Methods to Increase Consumer Confidence in Premium Olive Oils Using a Forston Labs NavSpec+

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1 Methods to Increase Consumer Confidence in Premium Olive Oils Using a Forston Labs NavSpec+ Abstract: A rapidly growing consumer driven market for premium Olive Oils has led to low consumer confidence and financial losses due to counterfeit products. In response, the USDA recently released the first change in Olive Oil Standards in over 60 years. Compliance with these voluntary standards is time consuming, costly and generally requires analysis in a laboratory. Described are Spectrophotometric/Fluorometric methods to help assure the highest grade of product requiring no sample preparation, little training, and little cost. The analysis is done with highly portable equipment, and can be accomplished at or near each distribution point in the supply chain. In 2007, the U.S. Marshals Service seized 10,939 cases of Extra Virgin Olive Oil and Pomace Olive Oil, valued at approximately $628,000 in Long Island City, New York. The oil being sold as Extra Virgin Olive Oil and Pomace Olive Oil was actually soybean oil. Extra virgin is the top grade of olive oil according to standards established by the International Olive Council (IOC) and the United States Department of Agriculture (USDA). It demands a premium price, as much as ten times that of a lower grade. This price differential is the primary motivation for adulteration and/or counterfeit labeling at any point in which a sale of the oil occurs. A recent study i showed that greater than 65% of bottles labeled imported Extra Virgin Olive Oil are either a cheaper grade of olive oil or are adulterated with another type of oil. Given that the U.S. imported over 275,000 tons of these oils from the 2008/2009 crop year ii a seizure of this size is likely only a small portion of adulterated products reaching the consumer.

2 U.S. consumers growing awareness of perceived health benefits of olive oil consumption have contributed to both domestic production and import levels. Olive oil imports in 2009 were 163% of what they were in iii This growth rate is expected to accelerate. Sadly, higher premium prices to the consumer do not guarantee value as the previously mentioned UC Davis study identified many leading brands that produced samples not meeting this highest quality grade. In response to consumer awareness and producer demand, the USDA recently published revised standards for the grading of olive oil. These new standards which became effective October 25, 2010, replaced standards that had been in effect since In the 62 years between revisions technologies have changed. Advanced, low cost and easy to use instrumentation is now readily available all along the supply chain. The producer, the bulk handlers, the distributor and the retailer all can now do on-site testing of their products demonstrating to the consumer the premium value of their purchases. As U.S. Extra Virgin Olive Oil is the target of counterfeiters, it is useful to examine the standards for that product. While there is not presently a USDA sanctioned certification program available, according to the USDA: U.S. Extra Virgin Olive Oil is virgin olive oil which has excellent flavor and odor (median of defects equal to zero and median of fruitiness greater than zero) and a free fatty acid content, expressed as oleic acid, of not more than 0.8 grams per 100 grams, and meets the additional requirements as outlined in , as appropriate.

3 There are optional tests which can be performed but the required analysis on each lot includes but is not limited to the following: 1. Determination of the organoleptic characteristics; (Taste and Odor) 2. Determination of free fatty acid content (as oleic acid); 3. Determination of peroxide value; 4. Determination of absorbency in ultraviolet; 5. Determination of the fatty acid composition; 6. Trans fatty acid; 7. Desmethylsterol composition (% Total Sterol); and 8. Total sterol content 9. Stigmastadiene Taste and odor are objective evaluations usually done by trained testers with long experience. Other tests are done by skilled technicians and some stipulate the use of advanced methods such as Gas Chromatography. There are also other bellwethers of changes in quality, taste and odor. The greenish-yellow tint and distinctive fruity aroma of Extra Virgin Oil stems from the high level of chlorophyll and other volatiles extracted from the olive. As oil is processed to lower grades, the concentrations of these key constituents changes. Changes in chlorophyll content and loss of volatiles are good measures of product variation. Easy to use, low cost, portable spectrophotometer/fluorometers capable of wide spectrum analysis are now available providing tools for the relatively unskilled user. Product variations that the examiners senses may not be able to detect reliably, may be very evident when comparing the VIS/NIR spectrum and fluorescent attributes of two samples. The following example uses a Spectrophotomer/Fluorometer from Forston Labs with a handheld LabNavigator interface. The plug and play VIS-NIR NavSpec+ Spectrophotometer measures and displays between 350 and 980nm and has a built in Fluorometer with two selectable excitation wavelengths (405 and 500nm). The USDA absorbance measurements are made in the UV range and UV Spectrophotometers with these capabilities are also available from Forston Labs and others. Using the Fluorometer of the NavSpec+ as a secondary

4 method, the user can make a comparative measurement of chlorophyll content at their point in the distribution chain. At-point-of-transfer testing at increased intervals, verified as needed by formal analysis of questionable product, increases the detection risks of adulterated products. This increases the risk of detection to counterfeiters, increasing the security of the product purity. A sample of Olive Oil examined in the VIS-NIR range for Absorption creates peaks near 410nm and 665nm. As our example will show, the comparison of spectra of Extra Virgin Olive Oil and those of lesser grades are an indicator of purity. Natural variations in sources will occur and therefore VIS-NIR measurements of comparable samples may be somewhat misleading. A few minutes spent testing the same samples using the Fluorometer function of the instrument provides a higher level of confidence in the test results. A study in 2000 suggested that Fluorescence Spectra likely provides a simple, rapid test for adulteration of Extra Virgin Olive Oil. iv The unadulterated Extra Virgin Oil has a distinctive spectra and as the oils are further processed to lower grades, the change in the spectra can be dramatic. As the following example demonstrates a fast, simple method requiring virtually no sample preparation provides three points of reference for comparison in a graphical form. This method can be performed with handheld instrumentation by virtually any user using known grades as reference standards. Results that are comparable to those of the reference provide a significant level of confidence that the product is as it is purported to be. Results that are questionable raise a red flag indicating that confirmation from a full range testing lab will likely prove a lesser grade product is in hand.

5 Our example tests samples of: Extra Virgin Olive Oil from California Olive Ranch 100% Soy Bean Oil Extra Virgin Oil adulterated 50% by volume with Soy Bean Oil 100% Pure All Natural Olive Oil composed of refined olive oils and virgin olive oils from Berio A sample of each oil was first tested comparing the sample absorption vs wavelength between 380 and 950nm. Overlaying the data on a single chart as shown in Chart 1, it can be seen that the values vary considerably at 410 and 665nm. At these wavelengths the absorption values drop as does the content of Extra Virgin Oil. This follows the removal of chlorophyll and other volatiles during processing under pressure and the inherent differences in unlike oils such as Soy Bean Oil.

6 An additional point of comparison can be made using information from the previously mentioned study of the fluorescence of oils. The study showed that all the oils tested except for Extra Virgin Olive Oils, showed a strong fluorescence band in the nm. The study examined olive, olive residue, refined olive, corn, soybean, sunflower and cotton oils. Measuring the fluorescence of the same oil samples using the 405nm excitation capabilities of the NavSpec+ and examining them over the same nm range shows similar results as in Chart 2. The Extra Virgin Olive Oil fluoresces very little over the range while any adulteration or variation in type of oil results in a higher fluorescent value. Comparing the two charts, it is easy to see that the oils are chemically different from each other and in manners that would be expected. This simple, easy to use procedure that requires virtually no sample preparation places a high level of analytical abilities in the hands of virtually any user.

7 While not 100% definitive, the results obtained using a Spectrophotometer/Fluorometer to compare oil samples are valuable not only to distributors but to the consumers. High prices associated with consumer demand for quality products and the magnitude of annual imports and the costs associated with them require reliable tools that give assurance to the buyers. Simple, accurate and low cost testing methods at multiple points along the distribution chain increase the confidence that the consumer can place on their purchases. NOTE: A copy of the new USDA standards can be found at:

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9 i University of California at Davis, July 2010 ii International Olive Council, November 2010 iii North American Olive Oil Association, Chairman s Report, January 2010 iv Kyrikidis & Skarkalis: Journal of Aoac International Vol. 83, No. 6, 2000