52 replies to this topic

[spirilla01]

I wouldn´t buy my olive oil in a transparent bottle.

[TheFountain]

spirilla01, on 11 February 2013 - 08:37 AM, said:

I wouldn´t buy my olive oil in a transparent bottle.

Why not? You're seeing the color of what you are getting and it should be fine as long as you keep it out of the light. What do you buy?

[niner]

Olive oil is light sensitive; at least that's the going belief.  I don't remember seeing anything like a test where a clear bottle and a dark bottle are placed side by side in light, then the olive oil is compared.  However, the smart vendors who actually publish the chemistry of their oils all use dark bottles.  If you really want a good polyphenol content, get something robust from amphora nueva.  That's Veronica Foods' online outlet, and they are people who care about the stuff we care about.  Most of the olive oil-heads here have bought from Veronica.   I've been using their oil for several years now.

[spirilla01]

good point, as long as its kept out of the sun, you should be good.
I´ve always buy the Castelas Olive oil AOC harvested early november in tin can 25cl tin cans, so I can use them as I´m travelling a lot.
Always store them in the fridge and never expose it to room temperature more than necessary. Last years harvest had polyphenol content of almost 600 and its has a very peppery, grassy taste.
http://www.castelass...-can-250ml.html

[TheFountain]

niner, on 11 February 2013 - 02:36 PM, said:

Olive oil is light sensitive; at least that's the going belief.  I don't remember seeing anything like a test where a clear bottle and a dark bottle are placed side by side in light, then the olive oil is compared.  However, the smart vendors who actually publish the chemistry of their oils all use dark bottles.  If you really want a good polyphenol content, get something robust from amphora nueva.  That's Veronica Foods' online outlet, and they are people who care about the stuff we care about.  Most of the olive oil-heads here have bought from Veronica.   I've been using their oil for several years now.

When you guys say "the light" you mean primarily the sunlight right? The reason I linked up the Sclafani stuff is because he is one of the importers who actually fought for Olive oil standards in this country and against the whole problem of people diluting the oils with lesser oils. Is this stuff from amphora neuva certified to be 100% undiluted olive oil?

[motorcitykid]

Burn baby burn! I ditched Spectrum Spanish evoo after sampling Mcevoy's unfiltered Olio Nuovo. It's by far the most potent evo I've ever had the pleasure of tasting. Olive oil with fire!

Also,cold weather on the NE sometimes irritates my skin. Applying Mcevoy's high polyphenol evo externally significantly alleviated symptoms of a minor eczema flairup on my forearm. Itching stopped within minutes and the redness faded. Amazing!

[spirilla01]

I´ve a  lot of times that all lights affects olive oils, being sun light or artificial light in the stores.
Just to be safe, I always prefer cans or dark bottles.

[Turnbuckle]

Changes induced by UV radiation during virgin olive oil storage.

Quote

Abstract


The effects of UV radiation on the chemical and sensory characteristics of virgin olive oils (cv. Arbequina and Picual) were assessed. Even small doses of UV radiation induced oxidation of the virgin olive oil samples. Total phenols and fatty acids contents decreased during the process as well as the intensity of the bitter and fruity sensory attributes, while the intensity of the rancid sensory attribute notably increased. Acetaldehyde, 2-butenal, 2-pentenal, octane, octanal, hexanal, nonanal, and 2-decenal were the volatile compounds most affected, showing an important increase during the irradiation process. Nonanal, hexanal, and pentanal showed high correlation with the rancid sensory attribute (90%, 86%, and 86%, respectively). 2-Decenal and nonanal concentrations allowed us to predict the alteration level of the samples by mean of multiple Ridge regression.

http://www.ncbi.nlm....sunlight rancid

[RJ100]

Green glass blocks 100% of UVA and UVB.

http://www.ncbi.nlm....pubmed/19614895

[ta5]

spirilla01, on 11 February 2013 - 08:23 PM, said:

Always store them in the fridge and never expose it to room temperature more than necessary.

Michael Rae posted this to the CR list not too long ago:

Quote

>>>> Rodney wrote... [olive  oil] can then be kept in the refrigerator
>>>> (solid) and spooned out as  needed.

>>> In case Michael doesn't see this, I wanted to note that this  might
>>> be the opposite of what you should do. AFAIK, an oil changing  from
>>> solid to liquid out of refrigeration with every serving is likely
>>> to  be more peroxidized than oil kept for daily use in a cool, dark
>>> pantry or  cupboard. -  Taurus

>> Is there really any evidence that refrigerating olive oil and
>> spooning out daily as Rodney is suggesting can cause peroxidation?

It would depend on exactly how you were set up to do it, but I'd not
recommend it. Without getting into all the gory details: while keeping
EVOO at a continuous cold temperature is protective, the process of
congelation and thawing in EVOO is stressful on the oil for a variety of
reasons, and causes a rapid selective depletion of ortho-diphenols and a
spike in peroxides.

Calligaris, S., Sovrano, S., Manzocco, L. and Nicoli, M.C. (2006)
Influence of crystallization on the oxidative stability of extra virgin
olive oil. Journal of Agricultural and Food Chemistry, 54, 529-535.
http://pubs.acs.org/....1021/jf051808b

Michiel Jansen,  John Birch
Composition and stability of olive oil following partial crystallization
Food Research International 42 (2009) 826–831;
doi:10.1016/j.foodres.2009.03.013

Bonoli-Carbognin M., Cerretani L., Bendini A., Gallina Toschi T. and
Lercker G. The case of monovarietal olive oil: storage test at different
temperature. Industrie Alimentari. 2005 Nov; 44(452): 1135-1141.
http://www.frantoice...lina Toschi.pdf



(There is a LOT more on the optimal temperature for olive oil storage;
these are the main ones addressing the narrow question of this the phase
transition effect).

Repeatedly taking the stuff in and out of the fridge, especially a 'real
world' fridge where the temperature internally already varies
significantly ('cause it's being opened and closed repeatedly during the
day), would likely lead a subfraction of the stuff to be repeatedly
suffering this particular insult.

This would then be worsened if one were following Rodney's (prima facie
perfectly sensible) idea (which he may have gotten from Dean Pomerleau,
who suggested it on the List years ago), because in order to spoon it
out, you'd have to  store the oil in a wide-mouthed jar, which has a
large surface area exposed to air. This would make the phase-change
effects worse, because part of the mechanism of state-change
peroxidation in EVOO is hydrolysis of triglycerides to free fatty acids,
and FFA (in addition to being themselves more peroxidation-prone)
promote further peroxidation because their hydrophilic carboxy group
causes them to concentrated on the surface of the oil; this decreases
the surface tension of the oil, which increases the diffusion rate of
oxygen from the headspace into the oil.
http://onlinelibrary...6741.x/abstract

But for longer-term storage, this small, *one-time* effect of the
transition phase, first congealing at the beginning and then thawing out
at the end, is vastly swamped out by the much more profound, and
*ongoing* protective effect of having the oil at freezer temperatures,
while the same oil at room temperature progressively and ongoingly decays.

So: when one first gets an oil at peak freshness, one should keep a few
weeks' worth of oil somewhere between 8°C (as an ideal temperature, but
the minimum, because some EVOO will begin to congeal at that
temperature) and room temperature for daily use. But for longer-term
storage (at some point more than 2 weeks, but certainly by the 3 month
mark, and onward from there),keep the rest as *consistently* cold as you
can: again, I keep mine in the freezer.

And, it should IAC be in the dark.
>>
> Mediterranean people don't refrigerate their olive oil. They use a
> bottle within a month or so and that should be safe enough.

That depends on what you mean by 'safe enough.' No one is pretending
you're going to drop dead upon consumption of a tablespoon of the stuff,
any more than we'd say that about eating a spoonful of lard a day. The
question is what's best practice.

> Before we indulge in any further guesswork as to the oxidation of
> (any) oils, we should realize that none of us seems to be
> sufficiently qualified to do so, unless that person is a trained
> scientist and has the necessary (laboratory) facilities to
> investigate and to make *quantitative* evaluations or ... we have
> access to published investigations that cover closely the perceived
> problems.

See above .

-Michael

[niner]

ta5, on 12 February 2013 - 12:39 AM, said:

Michael Rae posted this to the CR list not too long ago:

Wow, I am constantly amazed at the stuff I learn here.  I would have thought that condensation on the cold olive oil would be the main problem.  I'm glad to hear that one-time freezing is ok, since I've been doing that for a while.  I bought a 'cube' of really good oil, which I think was about 10 liters.  It's lasted me a long time.  I bottled and froze it, and once thawed, the oil tastes like it's brand new.

[mikeinnaples]

spirilla01, on 11 February 2013 - 08:37 AM, said:

I wouldn´t buy my olive oil in a transparent bottle.

I was disappointed that the Evoo (for salad not c 60) I bought a few weeks ago from Trader Joe's was in a transparent bottle.

[mikeinnaples]

niner, on 12 February 2013 - 01:56 AM, said:

ta5, on 12 February 2013 - 12:39 AM, said:

Michael Rae posted this to the CR list not too long ago:

Wow, I am constantly amazed at the stuff I learn here.  I would have thought that condensation on the cold olive oil would be the main problem.  I'm glad to hear that one-time freezing is ok, since I've been doing that for a while.  I bought a 'cube' of really good oil, which I think was about 10 liters.  It's lasted me a long time.  I bottled and froze it, and once thawed, the oil tastes like it's brand new.

Looks like what I am planning will work out well. I bought 3 - 500ml bottles for c60. I will prepare everything and simply freeze two of the bottles for long term storage while keeping one out for use in the cupboard at room temp. Should keep my oil nice and healthy.

[Kevnzworld]

I keep mine in a wine storage cooler.  The optimal conditions for storing red wine and olive oil should be the same.  I also only buy EVOO that's harvest dated for freshness.

Edited by Kevnzworld, 12 February 2013 - 06:28 PM.

[RJ100]

The EVOO I have at home is in the dark and at room temp 72 degrees. Maybe not the ideal temp, but at the rate I go through it I'm not too worried.

As far as phenol content.. well how can you truly know without testing it. I just buy high quality California oil that has a recent harvest date. I generally have 2 on hand - a mild one for cooking and a more robust for drizzling on salads, breads, etc.

I've read that non-virgin OO is fine for cooking, but I've never tried it.

[nameless]

I've been doing the one time freezing thing. And then I just take each bottle out as I need it, and let it defrost for several days in my basement.

I may go the cube route like Niner did, next time I need to restock. But I went with bottles last time I stocked up on oil, as I have a feeling it'll be rather messy to bottle it all up (at least for me).

[spirilla01]

this was phenol content of the Castelas classic from 2011

The average value for both analyses:
444 mg of tyrosol per liter of olive oil sample K1
538 mg of tyrosol per liter of olive oil sample K2
They send me the official paper too.

[TheFountain]

spirilla01, on 11 February 2013 - 08:23 PM, said:

good point, as long as its kept out of the sun, you should be good.
I´ve always buy the Castelas Olive oil AOC harvested early november in tin can 25cl tin cans, so I can use them as I´m travelling a lot.
Always store them in the fridge and never expose it to room temperature more than necessary. Last years harvest had polyphenol content of almost 600 and its has a very peppery, grassy taste.
http://www.castelass...-can-250ml.html

How expensive is that stuff? And is it certified to be undiluted?

[TheFountain]

And does anyone know if the Amphora Nueva stuff is certified pure and undiluted?

[mikeinnaples]

Have you checked this one out? http://www.barianiol...irgin-olive-oil

Their harvest ended in December, so it should be quite fresh. I haven't seen any analysis of their current year's product, but last year's was one of the top oils tested in California in regards to purity and phenol content.

Quote

This extra virgin olive oil remains cold extracted and unfiltered to preserve its raw qualities and stored in temperature controlled stainless steel tanks until bottling.

I know not about the taste or the taste with c60.... yet. So I cannot speak on that.

Edited by mikeinnaples, 14 February 2013 - 02:14 PM.

[spirilla01]

The fountain, 7¤ for a 250ml can excluding shipping. I always buy in bulk in the beginning of december. Its a very early harvest and its very intense.
Another very good source of olive oil is http://shop.oeldorad...ges/es112124.sf situated in Frankfurt in Germany.
Whenever available the owner Elke lists the polyphenol content. free oleic acids and peroxide levels.

[spirilla01]

mikeinnaples, on 14 February 2013 - 02:12 PM, said:

Have you checked this one out? http://www.barianiol...irgin-olive-oil

Their harvest ended in December, so it should be quite fresh. I haven't seen any analysis of their current year's product, but last year's was one of the top oils tested in California in regards to purity and phenol content.

Quote

This extra virgin olive oil remains cold extracted and unfiltered to preserve its raw qualities and stored in temperature controlled stainless steel tanks until bottling.

I know not about the taste or the taste with c60.... yet. So I cannot speak on that.

Their Early harvest EVO looks very good indeed and the price is good too.

[TheFountain]

I bought some of that Amphora stuff, some of the spanish varietal and something else that apparently has high polyphenol content. Decent prices for decent sample sizes.

Just so everyone knows, I contacted the managers and asked about the dilution issue and these are not diluted with any other oil.