Meeting offers many food safety and quality learning opportunities

This year’s IFT Annual Meeting and Food Expo to be held June 10–14 in Dallas, Texas, offers a variety of new product introductions, seminars, and technical sessions for individuals in the food laboratory area. Pre-meeting continuing education programs of interest include those on mycotoxins, food sanitation, and food quality. Beyond the technical sessions on food chemistry, microbiology, and physical property measurement, sessions will highlight the description and definition of dietary fiber, hand washing vs glove usage, food allergens, and safety assessment of genetically modified foods.

The following are some highlights from exhibitors and sessions:

Assay available for genetically modified organisms
The introduction of genetically modified crops such as GMO soybeans has created a demand for tests that can quantify the amount of modified product in crops and foods. Qualicon, a DuPont Subsidiary, has developed an assay for quantifying the genetically modified content of soy protein. The assay is also applicable to other foods. Qualicon’s service laboratory provides this analysis to customers in the United States and Europe and soon in Asia. The closed-tube homogeneous PCR process uses Qualicon’s BAX^® detection system and DNA intercalating dye, SYBR Green-I. During each thermal cycle, fluorescence data is collected at an intermediate temperature between the extension and denaturation steps. As the specific PCR product is generated, the dye penetrates into the product and the total fluorescence signal increases. Because there is no detectable product during the early stages of PCR, the signal during this period becomes a baseline fluorescence value. Regression analysis of the fluorescence increase determines the cycle at which the increase exceeds 5% of the baseline fluorescence. This becomes the threshold cycle (CT). Standards with known levels of genetically modified DNA (0.5%-5.0%) are amplified and the fluorescence signal recorded after each cycle. A curve is generated based on the linear regression fit of CT vs. the log of percent genetically modified material. Unknown sample CT values are plotted against the standard curve and a genetically modified percentage is determined. Using a similar technique, the amount of total soy DNA can be quantified by targeting an amplification reaction to the lectin coding region of soybean DNA. The ratio of the amount of the modified insert to the total amount of soy DNA allows an accurate percentage of genetically modified material to be calculated. The assay can be targeted to screen for genetic modification in other food types as required. Information on the service will be presented by Qualicon Inc. at the New Products & Technologies–Session 1, held during the IFT Annual Meeting.
Paper 38-8, 9:00 a.m., Monday, June 12.

New rapid method for Campylobacter detection developed
Campylobacter is generally recognized as a major cause of foodborne illness. However, traditional cultural methods for the detection of Campylobacter are very complex, time consuming, and require a system of atmosphere modification to achieve satisfactory results. Tecra International will present information on a new method that has been developed for detection of Campylobacter in food and water samples. This method utilizes a single-step aerobic enrichment, at a single temperature, using a specially-formulated medium, followed by detection of the target pathogen using a highly specific and sensitive immunoassay. Information will be presented on a trial of more than 200 food, water, and environmental samples, which were used to compare the new method with the Australian and New Zealand standard method (AS/NZ 1766.2.13) or the FDA BAM standard method (using Bolton’s enrichment medium). A group of 100 food samples including raw chicken, lamb, pork, unpasteurized milk, and cream were tested for natural contamination. The new method detected 45 positive samples while the Australian and New Zealand standard method detected only 38 positive samples. A further 135 food samples consisting of the raw meats, a range of dairy products, cooked meat products, and mushrooms were tested for both natural contamination and recovery of an artificial inoculation of Campylobacter. The new method detected 93 positive samples while the FDA BAM method detected 92 positive samples. Results show that the new method performed better than the Australian method and was comparable to the FDA BAM standard method for the recovery and detection of Campylobacter from both inoculated and naturally contaminated samples. Using this new method, researchers can clear negative samples within 42 hr, compared with standard methods that require up to 4-5 days to obtain a result. Information on the new method will be presented by Tecra International Pty Ltd. at the New Products & Technologies–Session 1, held during the IFT Annual Meeting.
Paper 38-9, 9:00 a.m., Monday, June 12.

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Guided microwave spectrometry offers advantages for in-line food analysis
Reliable and repeatable in-line measurements can be influenced by several factors. These include: process temperature, density, color, flow-rate, particle size, pump turbulence, and air entrainment. Guided Microwave Spectrometry (GMS) is a one approach for performing multi-constituent analysis of materials whose makeup exhibits one or more of the above problem issues.

The composition of the process product can be determined with knowledge of a material’s dielectric constant. The material under test is placed in, or flows through a measurement chamber that mimics a section of RF waveguide. The scalar response of the waveguide is measured over a wide bandwidth at wavelengths long enough to mitigate errors that can be introduced by reflections due to particular size. From the changes in the key electrical properties— dielectric constant, conductivity, and molecular relaxation time—an analysis of constituent properties can be made. Because GMS is a non-contacting technology that measures the entire process stream (instead of only a small segment), the analysis of a sample is representative even if the mixture is non-homogenous. A typical GMS system consists of electronic controls and a non-intrusive, in-line sensor body, which is compatible with all standard process piping. The in-line sensor body is 3A and USDA-approved for food contact. Because of the unique transitional shape of the chamber, the electromagnetic energy is kept within the waveguide minimizing upstream and downstream turbulence effect. The parameters that are measured are the DC value of the dielectric constant, the DC value of the conductivity, and the molecular relaxation time. With the GMS technique, multiple component analysis becomes possible. Results obtained in measuring moisture, protein, and fat in various meat emulsions will be presented by Epsilon Industrial Inc. at the New Products & Technologies–Session 1, held during the IFT Annual Meeting. Information on measuring moisture in harvested grains, ground corn, process cereals, dough, and candy coatings will also be presented.
Paper 38-10, 9:00 a.m., Monday, June 12.

Real-time alcohol concentration measurement possible
Many companies, organizations, and governments depend on precise measurement of alcohol concentration for process control or taxation purposes. This presentation will provide information on using a Coriolis multiple variable sensor, which measures mass flow, density, and temperature to measure gross flow, net alcohol flow, and alcohol concentration in an online continuous process. The method uses the Organization Internationale De Metrologie Legale (OIML) tables as a baseline set of acceptable data. This data set includes alcohol volumetric concentration as well as 7 other tables of concentration data, and the coefficients and equations for calculating some of the tabular data. It takes significant processing time to calculate the entire range of alcohol concentration in the OIML tables, a smaller user defined range can be calculated with a much simpler algorithm. Given a range of density, concentration, and temperature points, a fourth order linear regression is performed in two directions over the data to calculate a density at reference temperature curve. Performing another fourth order linear regression over the density at reference temperature the data is converted to volumetric concentration. The user data range is then calculated using the derived coefficients and polynomial expansion. The data created from the reduced set of coefficients is compared against the original equations to calculate the mathematical residuals. Sensor accuracy is then determined by the combination of density measurement, temperature measurement, and mathematical residual errors. Entering the data into the sensor’s computer allows a final verification; the coefficients are recalculated to a single precision floating point, and the concentration calculation is performed in the sensor. After verification the unit is ready for use measuring the percentage volume of alcohol in a given application with known accuracy. Information on the new alcohol concentration measurement method will be presented by Micro Motion, Inc. at the New Products & Technologies–Session 1, held during the IFT Annual Meeting.
Paper 38-11, 9:00 a.m., Monday, June 12.

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Analytical in-line measurement of Bostwick
The food industry uses a Bostwick standard for measurement of product viscosity and shear characteristics. Knowledgeable customers request and look for specific Bostwick numbers with their purchase. The well-known Bostwick scale instrument is a simple guillotine slide gate which, upon opening, allows the product to flow horizontally across a scale marked in centimeters. The Bostwick number is the length of flow in a given time period (usually 30 sec). Because of a product’s non-Newtonian flow characteristics, attempts at correlating a Bostwick number with the analytical instrumentation of viscometer and refractometer proved unsuccessful. In-line optical analyzers using the principle of light absorption for the count of suspended solids demonstrated a correlation to the Bostwick scale. In September 1998, the Food Science Dept. of Purdue University conducted field trials with an optical analyzing system provided by McNab Inc. Data on tomato sauce showed a correlation between manual Bostwick measurements and the optical analyzer reading. A control loop back to the process was initiated where the optical analyzer was able to modulate a pump speed around a Bostwick setpoint. Laboratory trials have broadened the database to tomato purees, pizza sauce, tomato paste dilution, ketchup, and non-tomato products such as baby foods. The theory of light absorption for suspended solids as related to the Bostwick will be addressed. The market significance of this innovation is that for the first time there is an in-line, analytical measurement of Bostwick suitable for control loops and correlatable to the manual measurement. Laboratory data, pilot-plant data, and commercial data will be presented during the New Products & Technologies–Session 1, held during the IFT Annual Meeting.
Paper 38-12, 9:00 a.m., Monday, June 12.

Jack-knife testing of PLS models
The Unscrambler 7.5, by CAMO, Inc., released in April 1999, is a stand-alone statistical modeling software package for multivariate data analysis. The strength of this program is its ability to perform PLS (Partial Least Squares) regression. Such analysis is currently applied to numerous fields including chemometrics, marketing, product development, sensory, and finance to identify complex multivariate patterns and relationships. While many programs on the market provide PLS regression models, all suffer from a common deficiency. Namely, there is no way to determine which variables in the model are statistically significant. This leaves researchers guessing both the relevance and the strength of the relationships observed in the output of these various programs. The program to be discussed here has bridged this gap by incorporating a technique developed by Dr. Harald Martens specifically for this program. Uncertainly Testing, which has been published in refereed journals, provides a method utilizing a jack-knife procedure to identify, through statistical testing, the variables that are most important or significant in the given output. No other commercial program currently incorporates this technology or any other test of significance for use with PLS models. This innovative breakthrough overcomes what had been a significant shortcoming of the methodology and provides researchers with the ability to test the importance of individual variables in large complex models. As a result, smaller models can be defined in terms of a few important variables greatly simplifying the interpretation of the model and providing information that is more accessible to lay persons. For instance, product developers can focus on a small set of ingredients that relate to consumer liking, rather than having to adjust dozens of variables in an attempt to improve consumer liking of a product. Such a reduction in scope saves a great deal of time and money in the product development cycle. For more information on this software, see the presentation by CAMO Inc. at the New Products & Technologies–Session 2, held during the IFT Annual Meeting.
Paper 64-11, 9:00 a.m., Tuesday, June 13.

New sensory software released
Tragon Corp. has announced the release of their new Interactive Quantitative Descriptive Analysis (QDA^®) software program. The program performs standard QDA analyses such as analysis of variance, discriminant analysis, factor analysis, correlations, and various mean separation tests. The QDA system of product evaluations provides “fingerprints” of products to identify unique characteristics and provide development direction. The new Windows-based program features a menu driven point and click format for analyzing results from sensory tests. The new program is based on the S-Plus 4.5 statistical package. Most data capture systems produce files compatible with this software program. Dialog boxes allow the user the flexibility to choose statistical parameters for the analysis and subsequent reports and graphs. Graphical and numerical tools simplify panel performance tracking and measure differences among products.More information about the software can be gained from Tragon Corp.
Tragon Corp., Booth 8332.

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First-time exhibitor highlights temperature measurement
A first-time exhibitor, Cooper Instrument Corp., will be featuring their complete line of time, temperature, and humidity measurement instruments. They are highlighting two products: the DPP400W waterproof digital pen-style pocket test thermometer and the Mini Data Logger. The Mini Data Logger allows the user to track the temperature of perishable products by enclosing or attaching the unit to the product. The unit is a rugged, self-sufficient system that once setup to the user specifications, measures temperature and records the results in a protective memory section. If the temperature leaves the user-programmable range the logger will record when this happened, for how long the temperature stayed outside the range and if the temperature was too high or too low. During the initial setup, the user can select high and low temperature limits depending on the application. Once the data has been transferred to a PC, the user can view the data either by graph or table. All recording is done at a user defined increment rate of 1,2,5,10, and 30 min or 1,2,6, and 12 hr. The logger can store up to 2,000 readings. Cooper will also be featuring a new pocket test thermometer, the DPP400. The thermometer has been adapted for use in food-service applications by making the unit waterproof. The user can collect accurate temperature readings in steam-filled environments or in wet areas. The unit features an on/off button, automatic shut-off after 5 min of non-use, min/max temperature readings, ºF/ºC read-out option, and a hold feature that allows the user to hold the recorded temperature for documentation or until a better view of the display is obtained. The thermometer has a temperature range of -40 to 392ºC. For more information on these products or other temperature measurement devices see Cooper Instrument Corp.
Cooper Instrument Corp., Booth 1929.

New NIR analyzer introduced 
A new near infrared reflectance (NIR) analyzer, the KJT-270, for use in the laboratory and QA/QC applications has been introduced by Kett U.S. The analyzer is said to utilize a “smart sensor” design that integrates calibration and memory storage, measurement display, and data output from within the sensor itself. The unit’s multiple filter design provides the user with fully transferable calibrations. Users can calibrate a single system in one location and then ship fully calibrated and certified sensors to other plants by transferring the coefficient data only. The unit allows users to measure moisture, fat/oil, protein, ethanol, and other organic substances during any phase of processing. More information about the analyzer can be gained from Kett, U.S.
Kett U.S., Booth 1802.

New color measurement spectrophotometer introduced
HunterLab has introduced a new color measurement spectrophotometer, the ColorQuest^®XE for the food industry. The spectrophotometer is said to provide precision and reliability at an affordable price. It measures the color of solid or liquid food products for research and quality control applications. It features diffuse/8° geometry that measures both reflectance and transmittance as well as transmission haze. The instrument uses double beam optics and a long-life xenon lamp that virtually eliminates lamp replacement. Features include large/small area measurement with automated lens change and large transmission sample compartment. Accessories include a holder for measuring transparent liquids and a reflectance sample shelf for measuring the reflected color of near opaque solids and pastes. The unit includes software for collecting, displaying, analyzing, and storing data.
HunterLab, Booth 7745.

E-nose company offers portable unit
Cyrano Sciences has released their lightweight, portable electronic nose, the Cyranose™ 320, for use in the field to detect volatile compounds. The company claims that the device’s composite sensors can detect volatiles with molecular weights from 30 to 250. They have demonstrated the sensitivity and discrimination to pure solvents (butanol, toluene, DMSO), complex mixtures (commercially available perfumes), natural products (essential oils, coffees, fruits) and by products from the metabolic breakdown of bacteria. Upon exposure to a sample some of the sample will partition into the unit’s polymers. This causes the polymer to ‘swell’ and that swelling generally reduces the conductance through the sensor. This causes a resistance change that the device measures. The device incorporates a graphic LCD with back lighting. Connection ports will enable downloading of data into a spread-sheet package. Rapid response time, combined with easy one button operation provides an effective and accurate measure of the vapors present. Standard, easily replaceable or rechargeable batteries supply power. Housed in a robust, water-resistant case, the portable electronic nose may be used in a variety of food processing environments. The sensors in the unit have been shown to respond to a wide range of organic compounds, bacteria and natural products. The company will work with users to develop techniques for a particular application. For more information, see Cyrano Sciences.
Cyrano Sciences, Inc., Booth 1200.

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• The Microbiology Products division of 3M is offering the 3M Quick Swab, a ready-to-use environmental swab system. The product is designed for processing plant users of environmental swabbing systems to verify pre-operation sanitation effectiveness, monitor bacteria levels during production, or measure post-operational bacterial levels. The swab system consists of a five-inch, rayon-tipped swab containing neutralizing buffer to facilitate recovery of bacteria. The swabs an be used wet or dry to sample surfaces and quickly deliver 1.0mL of sample onto a 3M™ Petrifilm™ Plate or 3M™ Redigel™ Test. The system is said to be able to decrease overall cost per swab test by reducing the labor required to prepare, gather and plate the sample. There is no need to prepare neutralizing dilutents or use a pipette to add the sample to the plate or test. 3M will also be highlighting their Petrifilm Information Management System. This system automatically performs a colony count on Petrifilm Aerobic Count Plates, streamlining the practice of manually counting colonies. The system also securely manages microbial testing data, keeping histories, trends and current results. The system has everything the user needs toautomate a data capture and management system, from customized software to an optional bar code system that provides automated digitization of key information at the time of reading.
3M Microbiology Products, Booth 5406.

• Celsis International plc will offer barcode information capture for their rapid microbial contamination detection systems. User can scan barcode labels found on sample packaging or labels with a barcode reading device and the information will appear in the preprogrammed workloads of the system’s software.
Celsis International plc, Booth 232.

• The Direct Contact Food Analyzer (DCFA) is said to bring a new level of speed and convenience to routine NIR testing for food and beverage processors. The instrument’s open-platform design permits food samples to be analyzed inside their sample bags or other sealed containers. The user places the sample on the scanning stage, closes the lid, and clicks on the desired nutrient analysis. The system then returns accurate measurements of single or multiple constituents. Most solid foods, powders and semi-solid foods can be analyzed in a sample bag. Pastes, gels, slurries and highly scattering liquids can be analyzed conveniently in laboratory beakers. Many finished products like peanut butter and apple sauce can even be tested in the jar. Testing clear and semi-transparent liquids requires the use of optional liquid sample cells. These provide a choice of reproducible path-lengths for reflection analysis. The DCFA will also accept powder samples in the standard reflectance cups used by other Foss NIRSystems instruments. The DCFA can be calibrated to measure all the common nutrients of interest—fats, moisture, protein, fiber, sugars, and more—in liquid or solid samples. The user’s existing primary methods are normally used as a reference.
Foss NIRSystems, Booth 8745.

• Perkin Elmer will present their Spectrum One™, which is touted as an easy-to-use FT-IR system with their Wizard-driven software. Even infrequent users are said to be able to run turnkey analyses. The built-in IR Assistant interface guides the user through the analysis. Entire operating procedures can be fully automated–from sample to report. Each unit has a unique IP address and can be linked to any standard network.
Perkin Elmer Corp., Booth 9039.

• Cole Parmer will highlight a variety of measurement instruments for the food industry. Included will be the waterproof pHTestr 1DJ and 2 DJ. This new line of pocket-sized pH meterscontain double junction reference electrodes. The meters may be used in the lab, plant or field where a solution has heavy metal ions, sulfides, and proteins.
Cole-Parmer Co., Booth 2205.

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• The A2101 Water Activity Meter may be used to measure water activity of food or pharmaceutical products. The meter measures water activity within the range of 0.01 to 1.00 aW with an accuracy of 0.003 aW. The meter includes the following: a micro-processor based indicator, a ventilated probe, two sample holders, one pack each of large and small disposable sample cups, and five boxes of certified humidity standards (5, 10, 35, 80, and 95% RH/ 5 vials per box). To measure a sample, the user places a disposable cup with the sample inside the holder and the ventilated probe is placed on top of the sample holder. After pressing the enter key, the indicator begins monitoring the humidity data provided by the probe. A buzzer and an LED indicates when the measurement is completed. Typically, the meter provides accurate measurements in just 4 to 6 min per sample. The indicator can be optimized for up to 20 different products.
Rotronic Instrument Corp., Booth 7251.

• Michael G. Brown & Associates announces a new dough/flour test device called the ReoMixer that makes it possible to predict bread volume and dough process ability from one instrument. The system is a computerized 10-gram mixer that conforms to the AACC Mixograph standard that allows prediction of bread volume with typically 90% explained variance. This unit improves on the standard Mixograph measurements with a temperature controlled computerized mixing bowl and offers software for analysis of mixing curves. The unit may be used stand alone or mounted on a Stevens QTS-25 Texture Analyzer to combine Mixograph standard measurements with textural measurement. This allows the user to obtain mixing graphs, dough hardness, stickiness, relaxation, and extensibility in one package. The user can add flour and water to a bowl of the ReoMixer to obtain mixing curves and then may utilize uniformly prepared dough samples for texture measurements with the Texture Analyzer.
Michael G. Brown & Associates, Inc., Booth 3304.

• Cook times can be verified with the use of the ThermaZyme™ system from Advanced Instruments, Inc. Processors using the system can confirm that a product is properly cooked even after it has cooled or been frozen. This instrument-based assay measures residual acid phosphatase (ACP) activity in cooked meat samples. Because the ACP test provides quantitative results and ACP shows a curvilinear decrease as meat cooks, a direct correlation between ACP levels and temperature is established. With this system, the user can establish cooking parameters that yield higher production weights; eliminate the need to overcook meat; maintain product safety; and maximize return on production expenditures.
Advanced Instruments, Inc., Booth 2202.

• Non-glass pH probes for food applications are being offered by Sentron. The pH probes are intended to replace glass electrodes with a probe that contains a ISFET (Ion-Sensitive Field Effect Transistor) sensor. The probes are suited for measurement of any water-based sample evenunder harsh conditions. They are especially suited to applications where broken glass may be a hazard to the environment, the sample, or the user. All probes can be cleaned with a toothbrush and soap and can be stored dry. The company offers three series of probes in a variety of different tip designs to cover applications in liquids, semi- solids, and viscous solutions. Applications include the measurement of pH in meats, cheeses, dough, batters, sauces, jellies, and produce. The probes have large surface area reference diaphragms of porous Teflon to ensure good sample contact while preventing junction fouling and poisoning. The company offers three different series of probes: the Stream-Line Series is designed for general, low conductivity, and drier pH applications up to 105ºC; the Red-Line Series are designed for general-purpose applications to 60ºC; and the Hot-Line Series are resistant to highly aggressive chemicals to 105ºC.
Sentron, Booth 1004.

• Brookfield will feature their DV-III+ Rheometer. The rheometer can operate as either a stand-alone instrument or under computer control. It has built-in rheological algorithms to allow rapid and repeatable material characterization, including flow curves, yield points, time dependencies, and temperature profiles. The unit works with cone/plate and coaxial cylinder geometries as well as standard spindle sets.
Brookfield Engineering Laboratories, Booth 7550.

by JAMES GIESE
Associate Editor