|SMELSER, AMANDA - Former ARS Employee|
Submitted to: International Journal of Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/16/2012
Publication Date: 10/22/2012
Citation: Gurtler, J., Smelser, A., Niemira, B.A., Jin, Z.T., Yan, X., Geveke, D.J. 2012. Inactivation of Salmonella enterica on tomato stem scars by sanitizing solutions and vacuum perfusion. International Journal of Food Microbiology. 159:84-92.
Interpretive Summary: A study was conducted to find sanitizing solutions for destroying Salmonella from the stem scar of tomatoes with or without vacuum treatment applied. Tomato stem scars were inoculated with Salmonella, and treated with sanitizing solutions. Salmonella reductions on tomatoes for various sanitizers were as follows (listed in parenthesis): 90 parts per million (ppm) peracetic acid (95 percent), 200 ppm chlorine (97 percent), 190 ppm chlorine + vacuum treatment (99.4 percent), 0.2 normal sodium hydroxide (99.98), 2 percent total of lactic + acetic acids (99.996), 3 percent total of phosphoric + lactic acids (99.997), 3 percent total of fumaric + phosphoric acids (99.998). The following treatments all achieved more than 99.999 percent inactivation: 40 percent ethanol, 5.1 percent total of lactic + acetic + levulinic acids, 49 percent ethanol, 6 percent total of lactic + acetic, and a 0.2 molar sulfuric acid solution. Results from this study provide producers with sanitizing options for destroying 99.999% of Salmonella from the stem scar of tomatoes.
Technical Abstract: A study was conducted to find water-soluble sanitizing compounds effective at inactivating at least 5 log CFU/ml of Salmonella enterica from the stem scar of red round tomatoes during 2 min, room temperature immersion treatments. Vacuum perfusion was applied to tomatoes during some treatments to promote infiltration of sanitizer into the tomato stem scar tissue. Red round tomato stem scars were inoculated to 6.9 log CFU/stem scar with a four-serovar composite of Salmonella, air dried, and tomatoes were immersed in circulating sanitizing solutions for 2 min. Stem scars were excised, macerated in DE neutralizing broth and the homogenate was spiral plated. Log CFU/stem scar reductions for various sanitizers were as follows and are listed in parenthesis: 90 ppm peracetic acid (1.31), 200 ppm chlorine (1.53), 190 ppm chlorine + 15 inches of Hg vacuum perfusion (2.23), 0.2N NaOH (3.78), 2 percent total of lactic + acetic acids (4.35), 3 percent total of phosphoric + lactic acids (4.51), 3 percent total of fumaric + phosphoric acids (4.76), and 40 percent EtOH (4.81). Solutions that achieved at least 4.95 log reductions were 5.1 percent total of lactic + acetic + levulinic acids, 49 percent EtOH, 6 percent total of lactic + acetic, and 0.2M sulfuric acid. Results from this study provide producers with some sanitization options effective at inactivating at least 5 log CFU of Salmonella from the stem scar of red round tomatoes. These results may also help processors and scientists design future decontamination studies with tomatoes and other food commodities by incorporating combinations of chemical treatments that we have reported here.