A transportable fluorescence imagining system for detecting fecal contaminants

被引:21
作者
Lefcourt, AM [1 ]
Kim, MS [1 ]
Chen, YR [1 ]
机构
[1] USDA, Agr Res Serv, Instrumentat & Sensing Lab, Beltsville, MD 20705 USA
关键词
fluorescence; multispectral imaging; food safety; fecal contamination;
D O I
10.1016/j.compag.2005.01.002
中图分类号
S [农业科学];
学科分类号
09 ;
摘要
Feces are the primary source of many pathogenic organisms that can potentially contaminate agricultural commodities. Feces generally contain chlorophyll a and related compounds due to ingestion of plant materials. Fluorescent responses of these compounds to appropriate excitation can mark the presence of feces on animal carcasses, or on fruits or vegetables. We describe a transportable imaging system for detecting fecal contamination. The primary components of the system are a UV light source, an intensified camera with a six-position filter wheel, and software for controlling the system and automatically analyzing images. To test the system, diluted dairy feces were applied to surfaces of red delicious apples using stencils or a pipette. Comparisons of test results using a definitive set of four red-band filters demonstrated that the contrast between fluorescence responses of treated and untreated apple surfaces decreased with increasing wavelength, and was 25% greater at 668 compared to the best results obtained at 678, 685, or 700 nm. Using images acquired at 668 nm, automated algorithms based on either threshold or edge detection were 100% successful in detecting stenciled apples and 1:10 dilution spots applied with pipette, which contained approximately 300ng of dry matter. In a separate test, sets of feces-treated apples were washed at hourly intervals and then imaged. The contamination sites could not be detected when the contact time was less than 4 h, while 5 h of contact was sufficient to establish consistent fluorescence responses in images. Use of a modified system as a teaching tool demonstrated the robustness of the system and promoted public awareness that fecal contamination invisible to the naked eye can easily be detected with appropriate instrumentation. There are many potential uses for this system, including studying the efficacy of apple washing systems. Published by Elsevier B.V.
引用
收藏
页码:63 / 74
页数:12
相关论文
共 12 条
  • [1] [Anonymous], 2001, FED REGISTER, V66, P6137
  • [2] Emerging foodborne pathogens: Escherichia coli O157:H7 as a model of entry of a new pathogen into the food supply of the developed world
    Armstrong, GL
    Hollingsworth, J
    Morris, JG
    [J]. EPIDEMIOLOGIC REVIEWS, 1996, 18 (01) : 29 - 51
  • [3] Blackburn C. d. W., 2002, FOODBORNE PATHOGENS
  • [4] *FSIS, 2004, 64202 FSIS
  • [5] Hui Y.H., 2001, FOODBORNE DIS HDB
  • [6] Optimal fluorescence excitation and emission bands for detection of fecal contamination
    Kim, MS
    Lefcourt, AM
    Chen, YR
    [J]. JOURNAL OF FOOD PROTECTION, 2003, 66 (07) : 1198 - 1207
  • [7] Kim MS, 2002, T ASAE, V45, P2027
  • [8] LEFCOURT AM, 2003, APPL OPTICS, V42, P1
  • [9] Food-related illness and death in the United States
    Mead, PS
    Slutsker, L
    Dietz, V
    McCaig, LF
    Bresee, JS
    Shapiro, C
    Griffin, PM
    Tauxe, RV
    [J]. EMERGING INFECTIOUS DISEASES, 1999, 5 (05) : 607 - 625
  • [10] THRESHOLD SELECTION METHOD FROM GRAY-LEVEL HISTOGRAMS
    OTSU, N
    [J]. IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS, 1979, 9 (01): : 62 - 66