橄欖渣油(Olive Pomace Oil):不是你認為的那種油
由丹尼爾 · 威廉斯撰寫
於2010 年 9 月 09 日張貼在Olive Oil Times Contributor | Reporting from Barcelona
http://www.oliveoiltimes.com/olive-oil-basics/olive-oil-grades/olive-pomace-oil/6210
歸類：橄欖油的特色與級別
 
橄欖渣油的潛在危險： 便宜沒好貨
 
最近我母親在本地的雜貨店尋找橄欖油，她最後選擇了較便宜但是她以前從來沒有購買過的一種。這種油與其他知名品牌橄欖油放在一起。玻璃包裝精美，標籤上印有茂密的橄欖樹和飄揚的義大利國旗，但是在最下面有個神秘的標示就是"橄欖渣油"。
 
我母親不清楚"橄欖渣油"意味著什麼，但對其價格滿意以及被各種宣傳詞和廣告用語所吸引，我媽媽就買了。但是，就在打開瓶子時，或許由於標籤的誤導或是她自己的誤判，她立即注意到她購買了較低等級的橄欖油，沒有她平常購買的 EVOO所預期的味道及濃郁的口感。經過進一步的追查及諮詢，我們發現我的母親和很多在互聯網上強烈抱怨的其他消費者一樣，都是在不知情的情況下購買到劣質的混合橄欖油叫做"橄欖渣油"。
進一步研究發現向來以對橄欖油產品法令規範嚴格著稱的西班牙政府，事實上在 2001年7月暫時禁止出售這種曖昧的油。我以前從未聽過"橄欖渣油"，經過詢問後發現我的朋友和家人也沒聽過。我十分驚訝我自己和一般公眾對這項產品的無知，尤其考慮到使用這種不受管制但具有潛在危險的產品。那麼，到底什麼是"橄欖渣油"呢？
 
特級初榨橄欖油(Extra Virgin)被認為是"第一道冷壓"的橄欖油，而"橄欖渣油"連"第二道"都談不上。基本上，橄欖經由機械冷壓萃取後， 仍然有約 5-8%的油殘留在果渣內。雖然從果渣中提取油，技術上而言也可以說是來自橄欖的油，但是這種通過使用化學溶劑萃取的油，實在不宜被稱為為"橄欖油"。國際橄欖油協會橄欖油的政府間組織，負責置制定品質標準和監測)，清楚界定橄欖油必需是直接從橄欖果取得的油才能叫橄欖油，使用溶劑或再脂化過程取得的油就不能叫"橄欖油"。
 
[1] 冷壓過的橄欖渣包括果皮、果肉、果子及果莖等，這些固體殘留物所含的油量非常少以致無法用冷壓萃取，必須用化學溶劑（如,正己烷）在極高的溫度下才能萃取。雖然此一過程，同樣用於生產芥花油、葵花油和其他的蔬菜油，但是為什麼不受管制的"橄欖渣油"有時會含有高致癌和致突變的多環芳香烴 (PHAs)像苯並芘(Benzopyrenes)的有害成分呢？原因是橄欖的脂肪不完全燃燒就會產生苯並芘(Benzopyrenes)。在萃取"橄欖渣油"時，脂肪暴露在高溫下時，由於燃燒不完全而且無黑煙產生，在此情況下就有可能會產生苯並芘(Benzopyrenes)。
"橄欖渣油"萃取的過程如下：首先是將化學溶劑放進橄欖渣中，化學溶劑會溶解脂肪但不會溶解固態的橄欖渣等殘留物。然後，將溶解的脂肪加熱使溶劑完全而且乾淨的蒸發、這種加熱方式只要溫度不超過90攝氏度 (194 華氏度）基本上就完全不會留下任何種類的有害殘留物。使用此系統，最終產品是不可能含有像苯並芘(Benzopyrenes)的多環芳香烴(PHAs)的。之所以造成苯並芘污染是因為用於溶劑蒸發的加熱溫度超過 300攝氏度 (572 華氏）時所造成的。在這些情況下，脂肪液化成液態從橄欖渣中流出來，但問題是，極度高溫導致脂肪與橄欖渣產生部分燃燒，這可能會導致苯並芘(Benzopyrenes) 的快速積累。
 
[2] 在300攝氏度以上的情況下生成的油帶有明確的健康風險，風險程度完全取決於溫度的高低，及消費者消耗"橄欖渣油"的用量和頻率。由於污染的程度取決於"橄欖渣油"的萃取方式，因此衛生當局有必要訂定苯並芘(Benzopyrenes) 的容許量。苯並芘(Benzopyrenes) 是種高活性的脂肪，可以輕鬆地溶入細胞膜，並從而進入細胞的內部。其結果已被證實會引起細胞的氧化導致細胞的老化和死亡，或引起細胞中毒導致細胞核中基因物質的突變。在某些情況下，受損的細胞會不受控制地繁殖和傳播導致癌症腫瘤的發生。由於對"橄欖渣油"中苯並芘(Benzopyrenes) 的關注，西班牙政府於2001年7月臨時禁止所有"橄欖渣油"的出口直到完成測試並訂出具體容許量。其它國家也跟進：紐西蘭衛生及食物安全主管當局也要求回收幾個廠家所生產的"橄欖渣油"。
 
[3] 做為預防措施，德國主管消費者事務、營養和農業的部門也發出同樣的警告：呼籲德國政府和企業審查170噸從西班牙進口而含有"橄欖渣油"的產品。
 
[4] 後來，明顯地看出其他受影響的批次包括希臘(Bevelini橄欖渣油)和義大利 (Dentamano Olio Di Sansa De Oliva). 在 Bevelini 的產品中更發現苯並芘(Benzopyrenes) 的含量高達10億分之100 (100 ppb)，但是國際橄欖油協會建議的容許量不得高於10億分之2 (2 ppb)。
 
[5] 50倍高的劑量確實嚇人。雖然我們每天都暴露在苯並芘(Benzopyrenes) 之下，如石化燃料，垃圾燃燒、農業大火、 工業生產、煙草煙霧和車輛廢氣排放，但我們對多環芳烴的暴露應該愈低愈好，尤其是經由食物攝取時。
 
 
 
雖然有了容許量的規定，但是全世界的烹飪愛好者和橄欖油的鑒賞家仍高度抗拒使用橄欖渣油。從感官的角度來看，它缺乏風味、美味佳餚和初榨橄欖油的豐富而有益於健康的屬性。由於橄欖渣油的煙點高達240攝氏度，因此目前常被用於工業上或餐廳需要炸的食物上。有一點值得一提的是，橄欖渣油的銷售者會辯稱橄欖渣油的提煉過程與傳統的烹調油，如玉米、大豆、向日葵、紅花、油菜籽、或棉籽油的過程沒有什麼不同，因此吹噓仍保留橄欖油的基本脂肪結構和擁有高水準的果酸，所以對紓緩高血壓。如果你不慎買了一瓶橄欖渣油，而您不想用來烹飪但你也用不著把它扔掉，您可以把它用做肥皂、臉部潤濕劑、染髮劑或燒烤架的潤滑劑。有鑑於橄欖油的供給很充裕而且價格也不高，為了你的健康和烹飪的美味，我建議您還是只買特級初炸的橄欖油(extra virgin)。相信我，你的味蕾會感謝你的。
 
参考資料:
[1] “Trade Standard Applying to Olive Oils and Olive-Pomace Oils” (PDF)  International Olive Oil Council, November 2009
[2] “Los riesgos del aceite de orujo” José Juan Rodríguez.
[3] “Olive-Pomace Oil Questions and Answers” New Zealand Food Safety Authority.
[4] “Germany warns about Spanish olive-pomace oil” July 10, 2001.
[5] “Olive-Pomace Oil: Your questions answered” August 14, 2001.
[6] “Detection of Polycyclic Aromatic Hydrocarbons in Edible Olive Oils and Olive Pomace Oils” (PDF) International Olive Oil Council.

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Tags: Benzopyrene, grades of olive oil, IOC, olive pomace oil, USDA

 

 Olive Pomace Oil: Not What You Might Think
http://www.oliveoiltimes.com/olive-oil-basics/olive-oil-grades/olive-pomace-oil/6210
Posted on September 09 2010 | Categorized in: Featured, Grades of Olive Oil

By Daniel Williams
Olive Oil Times Contributor | Reporting from Barcelona

Potential Dangers of Pomace Olive Oil: Cheaper is Not Always Better
During my mother’s most recent search for olive oil at a local grocer, she ended up selecting a slightly cheaper option which she had never purchased previously. This oil was shelved with dozens of other well-known, respectable olive oils, packaged in an attractive glass bottle, adorned with a hearty olive tree and wavering Italian flag, and beneath it all, the mysterious label “pomace olive oil”.
Unsure of what this meant exactly, but pleased with the price and the promises of various hype words and advertising jargon, my mother made the buy. Later, however, upon opening the bottle, she immediately noticed that either because of obliquely misleading labeling or her own misinformation, she had clearly purchased a lesser grade of olive oil which lacked the expected flavor or full-bodied mouthfeel of her usual EVOO. The smell, taste and texture of the imposter was nothing like that of extra virgin, but these organoleptic characteristics had been hidden by the darkly-tinted container in which it was sold. Upon further inspection and a quick consultation of a number of sources, we found out that my mother, as well as a great number of other consumers complaining vehemently over the internet, had unwittingly purchased a bastardized blend of true olive oil and something called, “pomace oil”.
Further research revealed that the Spanish government, notorious for its strict regulation of olive oil products, had in fact temporarily banned the sale of this obscure oil in July 2001. I myself had never heard of pomace olive oil at all and after a quick survey of friends and family, I found out that I was not alone. I was astounded by my own ignorance of this particular product and that of the general public, especially considering the potential dangers of consuming pomace oil from unregulated producers. So, just what is pomace olive oil, exactly?
While extra virgin olive oil is often denoted as being “first cold-press”, what is termed “pomace oil” cannot even qualify as being “second press”. Once the typical, mechanized extraction of olive oil from the olive fruit is complete, some 5-8% of the oil still remains in the leftover olive pulp or “pomace”. Although the pomace oil that is extracted is still technically oil that comes from olives, this is done via the use of chemical solvents, and therefore should never be termed, directly or indirectly, as “olive oil”. The International Olive Council, the intergovernmental olive oil organization responsible for outlining quality standards and monitoring olive oil authenticity, clearly defines olive oil as, “oil obtained solely from the fruit of the olive tree, to the exclusion of oils obtained using solvents or re-esterification processes.”[1] The amount of oil contained in the leftover pomace, which consists of the solid remains of the olive including skins, pulp, seeds, and stems, is so minimal that it cannot be extracted by pressing, but only through the combined use of chemical solvents (like Hexane) and extremely high heat.
This very process, the same high heat technique used in producing canola, sunflower, and other vegetable oils, is why unregulated olive pomace oil sometimes contain harmful components known as polycyclic aromatic hydrocarbons (PAHs) like benzopyrene, which research has shown to be highly carcinogenic and mutagenic. Benzopyrenes result from the incomplete combustion of the fats present in the olives. When fats are exposed to levels of high heat, like in the pomace oil extraction processes where there is no complete combustion and no smoke is produced, benzopyrenes are likely to be produced as a result.
The process to extract olive pomace oil is as follows: a chemical solvent is first administered to the olive pomace which has the ability to dissolve the fats but not the rest of the solid pomace. This application extracts the oil and then afterward, in a refining process, the product is heated so that the solvent evaporates completely and cleanly without leaving any sort of harmful residue so long that this heating method does not exceed 90 degrees Celsius (194 degrees Farenheit). Using this system, the final product is not likely to contain polycyclic aromatic hydrocarbons (PAHs) like benzopyrene. The risk of benzopyrene contamination occurs when the heating method used to evaporate the solvent exceeds 300 degrees Celsius (572 degrees Farenheit). In these instances, the fat is liquefied into fluid and then drips out of the olive pomace, but the problem is that the insanely high heat results in the partial combustion of the oil with the rest of the physical pomace. This can cause the rapid accumulation of benzopyrenes in the final product.[2] In instances of heat applications above 300 degrees Celsius, the resulting oil comes with a definite health risk for consumers which depends entirely on the aggressiveness of the heat treatment as well as the amount and frequency of the pomace oil consumed. Because the degree of contamination depends on the type of treatment used, it is necessary for health authorities to clarify what kind of treatment has been applied to produce particular pomace oils and to establish a permissible limit of the amount of benzopyrenes present.
Benzopyrenes, being themselves highly reactive fats, can dissolve easily into cellular membranes and thereby enter a cell’s interior. This resulting action has been shown to cause either intracellular oxidation–the aging and death of cells–or an intoxication which results in the mutagenesis of the genetic material in the cell’ s nucleus. In some instances, this of course spreads as an uncontrolled multiplication of damaged cells which can result in a cancerous tumor. Concerned about the levels of PAHs like benzoyprene in pomace oil, the Spanish government introduced a temporary ban on pomace oil in July of 2001and halted all exports of pomace oil until  tests were conducted and limits of the allowable amounts of PAH’s present in the oil were made concrete. Other countries followed suit: the New Zealand Health and Food Safety authority recalled olive pomace oil from several manufacturers[3] and the German ministry acted similarly issuing this warning: “As a preventative health protection measure, the ministry for consumer affairs, nutrition and agriculture has appealed to the German states and industry to review the remains of the 170 tons of Spanish olive-pomace oil and products containing this oil.”[4]It later became apparent that other affected batches were produced in Greece (Bevelini Olive Pomace Oil) and others from Italy (Dentamano Olio Di Sansa De Oliva). In the Bevelini product, for example, a batch was reported to contain 100 parts per billion of benzopyrene. In contrast, the International Olive Oil Council advises that olive-pomace oil should contain less than 2 parts per billion of benzopyrene.[5] This is a frighteningly high figure, over 50 times the acceptable amount, and although human exposure to PAHs is something of the quotidian, as they are also created with the combustion of fossil fuels, burning trash, agricultural fires, industrial processes, tobacco smoke and vehicle exhaust emissions, nonetheless our exposure to PAHs should be as limited as much as possible, especially when ingesting food.
As a result, specific standards have been set in various regions of the world limiting the allowable amount of benzopyrenes in pomace olive oil. As mentioned previously, within the European Union and in member states of the IOC, the limit is 2 parts per billion or 2 micrograms per kilogram as decided in Resolution RES-1/93-IV/05 Madrid in November of 2005.[6] With that said, however, in other olive oil producing countries which are non-IOC members (India, emerging Middle Eastern producers, several Latin American states, and even the United States where retail grades have no legal meaning) such stringent standards are not enforced and therefore the purchase of pomace oil products from these regions is not advisable.
With that said however, even with the regulation of the amount of PAH’s in pomace oil, culinary aficionados and olive oil connoisseurs worldwide are still highly resistant to the idea of using olive pomace oil as a worthy cooking agent. From a sensory standpoint, it lacks the flavor, delicacy, and bountiful healthful properties of extra virgin olive oil. If used in the kitchen at all, pomace oil is mostly used in industrial settings or in restaurants as a deep frying agent because of its high smoke point (240 degrees Celsius). But it’s also important to note that the process by which pomace oil is extracted is no different to the process used to extract other conventional cooking oils such as corn, soy, sunflower, safflower, canola, or cottonseed and in comparison to these oils, pomace oil still retains olive oil’s basic lipid profile and therefore boasts high levels of oleanolic acid which has been proven to relieve states of hypertension and high blood pressure. If you do happen to buy a bottle of pomace oil accidentally and are still resistant to the idea of using it as a cooking agent, you need not throw it away as there are a number of alternative uses for it. No need to despair–unwanted pomace oil can be used to create soap, can be employed like olive oil as a facial moisturizer or hair conditioning treatment, or at the very least, for lubrication in greasing grill racks or pans. But with all of the available olive oils on the market today and with world prices at an all time low, it’s in your best interest from both a health and culinary standpoint to stick to extra virgin. Believe me, your taste buds will thank you.
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[1] “Trade Standard Applying to Olive Oils and Olive-Pomace Oils” (PDF)  International Olive Oil Council, November 2009
[2] “Los riesgos del aceite de orujo” José Juan Rodríguez.
[3] “Olive-Pomace Oil Questions and Answers” New Zealand Food Safety Authority.
[4] “Germany warns about Spanish olive-pomace oil” July 10, 2001.
[5] “Olive-Pomace Oil: Your questions answered” August 14, 2001.
[6] “Detection of Polycyclic Aromatic Hydrocarbons in Edible Olive Oils and Olive Pomace Oils” (PDF) International Olive Oil Council.

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Tags: Benzopyrene, grades of olive oil, IOC, olive pomace oil, USDA