Emerging Food Quality Assessment Techniques

Some new trends are occurring in food quality assessment techniques. New sampling techniques are being explored to automate and make this labor-intensive and critical analysis step more efficient. With increased awareness, the detection of genetically modified objects in foods is becoming an important consumer and food processor issue. And, finally, the storage and reporting of laboratory results is being enhanced with information management tools. 

Rapid Techniques. Rapid, quantitative techniques to prepare food for analysis are necessary to optimize routine quality testing of foods during processing and storage. Specific analytes must be easily detected with simple and standardized separation and testing.

• An example of an instrument that offers automation to the sampling process is O.I. Analytical’s new sample cleanup system called the AutoPrep 2000. The system is said to automate the separation of interfering coextractives from target analytes in environmental and food samples prior to gas chromatography or gas chromatography/ mass spectrometry analysis, extending the life of analytical columns. The system integrates an autosampler, allowing up to 60 samples to be automatically cleaned and collected in flasks. For more information, contact O.I. Analytical, P.O. Box 9010, College Station, TX 77842-9010 (phone 979-690-1711; fax 979-690-0440). 

• A new line of sample vials and accessories for chromatographic applications are described in a new 24-p brochure that contains useful information for scientists on more than eight new products segmented by instrument usage for a variety of high-performance liquid chromatography systems. New products featured include QuestVial™ glass vials, total recovery vials, and the LectraBond™ cap and septa designed to prevent the septa from being dislodged from the cap during use. Also included are charts on setting sample draw depths for low-volume inserts and troubleshooting information for common problems caused by sample vials within the lab environment. For more information, contact Waters Corp., 34 Maple St., Milford, MA 01757 (phone 800-252-4752). 

GMO Testing. The driving force for the high interest in testing for modified DNA sequences is the regulatory requirements for labeling being introduced in many markets around the world. What steps can food processors take to monitor and control the DNA profile of the ingredient flow into their plants? A primary step is to implement some type of identity preservation program. IP programs monitor agricultural products from the seed producer to the farm to the export vessel or processing plant. Another step is the detection of modified DNA in food products directly by polymerase chain reaction (PCR) techniques and indirectly by ELISA protein testing.  

• Eurofins Scientific, based in Brussels, Belgium, has instituted a new GMO detection program and is offering the program in all countries within its network to detect bioengineered foods and feed. The new validated system, called GMO Platinum Assay™, has been tested extensively during the past few months. It allows a more reliable conclusion as to whether food products and raw materials (maize, soya, starch, lecithin, rapeseed, and other foods) contain genetically altered material. The new test program is based on the development of improved primer/probe systems with a new chemistry to detect genetically modified DNA. The new systems are said to be more specific and more sensitive than any previously developed system. The advantage of this assay is that samples with very low GMO DNA content can be detected, because the assay is sensitive enough to find single DNA copy numbers. In addition, the new method reduces occurrence of false-positive results due to the improved specificity. 

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According to the company, DNA analysis of GMOs is currently conducted in only a few specialized labs. Since some conventional plants contain genetic sequences similar to those of modified sequences, false-positive results occur occasionally in other labs with traditional assays (i.e., the result wrongly implies that the sample has been genetically modified). This causes delays and additional costs (e.g., increased costs for importers as a result of longer storage times or rejection by customers). The application of the new technology will significantly reduce the risk of false-positives and offers economic advantages through superior reliability and specificity.  

The company maintains an internal proficiency testing program among its three GMO testing sites in Des Moines, Iowa, Hamburg, Germany, and Nantes, France, to help ensure high quality standards and comparability of results among all the laboratories. For more information, contact Eurofins Scientific, Inc., 1331 Union Ave., Ste. 1500, Memphis, TN 38104 (phone 901-272-7511). 

• Applied Biosystems has developed a new GMO detection and quantitation kit called TaqMan®. The kit allows for identifying GMOs in processed food, food ingredients, seed, and grain. The system uses the patented, fluorogenic 5' nuclease method with TaqMan probes, a real-time PCR technology. The system includes DNA sample preparation, automated PCR amplification and signal detection instruments, data analysis, comprehensive controls, and GMO quantitation software. The kit is said to eliminate the need for a technical staff trained in highly complex molecular techniques. 

The detection kit is the latest addition to the Applied Biosystems family of 5' nuclease assay-based kits for the detection of foodborne pathogens, including Salmonella, E. coli O157:H7, and Shiga toxins 1 and 2. This system targets the Cauliflower Mosaic Virus 35S promoter, a GMO-specific sequence present in all GMO soy and maize events approved for use in food by the European Union, and in the vast majority of GMO events approved by other countries. Both the European Union and Japan view this method as the premier technology for quantitating GMO content in food.  

Designed for use on the ABI Prism® 7000, 7700, and 7900HT Sequence Detection Systems, the kit can produce results in as little as 3 hr and process 1,152–3,456 sample wells every 24 hr. Of critical importance to commercial testing laboratories, the use of the kit with an Authorized Thermal Cycler conveys PCR service rights for GMO testing. For more information, contact Applied Biosystems, 850 Lincoln Centre Dr., Foster City, CA 94404 (phone 650-638-5800; fax 650-638-5884).  

LIMS. It is becoming increasingly important to store and be able to report laboratory sample results electronically with information management tools. Legislation is placing increasing pressure on the food processing industry to conform to the highest levels of food hygiene and safety. With this legislation is an increased need for documentation. For example, HACCP programs require that an extensive audit trail be kept. Results should also be electronically accessible for ease of use in reporting. In the laboratory environment, the staff must keep track of products, and the samples taken, as well as the test results. This control is usually carried out most effectively through laboratory software known as a laboratory information management system (LIMS). Within a secure information technology environment, the laboratory can prove that it meets audited requirements. Quality and safety programs require data to be both valid and traceable.  

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• Thermo Labsystems, London, U.K., recently released its latest LIMS called SampleManager2001, which allows compliance with regulatory authority accreditation schemes and external audits. Built-in security requires both operator approval during and completing a task, and work profiles conforming to GMP, NAMAS, EPA, FDA, and GLP guidelines. For straightforward audits, regulatory authorities can source audit reports directly from the LIMS. The software has an audit trail facility to monitor all data trail activity within the LIMS database. This offers security to protect against inadvertent changes to data, as well as against malicious alterations and damage to archived data. Audit-ready information is kept within special read-only tables in the LIMS, and can be archived to disk or magnetic tape.

With the release of the latest version, the company is offering several new functions. One of these is support for electronic signatures, in accordance with the FDA ruling in 21 CFR Part 11. Each signature, which can be applied to any piece of data, is stored with a checksum based on user-defined record files and verified by a 160-bit security algorithm. The user can also review incidences of electronic signature success or failure.

PRODUCTS & LITERATURE
Mad Cow Research is now being conduced at a new facility in France. The French National Atomic Research Center (CEA) has established a new L3 Biosafety Level 3 microbiology laboratory in Saclay, southwest of Paris. The new lab will be devoted to research into the diagnosis and treatment of prion diseases, for a better understanding of the origin of bovine spongiform encephalopathy (BSE). The facility will study its modes of inter- and intraspecies transmission, and work to develop diagnostic and therapeutic techniques. Last year, the French Ministry for Research created a Scientific Interest Group on prion infections, which was charged with coordinating and intensifying research in this field. Within this framework, a new laboratory was created in the Pharmcology and Immunology Dept. (SPI) of the CEA, to do research into the diagnosis of prion diseases and set up a therapeutic screening facility. The research program at the new lab will be carried out in three stages: the immediate application of a screening test for BSE, already developed for nerve tissue, to other related tissues such as spleen, ganglia, and intestine; in the short term, the development of a blood test for the preclinical diagnosis of scrapie in sheep; and in the medium term, the development of a blood test for the pre-clinical diagnosis of variant Creutzfeldt-Jakob disease. For more information, contact CEA, 31-33 rue de la Federation, 75752 Paris, Cedex 15, France (phone 011-33-1-40-56-18-35; www.cea.fr).

Laboratory Products for dairy, food, and water analysis are listed in the latest 2001/2002 Weber Scientific Catalog. The catalog includes bacteriological testing equipment, balances, dairy testing equipment, sampling supplies, thermometers, timers, and lab glassware. For a copy, contact Weber Scientific, 2732 Kuser Rd., Hamilton, NJ 08691-9430 (phone 800-328-8378 or 609-584-7677; fax 609-584-8388).

Shaking Flasks with respiration activity monitoring system, called Ramos, may be used to determine the respiration activity of microbial, mammalian, and plant cell cultures. The flasks are said to be more suitable for screening for efficient strains or optimization of media than stirred bioreactors. The system substantially enhances the performance of shaking flasks because it determines the oxygen transfer rate, the carbon dioxide transfer rate, and the respiratory quotient of biological cultures online under sterile conditions. According to the company, these factors are the most suitable measurable variables to quantify the physiological state of aerobic microorganisms. For more information, contact BioPro International, Inc., 265 Conklin St., Farmingdale, NY 11735 (phone 516-249-0099; fax 516-249-0494).

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Guide to Selecting an ICP is a 32-p booklet intended as a fundamental reference tool for anyone considering the purchase of an inductively coupled plasma (ICP) spectrometer. The booklet contains important information on ICPs, including a glossary of terminology with the latest ICP phraseology. To receive a copy of the booklet, contact Leeman Labs, Inc., 6 Wentworth Dr., Hudson, NH 03051 (phone 603-886-8400; fax 603-886-9141).

is a 32-p booklet intended as a fundamental reference tool for anyone considering the purchase of an inductively coupled plasma (ICP) spectrometer. The booklet contains important information on ICPs, including a glossary of terminology with the latest ICP phraseology. To receive a copy of the booklet, contact Leeman Labs, Inc., 6 Wentworth Dr., Hudson, NH 03051 (phone 603-886-8400; fax 603-886-9141).

Oscillating Rheometer, the RheoWave® 1 OSC–Rheometer (RW1), is said to be an affordable research-grade rheometer for advanced quality control of viscoelastic materials. The instrument may be used for the advanced rheometric characterization of fluids and melts. It is available in two torque ranges. The fluids version comes with two interchangeable, low-inertia, parallel plates which cover a wide range of thin fluids such as polymer solutions, stabilizers, thickeners, weak suspensions, emulsions, and foams. Zero shear viscosity can be determined with a creep recovery test. The melt version of the instrument uses standard cones/plates and provides five times higher torque for testing medium to high-viscosity materials. The instrument can be controlled through a display controller which stores up to 10 measuring procedures and 50 tests. Data can be printed online or at a later date. Alternatively, a PC can be used for complete remote control of rheometer and data analysis. For more information contact Thermo Haake, 53 W. Century Rd., Paramus, NJ 07652 (phone 201-265-7865; fax: 201-265-1977; www.thermohaake.com.).

Trichinella Assay, the Trichinella Swine Antibody Elisa Test Kit, will detect antibodies to Trichinella spiralis from blood, serum, plasma, or tissue fluid (meat juice) in about 30 min. The test has been cleared for veterinary use by the USDA Biologics Div., and can be used on swine both ante and post mortem. The kit is currently being used in the pilot of the USDA’s Trichinae Certification Program, which will provide consumers of fresh pork with the assurance that product is free of Trichinella. All components of the test kit are liquid and ready to use, with the exception of the need to perform a simple dilution of the wash concentrate. The assay is performed at room temperature, and the results can be read visually or with an ELISA reader. The kit is a microwell immunoassay employing 8-well breakaway strips, and includes positive and negative controls. For more information, contact SafePath Laboratories, LLC, 5909 Sea Lion Place, Suite D, Carlsbad, CA 92008 (phone 760-929-6787; fax 760-431-7759).

Rapid Ashing Systems in the Phoenix™ line are a group of microwave-powered muffle furnaces. They are available in two configurations—a high-temperature furnace reaching up to 1,200°C and a high-capacity furnace reaching 1,000°C—with a variety of options. The system features menu-driven software, program storage, internal calibration capabilities, and temperature control in automatic and ramping stages. According to the supplier, no fume hood space is needed, since smoke, fumes, and heat are removed continuously by a built-in exhaust system. For more information, contact CEM, P.O. Box 200, Matthhews, NC 28106-0200 (phone 704-821-7015).

by JAMES GIESE
Internet Editor