J Asks: How long can dry mixes, made with extra virgin olive oil (like pancake mix), sit on a shelf at room temperature? 

Olive Oil News:  We are certainly not the experts on this topic at the Olive Oil Source but I can give you some facts.   Olive oil will oxidize with exposure to air and dry mixes have very high surface areas for exposure. Using air-tight or inert gas packaging will help prevent oxidation. Anti-oxidant food additives will slow oxidation. Unfortunately auto-oxidation happens in the absence of oxygen and may be accelerated by exposure to other ingredients.

Olive oil has not been used traditionally in dry mixes because it is expensive, it permeates packaging because it is liquid at room temperature and it oxidizes more quickly. Trans saturated fats are ideal for dry mixes; they are cheap, solid and stable. Unfortunately they are not as good for your health. Large companies which supply the food industry with edible fats do a great job of advising their clients and doing research on the best use of their formulated fats in areas such as dry mixes. The olive oil industry has not done this traditionally because olive oil was out of the price range for this use. With new health concerns and interest in olive oil we are hoping that the IOOC and other olive oil organizations can come to the aid of manufacturers such as yourself with better advice on how to use our product.
Click for more about storage and oxidation

P Asks: Can you tell me where one can purchase raw olives in the San Francisco Bay Area?

Olive Oil News responds:  Maurice Penna of Penna Gourmet Olives will ship olives.

Nash and Dellene Dweik of Nash's Olive Oil also sell olives at farmer's markets and will ship.

Mark Asks: Are olives dyed to make them black?

Olive Oil News responds:  Olives naturally turn black as they ripen. When unripe they are green. As they ripen they get reddish, then purplish and finally black.

"Ripe Black Olives" in a can are actually olives which are neither black nor ripe when they are picked.  They are picked very green and then cured using dilute brine and lye solutions.  Lye treatments cause natural phenolic compounds in the olives to oxidize to a black color. Calcium chloride salts, iron salts (ferrous gluconate) and compressed air bubbled through the curing vats help develop the black color. So there is no black dye used but the olives are treated to make them a nice uniform dark black.

Home curing of olives without these added salts will result in mottled and brownish olives which taste just as good but are not as attractive.

The opposite tact is used to make a nice green California- style green-ripe olive. Air containing oxygen must be excluded to avoid natural oxidation and darkening of the skins.

For a great discussion on the California ripe olive industry, see Louise Ferguson's chapter in the Olive Production Manual put out by the University of California.

Bob Asks: Has anyone tried extraction using SFE (Super critical Extraction)? It is a method by which liquefied Carbon Dioxide is passed through the olive mash. It is less expensive and does not contain the organic solvents. It currently used for decaffeinating coffee. The CO2 acts like a strong organic solvent

Olive Oil News responds: Supercritical extraction has been used for years for lab analysis and for extraction of essential oils and is now being used for larger scale processes. We  don't know if anybody is doing that here in the US. Most of the olive oil produced here is not refined. Getting the majority of the oil out of olive paste is quick and economical with a centrifuge. Getting the last remaining oil out of the pomace is where the CO2 would be used.

Pilot plants for removing squalene from olive waste have been designed using supercritical CO2. Squalene is then hydrogenated to squalane for sale to the health food and pharmaceutical industries.

I don't know about expense but it would have the cachet of avoiding petrochemical residues and might even warrant organic certification. It of course would still not be considered extra virgin.

Sam Asks: In curing olives with lye is the olive oil saponified and removed in the rinsing process? Is there any fat of any sort left in the processed olive?

Olive Oil News responds: Unfortunately, there is plenty of fat left in olives after curing and no appreciable amount is removed. The olive oil is sequestered in tiny particles in the olive flesh and is not removed by the lye. 

Calories per olive: It depends on how big the olives are and what their oil content is. The large black canned olives are actually quite low in oil - sometimes only 7%, which is why they are table olives and are not used generally to make oil. Some smaller olives used primarily for oil making can have up to 35% oil content. Olives can range from 1 to 14 grams in weight.

There is about 1 tablespoon of olive oil (and about 120 calories) in:

20 medium Mission olives that have an oil content of 20%
40 small ripe black olives
20 jumbo ripe black olives
7 super colossal ripe black olives

Sam Asks: What agent is present in an unprocessed olive that makes it bitter? In pressing olives for oil, how is this bitterness removed?

Olive Oil News responds: Polyphenols and other primarily water soluble components make the olive bitter. When the oil is separated from the paste, the bitter substances are left behind in the fruit water and pulp.

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