Line-scan spatially offset Raman spectroscopy for inspecting subsurface food safety and quality

Abstract

ABSTRACT This paper presented a method for subsurface food inspection using a newly developed line-scan spatially offset Raman spectroscopy (SORS) technique. A 785 nm laser was used as a Raman excitation source. The line-shape SORS data was collected in a wavenumber range of 0–2815 cm i 1 using a detection module consisting of an imaging spectrograph and a CCD camera. A layered sample, which was created by placing a plastic sheet cut from the or iginal container on top of cane sugar, was used to test the capability for subsurface food inspec tion. A whole set of SORS data was acquired in an offset range of 0–36 mm (two sides of the laser) with a sp atial interval of 0.07 mm. Raman spectrum from the cane sugar under the plastic sheet was resolved using self-modeling mixture analysis algorithms, demonstrating the potential of the technique for authenticating foods and ingredients through packaging. The line-scan SORS measurement technique provides a new method for subsurface in spection of food safety and quality. Keywords: Raman spectroscopy, Lasers, Subsu rface detection, Food quality, Food safety, Mixture analysis