Texture Profile Analysis of Three Different Varieties of Marinated Tofu

Recent studies have shown a relationship between mechanical testing of food, called Texture Profile Analysis (TPA), and the texture of food. TPA measures such parameters as chewiness, gumminess, cohesiveness and firmness. Not only do these tests quantify the texture of the food, but it also evaluates the consistency of the manufacturing processes. The purpose of this test was to perform TPA on three different varieties of marinated tofu. The marinated tofu samples consisted of small, precut, trapezoidal-shaped specimens. For consistency of results, specimens of approximately the same thickness and width were selected and the ends of each were removed to aquire cubes with the dimensions of 12 mm x 12 mm.

The tests were performed on a 3345 system, equipped with a 50 N load cell and software with the TPA calculations module. A 6-in diameter compression platen was positioned at the base of the system and a 2-in diameter compression platen was positioned at the crosshead. The specimen was placed at the center of the lower platen and the top platen was lowered to a position just above the surface of the specimen. The software was programmed to move the crosshead at a speed 50 mm/min until a preload of 0.01 N was achieved. At that point the exact height of the specimen was measured, the testing speed increased to 300 mm/min and data collection began. The test consisted of two successive compression ramps to a value of 70% of the unloaded specimen height.

We were successfully able to perform texture analysis on three different marinated samples. The graphs show a significant difference in compressibility between Sample F and the other two samples. Test observations revealed that Sample F was far more compressible than the other two samples, such that the specimens broke apart during the test and fragments adhered to the upper platen, resulting in slight tensile force reading.