ARS | Publication request: Use of a portable hyperspectral imaging system for monitoring the efficacy of sanitation procedures in produce processing plants

Submitted to: Journal of Food Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 11, 2013
Publication Date: February 26, 2013
Citation: Lefcourt, A.M., Wiederoder, M., Kim, M.S., Lo, Y., Liu, N. 2013. Use of a portable hyperspectral imaging system for monitoring the efficacy of sanitation procedures in produce processing plants. Journal of Food Engineering. http://dx.doi.org/10.1016/j.jfoodeng.2013.02.019.

Interpretive Summary: Cleaning and sanitation of production surfaces and equipment plays a critical role in lowering the risk of food borne illness associated with consumption of fresh-cut produce. Currently, the primary means of judging the effectiveness of cleaning efforts is visual inspection. Recently, a hand-held imaging system was developed that features the ability to measure fluorescent responses at selected wavelengths. Fluorescent responses at a particular wavelength previously have been demonstrated to be a sensitive method for detecting organic materials. In this study, multiple trips were made to two commercial produce processing facilities to test the value of using fluorescence detection to monitor the effectiveness of cleaning efforts. By automatically cycling through three wavelengths (475, 520, and 675 nm), the camera operator could "see" contaminants remaining after cleaning that were not visible (or were barely visible) to the naked eye. Selection of wavelengths for detection was influenced by ambient lighting; the three wavelengths used correspond to troughs in the ambient lighting spectra at both test facilities; thus, increasing the ability to see the fluorescent responses. These results indicate that development of a consumer friendly fluorescence imaging system that incorporates the potential for imaging at multiple wavelengths is warranted, and that use of such a system is likely to reduce food safety risks. The device would have application anywhere food is processed. The results reported are of interest to scientists, regulators, and commercial entities concerned about food safety.

Technical Abstract: Cleaning and sanitation of production surfaces and equipment plays a critical role in lowering the risk of food borne illness associated with consumption of fresh-cut produce. Visual observation and sampling methods including ATP tests and cell culturing are commonly used to monitor the effectiveness of the cleaning procedures. This study tested the ability of a hand-held VIS hyperspectral imaging system to augment current monitoring methods. Multiple visits were made to two commercial fresh-cut processing facilities. Fluorescence-based detection and automated cycling among three wavelengths, 475, 520, and 675 nm, proved best for detecting a range of anomalies. Numerous deficiencies in existing cleaning protocols were identified. Plant personnel were able to devise changes in the protocols that eliminated most of the detected problems without increasing the net expenditure for cleaning efforts. In addition, imaging identified sites where ATP test results were higher when compared to results for adjacent areas.