| 摘要 |
The invention relates to a device for determining food viscosity as a primary food texture parameter, as well as for determining other important rheological quantities in liquid or semi-solid food, the device determining the viscosity as a product of the shearing strain and the ratio between the film thickness and the flowing rate of the food film during the strain it undergoes at various temperatures. According to the invention, the device consists of a parallelepipedic metal plate (2) provided at its bottom right part with a thermostated heating-cooling system (3) comprising, in its turn, a Peltier element (4) sheathed laterally and at the bottom with a thermal insulation (9) and, at the top, being in contact with a copper plate (10) for heat accumulation and for increasing the rate of transfer towards the parallelepipedic metal plate (2) on which the food (11) to be assessed is spread in the shape of a film or thin layer, the shearing strain test of the said food being performed using a mobile parallelepipedic metal plate (12) which is horizontally pulled by means of a calibrated weight (13), a wire framework (14) and a nylon thread (15) wound by two coils onto the wheel (16) mounted, in its turn, onto the shaft of a high resolution incremental rotation sensor (17), with a number of 10000 pulses per rotation, the transducer being used for determining the travel of the mobile parallelepipedic metal plate (12), the device also comprising a Michelson laser interferometer (18) for measuring the thickness of the food film under analysis and a mirror (19) attached to the mobile parallelepipedic metal plate (12), used for reflecting the laser radiation of the Michelson interferometer (18). |
