Fingerprinting biological materials

Abstract

A study for non-destructive measurement and analysis of agricultural products was undertaken. Some enhancements were made to a spectrophotometer, DK-2A to meet the requirements of low uniform error band when using the factor analysis method. The instrument was modified by adding an integrating sphere, optical transducer, and electronic interface linked to a computer. The instrument was calibrated using targets traceable to NITS standards of BaSO₄ with mixtures of Carbon Black. This gave a range of known reflectance and provided consistent and reproducible data every 5 nm wavelengths between 350 nm and 800 nm. The spectral wavelength bands of the different biological materials were studied with target factor analysis. Target factors were applied in biological materials to characterize the important spectral properties. Pigment of foods, chlorophyll, carotenoid and myoglobin were separated from the spectral response of oranges, apples and meat. Their respective spectral signatures were determined.