Irradiation and modified atmosphere packaging of endive influences survival and regrowth of Listeria monocytogenes and product sensory qualities

2005 ◽  
Vol 72 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Brendan A. Niemira ◽  
Xuetong Fan ◽  
Kimberly J.B. Sokorai
Food Control ◽  
2016 ◽  
Vol 59 ◽  
pp. 513-523 ◽  
Author(s):  
Victoria Heinrich ◽  
Marija Zunabovic ◽  
Lisa Nehm ◽  
Johannes Bergmair ◽  
Wolfgang Kneifel

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1211
Author(s):  
Paul Culliney ◽  
Achim Schmalenberger

Minimally processed ready-to-eat (RTE) vegetables are increasingly consumed for their health benefits. However, they also pose a risk of being ingested with food-borne pathogens. The present study investigated the ability of RTE spinach and rocket to support the growth of Listeria monocytogenes as previous studies provided contradicting evidence. Findings were compared to growth on iceberg lettuce that has repeatedly been shown to support growth. Products were inoculated with a three-strain mix of L. monocytogenes at 10 and 100 cfu g−1 and stored in modified atmosphere (4 kPa O2, 8 kPa CO2) at 8 °C over 7–9 days. Spinach demonstrated the highest growth potential rate of 2 to 3 log10 cfu g−1 over a 9-day period with only marginal deterioration in its visual appearance. Growth potential on rocket was around 2 log10 cfu g−1 over 9 days with considerable deterioration in visual appearance. Growth potential of iceberg lettuce was similar to that of rocket over a 7-day period. Growth curves fitted closely to a linear growth model, indicating none to limited restrictions of growth over the duration of storage. The high growth potentials of L. monocytogenes on spinach alongside the limited visual deterioration highlight the potential risks of consuming this raw RTE food product when contaminated.


2017 ◽  
Vol 80 (5) ◽  
pp. 740-749 ◽  
Author(s):  
Nuria García-Martínez ◽  
Pedro Andreo-Martínez ◽  
Luis Almela ◽  
Lucía Guardiola ◽  
José A. Gabaldón

ABSTRACT In recent years the sales of minimally processed vegetables have grown exponentially as a result of changes in consumer habits. The availability of artichoke buds as a ready-to-eat product would be, therefore, highly advantageous. However, minimally processed artichoke hearts are difficult to preserve because of their rapid browning and the proliferation of naturally occurring microorganisms. We developed artichoke hearts prepared as ready-to-eat products that maintain the characteristics of the fresh product. The microbiological stability, sensory qualities, and shelf life of the processed artichoke hearts were determined. During the shelf life, Salmonella, Listeria monocytogenes, and Escherichia coli counts were below the limits legally established by European regulations for minimally processed vegetables. The pH played an important role in microbial growth. Artichoke hearts had lower microbial counts in experiments conducted at pH 4.1 than in experiments conducted at pH 4.4, although the recommended threshold value for total plate count (7 log CFU/g) was not exceeded in either case. Sensory parameters were affected by the microorganisms, and artichoke products at lower pH had better sensory qualities. Vacuum impregnation techniques, modified atmosphere packaging, and low storage temperature were very effective for increasing the shelf life of minimally processed artichokes. The average shelf life was approximately 12 to 15 days.


2017 ◽  
Vol 2 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Kaytana Morgan ◽  
Noureddine Benkeblia

Abstract In this study, we investigated the effects of two modified atmosphere packaging films [Osmolux (Osx) and Oriented PolyPropylene (OPP)] on the microbiological and the sensory qualities of ackee fruit (Blighia sapida Köenig) arils stored during eight days under two refrigerated temperatures, 5 ±1°C and 10 ±1°C. The control samples of ackee arils were packaged in a macro-perforated highdensity polypropylene film (MP). The results showed that mesophilic aerobic bacteria (MAB), yeasts and moulds were lower under OPP, although MAB of MP was lower at 5°C. At 10°C, the pH of the ackee arils stored in Osx and OPP did not vary significantly, but the pH ofMP showed an increase from 5.32 to 5.95 and 5.83 at 5°C and 10°C, respectively. Results also showed that under OPP, weight losses were lower and averaged 0.12%and 0.19%after eight days storage at 5°C and 10°C, respectively, while the sensory quality attributes were preserved up to six days. Conclusively, OPP showed better attributes for MAP storage of ackee arils under refrigerated temperatures, although none of the two films were effective to reduce the chilling injury after the eight days storage.


2006 ◽  
Vol 69 (11) ◽  
pp. 2671-2680 ◽  
Author(s):  
ANDREW R. MICHAELSEN ◽  
JOSEPH G. SEBRANEK ◽  
JAMES S. DICKSON

This study was designed to determine the inhibitory effects of modified atmosphere packaging (MAP), both alone and in combination with potassium lactate and sodium diacetate (PLSD), on selected pathogens common to pork products. Effects of the treatments on product quality also were assessed. The hypothesis was that high-CO2 MAP would increase the effectiveness of PLSD for inhibition of pork pathogens. Fresh chops from untreated pork loins and loins that were injected with PLSD were inoculated with Salmonella enterica Typhimurium, and slices of untreated hams and hams that were injected with PLSD were inoculated with Listeria monocytogenes. The samples were subjected to vacuum packaging (VP) or MAP with high concentrations (99.5 to 100%) of CO2. Pathogens were enumerated periodically during storage at 4 and 10°C. Storage of pork chops at 4°C slowed the growth of Salmonella Typhimurium, and there was little difference in pathogen numbers between VP and MAP samples. L. monocytogenes growth on ham slices at 4°C was inhibited for up to 28 days by all of the treatments, but after 28 days, the VP-PLSD treatment had a greater inhibitory effect than did the other treatments. At 10°C, the PLSD and MAP treatments each effectively inhibited the growth of the pathogens on pork chops and ham slices when compared with controls (VP). However, the results obtained with MAP plus PLSD at 10°C were not different from those obtained with either MAP or PLSD alone. Therefore, the hypothesis was not supported; the high-CO2 atmosphere of the MAP did not increase the effectiveness of PLSD for inhibition of pathogens.


2006 ◽  
Vol 69 (1) ◽  
pp. 221-227 ◽  
Author(s):  
S. CAILLET ◽  
M. MILLETTE ◽  
M. TURGIS ◽  
S. SALMIERI ◽  
M. LACROIX

Radiosensitization of Listeria monocytogenes was determined in the presence of trans-cinnamaldehyde, Spanish oregano, winter savory, and Chinese cinnamon on peeled minicarrots packed under air or under a modified atmosphere (60% O2, 30% CO2, and 10% N2). Samples were inoculated with L. monocytogenes HPB 2812 serovar 1/2a (106 CFU/g) and were coated separately with each active compound (0.5%, wt/wt) before being packaged under air or the modified atmosphere and irradiated at doses from 0.07 to 2.4 kGy. Results indicated that the bacterium was more resistant to irradiation under air in the absence of active compound. The dose required to reduce L. monocytogenes population by 1 log CFU (D10) was 0.36 kGy for samples packed under air and 0.17 kGy for those packed under the modified atmosphere. The active compounds evaluated in this study had an effect on the radiation sensitivity of L. monocytogenes on carrots. The most efficient compound was trans-cinnamaldehyde, where a mean 3.8-fold increase in relative radiation sensitivity was observed for both atmospheres compared with the control. The addition of winter savory and Chinese cinnamon produced a similar increase in relative radiation sensitivity but only when samples where packed under modified atmosphere conditions.


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