You analyze food to identify ingredients and additives as well as undesirable substances such as mycotoxins, heavy metals or prohibited substances. Foreign material has to be identified with food analysis methods for safety reasons, as well as to maintain good customer relations. You use microscopy to identify glass fragments, metals, plastics and stones as well as fragments from the food itself. In your laboratory you proceed fertilizer and pesticide controls. You investigate causes of food deterioration and develop preservation methods. Also, the microstructure of food is of particular interest for you as it significantly affects properties, behavior, flavor and texture of food. You need to understand the processes leading to various structures such as foams, emulsions, dispersions, extrudes and fibers.
Examine foreign material with stereo microscopes with low magnifications. You’ll get a preliminary identification of the unknown material and can select the proper method for further analysis of the particle. Receive information about how the particle was generated, and whether it was incorporated into the product during manufacturing or inserted by the customer.
To carry out more profound examinations you use light microscopes with brightfield, polarization and fluorescence contrast. Some food components are birefringent, including starch, fats, plant cell walls, muscle fibers as well as many flavor ingredients. Polarization contrast is invaluable to examine such crystalline materials. In conjunction with Linkam heating stages you observe the effects of tempering (e.g. ageing) on those structures. To detect microorganisms such as bacteria fluorescence microscopy of stained samples is valuable for you. Gram staining is typically used to study and view bacteria such as Staphylococcus aureus, E. coli, Salmonella, Campylobacter and Shigella. Blue staining of starch with iodine is a valuable method as well as Fast Green FCF or Acid Fuchsin especially for the localization of proteins. Because most food materials contain large amounts of water and/or fat, Environmental Scanning Electron Microscopes (Environmental SEM) that enable control of both variable pressure and moisture within the sample chamber offer great advantages for the study of food systems without the need for either freezing or drying.
ZEISS Stemi 508
Stemi 508 is your apochromatic stereo microscope with 8:1 zoom for excellent image contrast and color accuracy. You observe and document your samples exactly as they are: rich in detail, sharp in focus and free from distortion or color fringes. The large working distance of up to 287 mm offers ample space for all sorts of samples. Using boom stands you can even examine larger samples. Just put cereals, meat, canned fruit and vegetable products, poultry and other food samples under the microscope – you don’t need special preparation. LED illumination is already integrated in the stand, including oblique light, reflected light, and transmitted light. To prepare samples for further investigations, the large working distance offers enough room for sample isolation and manipulation.
ZEISS Axio Imager
With Axio Imager, equipped with polarization contrast and Linkam heating stages you examine all kinds of thermal transitions such as phase transition of birefringent crystal structures, their melting characteristics and color changes. You can heat or cool your samples, while observing under the microscope. Define heating or cooling experiments. Document the temperature pattern in a time lapse series. The result you obtain is a log of the temperature and vacuum data in each time lapse image.
EVO is your environmental Scanning Electron Microscope which allows for detailed surface imaging at a higher magnification than a compound microscope. You observe materials interacting in real time under changing environmental conditions. Take control of the chamber environment and carry out detailed analyses of food samples in their natural hydrated state at different temperatures, pressures and humidities. In combination with Coolstage you easily move between vapor, liquid or ice. You can perform both freezing and heating processes in the SEM vacuum with the dovetail mounted stage that can be controlled thermally within the range of -30 to 50 ºC. An energy dispersive x-ray (EDX) detector delivers detailed elemental analysis of observed foreign material in food such as glass, metal, processing residues.