The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform

Elke Anklam - One of the best experts on this subject based on the ideXlab platform.

Thomas Wenzl - One of the best experts on this subject based on the ideXlab platform.

  • assessment of critical steps of a gc ms based indirect analytical method for the determination of fatty acid esters of monochloropropanediols mcpdes and of glycidol ges
    Food Control, 2017
    Co-Authors: Zuzana Zelinkova, Anupam Giri, Thomas Wenzl
    Abstract:

    Abstract Fatty acid esters of 2- and 3-chloropropanediol (MCPDEs) and fatty acid esters of glycidol (GEs) are commonly monitored in edible fats and oils. A recommendation issued by the European Commission emphasizes the need of generating data on the occurrence of these substances in a broad range of different foods. So far, analytical methods for the determination of MCPDEs and GEs are fully validated only for oils, fats and margarine. This manuscript presents the assessment of critical steps in the AOCS Cd 29a-13 method for the simultaneous determination of MCPDEs and GEs in the fat phase obtained from bakery and Potato Products, smoked and fried fish and meat, and other cereal Products. The trueness of the method is affected by the additional formation of 3-MBPD esters from monoacylglycerols (MAGs), which are frequently present in food. The overestimation of GE contents for some samples was confirmed by the comparison of results with results obtained by an independent analytical method (direct analysis of GE by HPLC-MS/MS). An additional sample pre-treatment by SPE was introduced to remove MAGs from fat prior to the GEs conversion, while the overall method sensitivity was not significantly affected. Trueness of the determination of GEs by the modified analytical procedure was confirmed by comparison with a direct analysis of GEs. The potential impact on accuracy of results of the final sample preparation step of the analytical procedure, the derivatization of free forms MCPD and MBPD with PBA, was evaluated as well. Different commercial batches of PBA showed differences in solubility in a non-polar organic solvent. The PBA derivatization in organic solvent did not affect precision and trueness of the method due to the isotopic standard dilution. However, method sensitivity might be significantly compromised.

  • proficiency test on the determination of acrylamide in Potato crisps final report
    2008
    Co-Authors: Lubomir Karasek, Szilard Szilagyi, Thomas Wenzl
    Abstract:

    The Institute for Reference Materials and Measurements (IRMM) of the European Commission’s Joint Research Centre (JRC) was requested by the Directorate General Health and Consumer Protection (DG SANCO) to organise a proficiency test on the determination of acrylamide Potato Products in 2007. The aim of this test was to support the implementation of the acrylamide monitoring Recommendation 2007/331/EC. The study was a dedicated collaborative trial and was free of charge for the participants. The organisation of the study as well as the evaluation of the results was done in accordance with “The International Harmonised Protocol for the Proficiency Testing of Analytical Chemistry Laboratories”. Altogether 42 laboratories from 16 EU member states subscribed for participation in the study. The participants were asked to determine the acrylamide content in the test sample by application of their usual in-house analysis methods. In total, 36 data sets were reported to the organisers of the study. The performance of laboratories was expressed by the z-score. The percentage of successful laboratories is lower in comparison to previous proficiency tests organised by IRMM. Reasons for this might be a more complex food matrix and/or the application of improper methods. However, the study showed the importance of continuous participation in proficiency testing schemes in order to achieve comparability of results.

  • collaborative trial validation study of two methods one based on high performance liquid chromatography tandem mass spectrometry and on gas chromatography mass spectrometry for the determination of acrylamide in bakery and Potato Products
    Journal of Chromatography A, 2006
    Co-Authors: Thomas Wenzl, Lubomir Karasek, Johan Rosen, Karlerik Hellenaes, Colin Crews, Laurence Castle, Elke Anklam
    Abstract:

    Abstract A European inter-laboratory study was conducted to validate two analytical procedures for the determination of acrylamide in bakery ware (crispbreads, biscuits) and Potato Products (chips), within a concentration range from about 20 μg/kg to about 9000 μg/kg. The methods are based on gas chromatography–mass spectrometry (GC–MS) of the derivatised analyte and on high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) of native acrylamide. Isotope dilution with isotopically labelled acrylamide was an integral part of both methods. The study was evaluated according to internationally accepted guidelines. The performance of the HPLC–MS/MS method was found to be superior to that of the GC–MS method and to be fit-for-the-purpose.

Jingsong Ye - One of the best experts on this subject based on the ideXlab platform.

  • use of invertase silencing in Potato to minimize losses from zebra chip and sugar ends
    2013
    Co-Authors: Richael Craig, Jingsong Ye, Caius Rommens
    Abstract:

    The present invention provides a convenient method for producing Potato Products such as chips and French fries that have lower incidence of sugar ends and less off-color development due to infection from the zebra chip pathogen.

  • low acrylamide french fries and Potato chips
    Plant Biotechnology Journal, 2008
    Co-Authors: Caius Rommens, Kathy Swords, Craig Richael, Jingsong Ye
    Abstract:

    Acrylamide is produced in starchy foods that are baked, roasted or fried at high temperatures. Concerns about the potential health issues associated with the dietary intake of this reactive compound led us to reduce the accumulation of asparagine, one of its main precursors, in the tubers of Potato (Solanum tuberosum). This metabolic change was accomplished by silencing two asparagine synthetase genes through ‘all-native DNA’ transformation. Glasshouse-grown tubers of the transformed intragenic plants contained up to 20-fold reduced levels of free asparagine. This metabolic change coincided with a small increase in the formation of glutamine and did not affect tuber shape or yield. Heat-processed Products derived from the low-asparagine tubers were also indistinguishable from their untransformed counterparts in terms of sensory characteristics. However, both French fries and Potato chips accumulated as little as 5% of the acrylamide present in wild-type controls. Given the important role of processed Potato Products in the modern Western diet, a replacement of current varieties with intragenic Potatoes could reduce the average daily intake of acrylamide by almost one-third.

Caius Rommens - One of the best experts on this subject based on the ideXlab platform.

  • use of invertase silencing in Potato to minimize losses from zebra chip and sugar ends
    2013
    Co-Authors: Richael Craig, Jingsong Ye, Caius Rommens
    Abstract:

    The present invention provides a convenient method for producing Potato Products such as chips and French fries that have lower incidence of sugar ends and less off-color development due to infection from the zebra chip pathogen.

  • low acrylamide french fries and Potato chips
    Plant Biotechnology Journal, 2008
    Co-Authors: Caius Rommens, Kathy Swords, Craig Richael, Jingsong Ye
    Abstract:

    Acrylamide is produced in starchy foods that are baked, roasted or fried at high temperatures. Concerns about the potential health issues associated with the dietary intake of this reactive compound led us to reduce the accumulation of asparagine, one of its main precursors, in the tubers of Potato (Solanum tuberosum). This metabolic change was accomplished by silencing two asparagine synthetase genes through ‘all-native DNA’ transformation. Glasshouse-grown tubers of the transformed intragenic plants contained up to 20-fold reduced levels of free asparagine. This metabolic change coincided with a small increase in the formation of glutamine and did not affect tuber shape or yield. Heat-processed Products derived from the low-asparagine tubers were also indistinguishable from their untransformed counterparts in terms of sensory characteristics. However, both French fries and Potato chips accumulated as little as 5% of the acrylamide present in wild-type controls. Given the important role of processed Potato Products in the modern Western diet, a replacement of current varieties with intragenic Potatoes could reduce the average daily intake of acrylamide by almost one-third.

Shakuntala H Thilsted - One of the best experts on this subject based on the ideXlab platform.

  • effect of home preparation practices on the content of provitamin a carotenoids in coloured sweet Potato varieties ipomoea batatas lam from kenya
    Innovative Food Science and Emerging Technologies, 2007
    Co-Authors: Ulla Kidmose, Lars Porskjaer Christensen, Sammy M Agili, Shakuntala H Thilsted
    Abstract:

    Abstract The content of β-carotene was determined in raw peeled, boiled peeled and roasted peeled roots of six orange- and yellow-fleshed sweet Potato varieties from Kenya to evaluate their vitamin A potential before and after household preparation. The boiling and roasting procedures were similar to traditional methods used in Kenya. Dried Products, chips and flour, of the variety Zapallo were also analysed. The varieties differed in dry matter and β-carotene content (1240–10,800 μg/100 g fresh weight (FW)) and thus in vitamin A content (100–830 RE/100 g FW). As sweet Potato roots are consumed after heating, the loss of all-trans-β-carotene during preparation should be taken into account. Boiling of roots of the selected varieties seemed to result in a higher true retention (TR) of all-trans-β-carotene than roasting and TR of all-trans-β-carotene seemed to be dependent on the variety (42–128%). Preparation of chips by drying resulted in a significant reduction of the all-trans-β-carotene content of approximately 21%, which was further reduced when flour was produced from chips. The varieties Tainung and SPK-004 can be recommended for consumption especially after boiling in order to enhance the vitamin A intake in Kenya. Both varieties have a high content of vitamin A, the losses after boiling are rather low and both varieties have high consumer acceptability. Industrial relevance The content and stability of β-carotene in sweet Potato is an issue that is particularly important for developing countries with high prevalence of vitamin A deficiency. In order to prolong the shelf life of sweet Potato, it is necessary to implement and develop industrial or small scale processing methods so that it is possible to produce sweet Potato Products with highest possible vitamin A values in these countries. In developed countries, focus is on innovation of new Products with a good taste and a high health value. Consequently, sweet Potato and sweet Potato Products might have a future as healthy foods in developed countries, and therefore there is a need to build up an industry that can provide the people in these countries with high quality sweet Potato foods.