Marshfield Food Safety works with companies to conduct microbiological and chemistry testing. Food testing is required to obtain a certificate of analysis for ready to eat and raw products at certain stages of processing. Customers are provided analyses to meet requirements for Food Process Evaluation.
Having A2LA Accreditation to ISO 17025:2005
assures our results will make you compliant with USDA FSIS, HACCP, US FDA FSMA, and other regulatory requirements. To search for a specific test you may view our food testing menu
or contact us to inquire. Food testing technologies are listed below.
Polymerase chain-reaction (PCR) testing identifies major pathogens like E.coli 0157:H7, Listeria monocytogenes, Salmonella and Campylobacter by detecting the organism's DNA. This extremely rapid, accurate testing technology can detect as few as one bacterial organism per sample in as little as eight hours. PCR is several hours faster than standard tests now used in the food industry. Extremely rapid product testing for the major food pathogens using this technology will increase the food safety protection for the food industry and consumer.
Enzyme-Linked Fluorescent Assay (ELFA) reveals pathogens by detecting their protein. This technology is currently the cheapest and most widely used in the food industry.
Cultures from food sources are grown on plates and visually examined for pathogenic species. This is the time-tested method of detection. Organisms can also be isolated and/or quantified using plate counts or MPN methods.
Shelf-life Verification allows clients to maximize stability of product and apply it to competitive pricing. Microorganism Strain Identification by Pulse-Field Gel Electrophoresis aids identification of spoilage organisms. Through strain identification,
DNA is abstracted, multiplied and mapped to isolate certain strands or unique variances that could be causing problems in stability. Molecular Pathogen Detection
The Atlas System
is a fully automated instrument that enhances the accuracy, speed, and efficiency of food safety testing through detection of molecular pathogens, including Listeria, Salmonella
, Escherichia coli
, and other
organisms commonly implicated in food contamination episodes.
Inductively Coupled Plasma (ICP)
We use ICP technology for elemental analyses. Our lab has two platforms of ICP on hand which include optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS). Using ICP-OES enables chemists to measure food for mineral content. The ICP-OES provides the fastest results for nutrition fact panels which is needed to print nutrition labels. Food testing is completed with ICP-MS to identify trace amounts of toxic metals. These metals are referred to as elemental impurities which include arsenic, cadmium, lead and mercury.
We have numerous chromatography systems in use that give our scientists the ability to separate compounds within food. Our automated systems separate food into its components including both natural and added ingredients. Compounds can be separated according to physical properties such as boiling point or their chemical properties such as polarity. A variety of detectors are used to measure and record data following the chromatographic separation. Highly specific detectors enable us to "see" very small amounts of chemicals to measure them in a sample of food. In our Marshfield lab we utilize liquid chromatography systems having operating pressures that exceed 15,000psi, there are gas chromatography systems, and ion chromatography.
Liquid Chromatography Analytical Systems at Marshfield Laboratory
A mass spectrometer is a detector technology that is capable of measuring mass-to-charge of a compound. Our skilled chemists calibrate and tune the systems for mass and fragment data using reference materials. Samples are then evaluated obtaining information about elemental composition and structural arrangement. This information is used to identify, confirm, and quantify how much of a chemical is in food. With implementation of Food Safety Modernization Act (FSMA) for the United States and international CODEX guidelines this technology has become very important to food testing. This is how most pesticides, antibiotics, and illegal compounds such as melamine and sudan dyes are identified in food. We have several mass spectrometers in use that are coupled to chromatography systems (LC-MS-MS & GC-MS-MS) and inductively coupled plasma system (ICP-MS). Pictured above is our Shimadzu LCMS-8050.
Chemistry for Food Safety (FSMA)
Toxic MetalsChemistry for Food QualitypHTotal SolidsWater ActivityNutrientsIngredientsChemistry for Proximates
Nutrients: Fatty Acids
Determination of fatty acid profile is required for nutrition labels. A food testing method will measure the amounts of saturated fat and unsaturated fat to produce a Fatty Acid Profile. Fatty Acid Profiles are an example in food testing where a range of results are possible which depend upon sample handling, technique, and interpretation of the data.
To provide Reliable Results for this assay, Marshfield Food Safety uses multiple chemistry techniques and more than 50 compounds are evaluated. Our method includes 16 saturated fats, 13 monounsaturated fats, 10 polyunsaturated fats and trans fat (which is 9 individual fatty acids plus the sum of the C18:1T isomers). We can also identify 4 omega-3's, 6 omega-6's, and 9 omega-9's with this assay, to specify essential versus non-essential fatty acids.
There are several steps along the way which begin with isolation of fat from the food sample. Next, fatty acids are chemically transformed into methyl esters using a process called methylation. The resulting Fatty Acid Methyl Esters (FAME) are then separated using Gas Chromatography and evaluated with Flame Ionization Detector (GC-FID). Each compound provides a chromatographic peak at a specific retention time. There are a large number of compounds that can be potentially detected, depending upon complexity of the food sample. See the image provided below. The chemist must identify and quantify each peak to determine the fatty acid profile.
Chromatogram of Fatty Acid Methyl Esters (FAME) by GC-FID
Services include but are not limited to:
Quality System Audits
Check Sample Programs
Process Control Chemistries
Other Process Control Parameter Measurements