Monitoring of fruit freshness using phase information in polarization reflectance spectroscopy.

The control of food quality and freshness is of growing interest for both consumers and the food industry. The optical absorption and scattering properties in fruits, for example, changes with the physiological and biochemical alterations in the tissues during ripening and storage. The absorption and scattering properties are nondestructively monitored using near-infrared (NIR) spectroscopy. NIR has proved to be one of the most efficient and advanced tools for continuous monitoring and controlling of process and product quality in the food processing industry. However, NIR spectroscopy is costly and needs reliable calibration. The basic spectral feature of fruit reflectance in the visible region is considered in this work for the development of algorithms to nondestructively monitor the ripening and decay of apples using phase information of the reflected light. The objective is to develop simple and low-cost instruments that could revolutionize the on/inline quality monitoring of foods.