Quantitative biospeckle spectral and angular analysis of tomatoes at different ripening stages

Quantitative biospeckle measurements in tomatoes at different ripening stages are reported. The biological activity was calculated with a correlation method using few seconds videos recorded with a low-cost, lensless webcam. 543 and 633 nm lasers were used as light sources similar or complementary to the tomato color. The webcam captures videos at different angles, close or away from the quasi-specular reflection. A new metric (ratio of the biospeckle activity at two wavelengths) was proposed, allowing for differentiating biological samples at different stages.