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NATIVE MICROFLORA (native + microflora)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

EFFECTIVENESS OF CHLORINE AND NISIN-EDTA TREATMENTS OF WHOLE MELONS AND FRESH-CUT PIECES FOR REDUCING NATIVE MICROFLORA AND EXTENDING SHELF-LIFE,

JOURNAL OF FOOD SAFETY, Issue 4 2002
DIKE O. UKUKU
ABSTRACT Efficacy of nisin-EDTA treatments as a sanitizing treatment for reducing native microflora of whole melons and extending shelf-life of fresh-cut pieces was compared to chlorine treatments. Whole cantaloupe and honeydew melons were washed with water, nisin (10 ,g/mL)-EDTA (0.02 M), or 200 ppm chlorine for 5 min at , 20C before fresh-cut preparation and storage at 5C for 15 days with periodic microbiological sampling. In addition, some fresh-cut pieces were washed with 10 ,g/mL nisin-EDTA or 50 ppm chlorine for 1 min before storage. Changes in appearance, odor, overall acceptability and the shelf-life of the minimally processed fresh-cut melons were investigated. Preliminary studies indicated that water washes, EDTA (0.002 to 0.2 M) or nisin (5 to 10 ,g/mL) were not effective in reducing the microflora of whole melon when used individually. Nisin-EDTA and chlorine treatments were significantly (P < 0.05) more effective in reducing native microflora than water washes. Nisin-EDTA treatments were significantly (P < 0.05) more effective than chlorine in reducing populations of yeast and mold and Pseudomonas spp. on whole melon surfaces but were not as effective as chlorine treatments for reducing aerobic mesophilic bacteria, lactic acid bacteria and total gram-negative bacteria. Microbial contaminants on fresh-cut pieces washed with 50 ppm chlorine or nisin-EDTA were further reduced. However, microbial populations increased throughout refrigerated storage irrespective of treatments. Odor, appearance, and overall acceptability ratings for cantaloupe and honeydew fresh-cut pieces treated with nisin-EDTA or chlorine were not significantly (P > 0.05) different from each other throughout the storage period (15 to 21 days). However, both treatments led to significantly (P < 0.05) improved ratings compared to the controls for the fresh-cut pieces at 9 to 12 days of storage and thereafter. The results of this study suggest that treatments with nisin-EDTA before and after fresh-cut processing would improve the quality and extend the shelf-life of fresh-cut melon. [source]

INFLUENCE OF WASHING TREATMENT ON NATIVE MICROFLORA AND ESCHERICHIA COLI POPULATION OF INOCULATED CANTALOUPES

JOURNAL OF FOOD SAFETY, Issue 1 2001
DIKE O. UKUKU
ABSTRACT The influence of chlorine or hydrogen peroxide treatment on populations of Escherichia coli 25922 on the external surface of inoculated cantaloupe was investigated. Surface treatment with 70% EtOH, followed by immersion in 108 CFU/mL E. coli inoculum deposited an average of 4.4 log10CFU/cm2 cell population on the cantaloupe surface. The efficncy of washing inoculated cantaloupe was dependent on storage interval between inoculation and treatment. Dipping the cantaloupes in solutions containing 1000 mg/L chlorine or 5% peroxide for 5 min, within 24 h of inoculation, caused a 2 log10 CFU/cm2 reduction of the indigenous surface microflora and a 3,4.0 log10 CFU/cm2 reduction in E. coli. The efficacy was less when the interval between inoculation and treatment exceeded 24 h. Chlorine appeared in be a better antimicrobial agent than hydrogen peroxide against F. coli ATCC 25922 inoculated on cantaloupe surfaces while hydrogen peroxide was better in reducing surface microflora of cantaloupe. [source]

EFFECTIVENESS OF CHLORINE AND NISIN-EDTA TREATMENTS OF WHOLE MELONS AND FRESH-CUT PIECES FOR REDUCING NATIVE MICROFLORA AND EXTENDING SHELF-LIFE,

JOURNAL OF FOOD SAFETY, Issue 4 2002
DIKE O. UKUKU
ABSTRACT Efficacy of nisin-EDTA treatments as a sanitizing treatment for reducing native microflora of whole melons and extending shelf-life of fresh-cut pieces was compared to chlorine treatments. Whole cantaloupe and honeydew melons were washed with water, nisin (10 ,g/mL)-EDTA (0.02 M), or 200 ppm chlorine for 5 min at , 20C before fresh-cut preparation and storage at 5C for 15 days with periodic microbiological sampling. In addition, some fresh-cut pieces were washed with 10 ,g/mL nisin-EDTA or 50 ppm chlorine for 1 min before storage. Changes in appearance, odor, overall acceptability and the shelf-life of the minimally processed fresh-cut melons were investigated. Preliminary studies indicated that water washes, EDTA (0.002 to 0.2 M) or nisin (5 to 10 ,g/mL) were not effective in reducing the microflora of whole melon when used individually. Nisin-EDTA and chlorine treatments were significantly (P < 0.05) more effective in reducing native microflora than water washes. Nisin-EDTA treatments were significantly (P < 0.05) more effective than chlorine in reducing populations of yeast and mold and Pseudomonas spp. on whole melon surfaces but were not as effective as chlorine treatments for reducing aerobic mesophilic bacteria, lactic acid bacteria and total gram-negative bacteria. Microbial contaminants on fresh-cut pieces washed with 50 ppm chlorine or nisin-EDTA were further reduced. However, microbial populations increased throughout refrigerated storage irrespective of treatments. Odor, appearance, and overall acceptability ratings for cantaloupe and honeydew fresh-cut pieces treated with nisin-EDTA or chlorine were not significantly (P > 0.05) different from each other throughout the storage period (15 to 21 days). However, both treatments led to significantly (P < 0.05) improved ratings compared to the controls for the fresh-cut pieces at 9 to 12 days of storage and thereafter. The results of this study suggest that treatments with nisin-EDTA before and after fresh-cut processing would improve the quality and extend the shelf-life of fresh-cut melon. [source]

Use of Bean Sprout Enterobacteriaceae Isolates as Biological Control Agents of Pseudomonas fluorescens

JOURNAL OF FOOD SCIENCE, Issue 1 2004
K. ENOMOTOArticle first published online: 28 JUN 200
ABSTRACT: Bean sprouts were cultivated under in vitro conditions as a model system to study the mechanism of bacteria-mediated spoilage in bean sprouts. Pseudomonas fluorescens, or Erwinia spp., were inoculated onto sprouts at several stages during cultivation. Five strains of Enterobacteriaceae isolated from the native microflora of sprouts prevented Pseudomonas -mediated spoilage by co-inoculating these cultures on seeds that were soaking in water. The population of P. fluorescens in co-inoculated liquid medium culture with a strain (B1) decreased slightly. The results indicated that the Enterobacteriaceae isolates tested played an important role in preventing Pseudomonas -mediated spoilage by growing competitively with P. fluorescens. [source]