Testing systems for foodstuffs and packaging - Zwick - #9

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9 Kramer Shear Cell The Kramer shear cell simulates a single bite on foodstuffs and provides information about bite characteristic, crispness and firmness. It is used for meat and fish products, small sized fruit and vegetables as well as for cereals and snacks like potato chips. The 5 or 10 shear blades drive at a constant speed through the specimen material, compressing, shearing and extruding it through the slotted base. The test is made on a defined sample quantity. The multiple blades provide a measurement on several positions at the same time thus local texture deviations are compensated for with this method. 1.5 Zwick Roell tools and fixtures Warner-Bratzler Shear Device In the Warner Bratzler test a blade cuts through a specimen. The shear behavior gives information about the toughness and tenderness of meat and fish products, the crunchiness of sausages as well as the bite characteristic of cakes and pastries. The straight blade is mainly used for rectangular specimens and the notched blade for round specimens like sausages. Because of the good reproducibility of the results, this test is widely used. OTMS cell The OTMS cell (Ottawa Texture Measuring System) determines the firmness of products by compression and extrusion. This shows characteristics like ripeness, tenderness, crispness or extrusion work on a defined sample quantity. This method is suited for products which are easy to extrude such as canned vegetables, cream cheese and pastries. But also for extrudates and cereals it can be used. Various extrusion plates and reduction inserts for the reduction of the volume enable an adaption for different specimen materials. The measurement of pure compression forces is possible with the use of the sealing plate.