27 No. 5
Fats, Oils, and Oilseeds Analysis and Production
by Richard Cantrill
One of the goals of IUPAC and part of the mission of the American Oil Chemists’ Society (AOCS) is to deliver technical information to audiences in regions of the world where access to the latest information may be limited. To this end, the two organizations held the IUPAC-AOCS Workshop on Fats, Oils, and Oilseeds Analysis and Production in Tunis, Tunisia, 6–8 December 2004. This workshop was the first time AOCS brought its expertise to the North African region. The program was tailored to the needs of the region, with a strong emphasis on oil processing and the requirements of the olive oil industry. Tunisia is the fourth largest olive-oil producing country after Italy, Spain, and Greece.
The workshop was opened by Souilem El Fehri, the chairman and general manager of the Office National de l’Huile (ONH) of Tunisia; Patrick Dysseler of the Institut Meurice, Brussels, Belgium, representing IUPAC; and Richard Cantrill, AOCS technical director. Each speaker stressed the importance of holding this timely workshop in Tunis and thanked the organizing committee for developing such a relevant and integrated program.
The plenary session was opened by Habib Essid, the executive director of the International Olive Oil Council headquartered in Madrid, Spain, who described the world production, consumption, and trade in olive oil. He was followed by Dysseler who presented new and advanced methods for oil analysis, and Delia Amaya from the University of Campinas, Brazil, who outlined some of the principles and expectations of vitamin fortification of lipid-based foods. The session was rounded out by Gerrit van Duijn, Unilever Research (Vlaardingen, Netherlands), who described the quality control points in the oil processing system.
In the short course on oil refining, many of the discussions centered on minor components that may be modified or lost at different stages in the process. An important factor in oil stability is the presence of tocopherols and minor sterol components; these may be lost or modified during deodorization. Their retention aids stability, whereas their removal enhances the economic value of the deodorizer distillate. These factors were clearly demonstrated for vegetable oils by Roland Verhé (University of Ghent, Belgium). Both Verhé and Wim de Greyt (De Smet, Zaventem, Belgium) highlighted the differences in deodorizer distillates obtained in the chemical and physical refining processes. Fereidoon Shahidi (Memorial University of Newfoundland, St. John’s, Canada) also pointed out the relationship between triglyceride molecular structure and edible oil stability in native and structured lipids of marine, single cell organisms and plants. Andrew Logan, Alfa Laval (Soborg, Denmark), and Klaus-Peter Eickhoff, Westfalia Separators (Oelde, Germany), discussed degumming and alkali refining and how the chosen processes predetermine the plant layout and use of separation equipment. Roberto Berbesi, Oil-Dry Corporation (Chicago, Illinois), described the use of different sorbent materials, conditions of use, and expectations in the bleaching step of oil refining.
Session III discussed many of the analytical techniques used by laboratories to determine oil quality and the extent to which unwanted materials are removed and advantageous components retained during processing. Regina Lago, EMBRAPA (Rio de Janiero, Brazil) presented discussed methods of fat extraction and the different compositions of the resulting material and its relationship to oil extraction in an industrial setting. In a presentation prepared by Michael Kennedy, Cargill (Minneapolis, Minnesota, USA), Cantrill described the AOCS Official Methods for ensuring vegetable oil-quality during refining. Chris Dayton, Bunge Foods Corporation (Bradley, Illinois, USA), described how many classical wet chemistry methods provide the basis for correlations used in the development of rapid physical methods that can be applied in real-time monitoring of oil processing. Florence Lacoste, ITERG (Institute for Fats and Oils, Bordeaux, France), described the determination and limits set for the presence of contaminants and undesirable components in edible oil. The session was concluded by Wolfgang Burk, Bruker (Karlsruhe, Germany), who described the use of “Time Delay” (low resolution) NMR equipment in the measurement of solid fat content and other parameters.
In the short course on oil processing, the use of bleaching earths and activated charcoal to remove unwanted compounds was discussed by Michel Remuzat, Süd Chemie (Choisy le Roi, France). De Greyt outlined the differences between chemical and enzymatic interesterifications and how these techniques are being used to produce oils with melting curves and solid fat contents useful for blending into margarines without resorting to using hydrogenated oils. Ignace Debruyne (Brussels, Belgium), a consultant to the American Soybean Association, detailed the conditions which can give rise to the development of off-flavors in refined oils and steps that can be taken to minimize them. He reminded the audience that a major premise is “good beans make good oil.”
Jesper Hansen, Gerstenberg Schröder (Copenhagen, Denmark) presented the latest trends in the production of trans fatty acid-free margarines, challenges in their production, and the incorporation of functional ingredients and phytosterols. The fractionation of the triglyceride portion of oils according to their melting points was described by Véronique Gibon, Fractionnement Tirtiaux (Fleurus, Belgium). Olein and stearin fractions can be produced from oils according to their molecular structures using sophisticated cooling and separation protocols. The process can be monitored using a number of analytical techniques. Peter Johnsen, NCAUR (National Center for Agricultural Utilization Research, Peoria, Illinois, USA), concluded the session with an outline of studies undertaken by a group of United States Department of Agriculture scientists. An example of this successful program was the development of mid-oleic sunflower oil with the National Sunflower Association, based in Bismarck, North Dakota, USA.
Classification and Adulteration
The closing session of the workshop focused on the classification of olive oil, and the detection of adulteration by official analytical methods. Details on olive-oil processing and olive-pomace-oil extraction were jointly presented by Samira Sefi and Tarek Amamou, ONH, (Tunis). Mention was made of the traditional and industrial methods used for the extraction and treatment of different classes of olive oil and their effects on the composition of minor components. The identification, analysis, and potential health benefits of minor components in olive oil were the subject of the presentation by Apostolos Kiritsakis, Technological Educational Institute (Thessaloniki, Greece). His presentation highlighted the importance of retention of these high-value components and prompted much discussion with earlier speakers.
The methods of analysis recognized by the IOOC and Codex Alimentarius for the establishment of the purity of olive oil were presented by Efi Christopoulou, Ministry of Development (Athens, Greece). There are two categories of such methods: those required to measure quality parameters and those required to determine the purity of the oil. Their use in the detection of adulterated olive oil was discussed by Lanfranco Conte, University of Udine (Italy). He outlined progress in the development of analytical methods to meet increasing levels of sophistication on the part of those involved in adulteration. Conte also discussed the use of sensory evaluation in the analysis of virgin olive oil. He speculated on the use of sensory fingerprints to confirm the specific geographic origins of extra-virgin olive oils.
Richard Cantrill <Richard.Cantrill@aocs.org> is technical director for AOCS. He was a member of the task group heading the corresponding IUPAC project #2002-011-2-600 (see Web below). The presentations from the meeting can be accessed on the AOCS Web site at <www.aocs.org/archives/analysis/papers.asp>.
This report originally appeared in inform (the International News on Fats, Oils, and Related Materials), March 2005, and is reprinted with permission.
last modified 22 August 2005.
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