Department of Microstructure and Mechanics of Biomaterials


When laser light illuminates an object due to interference of backscattered light a speckle pattern is formed on an observation plane. The speckle pattern is a composition of dark and light spots which is static for nonliving matter. When the laser light illuminates a biological sample the speckle pattern is no longer stable due to the physical and chemical processes occurring within the sample. This phenomenon is called dynamic laser speckle and for biological samples it is known as biospeckle. The movement of speckles is analysed to characterize biospeckle activity. Biological tissue is transparent to laser light, particularly in the range of red light. Therefore, biospeckle activity carries some information about the sample from a depth related to the penetration of the tissue by laser light.Therefore, the biospeckle method may be considered as a non-destructive method for monitoring fruit and vegetable quality. The biospeckle method may be used to monitor shelf life decay of fruits, prediction of the optimum harvest time or for the early detection of pathogen infection. We have developed a stand-alone device for recording and analysing biospeckle activity in fruits.