Efficacy of a Novel Sanitizer Composed of Lactic Acid and Peroxyacetic Acid against Single Strains of Nonpathogenic Escherichia coli K-12, Listeria innocua, and Lactobacillus plantarum in Aqueous Solution and on Surfaces of Romaine Lettuce and Spinach

2011 ◽  
Vol 74 (9) ◽  
pp. 1468-1474 ◽  
Author(s):  
KAI-LAI GRACE HO ◽  
DIEGO A. LUZURIAGA ◽  
KENNETH M. RODDE ◽  
SHANNON TANG ◽  
CUONG PHAN
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Lactobacillus Plantarum ◽  
Ph Value ◽  
Fresh Produce ◽  
Microbial Reduction ◽  
Listeria Innocua ◽  
Peroxyacetic Acid ◽  
Log Reduction ◽  
K 12

A novel sanitizer composed of lactic acid and peroxyacetic acid (LA-PAA) was developed as an alternative to chlorinated water (CW) for fresh produce processing. Single strains of Lactobacillus plantarum, nonpathogenic Escherichia coli K-12, and Listeria innocua were used to demonstrate the microbial efficacy of LA-PAA. LA-PAA achieved a >7.8-log reduction of L. innocua and L. plantarum suspended in water at 4°C for 20 s, and LA, PAA, and CW achieved reductions of 0.4, 4.8, and 2.7 log, respectively. LA-PAA, when compared with LA, PAA, and CW, enhanced the reduction of L. innocua attached to romaine leaves by >2.2 log, and improved the removal of E. coli attached to spinach leaves by >2.4 log. The exponential improvement in the microbial efficacy of LA-PAA showed synergism between LA and PAA. LA-PAA microbial efficacy was inversely proportional to pH value and directly correlated with residence time and concentration. Despite an improvement in microbial reduction through the addition of surfactant to LA-PAA, the usage of surfactant in washing fresh produce was impeded by excessive foaming during actual processing. Effects of organic matter on the performance of LA-PAA were minimal. External sensory evaluations showed that LA-PAA had no negative effects on the quality of lettuce and tender leaves. Temperature-abuse studies demonstrated that LA-PAA reduced decay by ~50% when compared with CW. Overall, these results support the premise that LA-PAA has significant potential to be an alternative to CW for fresh produce processing.

Reduction of Surrogates for Escherichia coli O157:H7 and Salmonella during the Production of Nonintact Beef Products by Chemical Antimicrobial Interventions

2015 ◽  
Vol 78 (5) ◽  
pp. 881-887 ◽  
Author(s):  
CARSON J. ULBRICH ◽  
LISA M. LUCIA ◽  
ASHLEY N. ARNOLD ◽  
T. MATTHEW TAYLOR ◽  
JEFFREY W. SAVELL ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Acid Treatment ◽  
Tap Water ◽  
Microbial Reduction ◽  
Sodium Chlorite ◽  
Escherichia Coli O157 ◽  
Peroxyacetic Acid ◽  
Acid Ph ◽  
Beef Products

The efficacy of chemical antimicrobials for controlling Escherichia coli O157:H7 and Salmonella during production of marinated nonintact beef products was evaluated using nonpathogenic surrogates. Boneless beef strip loins were inoculated with either approximately 5.8 or 1.9 log CFU/cm2 (high and low inoculation levels, respectively) of nonpathogenic rifampin-resistant E. coli. Inoculated strip loins were chilled at 2°C for 24 h, vacuum packaged, and aged for 7 to 24 days at 2°C. After aging, strip loins received no treatment (control) or one of five antimicrobial spray treatments: 2.5% l-lactic acid (pH 2.6), 5.0% l-lactic acid (pH 2.4), 1,050 ppm of acidified sodium chlorite (pH 2.8), 205 ppm of peroxyacetic acid (pH 5.2), or tap water (pH 8.6). Mean application temperatures were 53, 26, 20, and 18°C for lactic acid, water, peroxyacetic acid, and acidified sodium chlorite treatments, respectively. Treated and control strip loins were vacuum tumbled in a commercial marinade. Samples were collected throughout the experiment to track the effects of antimicrobial treatment and processing on inoculated surrogates. For high-inoculation strip loins, the 5.0% l-lactic acid treatment was most effective for reducing surrogates on meat surfaces before marination, producing a 2.6-log mean reduction. Peroxyacetic acid treatment resulted in the greatest reduction of surface-located surrogate microorganisms in marinated product. Water treatment resulted in greater internalization of surrogate microorganisms compared with the control, as determined by enumeration of surrogates from cored samples. Producers of nonintact beef products should focus on use of validated antimicrobial sprays that maximize microbial reduction and minimize internalization of surface bacteria into the finished product.

scholarly journals Comparison of Generally Recognized as Safe Organic Acids for Disinfecting Fresh-cut Lettuce

2018 ◽  
Author(s):  
Jiayi Wang ◽  
Dongbing Tao ◽  
Yubo Liu ◽  
Siwen Han ◽  
Fenge Zheng ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Organic Acids ◽  
Electrolyte Leakage ◽  
Sensory Quality ◽  
Fresh Produce ◽  
Microbial Reduction ◽  
Cold Chain ◽  
Minimal Processing ◽  
Log Reduction ◽  
Fresh Cut

ABSTRACTIn this study, we aimed to determine the organic acids (acetic, lactic, citric, malic, propionic, succinic, and tartaric acids; 1% and 0.5%, w/w or v/v) that were most effective for fresh-cut lettuce disinfection based on analysis of quality (i.e., color, electrolyte leakage, and sensory quality) and microbial examination. The results showed that these acids did not negatively affect the color quality (i.e., L*, a*, b*, whiteness index, and sensory color). Additionally, 0.5% lactic acid led to the lowest electrolyte leakage (0.83%), which was not significantly different (p > 0.05) from that of distilled water (0.46%). Lactic acid (1%) did not affect the sensory quality and led to the highest microbial reduction (1.45 log reduction in aerobic plate counts [APCs]; 2.31 log reduction in molds and yeasts [M&Y]) and was therefore recommended as the primary choice for lettuce disinfection. Malic acid (0.5%), with a 1.07% electrolyte leakage rate, 0.73 log reduction in APCs, and 1.40 log reduction in M&Y, was better than the other six acids (0.5%) and was recommended as a pH regulator and a potential synergistic agent for oxidizing sanitizers. Acetic acid (1%) negatively affected the sensory quality and led to the highest electrolyte leakage (2.90%). Microbial analysis showed that propionic acid (0.5% and 1%) was ineffective for disinfection of lettuce (p > 0.05); thus, acetic and propionic acids were not recommended. Our results provide insights into the choice of sanitizers and formula design in food safety.IMPORTANCESince chlorine is forbidden in several countries, generally recognized as safe organic acids are used in minimal processing industries and in household sanitizers. The disinfection efficacy of organic acids has been studied when used alone or with oxidizing sanitizers. However, since different antibacterial mechanisms, contact time, fresh produce, and concentration have been reported, the acids most effective for single fresh produce disinfection, especially that of lettuce, an important salad vegetable, are not known. Moreover, in developing countries, because of imperfections in field management, cold chain transportation, and minimal processing industry development, the demand for low-cost household sanitizers is greater than that for minimally processed fresh produce. In this work, microbial load in lettuce was determined after disinfecting with seven GRAS organic acids. The changes in quality were also determined. These results provide insights into the choice of minimal processing sanitizers and a formula design for household sanitizers.

Evaluation of Bactericidal Effects of Phenyllactic Acid on Escherichia coli O157:H7 and Salmonella Typhimurium on Beef Meat

2019 ◽  
Vol 82 (12) ◽  
pp. 2016-2022
Author(s):  
RUISHENG ZHENG ◽  
TONG ZHAO ◽  
YEN-CON HUNG ◽  
KOUSHIK ADHIKARI
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Salmonella Typhimurium ◽  
Microbial Reduction ◽  
Escherichia Coli O157 ◽  
Phenyllactic Acid ◽  
E Coli ◽  
Log Reduction ◽  
Beef Meat ◽  
Bactericidal Effects

ABSTRACT Bactericidal effects of various concentrations of phenyllactic acid on Shiga toxin–producing Escherichia coli (STEC), including E. coli O157:H7, O26:H11, O103:H2, and O121:H19, and on Salmonella Typhimurium DT104 in pure culture and microplates assays were studied. Beef cuts were surface sprayed with phenyllactic acid or lactic acid for inactivation of E. coli O157:H7 and Salmonella Typhimurium. The 1.5% phenyllactic acid inactivated all inoculated E. coli O157:H7, O26:H11, O103:H2, and O121:H19 and Salmonella Typhimurium DT104 (>6-log reduction) within 1 min of contact at 21°C, whereas 1.5% lactic acid did not result in microbial reduction. Microplate assays (for STEC and Salmonella Typhimurium DT104 at 10 to 100 CFU per well) indicated that concentrations of 0.25% phenyllactic acid or 0.25% lactic acid inhibited the growth of STEC and Salmonella Typhimurium DT104 incubated at 37°C for 24 h. Treatment of beef with 1.5% lactic acid or 1.5% phenyllactic acid reduced E. coli O157:H7 by 0.22 and 0.38 log CFU/cm2, respectively, within 5 min and reduced Salmonella Typhimurium DT104 by 0.12 and 0.86 log CFU/cm2, respectively. When meat treated with 1.5% phenyllactic acid was frozen at −20°C, inactivation of E. coli O157 and Salmonella Typhimurium DT104 was enhanced by 1.06 and 1.46 log CFU/cm2, respectively. Thus, treatment of beef with 1.5% phenyllactic acid significantly reduced the population of E. coli O157:H7 and Salmonella. HIGHLIGHTS

Reduction of Escherichia coli O157:H7 Counts on Whole Fresh Apples by Treatment with Sanitizers

2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
Author(s):  
MARCY A. WISNIEWSKY ◽  
BONITA A. GLATZ ◽  
MARK L. GLEASON ◽  
CHERYLL A. REITMEIER
Keyword(s):  
Escherichia Coli ◽  
Chlorine Dioxide ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Escherichia Coli O157 ◽  
Peroxyacetic Acid ◽  
Water Control ◽  
Buffer Solution ◽  
E Coli ◽  
Log Reduction

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.

Inactivation of Escherichia coli O157:H7, Salmonella enterica Serotype Enteritidis, and Listeria monocytogenes on Lettuce by Hydrogen Peroxide and Lactic Acid and by Hydrogen Peroxide with Mild Heat

2002 ◽  
Vol 65 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
CHIA-MIN LIN ◽  
SARAH S. MOON ◽  
MICHAEL P. DOYLE ◽  
KAY H. McWATTERS
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Sensory Characteristics ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Log Reduction

Iceberg lettuce is a major component in vegetable salad and has been associated with many outbreaks of foodborne illnesses. In this study, several combinations of lactic acid and hydrogen peroxide were tested to obtain effective antibacterial activity without adverse effects on sensory characteristics. A five-strain mixture of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis, and Listeria monocytogenes was inoculated separately onto fresh-cut lettuce leaves, which were later treated with 1.5% lactic acid plus 1.5% hydrogen peroxide (H2O2) at 40°C for 15 min, 1.5% lactic acid plus 2% H2O2 at 22°C for 5 min, and 2% H2O2 at 50°C for 60 or 90 s. Control lettuce leaves were treated with deionized water under the same conditions. A 4-log reduction was obtained for lettuce treated with the combinations of lactic acid and H2O2 for E. coli O157:H7 and Salmonella Enteritidis, and a 3-log reduction was obtained for L. monocytogenes. However, the sensory characteristics of lettuce were compromised by these treatments. The treatment of lettuce leaves with 2% H2O2 at 50°C was effective not only in reducing pathogenic bacteria but also in maintaining good sensory quality for up to 15 days. A ≤4-log reduction of E. coli O157:H7 and Salmonella Enteritidis was achieved with the 2% H2O2 treatment, whereas a 3-log reduction of L. monocytogenes was obtained. There was no significant difference (P > 0.05) between pathogen population reductions obtained with 2% H2O2 with 60- and 90-s exposure times. Hydrogen peroxide residue was undetectable (the minimum level of sensitivity was 2 ppm) on lettuce surfaces after the treated lettuce was rinsed with cold water and centrifuged with a salad spinner. Hence, the treatment of lettuce with 2% H2O2 at 50°C for 60 s is effective in initially reducing substantial populations of foodborne pathogens and maintaining high product quality.

scholarly journals PENGARUH KONSENTRASI STARTER BAKTERI Lactobacillus plantarum TERHADAP BEBERAPA KOMPONEN MUTU TEPUNG PORANG (Amorphophallus oncophyllus)

Pro Food ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 673
Author(s):  
Ade Irma Juliana ◽  
Moegiratul Amaro ◽  
Nazaruddin Nazaruddin
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Protein Content ◽  
Lactobacillus Plantarum ◽  
Analysis Of Variance ◽  
Ph Value ◽  
Significance Level ◽  
Randomized Design ◽  
Significant Difference ◽  
Polynomial Orthogonal

ABSTRACT               This study aims to determine the effect of Lactobacillus plantarum bacterial starter concentration on some quality of the porang flour. This study used experimental design one-factor Completely Randomized Design (CRD) consisted of BAL concentration (KB) of Lactobacillus plantarum with 6 treatments which is 0%, 5%, 10%, 15%, 20% and 25%. Each of treatment were repeated three times to obtain 18 unit samples. Data from observations were analyzed using analysis of variance (Analysis of Variance) at 5% significance level using Co-stat software. If there are significant differences, a further Polynomial Orthogonal and Honestly Significant Difference (BNJ) test is performed at a level of 5%. The parameters observed included pH value, protein content, water content, yield, total lactic acid bacteria, organoleptic parameters of color and aroma (hedonic and scoring). The results showed that the concentration of Lactobacillus plantarum bacterial 20% was the best treatment in producing porang flour, pH value 5.72, protein content 6.49%, yield 9.33%, total lactic acid bacteria 6.66 log CFU / g and color rather brown and slightly acidic aroma and somewhat preferred by panelists. Keywords: Porang flour, starter concentration, Lactobacillus plantarum   ABSTRAK             Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi starter bakteri Lactobacillus plantarum terhadap beberapa komponen mutu tepung porang. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan satu faktor yakni konsentrasi BAL (KB) jenis Lactobacillus plantarum dengan 6 perlakuan yaitu 0%, 5%, 10%, 15%, 20% dan 25%. Masing-masing perlakuan diulang sebanyak 3 kali sehingga diperoleh 18 unit percobaan. Data hasil pengamatan dianalisis menggunakan analisis keragaman (Analysis of Variance) pada taraf nyata 5% menggunakan software Co-stat. Apabila terdaapat beda nyata, dilakukan uji lanjut Polynomial Orthogonal dan Beda Nyata Jujur (BNJ) pada taraf 5%. Adapun parameter yang diamati meliputi nilai pH, kadar protein, kadar air, rendemen, total bakteri asam laktat, parameter organoleptik warna dan aroma (hedonik dan scoring). Hasil penelitian menunjukkan bahwa konsentrasi strater bakteri Lactobacillus plantarum 20% merupakan perlakuan terbaik dalam menghasilkan tepung porang nilai pH 5,72, kadar protein 6,49%, rendemen 9,33%, total bakteri asam laktat 6,66 log CFU/g serta warna agak coklat dan aroma agak asam serta agak disukai panelis.    Kata Kunci: Tepung porang, konsentrasi starter, Lactobacillus plantarum

scholarly journals Antimicrobial activity of lactic acid bacteria isolated from garri on Escherichia coli strains isolated from clinical and environmental samples

2020 ◽  
Vol 12 (4) ◽  
pp. 357-365
Author(s):  
H.I. Atta ◽  
A. Gimba ◽  
T. Bamgbose
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Plantarum ◽  
Lactobacillus Acidophilus ◽  
Plant Pathogens ◽  
Resistant Bacteria ◽  
Fermented Foods ◽  
Environmental Isolates ◽  
E Coli

Abstract. The production of bacteriocins by lactic acid bacteria affords them the ability to inhibit the growth of bacteria; they are particularly important in the biocontrol of human and plant pathogens. Lactic acid bacteria have been frequently isolated from fermented foods due to the high acidity these foods contain. In this study, lactic acid bacteria were isolated from garri, a popular Nigerian staple food, which is fermented from cassava, and their antagonistic activity against clinical and environmental isolates of Escherichia coli was determined. The species of Lactobacillus isolated include: Lactobacillus plantarum (50%), Lactobacillus fermentum (20%), Lactobacillus acidophilus (20%), and Lactobacillus salivarius (10%). Growth inhibition of the strains of E.coli was observed in Lactobacillus plantarum that inhibited the growth of both. The clinical and environmental isolates of E. coli were inhibited by Lactobacillus plantarum, while Lactobacillus acidophilus showed activity against only the clinical isolate. The greatest zone of inhibition against the strains of E. coli was recorded by Lactobacillus acidophilus (22.7±1.53 mm). The bacteriocins produced by Lactobacillus species have a good potential in the biocontrol of pathogens, and should be the focus of further studies on antibiotic resistant bacteria.

Bacteriophage T4 multiplication in a glucose-limited Escherichia coli biofilm

2001 ◽  
Vol 47 (7) ◽  
pp. 680-684 ◽  
Author(s):  
Brian D Corbin ◽  
Robert JC McLean ◽  
Gary M Aron
Keyword(s):  
Escherichia Coli ◽  
Bacteriophage T4 ◽  
Confocal Laser ◽  
Carbon Limitation ◽  
Viral Titer ◽  
Susceptibility To Infection ◽  
Log Reduction ◽  
T4 Bacteriophage ◽  
Order Of Magnitude ◽  
K 12

An Escherichia coli K-12 biofilm was grown at a dilution rate of 0.028 h-1 for 48 h in a glucose-limited chemostat coupled to a modified Robbins' device to determine its susceptibility to infection by bacteriophage T4. Bacteriophage T4 at a multiplicity of infection (MOI) of 10 caused a log reduction in biofilm density (expressed as colony forming units (CFU) per cm2) at 90 min postinfection. After 6 h, a net decrease and equilibrium in viral titer was seen. When biofilms were exposed to T4 phage at a MOI of 100, viral titer doubled after 90 min. After 6 h, viral titers (expressed as plaque forming units (PFU) per cm2) stabilized at levels approximately one order of magnitude higher than seen at a MOI of 10. Scanning confocal laser microscopy images also indicated disruption of biofilm morphology following T4 infection with the effects being more pronounced at a MOI of 100 than at a MOI of 10. These results imply that biofilms under carbon limitation can act as natural reservoirs for bacteriophage and that bacteriophage can have some influence on biofilm morphology.Key words: bacteriophage T4, biofilm, biofilm morphology, bacteriophage ecology, carbon limitation.

A microwire sensor for rapid detection of Escherichia coli K-12 in fresh produce

2011 ◽  
Vol 12 (4) ◽  
pp. 617-622 ◽  
Author(s):  
Sungkyun Kim ◽  
Lin Lu ◽  
Jae-Hyun Chung ◽  
Kyonghoon Lee ◽  
Yong Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Rapid Detection ◽  
Fresh Produce ◽  
K 12
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