Inactivation of Salmonella on Tomato Stem Scars by Edible Chitosan and Organic Acid Coatings†

2012 ◽  
Vol 75 (8) ◽  
pp. 1368-1372 ◽  
Author(s):  
T. JIN ◽  
J. B. GURTLER
Keyword(s):  
Acid Solution ◽  
Organic Acid ◽  
Storage Period ◽  
Allyl Isothiocyanate ◽  
Antimicrobial Efficacy ◽  
Antimicrobial Coatings ◽  
Chitosan Coating ◽  
Salmonella Serovars ◽  
Antimicrobial Intervention

This study was conducted to investigate the efficacy of antimicrobial coatings for inactivation of Salmonella on the surface of tomato stem scars. Scars were inoculated with a four-strain cocktail of Salmonella (serovars Montevideo, Newport, Saintpaul, and Typhimurium) and coated with acid-chitosan solutions. The chitosan coating with three acids (3A plus chitosan), the chitosan coating with one acid, and the three-acid solution without chitosan reduced the populations of Salmonella by 6.0, 3.6, and 5.3 log CFU per stem scar, respectively. Addition of allyl isothiocyanate (10 μl/ml) to the 3A plus chitosan coating did not significantly increase (P > 0.05) the antimicrobial efficacy. Although the populations of Salmonella in the controls (ca. 7.5 log CFU per stem scar) did not change significantly throughout the 14-day storage period at 10°C, Salmonella cells were reduced to undetectable levels (<0.7 log CFU per stem scar) in the samples treated with 3A plus chitosan coating after two days of storage, and no growth was observed for the remaining storage period. Results from this study demonstrate that coatings of acid plus chitosan provide an alternative antimicrobial intervention for decontamination of tomatoes.

Development of Antimicrobial Coatings for Improving the Microbiological Safety and Quality of Shell Eggs†

2013 ◽  
Vol 76 (5) ◽  
pp. 779-785 ◽  
Author(s):  
TONY Z. JIN ◽  
JOSHUA B. GURTLER ◽  
SI-QUAN LI
Keyword(s):  
Polylactic Acid ◽  
Allyl Isothiocyanate ◽  
Cross Contamination ◽  
Polymer Carrier ◽  
Antimicrobial Coatings ◽  
Shell Eggs ◽  
Chitosan Coating ◽  
Alternative Approach ◽  
Egg Shells

This study was conducted to develop antimicrobial coatings to decontaminate and prevent cross-contamination of shell eggs. Egg shells were inoculated with nalidixic acid–resistant Salmonella enterica Enteritidis strains OB030832, OB040159, and C405 and treated with antimicrobial coatings. Polylactic acid served as a nonedible polymer, and chitosan served as an edible polymer carrier of natural antimicrobials, including nisin, allyl isothiocyanate (AIT), lauric arginate ester (LAE), and organic acids. Increases of AIT concentrations or addition of nisin to AIT in either the polylactic acid or chitosan coating solutions resulted in greater reductions of Salmonella. Chitosan coatings with 0.1, 0.5, and 1.0% LAE reduced Salmonella by 1.7, 2.5, and 5.2 log CFU/cm2, respectively. Shell eggs treated with 1.0 and 0.5% LAE in chitosan coatings had nondetectable Salmonella cells (<0.5 log CFU/cm2) after 3 and 7 days of storage at 7°C, respectively, and no outgrowth was observed up to 28 days. Coating treatments significantly reduced weight loss of shell eggs during 12 weeks of storage at 7 or 4°C. This study demonstrates an alternative and effective intervention technology for decontaminating shell eggs and provides an alternative approach to reduce possible recalls and outbreaks associated with pathogen contamination on shell eggs and in egg products.

Effects of Cell Surface Charge and Hydrophobicity on Attachment of 16 Salmonella Serovars to Cantaloupe Rind and Decontamination with Sanitizers†

2006 ◽  
Vol 69 (8) ◽  
pp. 1835-1843 ◽  
Author(s):  
DIKE O. UKUKU ◽  
WILLIAM F. FETT
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Surface ◽  
Surface Charge ◽  
Storage Period ◽  
Bacterial Attachment ◽  
The Other ◽  
Average Percentage ◽  
Log Reduction ◽  
Cell Surface Charge ◽  
Salmonella Serovars

Adherence of bacteria to cantaloupe rind is favored by surface irregularities such as roughness, crevices, and pits, thus reducing the ability of washing or sanitizer treatments to remove or inactivate attached cells. In this study, we compared the surface charge and hydrophobicity of two cantaloupe-related outbreak strains of Salmonella Poona (RM2350 and G-91-1595) to those of 14 additional Salmonella strains using electrostatic and hydrophobic interaction chromatography. The relative abilities of the 16 strains to attach to cantaloupe surfaces and resist removal by washing with water, chlorine (200 ppm), or hydrogen peroxide (2.5%) for 5 min after a storage period of up to 7 days at 5 to 20°C also were determined. Whole cantaloupes were inoculated with each pathogen at 8.36 log CFU/ml, dried for 1 h inside a biosafety cabinet, stored, and then subjected to the washing treatments. Only the positive surface charge of the two cantaloupe-related strains of Salmonella Poona was significantly higher (P < 0.05) than that of the other strains. Initial bacterial attachment to cantaloupe surfaces ranged from 3.68 to 4.56 log CFU/cm2 (highest values for Salmonella Michigan, Newport, Oranienburg, and Mbandaka). The average percentage of the total bacterial population strongly attached to the cantaloupe surface for the Salmonella serovars studied ranged from 0.893 to 0.946 at 5°C and from 0.987 to 0.999 at 25°C. Washing inoculated melons with water did not produce a significant reduction in the concentration of the pathogens (P > 0.05). Chlorine and hydrogen peroxide treatments caused an average 3-log reduction when applied 20 to 40 min postinoculation. However, sanitizer treatments applied 60 min or more postinoculation were less effective (approximately 2.5-log reduction). No significant differences were noted in sanitizer efficacy against the individual strains (P > 0.05). The two cantaloupe-related outbreak Salmonella Poona strains did not significantly differ from the other Salmonella strains tested in negative cell surface charge or hydrophobicity, were not more effective in attaching to whole melon surfaces, and were not more resistant to the various washing treatments when present on rinds.

scholarly journals Studies on the Corrosion of Stainless Steels in Organic Acid Solution (5)

1968 ◽  
Vol 17 (4) ◽  
pp. 163-165
Author(s):  
Kazutaka Sakiyama ◽  
Shigetarô Hayashi
Keyword(s):  
Acid Solution ◽  
Organic Acid ◽  
Stainless Steels

scholarly journals Effect of Chitosan Dissolved in Different Acids on Its Ability to Control Postharvest Gray Mold of Table Grape

2009 ◽  
Vol 99 (9) ◽  
pp. 1028-1036 ◽  
Author(s):  
Gianfranco Romanazzi ◽  
Franka Mlikota Gabler ◽  
Dennis Margosan ◽  
Bruce E. Mackey ◽  
Joseph L. Smilanick
Keyword(s):  
Acid Solution ◽  
Succinic Acid ◽  
Gray Mold ◽  
Table Grape ◽  
Thompson Seedless ◽  
Grape Berries ◽  
Chitosan Coating ◽  
Ambient Storage ◽  
Storage Temperatures ◽  
Chitosan Lactate

Chitosan is a natural biopolymer that must be dissolved in an acid solution to activate its antimicrobial and eliciting properties. Among 15 acids tested, chitosan dissolved in 1% solutions of acetic, L-ascorbic, formic, L-glutamic, hydrochloric, lactic, maleic, malic, phosphorous, and succinic acid. To control gray mold, table grape berries were immersed for 10 s in these chitosan solutions that had been adjusted to pH 5.6. The reduction in decay among single berries of several cultivars (Thompson Seedless, Autumn Seedless, and grape selection B36-55) inoculated with Botrytis cinerea at 1 × 105 conidia/ml before or after immersion in chitosan acetate or formate, followed by storage at 15°C for 10 days, was ≈70%. The acids alone at pH 5.6 did not control gray mold. Decay among clusters of two cultivars (Thompson Seedless and Crimson Seedless) inoculated before treatment was reduced ≈60% after immersion in chitosan lactate or chitosan acetate followed by storage for 60 days at 0.5°C. The viscosity of solutions was 1.9 centipoises (cp) (ascorbate) to 306.4 cp (maleicate) and the thickness of chitosan coating on berries was 4.4 μm (acetate) to 15.4 μm (ascorbate), neither of which was correlated with solution effectiveness. Chitosan acetate was the most effective treatment which effectively reduced gray mold at cold and ambient storage temperatures, decreased CO2 and O2 exchange, and did not injure the grape berries.

Studies on the Corrosion of Stainless Steels in Organic Acid Solution (3)

1966 ◽  
Vol 15 (3) ◽  
pp. 112-116
Author(s):  
Kazutaka Sakiyama ◽  
Shigetarô Hayashi
Keyword(s):  
Acid Solution ◽  
Organic Acid ◽  
Stainless Steels

scholarly journals Effect of Shrimp Chitosan Coating on Physico-chemical Properties and Shelf Life Extension of Banana

2019 ◽  
Vol 6 (1) ◽  
pp. 41-54
Author(s):  
Md. Belal Hossain Sikder ◽  
M Muksitu Islam
Keyword(s):  
Weight Loss ◽  
Shelf Life ◽  
Disease Severity ◽  
Storage Period ◽  
Ash Content ◽  
Soluble Solids ◽  
Life Extension ◽  
Post Harvest ◽  
Chitosan Coating ◽  
Post Harvest Loss

Banana is highly perishable fruit and shelf life is short, which leads resulting post-harvest loss consistently in Bangladesh. To lessen the post-harvest loss and draw out the time span of the usability of banana, green mature bananas were treated with 0.5%, 0.75%, and 1% chitosan, individually. For the subsequent treatments, bananas were stored at room temperature. The viability of the coating in extending fruit’s shelf-life was assessed by evaluated total weight loss, ash content, total soluble solids (TSS), pH, titratable acidity (TA), disease severity and shelf life during the storage period. Chitosan coating reduced respiration activity, thus delaying ripening and the rate of decay due to senescence. The chitosan-coated banana samples had a better outcome on weight loss, ash content, pH, TSS, TA and disease severity values as compared to control samples. Banana coated with 1% chitosan showed less weight reduction and lessened obscuring than different treatments and control. Disease severity was astoundingly lessened by chitosan covering application. Chitosan coating extended banana up to the shelf life of more 2 to 4 days. From this investigation, it demonstrated that 1% chitosan was more appropriate in extending the shelf-life and better quality of banana during ripening and storage at ambient temperature.

scholarly journals Can Edible Coatings Maintain Sweet Pepper Quality after Prolonged Storage at Sub-Optimal Temperatures?

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 387
Author(s):  
Shani Kehila ◽  
Sharon Alkalai-Tuvia ◽  
Daniel Chalupovicz ◽  
Elena Poverenov ◽  
Elazar Fallik
Keyword(s):  
Storage Temperature ◽  
Gas Permeability ◽  
Chilling Injury ◽  
Storage Period ◽  
Co2 Production ◽  
Prolonged Storage ◽  
Layer By Layer ◽  
Fruit Storage ◽  
Chitosan Coating

This work evaluated the efficacies of different coatings: chitosan, gelatin and chitosan-gelatin applied layer-by-layer (LbL); for maintaining the quality of sweet peppers that were stored for 3 weeks at a sub-optimal temperature (1.5 °C) and at an optimal storage temperature (7 °C). After the cold-storage period, fruits were kept under marketing conditions (21 °C) for 3 more days. An edible chitosan coating (2%) effectively alleviated chilling injury and the incidence of decay, and also preserved the nutritional quality of sweet peppers that were kept for 3 weeks at 1.5 °C plus 3 more days at 21 °C. The chitosan coating was more effective than the two other coatings. All three coating treatments significantly reduced external CO2 production, as compared to uncoated control fruit. Storage temperatures did not significantly affect external CO2 production, although CO2 production was slightly higher at 1.5 °C. The chitosan coating exhibited good CO2 gas permeability properties and the peppers coated with that material had lower respiration rates than those in the other two experimental treatments or the control. From a practical point of view, chitosan coating could replace the plastic bags previously found to alleviate chilling injury in peppers that are stored at 1.5 °C as a quarantine treatment.

scholarly journals ControllingListeria monocytogenesScott A on Surfaces of Fully Cooked Turkey Deli Product Using Organic Acid-Containing Marinades as Postlethality Dips

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Gerardo Casco ◽  
Jennifer L. Johnson ◽  
T. Matthew Taylor ◽  
Carlos N. Gaytán ◽  
Mindy M. Brashears ◽  
...  
Keyword(s):  
Organic Acid ◽  
Sodium Citrate ◽  
Antimicrobial Agents ◽  
Storage Period ◽  
Sodium Lactate ◽  
Lag Phase ◽  
Refrigerated Storage ◽  
Potassium Lactate ◽  
Fully Cooked ◽  
Positive Controls

This study evaluated the efficacy of organic acids applied singly or in combination as postlethality dips to sliced uncured turkey deli loaves to inhibit the growth ofListeria monocytogenes(Lm) Scott A. Treatments consisted of sodium lactate (SL; 3.6%), potassium lactate (PL; 3.6%), sodium citrate (SC; 0.75%), a combination of SL and sodium diacetate (SDA; 0.25%), and a combination of SL/PL/SDA, alongside appropriate negative and positive controls. Products were inoculated with 104–105 CFU/mL streptomycin-resistant (1500 μg/mL) Lm Scott A prior to treatment. Products were then stored at ~4°C and sampled at 0, 7, 14, 21, 28, 42, and 56 d. The SL/SDA combination applied to turkey slices extended the lag phase through 21 days of refrigerated storage. Numbers of Lm Scott A rose by 0.7 log10 CFU/g through the 56 d storage period. The application of the SL/PL/SDA treatment to turkey product surfaces extended the lag phase through 42 d, with pathogen numbers declining after 21 d. Combination organic acid dips prolonged the lag phase for 2 to 6 wk on turkey product surfaces and can be useful as antimicrobial agents for Lm control on postlethality exposed sliced deli products.

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