Effect of Vacuum-Steam-Vacuum Treatment on Microbial Quality of Whole and Fresh-Cut Cantaloupe†

2006 ◽  
Vol 69 (7) ◽  
pp. 1623-1629 ◽  
Author(s):  
DIKE O. UKUKU ◽  
XUETONG FAN ◽  
MICHAEL F. KOZEMPEL
Keyword(s):  
Fruits And Vegetables ◽  
Vacuum Treatment ◽  
Microbial Quality ◽  
Pseudomonas Spp ◽  
Mesophilic Bacteria ◽  
Log Reduction ◽  
Fresh Cut ◽  
Yeasts And Molds ◽  
Spoilage Microflora

Minimally processed fruits and vegetables have a limited shelf life because of deterioration caused by spoilage microflora and physiological processes. Cutting may increase microbial spoilage of fruits through transfer of microflora on the outer surfaces to the interior tissue. The objectives of this study were to use the vacuum-steam-vacuum (VSV) process to reduce indigenous spoilage microflora on the surface of cantaloupes and to investigate the effects of such treatments on transfer of spoilage microflora from the cantaloupe surface to the fresh-cut melon during rind removal and cutting. Whole cantaloupes were treated in the VSV processor, and fresh-cut pieces prepared from treated and control samples were stored at 5 and 10°C for up to 9 days. Presence and growth of mesophilic bacteria, yeasts and molds, and Pseudomonas spp. were determined in fresh-cut samples during storage. Texture and color (CIE L*, a*, and b*) also were measured during storage. VSV treatment resulted in a 1.0-log reduction of aerobic mesophilic bacteria, a 2.0-log reduction of yeasts and molds, and a 1.5-log reduction of Pseudomonas spp. on cantaloupe surfaces. VSV treatment significantly reduced transfer of yeasts and molds and Pseudomonas spp. from whole cantaloupe surface to fresh-cut pieces during preparation (P < 0.05). Texture and color of the fresh-cut pieces prepared from the VSV-treated whole melons were similar to those of the controls. The results of this study indicate that the use of the VSV process to reduce the surface populations of yeasts and molds and Pseudomonas spp. on whole cantaloupes will reduce subsequent transfer of these microbes to fresh-cut pieces and enhance the microbial quality of the fresh-cut product.

Effect of Hot Water and Hydrogen Peroxide Treatments on Survival of Salmonella and Microbial Quality of Whole and Fresh-Cut Cantaloupe†

2004 ◽  
Vol 67 (3) ◽  
pp. 432-437 ◽  
Author(s):  
DIKE O. UKUKU ◽  
VLASTA PILIZOTA ◽  
GERALD M. SAPERS
Keyword(s):  
Hydrogen Peroxide ◽  
Initial Level ◽  
Agar Medium ◽  
Hot Water ◽  
Microbial Quality ◽  
Microbial Safety ◽  
Mesophilic Bacteria ◽  
Fresh Cut ◽  
Native Microflora

Cantaloupe melon has been associated with outbreaks of salmonellosis. Contamination might be introduced into the flesh from the rind by cutting or by contact of cut pieces with contaminated rinds. Our objectives were to investigate the efficacy of hot water or hot 5% hydrogen peroxide treatments in reducing the population of native microflora and inoculated Salmonella on cantaloupe rind and transfer to fresh-cut tissue during cutting. Whole cantaloupes, inoculated with a cocktail of Salmonella serovars to give 4.6 log CFU/cm2 and stored at 5 or 20°C for up to 5 days, were treated with hot water (70 or 97°C) or 5% hydrogen peroxide (70°C) for 1 min at 0, 1, 3, or 5 days postinoculation. Aerobic mesophilic bacteria and yeast and mold on treated whole melon and fresh-cut pieces were significantly (P < 0.05) reduced by all three treatments. Treatments with hot water (70 and 97°C) caused a 2.0- and 3.4-log CFU/cm2 reduction of Salmonella on whole cantaloupe surfaces irrespective of days of postinoculation storage prior to treatment up to 5 days at 5 or 20°C, respectively. Treatment with 5% hydrogen peroxide (70°C) caused a 3.8-log CFU/cm2 reduction of Salmonella. Fresh-cut pieces prepared from untreated inoculated melons and those treated with 70°C hot water were positive for Salmonella. However, fresh-cut pieces prepared from inoculated whole melon dipped in water (97°C) or hydrogen peroxide (70°C) for 60 s were negative for Salmonella, as determined by dilution plating onto agar medium, but were positive after enrichment at days 3 and 5 of storage at 5°C. The ability to detect Salmonella in fresh-cut pieces was dependent on the initial level of inoculation. The results of this study indicate that the use of hot water (97°C) or heated hydrogen peroxide to reduce the population of Salmonella on contaminated whole cantaloupes will enhance the microbial safety of the fresh-cut product.

Minimally Processed Vegetable Salads: Microbial Quality Evaluation

2007 ◽  
Vol 70 (5) ◽  
pp. 1277-1280 ◽  
Author(s):  
HANS FRÖDER ◽  
CECÍLIA GERALDES MARTINS ◽  
KATIA LEANI OLIVEIRA de SOUZA ◽  
MARIZA LANDGRAF ◽  
BERNADETTE D. G. M. FRANCO ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Microbiological Quality ◽  
Positive Sample ◽  
Fecal Coliforms ◽  
Microbial Quality ◽  
Biochemical Tests ◽  
Minimally Processed ◽  
Increasing Demand ◽  
Minimally Processed Vegetables

The increasing demand for fresh fruits and vegetables and for convenience foods is causing an expansion of the market share for minimally processed vegetables. Among the more common pathogenic microorganisms that can be transmitted to humans by these products are Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella. The aim of this study was to evaluate the microbial quality of a selection of minimally processed vegetables. A total of 181 samples of minimally processed leafy salads were collected from retailers in the city of Sao Paulo, Brazil. Counts of total coliforms, fecal coliforms, Enterobacteriaceae, psychrotrophic microorganisms, and Salmonella were conducted for 133 samples. L. monocytogenes was assessed in 181 samples using the BAX System and by plating the enrichment broth onto Palcam and Oxford agars. Suspected Listeria colonies were submitted to classical biochemical tests. Populations of psychrotrophic microorganisms >106 CFU/g were found in 51% of the 133 samples, and Enterobacteriaceae populations between 105 and 106 CFU/g were found in 42% of the samples. Fecal coliform concentrations higher than 102 CFU/g (Brazilian standard) were found in 97 (73%) of the samples, and Salmonella was detected in 4 (3%) of the samples. Two of the Salmonella-positive samples had <102 CFU/g concentrations of fecal coliforms. L. monocytogenes was detected in only 1 (0.6%) of the 181 samples examined. This positive sample was simultaneously detected by both methods. The other Listeria species identified by plating were L. welshimeri (one sample of curly lettuce) and L. innocua (2 samples of watercress). The results indicate that minimally processed vegetables had poor microbiological quality, and these products could be a vehicle for pathogens such as Salmonella and L. monocytogenes.

New antioxidant treatment with yerba mate (Ilex paraguariensis) infusion for fresh-cut apples: Modeling, optimization, and acceptability

2017 ◽  
Vol 24 (3) ◽  
pp. 223-231 ◽  
Author(s):  
Mariana Rodríguez-Arzuaga ◽  
Andrea M Piagentini
Keyword(s):  
Ascorbic Acid ◽  
Citric Acid ◽  
Antioxidant Capacity ◽  
Fruits And Vegetables ◽  
Ilex Paraguariensis ◽  
Yerba Mate ◽  
Instrumental Color ◽  
Fresh Cut ◽  
Natural Additive

Enzymatic browning affects the sensory and nutritional quality of fresh-cut apples and limits their shelf-life. Yerba mate ( Ilex paraguariensis), a plant widely consumed in South America as an infusion, could potentially be used in minimally processed fruits and vegetables as a natural additive to prevent browning, due to its high content of phenolic compounds with antioxidant capacity. The effects of the concentrations of ascorbic acid, citric acid, and yerba mate in an aqueous dipping solution on the instrumental color parameters, antioxidant capacity, and sensory quality of “Granny Smith” fresh-cut apples were modeled and the solution was optimized to obtain treated apples with maximum antioxidant capacity and minimum browning, without affecting the natural flavor of the fruits. The optimal composition obtained (1.2% yerba mate  + 0.9% citric acid + 1.0% ascorbic acid) increased the antioxidant capacity of the apples by 36%. The sensory acceptability test carried out on the “Granny Smith” fresh-cut apples treated with the optimal dipping solution showed that more than 78% of the surveyed consumers liked the color, flavor, and texture of the apples.

scholarly journals Microbiological evaluation of certain fruits and vegetables marketed in the city of Kenitra-Morocco

2021 ◽  
Vol 319 ◽  
pp. 01112
Author(s):  
Rahma Erahioui ◽  
Sultana Inekach ◽  
Hassna Jaber ◽  
Khadija Atfaoui ◽  
Noureddine Rhaim ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Microbiological Quality ◽  
Fecal Coliforms ◽  
Microbiological Analysis ◽  
Microbial Quality ◽  
Total Absence ◽  
Nutritional Qualities ◽  
Raw Foods ◽  
The City

Fruits and vegetables are essential for human health due to their nutritional qualities, but the consumption of raw foods leads to food safety problems as they are recognized as sources of transmission of infectious diseases. The objective of this work is to assess the microbiological quality of some fruits and vegetables marketed in the Kenitra city. The samples were purchased at the fruit and vegetable markets during the period from April to July 2018.The detection of microorganisms in the samples requires several steps which are weighing, dilution, isolation, enumeration and 'identification. The results of the microbiological analysis of fruits and vegetables studied show significant concentrations of the total aerobic mesophilic flora varies between 2.25 and 8.48 log10 CFU / ml, Concerning total coliforms the contamination rates vary between 1.92 and 8.42 log10UFC / ml, as well as the presence of fecal coliforms between 1.13 and 8.05 log10UFC / ml, in the same samples analyzed, strains such as: Escherichia coli, staphylococcus aureus and a total absence of salmonella and shegilla. In order to improve the safety and hygienic quality of fruits and vegetables, the application of good hygienic practices as well as continuous microbial quality control is necessary to protect the health of consumers.

Use of Chemical Sanitizers To Reduce Microbial Populations and Maintain Quality of Whole and Fresh-Cut Cantaloupe†

2009 ◽  
Vol 72 (12) ◽  
pp. 2453-2460 ◽  
Author(s):  
XUETONG FAN ◽  
BASSAM A. ANNOUS ◽  
LINDSEY A. KESKINEN ◽  
JAMES P. MATTHEIS
Keyword(s):  
Bacterial Population ◽  
Soluble Solids ◽  
Plate Count ◽  
Sodium Chlorite ◽  
Log Reduction ◽  
Plate Counts ◽  
Fresh Cut ◽  
Aerobic Plate Count ◽  
Native Microflora

Whole cantaloupes either not inoculated or inoculated with Salmonella Poona were submerged in water, 180 ppm of chlorine, acidified calcium sulfate (ACS: 1.2% Safe2O-ACS50), 1,000 ppm of acidified sodium chlorite (ASC), 80 ppm of peroxyacetic acid (PAA), and a combination of ACS and PAA for 10 min. Although only ASC and the combination of ACS and PAA significantly reduced the aerobic plate count of samples taken from the surface of whole cantaloupe (compared with samples taken from cantaloupe submerged in water only), all treatments reduced yeast and mold counts on the whole cantaloupe. However, none of the treatments of whole cantaloupes consistently reduced yeast and mold counts for the samples of fresh-cut cantaloupes. The aerobic plate counts for fresh-cut cantaloupe were reduced by 1 to 2 log CFU/g by sanitization of whole fruit with ASC, ACS, and the combination of ACS and PAA. The low bacterial population on the fresh-cut fruit was maintained during 14 days of storage at 4°C. All treatments had a limited effect on the population of Salmonella, achieving no more than a 1.5-log reduction of the pathogen inoculated on the surface of the whole cantaloupes. Salmonella was nondetectable via direct plating (with a detection limit of 0.4 log CFU/g) in fresh-cut cantaloupes prepared from whole cantaloupes treated with any of the sanitizers. However, after enrichment, Salmonella often was detectable. Color, texture, soluble solids, pH, ascorbic acid, and drip loss of cut cantaloupes were not consistently affected by any of the whole-fruit treatments. Overall, treatments of whole cantaloupe with ASC, ACS, and the combination of ACS and PAA at the concentrations tested permitted a significant reduction in Salmonella and native microflora of whole and cut fruit; however, Salmonella still could be found in cut cantaloupes from all treatments.

scholarly journals Effect of different initial C/N ratio of cow manure and straw on microbial quality of compost

2019 ◽  
Vol 8 (S1) ◽  
pp. 357-365
Author(s):  
M. A. Macias-Corral ◽  
J. A. Cueto-Wong ◽  
J. Morán-Martínez ◽  
L. Reynoso-Cuevas
Keyword(s):  
Dairy Manure ◽  
Microbial Reduction ◽  
The Other ◽  
Fecal Coliforms ◽  
Microbial Quality ◽  
Northern Mexico ◽  
Log Reduction ◽  
Helminth Eggs ◽  
Initial Carbon

Abstract Purpose The effect of different initial carbon to nitrogen (C/N) ratios on the prevalence of Salmonella spp., fecal coliforms and helminth eggs over composts produced from several mixtures of maize straw (S) and dairy manure (M) was investigated. Methods Four C/N ratios (21, 22, 27, and 38) were evaluated, including one with manure only (C/N 21). The composting process was performed under field conditions in northern Mexico. Results The process lasted 51 days; Salmonella spp. was reduced 1–2 log (> 94%) in most treatments, except for the C/N ratio of 27 which achieved < 1 log reduction (about 35%). Fecal coliforms elimination was 3–4 log (> 99%) in all treatments while helminth eggs achieved < 1 log (72–87%, depending on treatment). In this study, the mixture with initial C/N ratio of 22 (25% S + 75% M), which had the lowest amount of straw, resulted in the highest elimination of Salmonella spp., fecal coliforms, and helminth eggs. This mix complied with current Mexican sanitary regulations for compost use. The composts produced from the other C/N ratios complied only with the limits for one or two of the microorganisms that were analyzed. Conclusions The initial C/N ratios in compost from straw and manure influences microbial reduction. The final C/N of the mixes ranged from 14 to 16, indicative of stable compost. Compared to fecal coliforms, Salmonella spp. and helminth eggs were more resilient.

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