WORKSHOP - OIL QUALITY ISSUES

PCBS, DIOXINS AND HEAVY METALS IN OMEGA-3 OIL DERIVED FROM FISH OIL: LEVELS AND METHODS OF MEASUREMENT

MP Pujari,* A DeMocko,* Y Shen,* PA Sandford** and RA Clemens*. USC School of Pharmacy, 1985 Zonal Ave, Los Angeles, CA 90033*; Leiner Health Products, 901 East 233rd St, Carson, CA 90745-6204 **

Many health organizations support increased intake of polyunsaturated fatty acids to reduce the risk of cardiovascularand neurological disease in adults and to improve neural development in infants. Recent reports suggest some fish oil dietary supplements contain environmental contaminants, including PCBs, dioxins, and heavy metals at levels that may pose a health risk to vulnerable populations. In addition, some reports also indicate that these supplements do not provide the claimed levels of these fatty acids (linoleic, a-linolenic, arachidonic, eicospentaenoic, decosapentaenoic and docosahexaenoic). A closer examination of these reports indicates that some inappropriate analytical methods may have been applied to these dietary supplements. The current study analyzed 18 dietary fish oil and algal/fungal oil supplements according to EPA and AOAC methods and a proposed rapid screening ELISA procedure for PCBs, in addition to dioxins and heavy metals (Cd, As, Pb, Hg). The results of PCB analysis (42 congeners, which includes all 7 congeners listed in WHO monogram and all aroclors) from our laboratory indicated the none of the PCB congeners was detected except congeners 118 (2,3',4,4',5-pentachlorobiphenyl) and 180 (2,2',3,4,4',5,5'-heptachlorobiphenyl) which were detected < 1 ppb. On the other hand, the ELISA PCB screening procedure appeared to provide a high percentage of false positives. Dioxin expressed as TCDD (tetrachlorodibenzop-dioxin)-equivalents was not detected (< 0.01 ppb). None of the four heavy metals was detected (< 0.5 ppb) using ICP/MS. The fatty acid profile assessed on a GCMS demonstrated that these dietary supplements provided at least 100% of the label claim for the identified polyunsaturated fatty acids. These results from 18 dietary supplements of fish oil emphasize the importance of applying the appropriate analytical methods to these kinds of dietary supplements, especially those that may reduce one's risk of cardiovascular and neurological disease or potentially improve the neural development of infants.

MEASURING LIPID OXIDATION AND OTHER OIL QUALITY FACTORS BY FTIR SPECTROSCOPY
F.R. van de Voort and J. Sedman, McGill IR Group, Department of Food Science, McGill University, Montreal Canada

With the advent of Fourier transform infrared (FTIR) spectroscopy, in conjunction with developments in chemometrics and sample-handling techniques, the detailed functional-group information provided by mid-IR spectroscopy has been exploited to develop rapid and accurate instrumental methods for assessing oil quality. As a quantitative analytical tool, FTIR spectroscopy has been employed to measure a variety of quality parameters of edible oils traditionally determined by wet chemical methods, including those associated with assessment of lipid oxidation such as peroxide value (PV), anisidine value (AV), and free fatty acid (FFA) content. FTIR analysis has also afforded a practical means for evaluating oxidative stability (OS) in a short period of time at moderate temperatures that are considered representative of normal oil storage in relation to oxidation mechanisms. The concepts, approaches and benefits associated with FTIR oil analysis will be outlined in general terms, followed by principles and approaches associated with specific FTIR methods for measuring lipid oxidation (PV, FFA, OS and AV) in terms relevant to the analysis of highly unsaturated oils.

DETERMINATION OF TRANS FATS IN FISH OIL PRODUCTS AND ITS IMPLICATIONS
Jonathan M.Curtis, Michael Potvin, Kathy Henneberry, Ocean Nutrition Canada, Halifax, Nova Scotia Canada

Recent legislation loosely defines trans fats as including all non-conjugated trans isomers to exclude CLA isomers which are considered beneficial trans fats. Since the majority of dietary trans fat occurs in hydrogenated fats, which are usually medium length fatty acyl chains with low degrees of unsaturation, the standard methods for the analysis of trans fats which are principally FT-IR or GC methods, have been developed for these applications. In contrast to this situation, fish oils are comprised of primarily medium to long chain fatty acyl groups with high degrees of unsaturation. In addition to the trace amounts of trans fats naturally present in fish, low amounts of trans isomers are generated by thermal and oxidative processes which occur during oil extraction, purification and enrichment. Established analytical methods are not suitable for measuring low percentages of trans fats in the presence of large and legislation require measurement of this contribution. We have developed and validated a method which accurately and reproducibly measures trans isomers in fish oils using established principles. The method and relevance of the results in terms of overall trans fat intake will be discussed.

HISTORY AND DEVELOPMENT OF THE COUNCIL FOR RESPONSIBLE NUTRITION OMEGA-3 MONOGRAPH
Bjorn Rene, Doc's Guide Inc., Sarasota Florida

During the last decades there has been an enormously publicity of Omega-3 EPA and DHA positive health benefits. But at the end there was always a disclaimer that these substances were not controlled by the FDA and the quality was always questioned. After all the years in the industry we knew that there was good and bad quality oil in the marketplace. Therefore a group of producers and distributors of omega-3 oils gathered 3 years ago and agreed to do something with this. The Omega-3 working group was founded under the Council of Responsible Nutrition and one of the major issues was to develop quality standard for all omega-3 products and the voluntary monographs was finished and published in 2002 and we are now in the process of have the method listed in the USP.

DEVELOPMENT OF USP MONOGRAPHS FOR FISH OIL RICH IN OMEGA-3 FATTY ACIDS
Lawrence Evans III, Ph.D., Information and Standards Development (ISD); United States Pharmacopeia (USP)

Oils containing omega-3-fatty acids have received much attention as dietary supplements due to their reported health benefits. Fish and algae are the primary sources of these oils. Apart from the obvious difference in source, the other key distinction is the omega-3-fatty acid content. Hence these attributes suggest the need to develop multiple standards to appropriately describe the strength, quality, purity, and identity of the omega-3-fatty acids in the oils. The United States Pharmacopeia is addressing these issues by developing several monographs to establish standards for omega-3-fatty acids derived from fish and algae.

TECHNOLOGICAL CHALLENGES IN APPLYING FISH OIL IN FUNCTIONAL FOODS
Charlotte Jacobsen, Department of Seafood Research, Danish Institute for Fisheries ResearchBuilding 221, DTU, DK-2800 Kgs. Lyngby, Denmark.

Several studies have shown that a high intake of n-3 polyunsaturated fatty acids (PUFA) may prevent cardiovasculardiseases and may influence the neurological development in children. However, the daily intake of n-3 PUFA in theWestern world is lower than recommended by nutritionists. One way of increasing the intake of n-3 PUFA would be to enrich a range of food products with fish or algae oil rich in n-3 PUFA. If such lipids are to be successfully employedin foods, the sensory quality and shelf life of foods enriched with these lipids must be acceptable. Fish oil is highly susceptible to oxidation, which may lead to undesirable off-flavour formation. To obtain an acceptable shelf life of foods enriched with n-3 PUFA, it may be necessary to add antioxidants to the products. However, oxidation mechanisms in complex food systems are different from those in bulk oils. Compounds that are efficient antioxidantsin bulk oils may turn out to be prooxidants in complex food systems. Therefore, oxidation and antioxidant echanisms in real systems must be understood in order to efficiently prevent lipid oxidation. Strategies to retard lipidoxidation in functional lipids and foods enriched with n-3 PUFA will be discussed with particular emphasis on food systems based on mayonnaise and milk