58 replies to this topic

[spirilla01]

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

[TheFountain]

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]

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.

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]

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:

>>>> 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

Edited by Michael, 28 August 2013 - 12:50 AM.

[niner]

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]

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]

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]

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.

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]

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.

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.

[TheFountain]

So when buying from sites that list the Polyphenol content of their oils, what range should we be sticking to?

[TheFountain]

I just ordered some of the Organic Peruvian Barnea amd the Organic Peruvian Coratina from Amphora Nueve. These two had the highest Polyphenol content of all of them. Can't wait to try these bitter beauties.

[Michael]

the c60-thread mentioned that high-phenol OO has a burning taste in the throat. I am experiencing this too from an unfiltered, self-imported OO from Croatia.

Yes. I want to use the unfiltered stuff in the hopes that more phenols and other good stuff will be trapped in the fullerenes (might not happen).

You really don't want unfiltered olive oil. The material that's filtered (or gravitationally-separated/"racked") out of EVOO includes bits of olive fruit, microorganisms, and water droplets. While elements of this, when at peak freshness, can give a fresh and complex taste that some people like, the presence of these elements also leads to fermentation and nonenzymatic hydrolysis of the oil, leading to shorter shelf life and rapidly-degrading health benefits. And, it accentuates the freezing-thawing problem discussed earlier in the thread.

There are many different types of olives that olive oil is made from. Arbequina olives have a strong peppery finish.

Arbequina olives, along with Chemlali and Chétoui, are acually pretty much the lowest-polyphenol cultivars out there — see eg.

http://ucce.ucdavis..../2161/17348.pdf
http://books.google....bdr2sC&pg=PA160
http://www.docstoc.c...-OIL-PRODUCTION
http://www.aromadict...VOO_blog/?p=803

Stronger varietals are Picual (except the way it's grown in Australia), Frantoio, and Coratina. However, watering, weather, and milling conditions also play major role in polishing rocks into gemstones (or, more commonly, turning diamonds-in-the-rough into a pocketful of gravel).

Anyone have an opinion of stuff like this?

http://www.sclafanif...roduct_id=11123

It's unfiltered (see above); they say it's "extracted using an old world granite wheel" (sounds romantic, but makes lower-quality oil than modern hammer crushers and two-phase centrifuges); and the fact that they package it in clear glass, as others have noted, is a bad sign: it suggests they prefer aesthetics on the shelf over preserving the quality of their oil.

So when buying from sites that list the Polyphenol content of their oils, what range should we be sticking to?

Commercial olive oils typically range from 100-350 ppm. The evidence is pretty clear that ≥350 is better.

TheFountain, you really ought to know most of this from a private discussion to which you were party three years ago ....!

All: see my recommendations for ultra-premium EVOO (they are scattered in two places in this post: see first the section beginning "Another food that is definitely on my "must-consume" list" for criteria, and then the section beginning "Ultra-Premium EVOO Sourcing" for sourcing. Note that Amphora Nueva is VF's flagship store.

[TheFountain]

Anyone have an opinion of stuff like this?

http://www.sclafanif...roduct_id=11123

It's unfiltered (see above); they say it's "extracted using an old world granite wheel" (sounds romantic, but makes lower-quality oil than modern hammer crushers and two-phase centrifuges); and the fact that they package it in clear glass, as others have noted, is a bad sign: it suggests they prefer aesthetics on the shelf over preserving the quality of their oil.

So when buying from sites that list the Polyphenol content of their oils, what range should we be sticking to?

Commercial olive oils typically range from 100-350 ppm. The evidence is pretty clear that ≥350 is better.

TheFountain, you really ought to know most of this from a private discussion to which you were party three years ago ....!

I remember brief extracts from said conversation. I have been involved in martial arts training for the past year or so and have been forgetting some of the variables. Thanks for reminding me.

Edited by Michael, 23 August 2013 - 04:44 PM.

[TheFountain]

I just tried Bariani, due to being less pricey than Amprore Nueve, and my take on it is that you can taste the Polyphenols just as much as with the latter brand. It has that same zing, that same freshness, that same polyphenol punch.

I bought some on ebay for about 11$ from a reputable seller. The bottle is about 16 ounces, which is decent for this quality. I definitely recommend the brand.

Has Harvest and bottle date on each bottle. Fresh as can be.

[TheFountain]

Who else has gotten into the habit of preserving the phenol quality of their OVOO via refrigeration?

 

I find high phenol Olive oil has more of that polyphenol punch when it's cool vs when it's warm.