Jubilee conference on fats and oils held in the Czech Republic

The 50th International Conference on Fats and Oils was organized by UNILEVER ČR, together with the Czech Section on Fats and Oils, Detergents and Cosmetic Chemistry of the Czech Chemical Society. The anniversary conference took place in Strážnice in the region of southern Moravia between 16th and 18th May 2012. J. Brát, a representative of Unilever ČR, welcomed 34 participants and introduced the technical program comprising 20 oral presentations. In the main paper, V. Filip, president of the Section on Fats, Detergents and Cosmetic Chemistry, reviewed the developments in chemistry and technology of fats and oils in the Czech Republic in the last 50 years, and showed that the technical programs of annual conferences have included all the main achievements and their application in industry.

On the first day, the program was opened by P. Zehnálek with an overview dealing with rapeseed as the main oilseed in the Czech Republic. In the last growing season (2010/2011), rapeseed production reached 1 000 000 tons again. Rapeseed was grown on an area of 336 600 hectares. In comparison with the previous season (2009/2010), the yield slightly increased from 2.88 to 2.97 t/ha. Due to unfavorable climatic conditions in the growing season 2011/2012, considerably lower rapeseed production can be expected. P. Zehnálek in his presentation characterized the types of rapeseed varieties grown in the Czech Republic. J. Brát reported on the nutritional characteristics of rapeseed oil, which is preferred in some food applications because of its low content of saturated fatty acids and it is also an important source of polyunsaturated omega-3 fatty acids. M. Doležal examined the quality of margarines, blended fat spreads and some samples of butter, with an emphasis on their fatty acid profiles determined in 62 products taken from the Czech market. In soft margarines recommended from the nutritional point of view the percentages of saturated, MUFA and PUFA were in the range of 19.5–23.8%, 24.7–52.3%, and 22.5–52.7%, respectively, and omega-3 PUFA ranged from 4.3 to 11.1%. The content of trans isomers was indicated between 0.5 and 1.1%. M. Tesařová reported on the physical properties and composition of fatty acids in some blended fat spreads and shortenings (cooking fats) available on the Czech market. She concluded that the content of trans isomers in shortenings decreased from 25–35% in 2004 to 1–4% this year, and in blended fat spreads the range was 1–8%. But on the other hand, the products studied contained higher amounts of saturated fatty acids affecting their physical and rheological properties. Š. Schmidt focused on the quality of blended fat spreads and some samples of butter taken from the Slovak market. He found that the content of trans isomers in blended fat spreads was relatively low ranging from 1.8 to 3.2%. Compared with butter, the cholesterol content decreased due to the addition of vegetable fats. His results confirmed that the dominant addition was mostly palm oil or its fractions. It is probably advantageous for economic reasons, but not from a nutritional point of view. J. Dostálová studied more than 50 samples of chocolate toppings used in various confectionary products and muesli bars taken from the Czech market. She concluded that the low content of trans isomers can be considered positively, but partially hydrogenated fats have been mostly replaced by coconut fat, which is not nutritionally favorable. Unfortunately, the quality of chocolate toppings evaluated in muesli bars was not satisfactory because of the higher content of both trans isomers and saturated fatty acids. O. Benešová discussed the nutritional composition of ice cream. She introduced the development of new types of ice cream, with an emphasis on improving their nutritional value.

The program of the second day started with a paper on the thorough assessment of frying fats and oils presented by Z. Réblová. She discussed the chemistry of the components involved in the changes during frying process as well as the factors influencing the overall risk and toxicity of frying fats and oils, and she described a newly developed analytical method for determining the total prooxidant activity of frying fats and oils during the frying process, based on the oxidation of ascorbic acid. K. Cihelková studied the changes in sunflower and rapeseed oils during heat-treatment in the temperature range from 220 to 260°C. She found that high temperatures accelerated undesirable side reactions in oils caused by long-term heating, particularly the heat-induced trans isomerization reactions of PUFA, formation of cyclic fatty acids and intermolecular polymerization of TAGs. Š. Schmidt dealt with the influence of heating on the stability of fats. Compared with conventional heating, microwave heating accelerated fat oxidation, which was two to four times faster at 200°C. Rancimat test of microwave heated vegetable oils confirmed a significant decrease in their oxidative stability. I. Hrádková in her presentation compared the antioxidant effects of tocopherols and alkyl esters of caffeic acid in FAME prepared from sunflower oil. She found that methyl, ethyl, and propyl esters of caffeic acid were the most active. The antioxidant activity of propyl ester of caffeic acid was three times higher than that of α-tocopherol under the same conditions. Š. Schmidt reported on the changes in vegetable oils during storage. The results obtained showed that the best protection was achieved with brown bottles. Because edible oils are usually filled into clear PET bottles, they should be stored in the dark. J. Šmidrkal explained the synthetic pathways leading to the formation of chlorpropanediol esters (CPD) with palmitic acid, which served as a standard for chromatography and model experiments. He suggested the addition of a small amount of sodium or potassium bicarbonate to prevent the formation of CPD esters during deodorization, the latter being more appropriate.

On the last day, J. Kyselka focused on the oxidation and degradation reactions of cholesterol at elevated temperatures (100–200°C), particularly on the role of cholesterol hydroperoxides in the formation of primary and secondary oxidation products. R. Merkl investigated antioxidant and antimicrobial properties of alkyl esters of phenolic acids (vanillic, ferulic, caffeic, p-hydroxybenzoic, 3,4-dihydroxybenzoic, and 2,5-dihyroxybenzoic acids). Additionally, demethylenated piperic acid, in which methylenedioxy ring was open, was synthetized from piperin. Alkyl esters of caffeic acids showed the highest antioxidant effect. Comparable results were obtained with demethylenated piperic acid and its alkyl esters. The highest antimicrobial effect was found for butyl esters of benzoic acid derivatives tested. The objective of the paper presented by P. Štern was to compare the sensory and rheological parameters of chocolate spreads with different addition of hazelnut paste (0–13%). With the increasing content of hazelnut paste the plastic viscosity dropped while yield stress increased. The best results of sensory analysis were achieved at a higher content of hazelnut paste. F. Kreps together with L. Vrbiková discussed how technology affects the tocopherol retention in sunflower oil. They concluded that during the refining of sunflower oil on an industrial scale the tocopherol content decreased by 44%. The highest reduction was observed in the bleaching process (16%) and during deodorization (24%). During storage of refined oil in clear PET bottles exposed to light for 3 months, the tocopherol content further decreased by 39–50%. The last paper presented by F. Pudil covered the topic related to titanium dioxide (TiO₂) in foods. He reported that TiO₂ is listed as a generally safe substance for use in foods and cosmetics. This does not end the debate, however, as controversy over the safety of ultrafine or nanoparticles of TiO₂ still exists. If TiO₂ particles used to act as a sunscreen are small enough, they can penetrate the cells causing DNA damage after exposure to sunlight. He emphasized that relevant studies must be conducted to reach balanced conclusions about the effects of this form of TiO₂ on our health and well-being.

At the end of the conference, V. Filip expressed his thanks to J. Brát and his team from UNILEVER ČR for the excellent organization resulting in a very successful meeting. The 51st Conference on Fats and Oils is scheduled to take place on 15–17 May 2013.