Growth, Reduction, and Survival of Bacteria on Tomatoes 1

Transcription

1 FSHN12- Growth, Reduction, and Survival of Bacteria on Tomaes 1 Angela M. Valadez, Keith R. Schneider, and Michelle D. Danyluk 2 Fresh-market maes are a popular commodity in homes and food service around the world. In the United States, fresh-market maes are produced in every state, with commercial-scale production in about 2 states (USDA- ERS, 29). In terms of consumption, the ma is the nation s fourth most popular fresh-market vegetable behind potaes, lettuce, and onions (USAD-ERS, 29). In tal, approximately 5 billion pounds of fresh maes are eaten annually in the United States (CDC, 2). In 21, Florida produced 5% of the tal U.S. value of fresh-market maes behind California, Georgia, Virginia, and Tennessee (FDACS, 212; USDA-ERS, 28). Toma producers are committed taking proactive steps ensure and enhance the safety of the food they produce, in addition providing consistency in product quality and wholesomeness. Still, the inherent risks of contamination by foodborne pathogens present a challenge the produce industry and regulars. Since fresh-market maes are intended be consumed fresh, there is no kill-step in the processing that would eliminate pathogens in the event of contamination (Maitland et al., 211). As such, the concern for ma safety in the United States will continue grow as ma consumption increases. Even with the advancements in food processing and food safety controls employed by ma growers and packers, the risk UF/IFAS Pho / Thomas Wright for foodborne pathogens, including Salmonella enterica, be linked outbreaks of illness associated with ma consumption still exists. Fresh-produce handlers and processors have developed hazard analysis and critical control point (HACCP) plans where the critical control points (CCPs) are set in place 1. This document is FSHN12-, one of a series of the Food Science and Human Nutrition Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published May 212, June 212. Visit the EDIS website at 2. Angela M. Valadez, graduate research assistant, CREC (Citrus Research and Education Center, Lake Alfred, FL); Keith R. Schneider, associate professor, FSHN (Food Science and Human Nutrition Department, UF Main Campus); Michelle D. Danyluk (contact author), assistant professor, CREC; Institute of Food and Agricultural Sciences; University of Florida; Gainesville, FL 211. This review was supported by USDA NIFA Specialty Crops Research Initiative Grant and the Center for Produce Safety. The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized provide research, educational information and other services only individuals and institutions that function with non-discrimination with respect race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A&M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim Dean

2 help reduce contamination and aid in the prevention of cross-contamination (Hedberg et al., 1999). Currently, however, there exists no technology proven eliminate bacterial hazards in any fresh-market fruit or vegetable once contamination occurs (Maitland et al., 211). Many processing methods have been studied, a number of which warrant further examination of their efficacy as the search continues for fail-safe intervention strategies ensure the safety of fresh-market maes. This document, therefore, is intended highlight current ma safety related studies on the growth, reduction, and survival of bacteria on fresh-market maes. Enclosed are evaluated bacterial studies on natural antimicrobials including carvacrol (oregano), eugenol, β-resorcylic acid, trans-cinnamaldehyde (cinnamon), allyisothiocynail (mustard and horseradish), thymol, and thyme oil; detergents including chlorine dioxide (C lo 2), chlorine, carbon dioxide (CO 2), hydrogen peroxide (H 2O 2), sodium hypochlorite, ozone, sodium lauryl sulfate (SDS), tween8, acidified sodium chlorite (ASC), peroxyacetic acid (PAA), and calcinated calcium; and food processing studies including high pressure processing, irradiation, X-ray, and modified atmosphere packaging (MAP). Cross-contamination and shelf-life studies were also evaluated. The table focuses primarily on three categories: 1. By ma variety, including Round, Roma, plum, cherry, grape, vine, unknown red, green mature, mixed green red, and diced 2. By ma composition, including the ma stem, pulp, seeds, cotyledons, hypocotyls, and leaves. By bacteria, including acid-adapted and non-acid adapted Salmonella spp., Shigella spp., E. coli O15:H, Listeria monocygenes, Erwinia carovora, and Staphylococcus aureus The intended audience for this document includes ma processors, researchers, and government officials interested in ma safety: During evaluation of their current processing and sanitation facilities, ma processors can use the table as a reference as they seek alternative or adaptable technologies. Researchers can use this table as a guide innovate future experiments from current literature. Government officials can reference this table as current policies and regulations are evaluated and updated. Limited studies in ma sanitation, primarily focusing on salsa preparation and natural antimicrobial usage, are also featured here for home consumers. Overall, this ma safety review serves as a reference for everyone concerned in the safety of fresh-market maes. 2

3 Table 1 Toma publicatio n Round red S. Typhimurium S. Newport S. Javiana S. Braenderup (CDC) Dip inoculated for s at ~25 C and then dried overnight Unspecified time collection points Compared their labmodel (chicken replica), Pathogen Modeling Program, and ComBase CFU/ml preinoculation 1 1 CFU/ whole maes 1 2 CFU/g of cut ma postinoculation Their lab model (chicken replica) was more favorable compared the other models. ph..5 Researchers developed a mathematical model predict the growth rate of Salmonella (1 2 CFU/g 1 8 CFU/g) on cut maes as a function of incubation temp. Pan and Schaffner, 21 Roma Untreated (no washing or oiling) S. Enteritidis ATCC 1 S. Newport ATCC 92 S. Typhimurium ATCC 128 µl spot inoculated (s) 2 1 ClO 2 + sterile tap water (ppm) (High) (Low) log CFU/ml S. enterica A full minute of contact with ClO 2 at 2 and 1 ppm was required achieve a 5 log reduction of S. enterica on freshly spotinoculated maes. Immersing wet-inoculated maes in water ( ppm ClO 2 ) for 1 min alone reduced S. enterica by ~ 1.2 log CFU/cm 2. On inoculated fruit surfaces, populations decreased > log CFU/cm 2 during desiccation at 2 C for 2 h. Populations of air-dried Salmonella were not significantly reduced by ClO 2 at 2 ppm after 1 min. For each treatment, nine inoculated maes were immersed in 2 liters of ClO 2 or water for 2 s. Relative humidity 5% The study investigated the sanitizing effects of a ClO 2 solution on S. enterica in water, on ma surfaces, and between ma loads. Pao et al., 2 Roma Untreated (unwashed or oiled) S. Enteritidis ATCC 1 S. Newport ATCC 92 S. Typhimurium ATCC 128 ml of inoculum was distributed evenly over two synthetic polyethylene roller brushes rotating (s) 1 2 ClO 2 flow rate 5. ml/s NA Calculated brush contami- nation of.9 log CFU/cm Washing with ClO 2 at 5 ppm for 1 s reduced the transfer of Salmonella from revolving brushes fruit surfaces by.5 5. log cycles. The presence of ClO 2 lowered the Salmonella transfer runoff by 5.2. log cycles in comparison using water alone. The study tested the ability of ClO 2 at 5 ppm during spray washing of maes prevent Salmonella transfer from inoculated revolving brushes fruit and wash runoff. Crosscontamination study. Pao et al., 29

4 Toma Roma Untreated (unwashed or oiled) S. Enteritidis ATCC 1 S. Newport ATCC 92 S. Typhimurium ATCC 128 Spot inoculated Up sec ClO 2 or water spray washing for up s at either low or high flow rate (5. or 9. ml/s per fruit, respectively). For wet-inoculum trials, six fruits marked with circles were brushed on inoculated revolving brushes without spraying obtain cross-contamination for s simulate newly introduced contaminants. NA 5. log CFU/cm 2 on fruit surfaces Washing with ClO 2 at a low flow rate for 1 s generated a. 5.2 log CFU/cm 2 reduction of air-dried Salmonella on fruit surfaces. The study tested the ability of ClO 2 at 5 ppm during spray washing of maes prevent Salmonella transfer from fruit surface uninoculated revolving brushes. Pao et al., 29 Roma esculentum) S. Javiana S. Baildon (Purdue University Bacteria Collection) 1 µl spot inoculated Air dry, 1 h (s) ClO 2 gas (mg/liter) x 1 8 CFU/ml Range of log cfu/cm 2. The greatest reduction at 1 mg/l of ClO 2 and 18 s gave a post population.8 log cfu/cm 2. Relative humidity 9 95% ClO 2 parameters were then taken from this study that gave the optimal,, and 5 log reduction select for optimal treatment conditions. The data 1 mg/l for 18 s gave a >5 log reduction. Trinetta et al., 21 Ripe Roma esculentum cv Roma) S. Anatum F1 S. Stanley H558 S. Enteritidis PT Submerged for 1 min (h) (kgy ) log CFU/ml Reductions ranged from..2 log CFU/g (1.5 kgy). The irradiation sensitivity of Salmonella did not differ significantly with increasing refrigerated srage time. A 5-log reduction in dose would be approximately kgy. Cesium-1 at a dose rate of.89 kgy/h The study evaluated the influence of refrigerated srage time on the efficacy of irradiation for removing Salmonella from sliced Roma maes. Niemira 211

5 Toma Roma esculentum) A -serotype mixture of: S. Javiana S. Typhimurium (ATCC or personal collection) Spot inoculated NA X-ray (# kgy/1 min) Three or two strains of each bacterium were mixed with an equal volume give approximately 1 9 CFU/ml. ~. log CFU/ma reduction S. enterica was achieved by treatment with.5 kgy X-ray, respectively. More than a 5 log CFU/ma reduction was achieved at 1. or 1.5 kgy X-ray for all tested pathogens. Relative humidity 55 % Inactivation of inoculated Salmonella enterica on whole Roma ma surfaces. Mahmoud, 21 Roma esculentum) A 2-strain mixture of S. flexneri ATCC 9199 and ATCC 1222 Spot inoculated NA X-ray (#kgy/1 min) Three or two strains of each bacterium were mixed with an equal volume give approximately 1 9 CFU/ml. ~. log CFU/ma reduction of S. flexneri was achieved by treatment with.5 kgy X-ray, respectively. More than a 5 log CFU/ma reduction was achieved at 1. or 1.5 kgy X-ray for all tested pathogens. Relative humidity 55 % Inactivation of inoculated Shigella flexneri on whole Roma ma surfaces. Mahmoud, 21 Plum Wax was washed off with % ethanol followed by DI wash S. Poona S. Newport v. Baildon S. Braenderup S. Saintpaul (University of Georgia L. Beuchat) 1 µl spot inoculated, held dry for 1 h at 2 C 15 s 1 min min DI (control) Chlorine (1 ppm) Carvacrol (.25 and.5 %) Trans-cinnamaldehyde (.5 and.5%) Eugenol (.25 and.5%) b-resorcylic acid (.5 and 1. %) 25 C in water bath shaker 1 8 CFU/ml before inoculation and 1 CFU/ml post inoculation ~2 log CFU/ml for DI ~ log CFU/ml for Cl ~ log CFU/ml for Carvacrol (.25 and.5%) ~ log CFU/ml for Trans-cinnamaldehyde (.5 and.5%) 2.5 log CFU/ml for Eugenol (.25%) > log CFU/ml (.5%) log CFU/ml for b-resorcylic acid (.5 and 1. %) Mattson et al., 21 Cherry (fresh and uncoated) S. Enteritidis PT E1 (Uludag University) 5 µl spot inoculated for 1 h at 22 C 5 µl was injected in the stem scar with a sterile syringe 5 µl was pipetted on the stem scar Day at C: 1 Day at 22 C: 2 Air srage 22 Before inoculation: 8. and. log CFU/ml Post inoculation: (high). log CFU/ma; (low). log CFU/ma Spot inoculated: (High) ~ 5 log CFU/ma reduction at C and 22 C; (low) ~ log CFU/ma reduction Stem-scar syringe/pipetted: ~1 log CFU/ma growth at and 22 C Das et al., 2 5

6 Toma Cherry (fresh and uncoated) Cherry (fresh and uncoated) Cherry (fresh and uncoated) Cherry (fresh and uncoated) S. Enteritidis PT E1 (Uludag University) 5 µl spot inoculated for 1 h at 22 C 5 µl was injected in the stem scar with a sterile syringe 5 µl was pipetted on the stem scar S. Enteritidis PT E1 (Uludag University) 5 µl spot inoculated for 1 h at 22 C 5 µl was injected in the stem scar with a sterile syringe 5 µl was pipetted on the stem scar S. Enteritidis PT E1 (Uludag University) 5 µl spot inoculated for 1 h at 22 C S. Enteritidis PT E1 (Uludag University) 5 µl spot inoculated for 1 h at 22 C Cherry S. Typhimurium (ATCC 128, KCTC 221, KCTC 25) 1 ml spot inoculated Day at C: 1 Day at 22 C: 2 Day at C: 1 Day at 22 C: 2 Modified atmosphere packaging (LDPE film) 22 5% CO 2 22 Before inoculation: 8. and. log CFU/ml Post inoculation: (high). log CFU/ ma;(low). log CFU/ma Before inoculation: 8. and. log CFU/ml Post inoculation: (high). log CFU/ma; (low). log CFU/ma 2 min 1 mg/l ozone NA Before inoculation: 8. and. log CFU/ml Post inoculation: (high). log CFU/ma (low). log CFU/ma 2 min 5 and 2 mg/l ozone NA Before inoculation: 8. log CFU/ma Post inoculation:. log CFU/ma 1 day srage 1 mg/l chlorine dioxide (5 min) 5 kj m -2 UV-C (25 nm) irradiation Chlorine dioxide + UV-C irradiation Spot inoculated: (High) ~5 log CFU/ma reduction at C and 22 C; (low) ~ log CFU/ma reduction Stem-scar syringe/pipetted: ~1 log CFU ma growth at and 22 C Spot inoculated: (High) ~5 log CFU/ma reduction at C and 22 C; (low) ~ log CFU/ma reduction Stem-scar syringe/pipetted: ~1 log CFU/ma growth at and 22 C Detection: High/ h - the cells died completely High/1 h - the complete death time was 15 min Low/1 h and h - the complete death time was 5 min High/5 mg/1 h - there was a ~ log CFU/ma reduction High/5 mg/ h - there was a ~2.5 log CFU/ma reduction High/2 mg/h - death at 15 min High/2 mg/1h - death at 1 min 5.9 log CFU/g Chlorine dioxide + UV-C irradiation achieved the most effective among the three treatments, which eliminated detection. Chlorine dioxide achieved a 2.5 log CFU/g; UV-C irradiation achieved a 2.58 log CFU/g. 2% O 2 Das et al., 8% CO h or h attachment time of the cells on maes after inoculation 1 h or h attachment time of the cells on maes after inoculation Das et al., 2 Das et al., 2 Das et al., 2 Song et al., 211

7 Toma Cherry E. coli O15:H (NCTC 129) 1 ml spot inoculated 1 day srage 1 mg/l chlorine dioxide (5 min) 5 kj m -2 UV-C (25 nm) irradiation Chlorine dioxide + UV-C irradiation.21 log CFU/g Chlorine dioxide + UV-C irradiation achieved the most effective among the three treatments, which eliminated detection. Chlorine dioxide achieved a 2.2 log CFU/g; UV-C irradiation achieved a 2.5 log CFU/g. Song et al., 211 Grape S. Typhimurium S. Kentucky S. Senftenberg S. Enteritidis (University of Delaware Culture Collection) Inocula (25 ml) were deposited on intact surfaces form a drop and allowed air dry at 25 C for about 2 h. 5 min 1 min Chlorine (2 ppm) thymol (.2 and. mg/ml) thyme oil (2. mg/ml) carvacrol (. mg/ml) washing solutions NA 1 8 CFU/ml Thymol was the most effective among the three natural antimicrobial agents, which achieved >.1 log CFU/ml reductions of S. enterica serovars Typhimurium, Kentucky, Senftenberg, and Enteritidis on grape maes after a 5-min washing and >. log CFU/ml reductions after a 1-min washing. A >. log CFU/ml reduction in the S. enterica populations in comparison control was observed with the use of thymol solutions. Evaluated the antibacterial activities of thymol, carvacrol, and thyme oil compared chlorine against Salmonella spp. on grape maes during the washing procedure. Lu and Wu, 21 Grape esculentum Mill.) S. Poona (Cantaloupe) S. Stanley H 125 (Alfalfa sprouts) S. Baildon (Toma) S. Typhimurium DT 1 (Resistant multiple antibiotics) (Toma) (University of Georgia M. Harrison) Spot inoculated 1 µl At C and 1 C 1 At 25 C (h) 1 Allyl isothiocyanate (AIT, from mustard and horseradish) Carvacrol (from oregano) Cinnamaldehyde (from cinnamon) 5, 1, and 15 µl (equivalent 1.5, 8., and 125 µl/liter of air, respectively) of 9% pure carvacrol or 98% pure cinnamaldehyde or 1, 2, and µl (equivalent 8., 1., and. µl/liter of air, respectively) of 98% pure AIT 1 25 Whole grape maes 1 µl 9. log CFU/ ml placed on 1 separate spots AIT exhibited the highest antimicrobial activity followed by cinnamaldehyde. This level of AIT inactivated Salmonella on whole maes the detection limit of <2 log CFU/ ma at and 1 C in 1 d and by 1. log CFU/ma at 25 C in 1 h. Overall, greater inactivation occurred at 1 than at C and on the ma surface than between ma slice study. The study elucidated the effect of these antimicrobial activity on pathogen inactivation on ma skin (using whole maes) and on ma pulp (using sliced maes). Obaidat and Frank, 29

8 Toma Vine-ripened esculentum Mill., cv Rutgers) wax or oil S. Agona (Alfalfa sprouts) S. Baildon (Toma) (Orange juice) (Cantaloupe) (Toma) 5 µl spot inoculated Dip inoculated in 5 liters for 1 min 5 µl spray inoculated for 2 s with thin-layer chromagraphy reagent sprayer at 22 C for 1 or 2 h Agitated at 15 rpm for 5 min Chlorine (2 mg/ml) solution NA Spot and spray inocula each ma were.22 log CFU/ ma. Dip count could not be determined. Spot decreased by.8 and 2.2 log CFU/ml, respectively, within 1 and 2 h of drying. Spray-inoculated maes decreased by 1. and. log CFU/ ml within the same respective drying times 2 and 1 h. Populations of Salmonella declined substantially between 1 and 2 h of drying; reductions were high on spray-inoculated maes compared with spot-inoculated maes. Lang et al., 2 Vine-ripened Shigella exneri (ATCC 122) Shigella sonnei (ATCC 2591) Shigella boydii (ATCC 92) 2 min Sodium lauryl sulfate (SLS).1 % Tween 8 (polysorbate 8).1% 22 log CFU/ml Reductions of 1.5 log CFU/ ml were achieved. The study evaluated the efficacies of these detergents in removing Shigella from the surfaces of vine maes at different treatment temps. Raiden et al., 2 Vine-ripened A five-strain Salmonella cocktail: S. Typhimurium (ATCC 128) S. Agona (Alfalfa sprouts) S. Baildon (Lettuce/ma) (Cantaloupe) (Toma) (University of Georgia L. Beuchat) 2 min.1 % sodium lauryl sulfate (SLS).1% Tween 8 (polysorbate 8) 22 log CFU/ml Reductions of 1.5 log CFU/ ml were achieved. The study evaluated the efficacies of these detergents in removing Salmonella from the surfaces of vine maes at different treatment temps. Raiden et al., 2 8

9 Toma Firm maes at the light-red stage of ripeness, free of external defects Fully ripened (variety not known) Yes G9 (Toma) S. Baildon 1-99 (Toma) (University of Georgia L. Beuchat) Dip inoculated G9 (CDC) 1 ml inoculated on diced Red, ripened S. Braenderup (Toma) (CDC) Whole maes at room temp. (22 C) were spot inoculated (at stem scar) with.1 ml of inoculum. 2 min 2 ppm Cl 2 5% H 2 O log CFU/ ml 2 min. treatment; At 5 C (h) At 2 C (h) At C (h) 22 Sodium hypochlorite (.5%) 12 s High pressure processing (MPa) log CFU/g (Cl 2 ) 1.5 log CFU/g (H 2 O 2 ) ~.5 log CFU/g remained essentially constant in maes sred at 5 C for 21 h. Growth log CFU/g at C and 2 log CFU/g at 2 C 2 Whole skin:. log CFU/g Whole pulp: 5. CFU/g Whole Skin.15 log CFU/g reduction Whole pulp. log CFU/g reduction Efficacy of wash treatments in reducing population of Salmonella on dip-inoculated maes. Fate of in chopped ripe maes. To determine the effect of pressure reduce or eliminate the more pressure-resistant S. enterica ma outbreak serovar from whole red Round maes. Sapers and Jones, 2 Zhuang et al., 1995 Maitland et al., 211 9

10 Toma Red, ripened esculentum) Mature, red, ripe, organic ma esculentum) (Toma) (University of Georgia), resistant rifampicin 1 µl spot inoculated for 9 min at 22 C under 9% RH (Toma) (University of Georgia), resistant rifampicin 1 µl drops on the ma surface near the blossom; sred 22 C for 9 min Red, ripe Salmonella Enteritidis IFO-1, SE-1, SE-, SE- (Chicken feces); SE-2 (Bovine feces) (Japan) 1 µl spot inoculated Lycopersicon esculentum S. Agona (Alfalfa sprouts) S. Baildon (Toma) (Toma) (Orange juice) (Cantaloupe) 1 µl spot inoculated and air dried 2 22 h at 22 C. 1 1 (min) 9 NA 22 5 log CFU/ fruit before attachment; after attachment,.8 log CFU/ fruit NA 22 5 and 8 log CFU/1 µl min Calcinated calcium.5% (wt/vol) 2 ppm chlorine water Sterile distilled water (min) ClO 2 gas (mg/liter) log CFU/ma for Salmonella 22 8 log CFU/ma Growth: After 1 days of srage at C, the population increased., 1., 1.2, and 2.2 log CFU/ ma. A similar trend was observed at 22 C, although populations were lower than at C. Number is proportional srage time. The highest percentage of attachment (.%) after 9 min occurred on maes inoculated with the lowest population (.95 log CFU/ma). Treatment with 2 ppm chlorine and calcinated calcium resulted in 2. and. log CFU/ma. Reduction (log CFU/ma): Relative humidity (%):, 5, 85, 9 1% RH Effect of inoculum population on attachment of Salmonella on maes. Antimicrobials were sprayed on. Relative humidity: -2% Iturriaga et al., 2 Iturriaga et al., 2 Bari et al., 22 Sy et al., 25 1

11 Toma Hydroponic esculentum) S. Javiana (Toma) S. Baildon (Toma) (Toma) 1 µl spot inoculated and air dried 2 h at 22 C (min) 12 ClO 2 Gas (mg/liter) log CFU/ ma before drying and 8 log CFU/cm 2 after drying Reduction (log CFU/cm 2 ): ~2.5. ~. >5 Relative humidity: 85 9% Bhagat et al., 21 Hydroponic esculentum) Listeria monocygenes LCDC (Coleslaw/cabbage) and F2 (Ice cream) 1 µl spot inoculated and air dried 2 h at 22 C (min) 12 ClO 2 Gas (mg/liter) log CFU/ ma before drying and 8 log CFU/cm 2 after drying L. monocygenes ~.5, ~.5, >5 log CFU/cm 2 Relative humidity: 85 9% Bhagat et al., 21 Round, unripe, green Florida Cocktail of: S. Agona S. Poona (University of California Davis L. Harris) Rifampicin resistant Puncture: 1 µl aliquot inoculum Shaved, stem scars, and intact surfaces: 1 µl aliquot inoculum (s) ppm free chlorine, ph At 25 C:.52. log CFU/ml At C: 5..9 log CFU/ml Reductions at 12 s: At 25 C, Stem 1.8 log CFU/ml, Scrape 1.2 log CFU/ml, Puncture. log CFU/ml, Intact. log CFU/ml At C, Stem 1. log CFU/ml, Scrape.5 log CFU/l, Puncture.1 log CFU/ml, Intact.85 log CFU/ml Salmonella recovery was tested on four surface types: intact, punctures, shaves, and stem scars. Felkey et al., 2 Round, unripe, green Florida S. Agona S. Poona Ten-1 µl aliquot, spot inoculated around blossom scar log CFU/ ml Reduction by day 28: At 2 C/% RH,.1 log CFU/ml At 2 C/9% RH,.2 log CFU/ml At C/8% RH, 5 log CFU/ml Relative humidity (%):, 8, 9 Allen et al., 25 11

12 Toma Lightly waxed, mature green Lightly waxed, mature green Mature green esculentum cv Agriset, and Lycopersicon esculentum cv Solimar), sred at RT until ripe (Toma) (Cantaloupe) v. Poona (Cantaloupe) S. Hartford Orange juice S. Enteritidis (Eggs) (CDC) Ampicillin resistant, inoculated 5 µl near the blossom end of the ma (Toma) (Cantaloupe) S. Poona (Cantaloupe) S. Hartford Orange juice S. Enteritidis (Eggs) (CDC) Ampicillin resistant, inoculated 5 µl near the blossom end of the ma G9 (CDC) Rifampicin resistant 25 µl spot inoculated Tomaes were analyzed after srage for Tomaes were analyzed after srage for NA 2.2 log CFU/ ma Reduction of ~ log CFU/ma by day 1 NA CFU/g Growth of 2.5 log CFU/ma at 1 days NA NA Room temp. Four groups of 5 maes each were inoculated on the stem scars with a bacterial population of. 1, 5. 1,. 1 5,or 5. 1 CFU in 25 µl Detection: 1 st set, 95% detectable on 1 1 CFU 2 nd set, 1 5% on CFU rd set, no detection % RH Determine the survival characteristics of Salmonella inoculated on ma surfaces following srage at 2 C. Study attachment and infiltration of Salmonella in maes placed on the surface of water-saturated soil inoculated with the pathogen. Bacterial transfer by using a cutting knife from inoculated uninoculated maes. Bacteria were transferred by using a cutting knife from inoculated uninoculated maes at high CFU. Guo et al., 22 JFP Guo et al., 22 JFP Lin and Wei,

13 Toma Mature green esculentum cv Agriset, and Lycopersicon esculentum cv Solimar), sred at RT until ripe G9 (CDC) Rifampicin resistant 25 µl spot inoculated NA NA Room temp. 25 µl , 2.8 1, or CFU/ml in butterfield phosphate buffer or tryptic soy broth was placed on the stem scars of 1 maes yield a final population of,,, or, CFU. Detection:.8 % detectable by direct plating for, CFU, no detection for CFU,.2 9% detectable after h enrichment for, CFU Determination of the rate of bacterial detection following cutting of inoculated maes: introduction and/or transfer of bacterial contaminants by using a cutting knife could occur at a bacterial population as low as <1 CFU at the stem scar. Lin and Wei, 199 Mature green esculentum cv Agriset, and Lycopersicon esculentum cv Solimar), sred at RT until ripe G9 (CDC) Rifampicin resistant 25 µl spot inoculated NA NA Room temp. Four maes were each inoculated with.25 1,.25 1, or CFU in 25 µl at stem scar. Detection: At the lower inoculum dose of.25 x 1 CFU, colonies were found cluster at the stem scar region on TSA-RIF plates. However, as the inoculum levels were increased, the colonies were found spread from the stem scar region the center and botm of cut maes along the cutting direction of the knife. Bacterial distribution on the cut surface of ma halves. Lin and Wei, 199 Green ( Florida cultivar) S. Agona S. Poona (University of California - Davis L. Harris) Rifampicin resistant, spot inoculated (s) 2 treatment and 5 d study 2 ppm chlorine (ph.5) 5 1 µl of inoculums of CFU/ ml Salmonella cocktail Reduction of 9.19 >99.99 % at 12 sec on day 5 Effectiveness of 2 ppm chlorine (ph.5) treatment on smooth surface, stem scar tissue, and puncture wound of maes. Yuk et al., 25 1

14 Toma Green ( Florida cultivar) S. Agona S. Poona (University of California - Davis L. Harris) Rifampicin resistant Spot inoculated (s) 2 treatment and 5 d study 1,2 ppm acidified sodium chlorite (ASC; ph 2.5) 5-1 µl of inoculums of CFU/ ml Salmonella cocktail Reduction of 98.5 >99.99 % at 12 sec on day 5 Effectiveness of 12 ppm acidified sodium chlorite wash on smooth surface, stem scar tissue, and puncture wound of maes. Yuk et al., 25 Green ( Florida cultivar) S. Agona S. Poona (University of California - Davis L. Harris) Rifampicin resistant Spot inoculated (s) 2 treatment and 5 d study 8 ppm peroxyacetic acid (PAA) 5 1 µl of inoculums of CFU/ ml Salmonella cocktail Reduction of 9.9 >99.99 % at 12 sec on day 5 Effectiveness of 8 ppm peroxyacetic acid treatment on smooth surface, stem scar tissue, and puncture wound of maes. Yuk et al., 25 Green ( Florida cultivar) S. Agona S. Poona (University of California - Davis L. Harris) Rifampicin resistant Spot inoculated 1 h treatment and 5 d study 1 mg chlorine dioxide (ClO 2 ) gas treatment 5 1 µl of inoculums of CFU/ ml Salmonella cocktail Reduction of 99.5 >99.99 % at 12 sec on day 5 Effectiveness of chlorine dioxide (ClO 2 ) gas treatment on smooth surface, stem scar tissue, and puncture wound of maes. Yuk et al., 25 1

15 Toma Green ( Florida cultivar) Mature green (Sunny cultivar) S. Agona S. Poona (University of California - Davis L. Harris) Rifampicin resistant Spot inoculated G9 (CDC) Batches of maes (18 2) were submerged and constantly agitated in the bacterial suspension for 2 min and were then air dried in a laminar flow hood at 22 C for h. NA Srage ppm chlorine (ph.5), a 12 ppm acidified sodium chlorite (ASC; ph 2.5) a chlorine dioxide (ClO 2 ), gas treatment NA µl of inoculums of CFU/ ml Salmonella cocktail ~1.5 log CFU/ cm 2 Reduction of >99.99 % at 12 sec on day 5 Growth: Pathogen did not change significantly on maes sred at 1 C throughout the 18-day srage period. Significant increases in the population of occurred within days and within 1 day when maes were sred at 2 and C, respectively. A log CFU/cm 2 growth at C 2 min in the chlorine bath (2 ppm, 5 C, ph.5) as the initial treatment, followed by a s washing in acidified sodium chlorite (12 ppm, 5 C, ph 2.5), and then maes were treated with chlorine dioxide gas for 1 hour at room temp. (2 C ± 2 C) in a 22-quart vessel Relative humidity 5 % Effectiveness of combination treatment on smooth surface, stem scar tissue, and puncture wound of maes. Fate of on ma surfaces. Yuk et al., 25 Zhuang et al.,

16 Toma Mature green (Sunny cultivar) G9 (CDC) 1 maes were submerged and constantly agitated for 2 min, dried, placed in plastic bags, and sred at 1 or 2 C. Srage at 1 C At 2 C NA 1 2 ~.5 log CFU/g Growth: A significantly higher number of cells were taken up by core tissue when maes at 25 C were dipped in suspension at 1 C compared with the number of cells taken up by maes dipped in suspensions at 25 or C. Tomaes remained essentially constant throughout subsequent srage for 18 days at 1 C. Srage of maes at 2 C resulted in significant increases in the population of in core tissues within, 5, and 18 days of srage of maes that had been dipped in suspension at 1, 25, and C. Uptake of S. Montevideo by core tissue. Effect of temp. differential between maes (25 C) and dip suspension (1, 25, or C) on uptake of by core tissue, and effect of subsequent srage temp. (1 or 2 C) on survival. Zhuang et al., 1995 Mature green (Sunny cultivar) G9 (CDC) Batches (18 22) of maes were submerged in the suspension, constantly agitated for 2 min, air dried for 5 h, and sred at 25 C for 18 h. 2-min treatment Free Cl 2 (ppm) NA ~.95 log CFU/ cm 2 on surface and unknown in core Dipping in a solution contain- ing 2 ppm chlorine for 2 min resulted in approximately 1.5 log reduction in the number of viable on the surfaces of maes. Concentrations of 11 2 ppm significantly reduce the number of viable cells. Efficacy of chlorine for inactivating S. Montevideo. Zhuang et al.,

17 Toma Freshly-harvested Unripened (green), and ripened Separately: S. Javiana 591 (Chicken feces) S. Javiana 2 (Bovine feces) (Toma) S. Newport (Alfalfa sprouts) v. Enteritidis (Egg) S. Hadar (Poultry house) S. Typhimurium (Pork slaughter line) S. Dublin (Raw milk) S. Senftenberg (Alfalfa sprouts) S. Infantis (Clinical isolate) (University of Guelph Culture Collection) 1 NA CFU/ml Growth (internal and exter- nal) was promoted at the high incubation temp. (25 C) and high relative humidity (95%), although this was serovar dependent. The growth and persistence of Salmonella introduced on and in ripened (red) maes was serovar dependent. Salmonella serovars Enteritidis, Typhimurium, and Dublin were less adapted grow in or on intact red maes than were serovars Hadar, Montevideo, or Newport. Vacuum chamber (operating at 1 Pa), 5 or 95% RH Inoculation of ma fruit on surface and internally. Shi et al., 2 Mature, red, ripe ma; green ma; ripened matillo (Physalis ixocarpa) (Toma) (University of Georgia) Rifampicin resistant 1 µl spot inoculated 9 min NA log CFU/fruit Population ranged from. 5. log CFU/fruit). Temp. and RH alone did not affect the number of cells attached the ma or matillo surface. Both the type of product and interaction of temp. and RH showed a significant effect on the attachment of Salmonella Montevideo the surface of maes and matillos. Relative humidity (%): 5, 85, 9 Influence of relative humidity, temp., and stage of ripening on attachment of Salmonella maes and matillos. Iturriaga et al., 2 1

18 Toma Mature green through fully red maes of the Sunny variety G9 (CDC) Rifampicin resistant 25-µl aliquots on the stem scar of each ma s 1 min 2 min Free chlorine (ppm) 1 Room temp. 8.9 log CFU/ ma skin circle in DI.25 log CFU/ ma skin circle in TSB Low.98 log CFU/stem scar in DI High 8.9 log CFU/stem scar in DI After 2 min, 1.9 (DI) 5.95 (TSB) log CFU/ma skin circle and Low 1.2 log CFU/stem scar After 1 min, High 1. log CFU/ stem scar Efficacy of aqueous chlorine solutions against populations of located on the surface, wounded areas, or stem scars of maes. Wei et al., 1995 Mature green through fully red maes of the Sunny variety G9 (CDC).5 ml aliquot added s 1 min 2 min Free chlorine (ppm) Room temp. Tryptic soy broth:.2, 5.99, 9. log CFU/ml Butterfield buffer: 9. log CFU/ml DI: 9. log CFU/ml After 2 min for TSB, 2. (5 ppm),.1 (5 ppm),.18 (1 ppm) log CFU/ml Buffer, 8.9 log CFU/ml (1 ppm) DI, 8. log CFU/ml (1 ppm) Efficacy of aqueous chlorine against populations suspended in distilled water, in growth medium, or on the dried surface of glass beads (a model for cellular attachment or embedding in particulates). Wei et al., 1995 Mature green through fully red maes of the Sunny variety G9 (CDC) 25 µl aliquot added Growth (h) Survival 1 2 NA Growth 25 C Survival 2 C 25 C Growth: 9. log CFU/ml 9.8 CFU/ml Survival: 25 µl of low., medium 5., or high 8. log CFU/ml, which dried up be.1,.1, and.1 log CFU/ml Growth: Low ~1.5 log CFU/wounded area growth Medium ~. log CFU/wounded area High no growth. Ripeness had no apparent effect on bacterial growth. Survival, relative humidity: 8 and 2% Determine the ability of grow and/or survive on ma surfaces, including the unbroken skin, wounded areas, growth cracks, or stem scars. Wei et al.,

19 Toma Roma esculentum) A -strain mixture of E. coli O15:H (C92, EDL9, and 2P) Spot inoculated NA X-ray (#kgy/1 min) Three or two strains of each bacterium were mixed with an equal volume give approximately 1-9 CFU/ml. ~.2 log CFU/ma reduction of E. coli O15:H were achieved by treatment with.5 kgy X-ray. More than a 5 log CFU/ma reduction was achieved at 1. or 1.5 kgy X-ray for all tested pathogens. Relative humidity: 55 % Inactivation of inoculated Escherichia coli O15:H on whole Roma ma surfaces. Mahmoud, 21 Vine-ripened Esculentum Mill. cv Rutgers) E. coli O15:H strains LJH55 (Apple cider), SEA-1B88 (Apple cider), CDC-58 (Cantaloupe), H1 (Lettuce), and F5 (Alfalfa sprouts) 5 µl spot inoculated or dip inoculated in 5 liters for 1 min or 5 µl spray inoculated for 2 sec with thin- layer chromagraphy reagent sprayer at 22 C for 1 or 2 h Agitated at 15 rpm for 5 min Chlorine (2 mg/ml) solution NA Spot and spray inocula each ma were.21, log CFU/ ml. Dip could not be determined. Spot inoculation was reduced by 1. and.1 log CFU/ml after drying times of 1 and 2 h. Spray-inoculated maes were 1. and. log CFU/ml at 1 and 2 h, no recovery from chlorine. Evaluate methods for applying inoculum and examine the effect of inoculum drying time on survival and recovery of foodborne pathogens inoculated on the surface of raw, ripe maes. Lang et al., 2 Firm ma at the lightred stage of ripeness, free of external defects E. coli NRRL B- (ATCC 9), a nonpathogenic surrogate for Salmonella (USDA-ARS-NCAUR - L.K. Nakamura) (min) 2 5 5% H 2 O log CFU/ml Reduction of log CFU/g Effect of treatment time and surfactant addition on efficacy of 5% H 2 O 2 in reduc- ing population of E. coli NRRL B- on dip-inoculated maes held 2 h at 2 C prior treatment. Sapers and Jones, 2 19

20 Toma Firm ma at the lightred stage of ripeness, free of external defects Firm ma at the lightred stage of ripeness, free of external defects E. coli NRRL B- (ATCC 9), a nonpathogenic surrogate for Salmonella (USDA-ARS-NCAUR L.K. Nakamura) E. coli NRRL B- (ATCC 9), a nonpathogenic surrogate for Salmonella (USDA- ARS-NCAUR - L.K. Nakamura) Red, ripe E. coli O15:H CR-, MN-28, MY- 29, DT- (Bovine feces) (Japan) 1 µl spot inoculated Roma esculentum) A -strain mixture of L. monocygenes (Scott A, F59 and LCDC 81-81) Spot inoculated (h) 2 8 1% or 5 % H 2 O 2 (2 min or 15 min) log CFU/g (8 h) Reduction of log CFU/g (8 h) Efficacy of H 2 O 2 in reducing the population of E. coli NRRL B- on dip-inoculated maes, as affected by post-inoculation srage at 2 C. 8 h 2 ppm chlorine.98 log CFU/mL Reduction of 1.1 CFU/g Efficacy of water rinse and 2 ppm Cl 2 treatment in reducing the population of E. coli NRRL B- on dip-inoculated maes, as affected by post-inoculation srage at C. min Calcinated calcium.5% (wt/vol), 2 ppm chlorine water, or sterile distilled water NA X-ray (#kgy/1 min) log CFU/ma for E. coli O15:H; 22 Three or two strains of each bacterium were mixed with an equal volume give approximately 1-9 CFU/ml Treatment with 2 ppm chlorine and calcinated calcium resulted in. and.85 log reductions of E. coli O15:H, respectively. ~2. log CFU/ma reduction of L. monocygenes were achieved by treatment with.5 kgy X-ray, respectively. More than a 5 log CFU/ma reduction was achieved at 1. or 1.5 kgy X-ray for all tested pathogens. Antimicrobials were sprayed on. Relative humidity: 55 % Inactivation of inoculated Listeria monocygenes on whole Roma ma surfaces. Sapers and Jones, 2 Sapers and Jones, 2 Bari et al., 22 Mahmoud, 21 2

21 Toma Vine-ripened esculentum Mill. cv Rutgers) L. monocygenes strains G191 (Coleslaw), F8255 (Peach/plum), F89 (Corn), HO222 (Pota), and F82 (Celery) 5 µl spot inoculated or dip inoculated in 5 liters for 1 min or 5 µl spray inoculated for 2 sec with thin- layer chromagraphy reagent sprayer at 22 C for 1 or 2 h Agitated at 15 rpm for 5 min Sterile deionized water (control) or chlorine (2 mg/ml) solution NA L. monocygenes spot and spray inocula each ma were. log CFU/ml. Dip could not be determined. Spot reduced by 1. and 1.5 log CFU/ml within 1 and 2 h. Reductions on spray-inoculated maes were.52 and 1.5 log CFU/ml for 1 and 2 h. L. monocygenes is known be more resistant than E. coli O15:H and Salmonella stresses. Higher numbers of cells were recovered from dip-inoculated maes compared with spot- or sprayinoculated maes, regardless of drying time or treatment. Lang et al., 2 Red, ripe Listeria monocygenes ATCC 25, ATCC 959, JCM, JCM 2, JCM 1 1 µl spot inoculated min Calcinated calcium.5% (wt/vol) 2 ppm chlorine water sterile distilled water log CFU/ma for L. monocygenes Treatment with 2 ppm chlorine and calcinated calcium reduced L. monocygenes numbers by 2.2 and.59 log CFU per ma, respectively. Antimicrobials were sprayed on Bari et al., 22 Roma Untreated (no washing, oiling, or waxing) E. carovora ATCC 95, ATCC 1559, ATCC 2522 µl spot inoculated (s) 2 1 ClO 2 (ppm) (High) (Low) log CFU/ml E. carovora. A full minute of contact with ClO 2 at 2 and 1 ppm was required achieve a 5 log reduction of E. carovora on freshly spot-inoculated maes. Immersing wet-inoculated maes in water ( ppm ClO 2 ) for 1 min alone reduced E. carovora by about 1.9 log CFU/cm 2. On inoculated fruit surfaces, populations decreased > log CFU/cm 2 during desiccation at 2 C for 2 h. Populations of air-dried Erwinia were not significantly reduced by ClO 2 at 2 ppm after 1 min. For each treatment, nine inoculated maes were immersed in 2 liters of ClO 2 or water for 2 s. Relative humidity: 5% Researchers investigated the sanitizing effects of a ClO 2 solution on E. carovora in water, on ma surfaces, and between ma loads. Pao et al., 2 21

22 Toma Roma, diced at the lightred red stages S. Agona (Alfalfa sprouts) S. Baildon (Diced ma) (Orange juice) (Canataloupe) (Toma) Acid- and non-acid adapted environment, 5ml inoculation of inoculums in 5 g diced maes Diced Separately: S. Enteritidis NVI 15 (Cow) S. Infantis NVI 11 (Broiler chicken) S. Typhimurium NVI 199 (Broiler chicken) (Finland) Spot inoculated Diced, Round, red, ripened ma S. Braenderup (Toma) (CDC) Diced maes at room temp. (22 C) were spot inoculated (at stem scar) with.1 ml of inoculum NA NA 12 s High pressure processing (MPa) (only 8 h) 22 Acid low.88 log CFU/g Acid high 2.88 log CFU/g acid low.99 log CFU/g acid high 2.99 log CFU/g Growth at 1 days for: Acid low at 12 C and 21 C, ~1.2 and ~8.22 log CFU/g. Acid high at 12 C and 21 C, ~.2 log CFU/g and ~5.2 log CFU/g. acid low at 12 C and 21 C, ~1.1 log CFU/g and ~.1 log CFU/g. acid high at 12 C and 21 C, ~.81 CFU/g, and ~.81 log CFU/g CFU/g Growth: S. Infantis - growth at C; At 8 h, CFU/g at 22 C, and.5 1 CFU/g at C. S. Enteritidis - growth at C; At 8 h, CFU/g at 22 C, and 1 CFU/g at C. S. Typhimurium - growth at C; At 8 h, CFU/g at 22 C, and 5 1 CFU/g at C. 2 Diced, 5.9 log CFU/g 55 MPa Diced,.5 log CFU/g reduction Survival and growth of acidadapted and not acid-adapted cells in diced Roma maes. To determine the effect of pressure reduce or remove S. enterica from whole red Round maes. Beuchat and Mann, 28 Asplund and Nurmi, 1991 Maitland et al.,

23 Toma Diced grape ma Lycopersicon esculentum mill. S. Poona (Cantaloupe) S. Stanley H 125 (Alfalfa sprouts) S. Baildon (Toma) S. Typhimurium DT 1 (Resistant multiple antibiotics) (Toma) (University of Georgia M. Harrison) Spot inoculated 1 µl At C and 1 C 1 At 25 C (h) 1 Allyl isothiocyanate (AIT, from mustard and horseradish) Carvacrol (from oregano) Cinnamaldehyde (from cinnamon) 5, 1, and 15 µl (equivalent 1.5, 8., and 125 µl/liter of air, respectively) of 9% pure carvacrol or 98% pure cinnamaldehyde or 1, 2, and µl (equivalent 8., 1., and. µl/liter of air, respectively) of 98% pure AIT 1 25 Sliced maes, 1 µl. log CFU/ml placed on 1 separate spots AIT exhibited the highest antimicrobial activity followed by cinnamaldehyde. The lowest level of AIT (8. µl/liter of air) inactivated Salmonella on sliced maes by 1. and.5 log at and 1 C, respectively, in 1 days and by 2.8 log at 25 C in 1 h. Overall, greater inactivation occurred at 1 than at C and on the ma surface than between slices. Elucidate the effect of antimicrobials activity on pathogen inactivation on ma skin (using whole maes). Obaidat and Frank, 29 Stem scar tissue light red, Round S. Agona (Alfalfa sprouts) S. Baildon (Diced ma) (Orange juice) (Cantaloupe) (Toma) Acid- and nonacid adapted environment, 2 µl syringe inoculated 1 NA Acid-adapted and not acidadapted cells: Round, light red, 2.5 and 1.8 CFU/g Growth at 1 days for Light red, Round: Acid-adapted stem at 12 C and 21 C, ~2.5 log CFU/g and ~.5 log CFU/g t acid-adapted stem at 21 C and 21 C, ~. log CFU/g and ~2. log CFU/g Survival and growth of acidadapted and not acid-adapted cells in Round maes. Beuchat and Mann, 28 2

24 Toma Stem scar tissue of lightred Roma S. Agona (Alfalfa sprouts) S. Baildon (Diced ma) (Orange juice) (Cantaloupe) (Toma) Acid- and nonacid adapted environment, 2 µl syringe inoculated 1 NA Acid-adapted and not acidadapted cells: Roma, light red, 2. and 2.1 CFU/g Growth at 1 days, Roma light red: Acid-adapted stem at 12 C and 21 C, ~1.5 log CFU/g and ~.8 log CFU/g t acid-adapted stem at 21 C and 21 C, ~2.29 log CFU/g and ~.19 log CFU/g Survival and growth of acidadapted and not acid adapted cells in Roma maes. Beuchat and Mann, 28 Stem scar tissues of Round and Roma, initially at the turning and/ or pink stages of ripeness S. Agona (Alfalfa sprouts) S. Baildon (Diced ma) (Orange juice) (Cantaloupe) (Toma) 2 µl syringe inoculated 12 C C 1 1 NA Pre-inoculation log CFU/ml and post-inoculation.8 log CFU/g Growth: Salmonella increased significantly in the stem scar of maes sred at both temps.. Higher populations (.9 8. log CFU/g) were reached at 21 C than at 12 C (..9 log CFU/g) in maes sred for 1 and 2 days, respectively Tomaes were held up 2 days at 12 or 21 C with 15 and % relative humidity before experiment. Survival and growth of Salmonella in Round and Roma maes. Beuchat and Mann, 28 Stem scar on the skin surface of grape ma S. Agona (Alfalfa sprouts) S. Baildon (Diced ma) (Orange juice) (Cantaloupe) (Toma) t adapted acidic environment 2 µl inoculated 1 d NA log CFU/ml (5 CFU/ml) Growth at 1 days: Stem at 12 C and 21 C, ~2.5 and ~.5 log CFU/g Survival and growth of Salmonella in and on grape maes. Beuchat and Mann, 28 2

25 Toma Stem scar tissue of green ma S. Agona (Alfalfa sprouts) S. Baildon (Diced ma) (Orange juice) (Cantaloupe) (Toma) Acid- and non-acid adapted environment 2 µl syringe inoculated 1 NA Acid-adapted and not acidadapted cells: Green, 2. and 1.8 log CFU/g Growth at 1 days for Green: Acid-adapted stem at 12 C and 21 C, ~. log CFU/g and ~1. log CFU/g t acid-adapted stem at 21 C, ~.22 log CFU/g Survival and growth of acidadapted and not acid-adapted cells in green maes. Beuchat and Mann, 28 Round - Pulp of light red S. Agona (Alfalfa sprouts) S. Baildon (Diced ma) (Orange juice) (Cantaloupe) (Toma) Acid- and non-acid adapted environment 2 µl syringe inoculated 1 NA Acid-adapted and not acidadapted cells: Round, light red, 2.5 and 1.8 CFU/g Growth at 1 days for Light red Round: Acid pulp at 12 C and 21 C, ~.95 log CFU/ml and ~5.5 log CFU/ml t acid-adapted pulp at 12 C and 21 C, ~2. log CFU/g and ~5.5 log CFU/g. Survival and growth of acidadapted and not acid adapted cells in Round maes. Beuchat and Mann, 28 Round and Roma ma pulp (radial pericarp) initially at the turning and/ or pink stages of ripeness S. Agona S. Baildon 2 µl syringe inoculated 12 C C 1 1 NA Pre-inoculation log CFU/ml, and post-inoculation.8 log CFU/g Growth: Salmonella increased significantly in the pulp tissues of maes sred at both temps. Higher populations (.9 8. log CFU/g) were reached at 21 C than at 12 C (..9 log CFU/g) in maes sred for 1 and 2 days, respectively. Tomaes were held up 2 days at 12 or 21 C with 15 and % relative humidity before experiment. Survival and growth of Salmonella in Round and Roma maes. Beuchat and Mann, 28 25

26 Toma Pulp of lightred Roma ma S. Agona S. Baildon Acid- and non-acid adapted environment 2 µl syringe inoculated 1 NA Acid-adapted and not acid adapted cells: Roma light red 2. and 2.1 CFU/g Growth at 1 days Roma light red: Acid-adapted pulp at 12 C and 21 C, ~.5 log CFU/ml and ~. log CFU/ml t acid-adapted pulp at 12 C and 21 C, ~.29 log CFU/g and ~5.19 log CFU/g Survival and growth of acidadapted and not acid-adapted cells in Roma maes. Beuchat and Mann, 28 Pulp tissues on the skin surface of grape ma S. Agona S. Baildon Acid- and non-acid adapted environment 2 µl syringe inoculated 1 d NA log CFU/ml (5 CFU/ml) Growth at 1 days: Pulp at 12 C and 21 C, ~.5 and ~.85 log CFU/g Survival and growth of Salmonella in and on grape maes. Beuchat and Mann, 28 Pulp of green ma S. Agona S. Baildon Acid- and non-acid adapted environment 2 µl syringe inoculated 1 NA Acid-adapted and not acidadapted cells: Green 2. and 1.8 log CFU/g Growth at 1 days for Green: Acid-adapted pulp at 12 C and 21 C, ~1. log CFU/ml and ~. log CFU/ml t acid-adapted pulp at 12 C and 21 C, ~1.52 log CFU/g and ~.2 log CFU/g. Survival and growth of acidadapted and not acid-adapted cells in green maes. Beuchat and Mann, 28 Salsa with either fresh Roma ma or canned whole ma, different salsa recipes S. Typhimurium, DT 1 (Beef isolate) and PTC 1 (Poultry isolate) two S. Enteritidis, H9 (Clinical iso- late) and MH2981 (Environmental isolate) one S. Heidelberg, MH251 (Turkey isolate) 1 µl spot inoculated 1 2 NA log CFU/ ma Salsa, depending on its ingredients, could be inhibiry, or support the survival and possibly growth of, Salmonella during srage. Salsa can be formulated with ingredient combinations such as lime juice plus fresh garlic prevent or suppress the growth of Salmonella. Inoculated whole maes, then chopped them Fate of Salmonella in salsas. Ma et al., 21 2

27 Toma Salsa, ripened Roma ma, intact S. Typhimurium, DT 1 (Beef isolate) and PTC 1 (Poultry isolate) two S. Enteritidis, H9 (Clinical iso- late) and MH2981 (Environmental isolate) one S. Heidelberg, MH251 (Turkey isolate) 2 µl spot inoculated, air dried 1 h RT NA Inoculated at 5. log CFU/g and after spotinoculation was 2. log CFU/g Growth on surface of raw whole ma: At 21 C, -5 log CFU/g growth growth observed at and 12 C Relative humidity: 55-5% Inoculated whole maes, then chopped them Survival and growth of Salmonella on intact ma, jalapeño, and cilantro. Ma et al., 21 Salsa, ripened Roma ma, diced S. Typhimurium, DT 1 (Beef isolate) and PTC 1 (Poultry isolate) two S. Enteritidis, H9 (Clinical iso- late) and MH2981 (Environmental isolate) one S. Heidelberg, MH251 (Turkey isolate) 1 µl spot inoculated NA ~ log CFU/g Growth on chopped ma: growth at C (kept at - log CFU/g) Growth at 12 C at.2 log CFU/g and a decrease in growth at <1 log CFU/g (day 2) at 21 C Survival and growth of Salmonella in chopped maes, jalapeño peppers, and cilantro. Ma et al., 21 Restaurantmade salsa with red ma S. Enteritidis S. Typhimurium S. Thompson ATCC 891 Spot inoculated on salsa container For 2 C (h) 2 2 For C 1 5 NA CFU/ sample Comparison of detection methods between CHROMagar, XLD, and RapidCheck SELECT. Rapid- Check SELECT was best detect Salmonella under both temps. at all time points except 5 s, d at C. Franco et al., 21 2

28 Toma Restaurantmade salsa with red ma S. aureus ATCC 292, ATCC 12-U, and ATCC 558 Spot inoculated on salsa container For 2 C (h) 2 2 For C 1 5 NA 2 Low (.2 log CFU/g) High (.2 log CFU/g) At 2 C, 1.1 log CFU/g for low and. log CFU/g for high At C, 1. log CFU/g for low and 2.5 log CFU/g for high ph at C ranged from.9.5 ph at 2 C ranged from.95. Survival study. Franco et al., 21 Cultivar Better Boy ma seeds grown for days or until cotyledons emerged (Toma) (Cantaloupe) S. Poona (Cantaloupe) S. Hartford (Orange juice) S. Enteritidis (Eggs) (CDC) All ampicillin resistant Plants with intact or cut roots were then transferred trays containing liters of Hoagland solution inoculated with the five-serotype mixture. d NA 25 C Hoagland solution modified contain ampicillin (1 g/ml) in order obtain a preparation containing.55 log CFU/ml Detection: Within 1 day of exposure of plant roots nutrient solution containing ca..5 log CFU of the pathogen/ml, populations were. log CFU/g of hypocotyls and cotyledons, and. log CFU/g of stems. Populations >. log CFU/g of hypocotyl/cotyledon, stem, and leaf tissue of plants grown for 9 days were detected. Hypocotyls, cotyledons, stem, leaves Investigate the possibility of association of Salmonellae with hypocotyls, cotyledons, stems, and leaves of young plants grown in a hydroponic nutrient solution inoculated with the pathogen. Guo et al., 22 AEM 28