naa a22 4500 510727468 CHVBK 20180411082940.0 cr unu---uuuuu 180411e20131101xx s 000 0 eng 10.1007/s11947-012-0989-0 doi (NATIONALLICENCE)springer-10.1007/s11947-012-0989-0 Inactivation of Escherichia coli Population on Fruit Surfaces Using Ultraviolet-C Light: Influence of Fruit Surface Characteristics [Elektronische Daten] [Roopesh Syamaladevi, Xiaonan Lu, Shyam Sablani, Sunil Insan, Achyut Adhikari, Karen Killinger, Barbara Rasco, Amit Dhingra, Amit Bandyopadhyay, Uday Annapure] Ultraviolet-C (UV-C 254nm) light is a possible alternative for chemical disinfection of fresh fruits. However, studies on the influence of surface characteristics on the kinetics of UV-C inactivation of microorganisms on fruits are limited. In this study, UV-C inactivation of generic Escherichia coli (ATCC 23716), a nonpathogenic surrogate strain for E. coli O157:H7, was inoculated onto the skin surface intact pear, pear with surface wounds, and the skin surface of intact peach. Disc shaped (0.057m diameter × 0.01m height) fruit surface were exposed at room temperature to UV-C light ranging from 0 to 7.56 ± 0.52kJ/m2 and microbial inactivation kinetics was determined. Maximum reductions of 3.70 ± 0.125 log CFU/g were achieved for E. coli on intact pear surfaces (P < 0.05), with lesser reduction on wounded pear (3.10 ± 0.329 log CFU/g) and peach surfaces (2.91 ± 0.284 log CFU/g) after 4min UV-C exposure at 7.56kJ/m2 UV. The Weibull scale factor (α) values of UV-C inactivation for E. coli on an intact pear surface was 0.001 ± 0.0007min (0.235 ± 0.001kJ/m2), wounded pear surface, 0.003 ± 0.001min (0.240 ± 0.002kJ/m2) and peach surface, 0.004 ± 0.0004 (0.241 ± 0.0008kJ/m2). The time required for a 90% reduction in E. coli cell numbers or the reliable life time (t R) calculated with the Weibull model for intact pear surfaces (0.019 ± 0.009min, 0.268 ± 0.017kJ/m2) was smaller than for wounded pear (0.062 ± 0.013min, 0.348 ± 0.024kJ/m2) and peach surfaces (0.074 ± 0.012, 0.371 ± 0.012kJ/m2), suggesting that the wounds on pear surfaces and trichomes (100-1000μm) on peach surfaces helped to shield and protect microorganisms from UV-C radiation. There was likely a more uniform distribution of bacterial cells onto pear surfaces due to its smaller surface roughness, spreading coefficient, and hydrophobic nature compared to peach. Fourier transform infrared spectroscopy indicate that bacterial membrane damage (phospholipids, protein secondary structures, and polysaccharides) and changes to DNA/RNA in E. coli resulted from UV-C treatment. UV-C can reduce E. coli populations on fresh fruit surfaces, but the efficacy of UV treatment is dependent upon the morphological and surface properties of the fruit and surface integrity. Springer Science+Business Media New York, 2012 Atomic force microscopy nationallicence FT-IR spectroscopy nationallicence Scanning electron microscopy nationallicence Surface disinfection nationallicence Surface morphology nationallicence Syamaladevi Roopesh Biological Systems Engineering Department, Washington State University, P.O Box 646120, 99164-6120, Pullman, WA, USA aut Lu Xiaonan School of Food Science, Washington State University, P.O Box 6463760, 99164-6376, Pullman, WA, USA aut Sablani Shyam Biological Systems Engineering Department, Washington State University, P.O Box 646120, 99164-6120, Pullman, WA, USA aut Insan Sunil Biological Systems Engineering Department, Washington State University, P.O Box 646120, 99164-6120, Pullman, WA, USA aut Adhikari Achyut School of Food Science, Washington State University, P.O Box 6463760, 99164-6376, Pullman, WA, USA aut Killinger Karen School of Food Science, Washington State University, P.O Box 6463760, 99164-6376, Pullman, WA, USA aut Rasco Barbara School of Food Science, Washington State University, P.O Box 6463760, 99164-6376, Pullman, WA, USA aut Dhingra Amit Department of Horticulture and Landscape Architecture, Washington State University, PO Box 646414, 99164-6414, Pullman, WA, USA aut Bandyopadhyay Amit School of Mechanical and Materials Engineering, Washington State University, PO BOX 642920, 99164-2920, Pullman, WA, USA aut Annapure Uday Department of Food Engineering and Technology, Institute of Chemical Technology, Nathalal Parekh Marg, 400019, Matunga, Mumbai, India aut Food and Bioprocess Technology Springer US; http://www.springer-ny.com 6/11(2013-11-01), 2959-2973 1935-5130 6:11<2959 2013 6 11947 https://doi.org/10.1007/s11947-012-0989-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11947-012-0989-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Syamaladevi Roopesh Biological Systems Engineering Department, Washington State University, P.O Box 646120, 99164-6120, Pullman, WA, USA aut NATIONALLICENCE 700 1- Lu Xiaonan School of Food Science, Washington State University, P.O Box 6463760, 99164-6376, Pullman, WA, USA aut NATIONALLICENCE 700 1- Sablani Shyam Biological Systems Engineering Department, Washington State University, P.O Box 646120, 99164-6120, Pullman, WA, USA aut NATIONALLICENCE 700 1- Insan Sunil Biological Systems Engineering Department, Washington State University, P.O Box 646120, 99164-6120, Pullman, WA, USA aut NATIONALLICENCE 700 1- Adhikari Achyut School of Food Science, Washington State University, P.O Box 6463760, 99164-6376, Pullman, WA, USA aut NATIONALLICENCE 700 1- Killinger Karen School of Food Science, Washington State University, P.O Box 6463760, 99164-6376, Pullman, WA, USA aut NATIONALLICENCE 700 1- Rasco Barbara School of Food Science, Washington State University, P.O Box 6463760, 99164-6376, Pullman, WA, USA aut NATIONALLICENCE 700 1- Dhingra Amit Department of Horticulture and Landscape Architecture, Washington State University, PO Box 646414, 99164-6414, Pullman, WA, USA aut NATIONALLICENCE 700 1- Bandyopadhyay Amit School of Mechanical and Materials Engineering, Washington State University, PO BOX 642920, 99164-2920, Pullman, WA, USA aut NATIONALLICENCE 700 1- Annapure Uday Department of Food Engineering and Technology, Institute of Chemical Technology, Nathalal Parekh Marg, 400019, Matunga, Mumbai, India aut NATIONALLICENCE 773 0- Food and Bioprocess Technology Springer US; http://www.springer-ny.com 6/11(2013-11-01), 2959-2973 1935-5130 6:11<2959 2013 6 11947 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer