Photon Migration Spectroscopy Sensor (PMSS)

The Phase I effort consists of designing a portable multi-wavelength high-frequency instrument for rapid non-invasive monitoring of the optical properties of agricultural commodities. The basic design for the instrument will be a recently developed high bandwidth, single-wavelength, diode-based Frequency-Domain Photon Migration (FDPM) device. In Phase I we will modify this instrument by conducting near-infared absorption and scattering measurements in representative agricultural commodities such as meat, poultry, fish, fruit, and dairy products. These studies will serve as proof-of-principle and will provide essential PMSS design of information on optimal modulation frequencies and optical wavelengths (3 to 5 laser diodes) for quantitatively measuring absorption and scattering in these commodities and correlating these parameters to features such as freshness, fat content, degree of hydration, contamination, and damage. These results will be incorporated into a dedicated, portable and low cost PMSS device in Phase II which is suitable for large-scale, non-invasive monitoring of various agricultural products.