look they have already been roasted.Anybody have any idea where I might get organic unroasted pistachios that I could roast myself?

Thanks!

Piste

Hmm I might starts toasting/roasting nuts in my oven instead of on the hob, I havent a clue what temperature things on the hob are, but I suspect I'm overcooking my pine nuts

rubadub

cozmik wrote: »

I'm trying to find pistachios but everywhere I look they have already been roasted.Anybody have any idea where I might get organic unroasted pistachios that I could roast myself?

Thanks!

Yep, again the asian shops, and they come ready shelled! about €12 per kilo which is dirt cheap, especially since there is no shell weight.

They are becoming rarer though, last I saw them was in one in Moore street, and one near the end of henry street, possibly mary street, going towards capel street. But they were only in 1 kilo bags.

I am 90% sure they were unsalted and not roasted.

cozmik

Well I gave this low heat roasting a test with some plain peanuts I bought today and after 20 mins there was no change in aroma so I added another 10 mins but nothing gave it one last try with another 10 mins but no joy.

cozmik

This is how it's done commercially.

The peanut butter manufacturers first dry roast the peanuts. Dry roasting is done by either the batch or continuous method. In the batch method, peanuts are roasted in 400-pound lots in a revolving oven heated to about 800 degrees Fahrenheit (426.6 degrees Celsius). The peanuts are heated at 320 degrees Fahrenheit (160 degrees Celsius) and held at this temperature for 40 to 60 minutes to reach the exact degree of doneness. All the nuts in each batch must be uniformly roasted.

http://www.enotes.com/how-products-encyclopedia/peanut-butter

Unfortuantely it looks like the only way to enhance the flavour of nuts is by using very high and damaging tempatures.

cozmik

http://www3.interscience.wiley.com/journal/120042654/abstract?CRETRY=1&SRETRY=0

Effect of salting and roasting on the lipids of Iranian pistachio kernels
GHASSEM G. KASHANI 1 L. R. G. VALADON 1
1 Authors' address: Department of Botany, Royal Holloway College, University of London, Egham, Surrey TW20 OEX.
Copyright 1983 Blackwell Scientific Publications
ABSTRACT
The simple lipids which make up 95% total lipids of Iranian pistachio kernels were identified as sterols and their esters; mono-, di- and tri-glycerides; and free fatty acids while the complex lipids were sterolglycosides; mono- and di-galactosyldiglycerides; cardiolipin, phosphatidyl-choline, -ethanolamine, -serine and -inositol; sphingolipid and phosphatidic acid. After salting and roasting, there was an increase in free fatty acids and in phosphatidic acid. Total fatty acids made up of C14:0, C16:0, C18:1, C18:2, C18:3 and C20:O were not significantly altered after roasting, nor was the iodine value, nor the malonaldehyde content. However, the peroxide value was increased.

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chcaban

Finding good raw nuts will become more difficult. Both EU and USA/FDA have decided that many nuts must be pasteurized before entering commerce. Contamination by salmonella has been documented and can be a risk if nuts are eaten raw or if they are insufficiently roasted. Pasteurization of raw nuts naturally occurs in roasting but then the nuts are no longer raw. Raw nuts can be pasturized in other ways to avoid heating but some changes in flavor can be possible. Raw nut Pasteurization can be done with irradiation, ethylene oxide, exposure to steam. Then the nuts look raw and can be sold as raw. This means that buying raw nuts from traditional markets may be the only possible source since the raw nuts sold in supermarkets and by food service distributors will either disappear or they will be pasteurized. Buying nuts out of a sack in Uncle Ahab's market stall will still be possible because not all of this kind of foodstuff is really exposed to import inspection. Buying in-shell raw nuts (Almonds, pistacios, groundnuts/peanuts, etc.) is the best way to avoid the greater risk of contamination. Then inspect them and discard thse with broken or wormholed shells. This obviously does not apply to some "nuts" such as pinones (pine nuts) which are only available in the naked form.